[PATCH] 30_all_jpeg-crop.patch

http://sylvana.net/jpegcrop/

same thing as Debian's 100_crop.dpatch and 200_crop_man.dpatch from
libjpeg6b_6b-10

5 files changed, 1024 insertions, 274 deletions

diff --git a/jerror.h b/jerror.h
index fc2fffe..41a69d5 100644
--- a/jerror.h
+++ b/jerror.h
@@ -45,6 +45,7 @@ JMESSAGE(JERR_BAD_ALIGN_TYPE, "ALIGN_TYPE is wrong, please fix")
 JMESSAGE(JERR_BAD_ALLOC_CHUNK, "MAX_ALLOC_CHUNK is wrong, please fix")
 JMESSAGE(JERR_BAD_BUFFER_MODE, "Bogus buffer control mode")
 JMESSAGE(JERR_BAD_COMPONENT_ID, "Invalid component ID %d in SOS")
+JMESSAGE(JERR_BAD_CROP_SPEC, "Invalid crop request")
 JMESSAGE(JERR_BAD_DCT_COEF, "DCT coefficient out of range")
 JMESSAGE(JERR_BAD_DCTSIZE, "IDCT output block size %d not supported")
 JMESSAGE(JERR_BAD_HUFF_TABLE, "Bogus Huffman table definition")
diff --git a/jpegtran.1 b/jpegtran.1
index 6de18e2..4e5b33c 100644
--- a/jpegtran.1
+++ b/jpegtran.1
@@ -131,6 +131,40 @@ followed by
 .B \-rot 180 -trim
 trims both edges.
 .PP
+If you are only interested by perfect transformation, add the
+.B \-perfect
+switch:
+.TP
+.B \-perfect
+Fails with an error if the transformation is not perfect. For example
+you may want to do
+.TP
+.B (jpegtran \-rot 90 -perfect foo.jpg || djpeg foo.jpg| pnmflip \-r90 | cjpeg)
+to do a perfect rotation if available or an approximated one if
+not.
+.PP
+We also offer a lossless-crop option, which discards data outside a given
+image region but losslessly preserves what is inside.  Like the rotate and
+flip transforms, lossless crop is restricted by the JPEG format: the upper
+left corner of the selected region must fall on an iMCU boundary.  If this
+does not hold for the given crop parameters, we silently move the upper left
+corner up and/or left to make it so, simultaneously increasing the region
+dimensions to keep the lower right crop corner unchanged.  (Thus, the
+output image covers at least the requested region, but may cover more.)
+
+Note: 
+.B \-perfect
+and
+.B lossless-crop
+are enhancements from http://sylvana.net/jpegcrop/ that may not be available on
+non-Debian systems.
+
+The image can be losslessly cropped by giving the switch:
+.TP
+.B \-crop WxH+X+Y
+Crop to a rectangular subarea of width W, height H starting at point X,Y.
+.PP
+.PP
 Another not-strictly-lossless transformation switch is:
 .TP
 .B \-grayscale
@@ -231,7 +265,9 @@ Arithmetic coding is not supported for legal reasons.
 .PP
 The transform options can't transform odd-size images perfectly.  Use
 .B \-trim
-if you don't like the results without it.
+or
+.B \-perfect
+if you don't like the results.
 .PP
 The entire image is read into memory and then written out again, even in
 cases where this isn't really necessary.  Expect swapping on large images,
diff --git a/jpegtran.c b/jpegtran.c
index 20ef111..44c061a 100644
--- a/jpegtran.c
+++ b/jpegtran.c
@@ -1,7 +1,7 @@
 /*
  * jpegtran.c
  *
- * Copyright (C) 1995-1997, Thomas G. Lane.
+ * Copyright (C) 1995-2001, Thomas G. Lane.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
@@ -64,8 +64,10 @@ usage (void)
 #endif
 #if TRANSFORMS_SUPPORTED
   fprintf(stderr, "Switches for modifying the image:\n");
+  fprintf(stderr, "  -crop WxH+X+Y  Crop to a rectangular subarea\n");
   fprintf(stderr, "  -grayscale     Reduce to grayscale (omit color data)\n");
   fprintf(stderr, "  -flip [horizontal|vertical]  Mirror image (left-right or top-bottom)\n");
+  fprintf(stderr, "  -perfect       Fail if there is non-transformable edge blocks\n");
   fprintf(stderr, "  -rotate [90|180|270]         Rotate image (degrees clockwise)\n");
   fprintf(stderr, "  -transpose     Transpose image\n");
   fprintf(stderr, "  -transverse    Transverse transpose image\n");
@@ -133,7 +135,9 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
   copyoption = JCOPYOPT_DEFAULT;
   transformoption.transform = JXFORM_NONE;
   transformoption.trim = FALSE;
+  transformoption.perfect = FALSE;
   transformoption.force_grayscale = FALSE;
+  transformoption.crop = FALSE;
   cinfo->err->trace_level = 0;
 
   /* Scan command line options, adjust parameters */
@@ -160,7 +164,7 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
       exit(EXIT_FAILURE);
 #endif
 
-    } else if (keymatch(arg, "copy", 1)) {
+    } else if (keymatch(arg, "copy", 2)) {
       /* Select which extra markers to copy. */
       if (++argn >= argc)	/* advance to next argument */
 	usage();
@@ -173,6 +177,20 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
       } else
 	usage();
 
+    } else if (keymatch(arg, "crop", 2)) {
+      /* Perform lossless cropping. */
+#if TRANSFORMS_SUPPORTED
+      if (++argn >= argc)	/* advance to next argument */
+	usage();
+      if (! jtransform_parse_crop_spec(&transformoption, argv[argn])) {
+	fprintf(stderr, "%s: bogus -crop argument '%s'\n",
+		progname, argv[argn]);
+	exit(EXIT_FAILURE);
+      }
+#else
+      select_transform(JXFORM_NONE);	/* force an error */
+#endif
+
     } else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
       /* Enable debug printouts. */
       /* On first -d, print version identification */
@@ -233,7 +251,12 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv,
 	usage();
       outfilename = argv[argn];	/* save it away for later use */
 
-    } else if (keymatch(arg, "progressive", 1)) {
+    } else if (keymatch(arg, "perfect", 2)) {
+      /* Fail if there is any partial edge MCUs that the transform can't
+       * handle. */
+      transformoption.perfect = TRUE;
+
+    } else if (keymatch(arg, "progressive", 2)) {
       /* Select simple progressive mode. */
 #ifdef C_PROGRESSIVE_SUPPORTED
       simple_progressive = TRUE;
@@ -342,8 +365,10 @@ main (int argc, char **argv)
   jvirt_barray_ptr * src_coef_arrays;
   jvirt_barray_ptr * dst_coef_arrays;
   int file_index;
-  FILE * input_file;
-  FILE * output_file;
+  /* We assume all-in-memory processing and can therefore use only a
+   * single file pointer for sequential input and output operation. 
+   */
+  FILE * fp;
 
   /* On Mac, fetch a command line. */
 #ifdef USE_CCOMMAND
@@ -406,24 +431,13 @@ main (int argc, char **argv)
 
   /* Open the input file. */
   if (file_index < argc) {
-    if ((input_file = fopen(argv[file_index], READ_BINARY)) == NULL) {
-      fprintf(stderr, "%s: can't open %s\n", progname, argv[file_index]);
+    if ((fp = fopen(argv[file_index], READ_BINARY)) == NULL) {
+      fprintf(stderr, "%s: can't open %s for reading\n", progname, argv[file_index]);
       exit(EXIT_FAILURE);
     }
   } else {
     /* default input file is stdin */
-    input_file = read_stdin();
-  }
-
-  /* Open the output file. */
-  if (outfilename != NULL) {
-    if ((output_file = fopen(outfilename, WRITE_BINARY)) == NULL) {
-      fprintf(stderr, "%s: can't open %s\n", progname, outfilename);
-      exit(EXIT_FAILURE);
-    }
-  } else {
-    /* default output file is stdout */
-    output_file = write_stdout();
+    fp = read_stdin();
   }
 
 #ifdef PROGRESS_REPORT
@@ -431,7 +445,7 @@ main (int argc, char **argv)
 #endif
 
   /* Specify data source for decompression */
-  jpeg_stdio_src(&srcinfo, input_file);
+  jpeg_stdio_src(&srcinfo, fp);
 
   /* Enable saving of extra markers that we want to copy */
   jcopy_markers_setup(&srcinfo, copyoption);
@@ -443,6 +457,15 @@ main (int argc, char **argv)
    * jpeg_read_coefficients so that memory allocation will be done right.
    */
 #if TRANSFORMS_SUPPORTED
+  /* Fails right away if -perfect is given and transformation is not perfect.
+   */
+  if (transformoption.perfect &&
+      !jtransform_perfect_transform(srcinfo.image_width, srcinfo.image_height,
+      srcinfo.max_h_samp_factor * DCTSIZE, srcinfo.max_v_samp_factor * DCTSIZE,
+      transformoption.transform)) {
+    fprintf(stderr, "%s: transformation is not perfect\n", progname);
+    exit(EXIT_FAILURE);
+  }
   jtransform_request_workspace(&srcinfo, &transformoption);
 #endif
 
@@ -463,11 +486,32 @@ main (int argc, char **argv)
   dst_coef_arrays = src_coef_arrays;
 #endif
 
+  /* Close input file, if we opened it.
+   * Note: we assume that jpeg_read_coefficients consumed all input
+   * until JPEG_REACHED_EOI, and that jpeg_finish_decompress will
+   * only consume more while (! cinfo->inputctl->eoi_reached).
+   * We cannot call jpeg_finish_decompress here since we still need the
+   * virtual arrays allocated from the source object for processing.
+   */
+  if (fp != stdin)
+    fclose(fp);
+
+  /* Open the output file. */
+  if (outfilename != NULL) {
+    if ((fp = fopen(outfilename, WRITE_BINARY)) == NULL) {
+      fprintf(stderr, "%s: can't open %s for writing\n", progname, outfilename);
+      exit(EXIT_FAILURE);
+    }
+  } else {
+    /* default output file is stdout */
+    fp = write_stdout();
+  }
+
   /* Adjust default compression parameters by re-parsing the options */
   file_index = parse_switches(&dstinfo, argc, argv, 0, TRUE);
 
   /* Specify data destination for compression */
-  jpeg_stdio_dest(&dstinfo, output_file);
+  jpeg_stdio_dest(&dstinfo, fp);
 
   /* Start compressor (note no image data is actually written here) */
   jpeg_write_coefficients(&dstinfo, dst_coef_arrays);
@@ -488,11 +532,9 @@ main (int argc, char **argv)
   (void) jpeg_finish_decompress(&srcinfo);
   jpeg_destroy_decompress(&srcinfo);
 
-  /* Close files, if we opened them */
-  if (input_file != stdin)
-    fclose(input_file);
-  if (output_file != stdout)
-    fclose(output_file);
+  /* Close output file, if we opened it */
+  if (fp != stdout)
+    fclose(fp);
 
 #ifdef PROGRESS_REPORT
   end_progress_monitor((j_common_ptr) &dstinfo);
diff --git a/transupp.c b/transupp.c
index e5ec564..ff0f275 100644
--- a/transupp.c
+++ b/transupp.c
@@ -1,7 +1,7 @@
 /*
  * transupp.c
  *
- * Copyright (C) 1997, Thomas G. Lane.
+ * Copyright (C) 1997-2001, Thomas G. Lane.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
@@ -20,6 +20,7 @@
 #include "jinclude.h"
 #include "jpeglib.h"
 #include "transupp.h"		/* My own external interface */
+#include <ctype.h>		/* to declare isdigit() */
 
 
 #if TRANSFORMS_SUPPORTED
@@ -28,7 +29,8 @@
  * Lossless image transformation routines.  These routines work on DCT
  * coefficient arrays and thus do not require any lossy decompression
  * or recompression of the image.
- * Thanks to Guido Vollbeding for the initial design and code of this feature.
+ * Thanks to Guido Vollbeding for the initial design and code of this feature,
+ * and to Ben Jackson for introducing the cropping feature.
  *
  * Horizontal flipping is done in-place, using a single top-to-bottom
  * pass through the virtual source array.  It will thus be much the
@@ -42,6 +44,13 @@
  * arrays for most of the transforms.  That could result in much thrashing
  * if the image is larger than main memory.
  *
+ * If cropping or trimming is involved, the destination arrays may be smaller
+ * than the source arrays.  Note it is not possible to do horizontal flip
+ * in-place when a nonzero Y crop offset is specified, since we'd have to move
+ * data from one block row to another but the virtual array manager doesn't
+ * guarantee we can touch more than one row at a time.  So in that case,
+ * we have to use a separate destination array.
+ *
  * Some notes about the operating environment of the individual transform
  * routines:
  * 1. Both the source and destination virtual arrays are allocated from the
@@ -54,20 +63,65 @@
  *    and we may as well take that as the effective iMCU size.
  * 4. When "trim" is in effect, the destination's dimensions will be the
  *    trimmed values but the source's will be untrimmed.
- * 5. All the routines assume that the source and destination buffers are
+ * 5. When "crop" is in effect, the destination's dimensions will be the
+ *    cropped values but the source's will be uncropped.  Each transform
+ *    routine is responsible for picking up source data starting at the
+ *    correct X and Y offset for the crop region.  (The X and Y offsets
+ *    passed to the transform routines are measured in iMCU blocks of the
+ *    destination.)
+ * 6. All the routines assume that the source and destination buffers are
  *    padded out to a full iMCU boundary.  This is true, although for the
  *    source buffer it is an undocumented property of jdcoefct.c.
- * Notes 2,3,4 boil down to this: generally we should use the destination's
- * dimensions and ignore the source's.
  */
 
 
 LOCAL(void)
-do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
-	   jvirt_barray_ptr *src_coef_arrays)
-/* Horizontal flip; done in-place, so no separate dest array is required */
+do_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+	 jvirt_barray_ptr *src_coef_arrays,
+	 jvirt_barray_ptr *dst_coef_arrays)
+/* Crop.  This is only used when no rotate/flip is requested with the crop. */
+{
+  JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
+  int ci, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  jpeg_component_info *compptr;
+
+  /* We simply have to copy the right amount of data (the destination's
+   * image size) starting at the given X and Y offsets in the source.
+   */
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+	 dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+	 (JDIMENSION) compptr->v_samp_factor, TRUE);
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	 dst_blk_y + y_crop_blocks,
+	 (JDIMENSION) compptr->v_samp_factor, FALSE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
+			dst_buffer[offset_y],
+			compptr->width_in_blocks);
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_flip_h_no_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+		   JDIMENSION x_crop_offset,
+		   jvirt_barray_ptr *src_coef_arrays)
+/* Horizontal flip; done in-place, so no separate dest array is required.
+ * NB: this only works when y_crop_offset is zero.
+ */
 {
-  JDIMENSION MCU_cols, comp_width, blk_x, blk_y;
+  JDIMENSION MCU_cols, comp_width, blk_x, blk_y, x_crop_blocks;
   int ci, k, offset_y;
   JBLOCKARRAY buffer;
   JCOEFPTR ptr1, ptr2;
@@ -79,17 +133,19 @@ do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
    * mirroring by changing the signs of odd-numbered columns.
    * Partial iMCUs at the right edge are left untouched.
    */
-  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+  MCU_cols = srcinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
 
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
     comp_width = MCU_cols * compptr->h_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
     for (blk_y = 0; blk_y < compptr->height_in_blocks;
 	 blk_y += compptr->v_samp_factor) {
       buffer = (*srcinfo->mem->access_virt_barray)
 	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	/* Do the mirroring */
 	for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
 	  ptr1 = buffer[offset_y][blk_x];
 	  ptr2 = buffer[offset_y][comp_width - blk_x - 1];
@@ -105,6 +161,79 @@ do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	    *ptr2++ = -temp1;
 	  }
 	}
+	if (x_crop_blocks > 0) {
+	  /* Now left-justify the portion of the data to be kept.
+	   * We can't use a single jcopy_block_row() call because that routine
+	   * depends on memcpy(), whose behavior is unspecified for overlapping
+	   * source and destination areas.  Sigh.
+	   */
+	  for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
+	    jcopy_block_row(buffer[offset_y] + blk_x + x_crop_blocks,
+			    buffer[offset_y] + blk_x,
+			    (JDIMENSION) 1);
+	  }
+	}
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+	   jvirt_barray_ptr *src_coef_arrays,
+	   jvirt_barray_ptr *dst_coef_arrays)
+/* Horizontal flip in general cropping case */
+{
+  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, k, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JBLOCKROW src_row_ptr, dst_row_ptr;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  /* Here we must output into a separate array because we can't touch
+   * different rows of a single virtual array simultaneously.  Otherwise,
+   * this is essentially the same as the routine above.
+   */
+  MCU_cols = srcinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_width = MCU_cols * compptr->h_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+	 dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+	 (JDIMENSION) compptr->v_samp_factor, TRUE);
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	 dst_blk_y + y_crop_blocks,
+	 (JDIMENSION) compptr->v_samp_factor, FALSE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	dst_row_ptr = dst_buffer[offset_y];
+	src_row_ptr = src_buffer[offset_y];
+	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+	  if (x_crop_blocks + dst_blk_x < comp_width) {
+	    /* Do the mirrorable blocks */
+	    dst_ptr = dst_row_ptr[dst_blk_x];
+	    src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
+	    /* this unrolled loop doesn't need to know which row it's on... */
+	    for (k = 0; k < DCTSIZE2; k += 2) {
+	      *dst_ptr++ = *src_ptr++;	 /* copy even column */
+	      *dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
+	    }
+	  } else {
+	    /* Copy last partial block(s) verbatim */
+	    jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
+			    dst_row_ptr + dst_blk_x,
+			    (JDIMENSION) 1);
+	  }
+	}
       }
     }
   }
@@ -113,11 +242,13 @@ do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 
 LOCAL(void)
 do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
 	   jvirt_barray_ptr *src_coef_arrays,
 	   jvirt_barray_ptr *dst_coef_arrays)
 /* Vertical flip */
 {
   JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
   int ci, i, j, offset_y;
   JBLOCKARRAY src_buffer, dst_buffer;
   JBLOCKROW src_row_ptr, dst_row_ptr;
@@ -131,33 +262,38 @@ do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
    * of odd-numbered rows.
    * Partial iMCUs at the bottom edge are copied verbatim.
    */
-  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+  MCU_rows = srcinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
 
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
     comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
 	 dst_blk_y += compptr->v_samp_factor) {
       dst_buffer = (*srcinfo->mem->access_virt_barray)
 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
-      if (dst_blk_y < comp_height) {
+      if (y_crop_blocks + dst_blk_y < comp_height) {
 	/* Row is within the mirrorable area. */
 	src_buffer = (*srcinfo->mem->access_virt_barray)
 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
-	   comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
+	   comp_height - y_crop_blocks - dst_blk_y -
+	   (JDIMENSION) compptr->v_samp_factor,
 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
       } else {
 	/* Bottom-edge blocks will be copied verbatim. */
 	src_buffer = (*srcinfo->mem->access_virt_barray)
-	  ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
+	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	   dst_blk_y + y_crop_blocks,
 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
       }
       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
-	if (dst_blk_y < comp_height) {
+	if (y_crop_blocks + dst_blk_y < comp_height) {
 	  /* Row is within the mirrorable area. */
 	  dst_row_ptr = dst_buffer[offset_y];
 	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+	  src_row_ptr += x_crop_blocks;
 	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
 	       dst_blk_x++) {
 	    dst_ptr = dst_row_ptr[dst_blk_x];
@@ -173,7 +309,8 @@ do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	  }
 	} else {
 	  /* Just copy row verbatim. */
-	  jcopy_block_row(src_buffer[offset_y], dst_buffer[offset_y],
+	  jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
+			  dst_buffer[offset_y],
 			  compptr->width_in_blocks);
 	}
       }
@@ -184,11 +321,12 @@ do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 
 LOCAL(void)
 do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	      JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
 	      jvirt_barray_ptr *src_coef_arrays,
 	      jvirt_barray_ptr *dst_coef_arrays)
 /* Transpose source into destination */
 {
-  JDIMENSION dst_blk_x, dst_blk_y;
+  JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
   int ci, i, j, offset_x, offset_y;
   JBLOCKARRAY src_buffer, dst_buffer;
   JCOEFPTR src_ptr, dst_ptr;
@@ -201,6 +339,8 @@ do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
    */
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
 	 dst_blk_y += compptr->v_samp_factor) {
       dst_buffer = (*srcinfo->mem->access_virt_barray)
@@ -210,11 +350,12 @@ do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
 	     dst_blk_x += compptr->h_samp_factor) {
 	  src_buffer = (*srcinfo->mem->access_virt_barray)
-	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	     dst_blk_x + x_crop_blocks,
 	     (JDIMENSION) compptr->h_samp_factor, FALSE);
 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
-	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
 	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y + y_crop_blocks];
 	    for (i = 0; i < DCTSIZE; i++)
 	      for (j = 0; j < DCTSIZE; j++)
 		dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -228,6 +369,7 @@ do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 
 LOCAL(void)
 do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
 	   jvirt_barray_ptr *src_coef_arrays,
 	   jvirt_barray_ptr *dst_coef_arrays)
 /* 90 degree rotation is equivalent to
@@ -237,6 +379,7 @@ do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
  */
 {
   JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
   int ci, i, j, offset_x, offset_y;
   JBLOCKARRAY src_buffer, dst_buffer;
   JCOEFPTR src_ptr, dst_ptr;
@@ -246,11 +389,13 @@ do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
    * at the (output) right edge properly.  They just get transposed and
    * not mirrored.
    */
-  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+  MCU_cols = srcinfo->image_height / (dstinfo->max_h_samp_factor * DCTSIZE);
 
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
     comp_width = MCU_cols * compptr->h_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
 	 dst_blk_y += compptr->v_samp_factor) {
       dst_buffer = (*srcinfo->mem->access_virt_barray)
@@ -259,15 +404,26 @@ do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
 	     dst_blk_x += compptr->h_samp_factor) {
-	  src_buffer = (*srcinfo->mem->access_virt_barray)
-	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
-	     (JDIMENSION) compptr->h_samp_factor, FALSE);
+	  if (x_crop_blocks + dst_blk_x < comp_width) {
+	    /* Block is within the mirrorable area. */
+	    src_buffer = (*srcinfo->mem->access_virt_barray)
+	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	       comp_width - x_crop_blocks - dst_blk_x -
+	       (JDIMENSION) compptr->h_samp_factor,
+	       (JDIMENSION) compptr->h_samp_factor, FALSE);
+	  } else {
+	    /* Edge blocks are transposed but not mirrored. */
+	    src_buffer = (*srcinfo->mem->access_virt_barray)
+	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	       dst_blk_x + x_crop_blocks,
+	       (JDIMENSION) compptr->h_samp_factor, FALSE);
+	  }
 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
-	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
-	    if (dst_blk_x < comp_width) {
+	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+	    if (x_crop_blocks + dst_blk_x < comp_width) {
 	      /* Block is within the mirrorable area. */
-	      dst_ptr = dst_buffer[offset_y]
-		[comp_width - dst_blk_x - offset_x - 1];
+	      src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
+		[dst_blk_y + offset_y + y_crop_blocks];
 	      for (i = 0; i < DCTSIZE; i++) {
 		for (j = 0; j < DCTSIZE; j++)
 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -277,7 +433,8 @@ do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	      }
 	    } else {
 	      /* Edge blocks are transposed but not mirrored. */
-	      dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+	      src_ptr = src_buffer[offset_x]
+		[dst_blk_y + offset_y + y_crop_blocks];
 	      for (i = 0; i < DCTSIZE; i++)
 		for (j = 0; j < DCTSIZE; j++)
 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -292,6 +449,7 @@ do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 
 LOCAL(void)
 do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
 	    jvirt_barray_ptr *src_coef_arrays,
 	    jvirt_barray_ptr *dst_coef_arrays)
 /* 270 degree rotation is equivalent to
@@ -301,6 +459,7 @@ do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
  */
 {
   JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
   int ci, i, j, offset_x, offset_y;
   JBLOCKARRAY src_buffer, dst_buffer;
   JCOEFPTR src_ptr, dst_ptr;
@@ -310,11 +469,13 @@ do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
    * at the (output) bottom edge properly.  They just get transposed and
    * not mirrored.
    */
-  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+  MCU_rows = srcinfo->image_width / (dstinfo->max_v_samp_factor * DCTSIZE);
 
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
     comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
 	 dst_blk_y += compptr->v_samp_factor) {
       dst_buffer = (*srcinfo->mem->access_virt_barray)
@@ -324,14 +485,15 @@ do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
 	     dst_blk_x += compptr->h_samp_factor) {
 	  src_buffer = (*srcinfo->mem->access_virt_barray)
-	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	     dst_blk_x + x_crop_blocks,
 	     (JDIMENSION) compptr->h_samp_factor, FALSE);
 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
 	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
-	    if (dst_blk_y < comp_height) {
+	    if (y_crop_blocks + dst_blk_y < comp_height) {
 	      /* Block is within the mirrorable area. */
 	      src_ptr = src_buffer[offset_x]
-		[comp_height - dst_blk_y - offset_y - 1];
+		[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
 	      for (i = 0; i < DCTSIZE; i++) {
 		for (j = 0; j < DCTSIZE; j++) {
 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -341,7 +503,8 @@ do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	      }
 	    } else {
 	      /* Edge blocks are transposed but not mirrored. */
-	      src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+	      src_ptr = src_buffer[offset_x]
+		[dst_blk_y + offset_y + y_crop_blocks];
 	      for (i = 0; i < DCTSIZE; i++)
 		for (j = 0; j < DCTSIZE; j++)
 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -356,6 +519,7 @@ do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 
 LOCAL(void)
 do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
 	    jvirt_barray_ptr *src_coef_arrays,
 	    jvirt_barray_ptr *dst_coef_arrays)
 /* 180 degree rotation is equivalent to
@@ -365,89 +529,93 @@ do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
  */
 {
   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
   int ci, i, j, offset_y;
   JBLOCKARRAY src_buffer, dst_buffer;
   JBLOCKROW src_row_ptr, dst_row_ptr;
   JCOEFPTR src_ptr, dst_ptr;
   jpeg_component_info *compptr;
 
-  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
-  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+  MCU_cols = srcinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+  MCU_rows = srcinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
 
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
     comp_width = MCU_cols * compptr->h_samp_factor;
     comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
 	 dst_blk_y += compptr->v_samp_factor) {
       dst_buffer = (*srcinfo->mem->access_virt_barray)
 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
-      if (dst_blk_y < comp_height) {
+      if (y_crop_blocks + dst_blk_y < comp_height) {
 	/* Row is within the vertically mirrorable area. */
 	src_buffer = (*srcinfo->mem->access_virt_barray)
 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
-	   comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
+	   comp_height - y_crop_blocks - dst_blk_y -
+	   (JDIMENSION) compptr->v_samp_factor,
 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
       } else {
 	/* Bottom-edge rows are only mirrored horizontally. */
 	src_buffer = (*srcinfo->mem->access_virt_barray)
-	  ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
+	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	   dst_blk_y + y_crop_blocks,
 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
       }
       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
-	if (dst_blk_y < comp_height) {
+	dst_row_ptr = dst_buffer[offset_y];
+	if (y_crop_blocks + dst_blk_y < comp_height) {
 	  /* Row is within the mirrorable area. */
-	  dst_row_ptr = dst_buffer[offset_y];
 	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
-	  /* Process the blocks that can be mirrored both ways. */
-	  for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
+	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
 	    dst_ptr = dst_row_ptr[dst_blk_x];
-	    src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
-	    for (i = 0; i < DCTSIZE; i += 2) {
-	      /* For even row, negate every odd column. */
-	      for (j = 0; j < DCTSIZE; j += 2) {
-		*dst_ptr++ = *src_ptr++;
-		*dst_ptr++ = - *src_ptr++;
+	    if (x_crop_blocks + dst_blk_x < comp_width) {
+	      /* Process the blocks that can be mirrored both ways. */
+	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
+	      for (i = 0; i < DCTSIZE; i += 2) {
+		/* For even row, negate every odd column. */
+		for (j = 0; j < DCTSIZE; j += 2) {
+		  *dst_ptr++ = *src_ptr++;
+		  *dst_ptr++ = - *src_ptr++;
+		}
+		/* For odd row, negate every even column. */
+		for (j = 0; j < DCTSIZE; j += 2) {
+		  *dst_ptr++ = - *src_ptr++;
+		  *dst_ptr++ = *src_ptr++;
+		}
 	      }
-	      /* For odd row, negate every even column. */
-	      for (j = 0; j < DCTSIZE; j += 2) {
-		*dst_ptr++ = - *src_ptr++;
-		*dst_ptr++ = *src_ptr++;
+	    } else {
+	      /* Any remaining right-edge blocks are only mirrored vertically. */
+	      src_ptr = src_row_ptr[x_crop_blocks + dst_blk_x];
+	      for (i = 0; i < DCTSIZE; i += 2) {
+		for (j = 0; j < DCTSIZE; j++)
+		  *dst_ptr++ = *src_ptr++;
+		for (j = 0; j < DCTSIZE; j++)
+		  *dst_ptr++ = - *src_ptr++;
 	      }
 	    }
 	  }
-	  /* Any remaining right-edge blocks are only mirrored vertically. */
-	  for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
-	    dst_ptr = dst_row_ptr[dst_blk_x];
-	    src_ptr = src_row_ptr[dst_blk_x];
-	    for (i = 0; i < DCTSIZE; i += 2) {
-	      for (j = 0; j < DCTSIZE; j++)
-		*dst_ptr++ = *src_ptr++;
-	      for (j = 0; j < DCTSIZE; j++)
-		*dst_ptr++ = - *src_ptr++;
-	    }
-	  }
 	} else {
 	  /* Remaining rows are just mirrored horizontally. */
-	  dst_row_ptr = dst_buffer[offset_y];
 	  src_row_ptr = src_buffer[offset_y];
-	  /* Process the blocks that can be mirrored. */
-	  for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
-	    dst_ptr = dst_row_ptr[dst_blk_x];
-	    src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
-	    for (i = 0; i < DCTSIZE2; i += 2) {
-	      *dst_ptr++ = *src_ptr++;
-	      *dst_ptr++ = - *src_ptr++;
+	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+	    if (x_crop_blocks + dst_blk_x < comp_width) {
+	      /* Process the blocks that can be mirrored. */
+	      dst_ptr = dst_row_ptr[dst_blk_x];
+	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
+	      for (i = 0; i < DCTSIZE2; i += 2) {
+		*dst_ptr++ = *src_ptr++;
+		*dst_ptr++ = - *src_ptr++;
+	      }
+	    } else {
+	      /* Any remaining right-edge blocks are only copied. */
+	      jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
+			      dst_row_ptr + dst_blk_x,
+			      (JDIMENSION) 1);
 	    }
 	  }
-	  /* Any remaining right-edge blocks are only copied. */
-	  for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
-	    dst_ptr = dst_row_ptr[dst_blk_x];
-	    src_ptr = src_row_ptr[dst_blk_x];
-	    for (i = 0; i < DCTSIZE2; i++)
-	      *dst_ptr++ = *src_ptr++;
-	  }
 	}
       }
     }
@@ -457,6 +625,7 @@ do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 
 LOCAL(void)
 do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	       JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
 	       jvirt_barray_ptr *src_coef_arrays,
 	       jvirt_barray_ptr *dst_coef_arrays)
 /* Transverse transpose is equivalent to
@@ -470,18 +639,21 @@ do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
  */
 {
   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
   int ci, i, j, offset_x, offset_y;
   JBLOCKARRAY src_buffer, dst_buffer;
   JCOEFPTR src_ptr, dst_ptr;
   jpeg_component_info *compptr;
 
-  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
-  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+  MCU_cols = srcinfo->image_height / (dstinfo->max_h_samp_factor * DCTSIZE);
+  MCU_rows = srcinfo->image_width / (dstinfo->max_v_samp_factor * DCTSIZE);
 
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
     comp_width = MCU_cols * compptr->h_samp_factor;
     comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
 	 dst_blk_y += compptr->v_samp_factor) {
       dst_buffer = (*srcinfo->mem->access_virt_barray)
@@ -490,17 +662,26 @@ do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
 	     dst_blk_x += compptr->h_samp_factor) {
-	  src_buffer = (*srcinfo->mem->access_virt_barray)
-	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
-	     (JDIMENSION) compptr->h_samp_factor, FALSE);
+	  if (x_crop_blocks + dst_blk_x < comp_width) {
+	    /* Block is within the mirrorable area. */
+	    src_buffer = (*srcinfo->mem->access_virt_barray)
+	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	       comp_width - x_crop_blocks - dst_blk_x -
+	       (JDIMENSION) compptr->h_samp_factor,
+	       (JDIMENSION) compptr->h_samp_factor, FALSE);
+	  } else {
+	    src_buffer = (*srcinfo->mem->access_virt_barray)
+	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+	       dst_blk_x + x_crop_blocks,
+	       (JDIMENSION) compptr->h_samp_factor, FALSE);
+	  }
 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
-	    if (dst_blk_y < comp_height) {
-	      src_ptr = src_buffer[offset_x]
-		[comp_height - dst_blk_y - offset_y - 1];
-	      if (dst_blk_x < comp_width) {
+	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+	    if (y_crop_blocks + dst_blk_y < comp_height) {
+	      if (x_crop_blocks + dst_blk_x < comp_width) {
 		/* Block is within the mirrorable area. */
-		dst_ptr = dst_buffer[offset_y]
-		  [comp_width - dst_blk_x - offset_x - 1];
+		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
+		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
 		for (i = 0; i < DCTSIZE; i++) {
 		  for (j = 0; j < DCTSIZE; j++) {
 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -516,7 +697,8 @@ do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 		}
 	      } else {
 		/* Right-edge blocks are mirrored in y only */
-		dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+		src_ptr = src_buffer[offset_x]
+		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
 		for (i = 0; i < DCTSIZE; i++) {
 		  for (j = 0; j < DCTSIZE; j++) {
 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -526,11 +708,10 @@ do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 		}
 	      }
 	    } else {
-	      src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
-	      if (dst_blk_x < comp_width) {
+	      if (x_crop_blocks + dst_blk_x < comp_width) {
 		/* Bottom-edge blocks are mirrored in x only */
-		dst_ptr = dst_buffer[offset_y]
-		  [comp_width - dst_blk_x - offset_x - 1];
+		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
+		  [dst_blk_y + offset_y + y_crop_blocks];
 		for (i = 0; i < DCTSIZE; i++) {
 		  for (j = 0; j < DCTSIZE; j++)
 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -540,7 +721,8 @@ do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 		}
 	      } else {
 		/* At lower right corner, just transpose, no mirroring */
-		dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+		src_ptr = src_buffer[offset_x]
+		  [dst_blk_y + offset_y + y_crop_blocks];
 		for (i = 0; i < DCTSIZE; i++)
 		  for (j = 0; j < DCTSIZE; j++)
 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
@@ -554,8 +736,116 @@ do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 }
 
 
+/* Parse an unsigned integer: subroutine for jtransform_parse_crop_spec.
+ * Returns TRUE if valid integer found, FALSE if not.
+ * *strptr is advanced over the digit string, and *result is set to its value.
+ */
+
+LOCAL(boolean)
+jt_read_integer (const char ** strptr, JDIMENSION * result)
+{
+  const char * ptr = *strptr;
+  JDIMENSION val = 0;
+
+  for (; isdigit(*ptr); ptr++) {
+    val = val * 10 + (JDIMENSION) (*ptr - '0');
+  }
+  *result = val;
+  if (ptr == *strptr)
+    return FALSE;		/* oops, no digits */
+  *strptr = ptr;
+  return TRUE;
+}
+
+
+/* Parse a crop specification (written in X11 geometry style).
+ * The routine returns TRUE if the spec string is valid, FALSE if not.
+ *
+ * The crop spec string should have the format
+ *	<width>x<height>{+-}<xoffset>{+-}<yoffset>
+ * where width, height, xoffset, and yoffset are unsigned integers.
+ * Each of the elements can be omitted to indicate a default value.
+ * (A weakness of this style is that it is not possible to omit xoffset
+ * while specifying yoffset, since they look alike.)
+ *
+ * This code is loosely based on XParseGeometry from the X11 distribution.
+ */
+
+GLOBAL(boolean)
+jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)
+{
+  info->crop = FALSE;
+  info->crop_width_set = JCROP_UNSET;
+  info->crop_height_set = JCROP_UNSET;
+  info->crop_xoffset_set = JCROP_UNSET;
+  info->crop_yoffset_set = JCROP_UNSET;
+
+  if (isdigit(*spec)) {
+    /* fetch width */
+    if (! jt_read_integer(&spec, &info->crop_width))
+      return FALSE;
+    info->crop_width_set = JCROP_POS;
+  }
+  if (*spec == 'x' || *spec == 'X') {	
+    /* fetch height */
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_height))
+      return FALSE;
+    info->crop_height_set = JCROP_POS;
+  }
+  if (*spec == '+' || *spec == '-') {
+    /* fetch xoffset */
+    info->crop_xoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_xoffset))
+      return FALSE;
+  }
+  if (*spec == '+' || *spec == '-') {
+    /* fetch yoffset */
+    info->crop_yoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_yoffset))
+      return FALSE;
+  }
+  /* We had better have gotten to the end of the string. */
+  if (*spec != '\0')
+    return FALSE;
+  info->crop = TRUE;
+  return TRUE;
+}
+
+
+/* Trim off any partial iMCUs on the indicated destination edge */
+
+LOCAL(void)
+trim_right_edge (jpeg_transform_info *info, JDIMENSION full_width)
+{
+  JDIMENSION MCU_cols;
+
+  MCU_cols = info->output_width / (info->max_h_samp_factor * DCTSIZE);
+  if (MCU_cols > 0 && info->x_crop_offset + MCU_cols ==
+      full_width / (info->max_h_samp_factor * DCTSIZE))
+    info->output_width = MCU_cols * (info->max_h_samp_factor * DCTSIZE);
+}
+
+LOCAL(void)
+trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height)
+{
+  JDIMENSION MCU_rows;
+
+  MCU_rows = info->output_height / (info->max_v_samp_factor * DCTSIZE);
+  if (MCU_rows > 0 && info->y_crop_offset + MCU_rows ==
+      full_height / (info->max_v_samp_factor * DCTSIZE))
+    info->output_height = MCU_rows * (info->max_v_samp_factor * DCTSIZE);
+}
+
+
 /* Request any required workspace.
  *
+ * This routine figures out the size that the output image will be
+ * (which implies that all the transform parameters must be set before
+ * it is called).
+ *
  * We allocate the workspace virtual arrays from the source decompression
  * object, so that all the arrays (both the original data and the workspace)
  * will be taken into account while making memory management decisions.
@@ -569,9 +859,13 @@ jtransform_request_workspace (j_decompress_ptr srcinfo,
 			      jpeg_transform_info *info)
 {
   jvirt_barray_ptr *coef_arrays = NULL;
+  boolean need_workspace, transpose_it;
   jpeg_component_info *compptr;
-  int ci;
+  JDIMENSION xoffset, yoffset, width_in_iMCUs, height_in_iMCUs;
+  JDIMENSION width_in_blocks, height_in_blocks;
+  int ci, h_samp_factor, v_samp_factor;
 
+  /* Determine number of components in output image */
   if (info->force_grayscale &&
       srcinfo->jpeg_color_space == JCS_YCbCr &&
       srcinfo->num_components == 3) {
@@ -581,55 +875,181 @@ jtransform_request_workspace (j_decompress_ptr srcinfo,
     /* Process all the components */
     info->num_components = srcinfo->num_components;
   }
+  /* If there is only one output component, force the iMCU size to be 1;
+   * else use the source iMCU size.  (This allows us to do the right thing
+   * when reducing color to grayscale, and also provides a handy way of
+   * cleaning up "funny" grayscale images whose sampling factors are not 1x1.)
+   */
+
+  switch (info->transform) {
+  case JXFORM_TRANSPOSE:
+  case JXFORM_TRANSVERSE:
+  case JXFORM_ROT_90:
+  case JXFORM_ROT_270:
+    info->output_width = srcinfo->image_height;
+    info->output_height = srcinfo->image_width;
+    if (info->num_components == 1) {
+      info->max_h_samp_factor = 1;
+      info->max_v_samp_factor = 1;
+    } else {
+      info->max_h_samp_factor = srcinfo->max_v_samp_factor;
+      info->max_v_samp_factor = srcinfo->max_h_samp_factor;
+    }
+    break;
+  default:
+    info->output_width = srcinfo->image_width;
+    info->output_height = srcinfo->image_height;
+    if (info->num_components == 1) {
+      info->max_h_samp_factor = 1;
+      info->max_v_samp_factor = 1;
+    } else {
+      info->max_h_samp_factor = srcinfo->max_h_samp_factor;
+      info->max_v_samp_factor = srcinfo->max_v_samp_factor;
+    }
+    break;
+  }
+
+  /* If cropping has been requested, compute the crop area's position and
+   * dimensions, ensuring that its upper left corner falls at an iMCU boundary.
+   */
+  if (info->crop) {
+    /* Insert default values for unset crop parameters */
+    if (info->crop_xoffset_set == JCROP_UNSET)
+      info->crop_xoffset = 0;	/* default to +0 */
+    if (info->crop_yoffset_set == JCROP_UNSET)
+      info->crop_yoffset = 0;	/* default to +0 */
+    if (info->crop_xoffset >= info->output_width ||
+	info->crop_yoffset >= info->output_height)
+      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+    if (info->crop_width_set == JCROP_UNSET)
+      info->crop_width = info->output_width - info->crop_xoffset;
+    if (info->crop_height_set == JCROP_UNSET)
+      info->crop_height = info->output_height - info->crop_yoffset;
+    /* Ensure parameters are valid */
+    if (info->crop_width <= 0 || info->crop_width > info->output_width ||
+	info->crop_height <= 0 || info->crop_height > info->output_height ||
+	info->crop_xoffset > info->output_width - info->crop_width ||
+	info->crop_yoffset > info->output_height - info->crop_height)
+      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+    /* Convert negative crop offsets into regular offsets */
+    if (info->crop_xoffset_set == JCROP_NEG)
+      xoffset = info->output_width - info->crop_width - info->crop_xoffset;
+    else
+      xoffset = info->crop_xoffset;
+    if (info->crop_yoffset_set == JCROP_NEG)
+      yoffset = info->output_height - info->crop_height - info->crop_yoffset;
+    else
+      yoffset = info->crop_yoffset;
+    /* Now adjust so that upper left corner falls at an iMCU boundary */
+    info->output_width =
+      info->crop_width + (xoffset % (info->max_h_samp_factor * DCTSIZE));
+    info->output_height =
+      info->crop_height + (yoffset % (info->max_v_samp_factor * DCTSIZE));
+    /* Save x/y offsets measured in iMCUs */
+    info->x_crop_offset = xoffset / (info->max_h_samp_factor * DCTSIZE);
+    info->y_crop_offset = yoffset / (info->max_v_samp_factor * DCTSIZE);
+  } else {
+    info->x_crop_offset = 0;
+    info->y_crop_offset = 0;
+  }
 
+  /* Figure out whether we need workspace arrays,
+   * and if so whether they are transposed relative to the source.
+   */
+  need_workspace = FALSE;
+  transpose_it = FALSE;
   switch (info->transform) {
   case JXFORM_NONE:
+    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
+      need_workspace = TRUE;
+    /* No workspace needed if neither cropping nor transforming */
+    break;
   case JXFORM_FLIP_H:
-    /* Don't need a workspace array */
+    if (info->trim)
+      trim_right_edge(info, srcinfo->image_width);
+    if (info->y_crop_offset != 0)
+      need_workspace = TRUE;
+    /* do_flip_h_no_crop doesn't need a workspace array */
     break;
   case JXFORM_FLIP_V:
-  case JXFORM_ROT_180:
-    /* Need workspace arrays having same dimensions as source image.
-     * Note that we allocate arrays padded out to the next iMCU boundary,
-     * so that transform routines need not worry about missing edge blocks.
-     */
-    coef_arrays = (jvirt_barray_ptr *)
-      (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
-	SIZEOF(jvirt_barray_ptr) * info->num_components);
-    for (ci = 0; ci < info->num_components; ci++) {
-      compptr = srcinfo->comp_info + ci;
-      coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
-	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
-	 (JDIMENSION) jround_up((long) compptr->width_in_blocks,
-				(long) compptr->h_samp_factor),
-	 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
-				(long) compptr->v_samp_factor),
-	 (JDIMENSION) compptr->v_samp_factor);
-    }
+    if (info->trim)
+      trim_bottom_edge(info, srcinfo->image_height);
+    /* Need workspace arrays having same dimensions as source image. */
+    need_workspace = TRUE;
     break;
   case JXFORM_TRANSPOSE:
+    /* transpose does NOT have to trim anything */
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
   case JXFORM_TRANSVERSE:
+    if (info->trim) {
+      trim_right_edge(info, srcinfo->image_height);
+      trim_bottom_edge(info, srcinfo->image_width);
+    }
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
   case JXFORM_ROT_90:
+    if (info->trim)
+      trim_right_edge(info, srcinfo->image_height);
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
+  case JXFORM_ROT_180:
+    if (info->trim) {
+      trim_right_edge(info, srcinfo->image_width);
+      trim_bottom_edge(info, srcinfo->image_height);
+    }
+    /* Need workspace arrays having same dimensions as source image. */
+    need_workspace = TRUE;
+    break;
   case JXFORM_ROT_270:
-    /* Need workspace arrays having transposed dimensions.
-     * Note that we allocate arrays padded out to the next iMCU boundary,
-     * so that transform routines need not worry about missing edge blocks.
-     */
+    if (info->trim)
+      trim_bottom_edge(info, srcinfo->image_width);
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
+  }
+
+  /* Allocate workspace if needed.
+   * Note that we allocate arrays padded out to the next iMCU boundary,
+   * so that transform routines need not worry about missing edge blocks.
+   */
+  if (need_workspace) {
     coef_arrays = (jvirt_barray_ptr *)
       (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
-	SIZEOF(jvirt_barray_ptr) * info->num_components);
+		SIZEOF(jvirt_barray_ptr) * info->num_components);
+    width_in_iMCUs = (JDIMENSION)
+      jdiv_round_up((long) info->output_width,
+		    (long) (info->max_h_samp_factor * DCTSIZE));
+    height_in_iMCUs = (JDIMENSION)
+      jdiv_round_up((long) info->output_height,
+		    (long) (info->max_v_samp_factor * DCTSIZE));
     for (ci = 0; ci < info->num_components; ci++) {
       compptr = srcinfo->comp_info + ci;
+      if (info->num_components == 1) {
+	/* we're going to force samp factors to 1x1 in this case */
+	h_samp_factor = v_samp_factor = 1;
+      } else if (transpose_it) {
+	h_samp_factor = compptr->v_samp_factor;
+	v_samp_factor = compptr->h_samp_factor;
+      } else {
+	h_samp_factor = compptr->h_samp_factor;
+	v_samp_factor = compptr->v_samp_factor;
+      }
+      width_in_blocks = width_in_iMCUs * h_samp_factor;
+      height_in_blocks = height_in_iMCUs * v_samp_factor;
       coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
 	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
-	 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
-				(long) compptr->v_samp_factor),
-	 (JDIMENSION) jround_up((long) compptr->width_in_blocks,
-				(long) compptr->h_samp_factor),
-	 (JDIMENSION) compptr->h_samp_factor);
+	 width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);
     }
-    break;
   }
+
   info->workspace_coef_arrays = coef_arrays;
 }
 
@@ -642,14 +1062,8 @@ transpose_critical_parameters (j_compress_ptr dstinfo)
   int tblno, i, j, ci, itemp;
   jpeg_component_info *compptr;
   JQUANT_TBL *qtblptr;
-  JDIMENSION dtemp;
   UINT16 qtemp;
 
-  /* Transpose basic image dimensions */
-  dtemp = dstinfo->image_width;
-  dstinfo->image_width = dstinfo->image_height;
-  dstinfo->image_height = dtemp;
-
   /* Transpose sampling factors */
   for (ci = 0; ci < dstinfo->num_components; ci++) {
     compptr = dstinfo->comp_info + ci;
@@ -674,46 +1088,159 @@ transpose_critical_parameters (j_compress_ptr dstinfo)
 }
 
 
-/* Trim off any partial iMCUs on the indicated destination edge */
+/* Adjust Exif image parameters.
+ *
+ * We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.
+ */
 
 LOCAL(void)
-trim_right_edge (j_compress_ptr dstinfo)
+adjust_exif_parameters (JOCTET FAR * data, unsigned int length,
+			JDIMENSION new_width, JDIMENSION new_height)
 {
-  int ci, max_h_samp_factor;
-  JDIMENSION MCU_cols;
+  boolean is_motorola; /* Flag for byte order */
+  unsigned int number_of_tags, tagnum;
+  unsigned int firstoffset, offset;
+  JDIMENSION new_value;
+
+  if (length < 12) return; /* Length of an IFD entry */
+
+  /* Discover byte order */
+  if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)
+    is_motorola = FALSE;
+  else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)
+    is_motorola = TRUE;
+  else
+    return;
+
+  /* Check Tag Mark */
+  if (is_motorola) {
+    if (GETJOCTET(data[2]) != 0) return;
+    if (GETJOCTET(data[3]) != 0x2A) return;
+  } else {
+    if (GETJOCTET(data[3]) != 0) return;
+    if (GETJOCTET(data[2]) != 0x2A) return;
+  }
 
-  /* We have to compute max_h_samp_factor ourselves,
-   * because it hasn't been set yet in the destination
-   * (and we don't want to use the source's value).
-   */
-  max_h_samp_factor = 1;
-  for (ci = 0; ci < dstinfo->num_components; ci++) {
-    int h_samp_factor = dstinfo->comp_info[ci].h_samp_factor;
-    max_h_samp_factor = MAX(max_h_samp_factor, h_samp_factor);
+  /* Get first IFD offset (offset to IFD0) */
+  if (is_motorola) {
+    if (GETJOCTET(data[4]) != 0) return;
+    if (GETJOCTET(data[5]) != 0) return;
+    firstoffset = GETJOCTET(data[6]);
+    firstoffset <<= 8;
+    firstoffset += GETJOCTET(data[7]);
+  } else {
+    if (GETJOCTET(data[7]) != 0) return;
+    if (GETJOCTET(data[6]) != 0) return;
+    firstoffset = GETJOCTET(data[5]);
+    firstoffset <<= 8;
+    firstoffset += GETJOCTET(data[4]);
   }
-  MCU_cols = dstinfo->image_width / (max_h_samp_factor * DCTSIZE);
-  if (MCU_cols > 0)		/* can't trim to 0 pixels */
-    dstinfo->image_width = MCU_cols * (max_h_samp_factor * DCTSIZE);
-}
+  if (firstoffset > length - 2) return; /* check end of data segment */
 
-LOCAL(void)
-trim_bottom_edge (j_compress_ptr dstinfo)
-{
-  int ci, max_v_samp_factor;
-  JDIMENSION MCU_rows;
+  /* Get the number of directory entries contained in this IFD */
+  if (is_motorola) {
+    number_of_tags = GETJOCTET(data[firstoffset]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[firstoffset+1]);
+  } else {
+    number_of_tags = GETJOCTET(data[firstoffset+1]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[firstoffset]);
+  }
+  if (number_of_tags == 0) return;
+  firstoffset += 2;
+
+  /* Search for ExifSubIFD offset Tag in IFD0 */
+  for (;;) {
+    if (firstoffset > length - 12) return; /* check end of data segment */
+    /* Get Tag number */
+    if (is_motorola) {
+      tagnum = GETJOCTET(data[firstoffset]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[firstoffset+1]);
+    } else {
+      tagnum = GETJOCTET(data[firstoffset+1]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[firstoffset]);
+    }
+    if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */
+    if (--number_of_tags == 0) return;
+    firstoffset += 12;
+  }
 
-  /* We have to compute max_v_samp_factor ourselves,
-   * because it hasn't been set yet in the destination
-   * (and we don't want to use the source's value).
-   */
-  max_v_samp_factor = 1;
-  for (ci = 0; ci < dstinfo->num_components; ci++) {
-    int v_samp_factor = dstinfo->comp_info[ci].v_samp_factor;
-    max_v_samp_factor = MAX(max_v_samp_factor, v_samp_factor);
+  /* Get the ExifSubIFD offset */
+  if (is_motorola) {
+    if (GETJOCTET(data[firstoffset+8]) != 0) return;
+    if (GETJOCTET(data[firstoffset+9]) != 0) return;
+    offset = GETJOCTET(data[firstoffset+10]);
+    offset <<= 8;
+    offset += GETJOCTET(data[firstoffset+11]);
+  } else {
+    if (GETJOCTET(data[firstoffset+11]) != 0) return;
+    if (GETJOCTET(data[firstoffset+10]) != 0) return;
+    offset = GETJOCTET(data[firstoffset+9]);
+    offset <<= 8;
+    offset += GETJOCTET(data[firstoffset+8]);
   }
-  MCU_rows = dstinfo->image_height / (max_v_samp_factor * DCTSIZE);
-  if (MCU_rows > 0)		/* can't trim to 0 pixels */
-    dstinfo->image_height = MCU_rows * (max_v_samp_factor * DCTSIZE);
+  if (offset > length - 2) return; /* check end of data segment */
+
+  /* Get the number of directory entries contained in this SubIFD */
+  if (is_motorola) {
+    number_of_tags = GETJOCTET(data[offset]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[offset+1]);
+  } else {
+    number_of_tags = GETJOCTET(data[offset+1]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[offset]);
+  }
+  if (number_of_tags < 2) return;
+  offset += 2;
+
+  /* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */
+  do {
+    if (offset > length - 12) return; /* check end of data segment */
+    /* Get Tag number */
+    if (is_motorola) {
+      tagnum = GETJOCTET(data[offset]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[offset+1]);
+    } else {
+      tagnum = GETJOCTET(data[offset+1]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[offset]);
+    }
+    if (tagnum == 0xA002 || tagnum == 0xA003) {
+      if (tagnum == 0xA002)
+	new_value = new_width; /* ExifImageWidth Tag */
+      else
+	new_value = new_height; /* ExifImageHeight Tag */
+      if (is_motorola) {
+	data[offset+2] = 0; /* Format = unsigned long (4 octets) */
+	data[offset+3] = 4;
+	data[offset+4] = 0; /* Number Of Components = 1 */
+	data[offset+5] = 0;
+	data[offset+6] = 0;
+	data[offset+7] = 1;
+	data[offset+8] = 0;
+	data[offset+9] = 0;
+	data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);
+	data[offset+11] = (JOCTET)(new_value & 0xFF);
+      } else {
+	data[offset+2] = 4; /* Format = unsigned long (4 octets) */
+	data[offset+3] = 0;
+	data[offset+4] = 1; /* Number Of Components = 1 */
+	data[offset+5] = 0;
+	data[offset+6] = 0;
+	data[offset+7] = 0;
+	data[offset+8] = (JOCTET)(new_value & 0xFF);
+	data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);
+	data[offset+10] = 0;
+	data[offset+11] = 0;
+      }
+    }
+    offset += 12;
+  } while (--number_of_tags);
 }
 
 
@@ -736,18 +1263,22 @@ jtransform_adjust_parameters (j_decompress_ptr srcinfo,
 {
   /* If force-to-grayscale is requested, adjust destination parameters */
   if (info->force_grayscale) {
-    /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
-     * properly.  Among other things, the target h_samp_factor & v_samp_factor
-     * will get set to 1, which typically won't match the source.
-     * In fact we do this even if the source is already grayscale; that
-     * provides an easy way of coercing a grayscale JPEG with funny sampling
-     * factors to the customary 1,1.  (Some decoders fail on other factors.)
+    /* First, ensure we have YCbCr or grayscale data, and that the source's
+     * Y channel is full resolution.  (No reasonable person would make Y
+     * be less than full resolution, so actually coping with that case
+     * isn't worth extra code space.  But we check it to avoid crashing.)
      */
-    if ((dstinfo->jpeg_color_space == JCS_YCbCr &&
-	 dstinfo->num_components == 3) ||
-	(dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
-	 dstinfo->num_components == 1)) {
-      /* We have to preserve the source's quantization table number. */
+    if (((dstinfo->jpeg_color_space == JCS_YCbCr &&
+	  dstinfo->num_components == 3) ||
+	 (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
+	  dstinfo->num_components == 1)) &&
+	srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&
+	srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {
+      /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
+       * properly.  Among other things, it sets the target h_samp_factor &
+       * v_samp_factor to 1, which typically won't match the source.
+       * We have to preserve the source's quantization table number, however.
+       */
       int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
       jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
       dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
@@ -755,50 +1286,52 @@ jtransform_adjust_parameters (j_decompress_ptr srcinfo,
       /* Sorry, can't do it */
       ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
     }
+  } else if (info->num_components == 1) {
+    /* For a single-component source, we force the destination sampling factors
+     * to 1x1, with or without force_grayscale.  This is useful because some
+     * decoders choke on grayscale images with other sampling factors.
+     */
+    dstinfo->comp_info[0].h_samp_factor = 1;
+    dstinfo->comp_info[0].v_samp_factor = 1;
   }
 
-  /* Correct the destination's image dimensions etc if necessary */
+  /* Correct the destination's image dimensions as necessary
+   * for crop and rotate/flip operations.
+   */
+  dstinfo->image_width = info->output_width;
+  dstinfo->image_height = info->output_height;
+
+  /* Transpose destination image parameters */
   switch (info->transform) {
-  case JXFORM_NONE:
-    /* Nothing to do */
-    break;
-  case JXFORM_FLIP_H:
-    if (info->trim)
-      trim_right_edge(dstinfo);
-    break;
-  case JXFORM_FLIP_V:
-    if (info->trim)
-      trim_bottom_edge(dstinfo);
-    break;
   case JXFORM_TRANSPOSE:
-    transpose_critical_parameters(dstinfo);
-    /* transpose does NOT have to trim anything */
-    break;
   case JXFORM_TRANSVERSE:
-    transpose_critical_parameters(dstinfo);
-    if (info->trim) {
-      trim_right_edge(dstinfo);
-      trim_bottom_edge(dstinfo);
-    }
-    break;
   case JXFORM_ROT_90:
-    transpose_critical_parameters(dstinfo);
-    if (info->trim)
-      trim_right_edge(dstinfo);
-    break;
-  case JXFORM_ROT_180:
-    if (info->trim) {
-      trim_right_edge(dstinfo);
-      trim_bottom_edge(dstinfo);
-    }
-    break;
   case JXFORM_ROT_270:
     transpose_critical_parameters(dstinfo);
-    if (info->trim)
-      trim_bottom_edge(dstinfo);
     break;
   }
 
+  /* Adjust Exif properties */
+  if (srcinfo->marker_list != NULL &&
+      srcinfo->marker_list->marker == JPEG_APP0+1 &&
+      srcinfo->marker_list->data_length >= 6 &&
+      GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&
+      GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&
+      GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&
+      GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&
+      GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&
+      GETJOCTET(srcinfo->marker_list->data[5]) == 0) {
+    /* Suppress output of JFIF marker */
+    dstinfo->write_JFIF_header = FALSE;
+    /* Adjust Exif image parameters */
+    if (dstinfo->image_width != srcinfo->image_width ||
+	dstinfo->image_height != srcinfo->image_height)
+      /* Align data segment to start of TIFF structure for parsing */
+      adjust_exif_parameters(srcinfo->marker_list->data + 6,
+	srcinfo->marker_list->data_length - 6,
+	dstinfo->image_width, dstinfo->image_height);
+  }
+
   /* Return the appropriate output data set */
   if (info->workspace_coef_arrays != NULL)
     return info->workspace_coef_arrays;
@@ -816,40 +1349,108 @@ jtransform_adjust_parameters (j_decompress_ptr srcinfo,
  */
 
 GLOBAL(void)
-jtransform_execute_transformation (j_decompress_ptr srcinfo,
-				   j_compress_ptr dstinfo,
-				   jvirt_barray_ptr *src_coef_arrays,
-				   jpeg_transform_info *info)
+jtransform_execute_transform (j_decompress_ptr srcinfo,
+			      j_compress_ptr dstinfo,
+			      jvirt_barray_ptr *src_coef_arrays,
+			      jpeg_transform_info *info)
 {
   jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
 
+  /* Note: conditions tested here should match those in switch statement
+   * in jtransform_request_workspace()
+   */
   switch (info->transform) {
   case JXFORM_NONE:
+    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
+      do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	      src_coef_arrays, dst_coef_arrays);
     break;
   case JXFORM_FLIP_H:
-    do_flip_h(srcinfo, dstinfo, src_coef_arrays);
+    if (info->y_crop_offset != 0)
+      do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+		src_coef_arrays, dst_coef_arrays);
+    else
+      do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,
+			src_coef_arrays);
     break;
   case JXFORM_FLIP_V:
-    do_flip_v(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+    do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	      src_coef_arrays, dst_coef_arrays);
     break;
   case JXFORM_TRANSPOSE:
-    do_transpose(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+    do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+		 src_coef_arrays, dst_coef_arrays);
     break;
   case JXFORM_TRANSVERSE:
-    do_transverse(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+    do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+		  src_coef_arrays, dst_coef_arrays);
     break;
   case JXFORM_ROT_90:
-    do_rot_90(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+    do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	      src_coef_arrays, dst_coef_arrays);
     break;
   case JXFORM_ROT_180:
-    do_rot_180(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+    do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	       src_coef_arrays, dst_coef_arrays);
     break;
   case JXFORM_ROT_270:
-    do_rot_270(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+    do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	       src_coef_arrays, dst_coef_arrays);
     break;
   }
 }
 
+/* jtransform_perfect_transform
+ *
+ * Determine whether lossless transformation is perfectly
+ * possible for a specified image and transformation.
+ *
+ * Inputs:
+ *   image_width, image_height: source image dimensions.
+ *   MCU_width, MCU_height: pixel dimensions of MCU.
+ *   transform: transformation identifier.
+ * Parameter sources from initialized jpeg_struct
+ * (after reading source header):
+ *   image_width = cinfo.image_width
+ *   image_height = cinfo.image_height
+ *   MCU_width = cinfo.max_h_samp_factor * DCTSIZE
+ *   MCU_height = cinfo.max_v_samp_factor * DCTSIZE
+ * Result:
+ *   TRUE = perfect transformation possible
+ *   FALSE = perfect transformation not possible
+ *           (may use custom action then)
+ */
+
+GLOBAL(boolean)
+jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,
+			     int MCU_width, int MCU_height,
+			     JXFORM_CODE transform)
+{
+  boolean result = TRUE; /* initialize TRUE */
+
+  switch (transform) {
+  case JXFORM_FLIP_H:
+  case JXFORM_ROT_270:
+    if (image_width % (JDIMENSION) MCU_width)
+      result = FALSE;
+    break;
+  case JXFORM_FLIP_V:
+  case JXFORM_ROT_90:
+    if (image_height % (JDIMENSION) MCU_height)
+      result = FALSE;
+    break;
+  case JXFORM_TRANSVERSE:
+  case JXFORM_ROT_180:
+    if (image_width % (JDIMENSION) MCU_width)
+      result = FALSE;
+    if (image_height % (JDIMENSION) MCU_height)
+      result = FALSE;
+    break;
+  }
+
+  return result;
+}
+
 #endif /* TRANSFORMS_SUPPORTED */
 
 
diff --git a/transupp.h b/transupp.h
index 5c2d32a..981b1ce 100644
--- a/transupp.h
+++ b/transupp.h
@@ -1,7 +1,7 @@
 /*
  * transupp.h
  *
- * Copyright (C) 1997, Thomas G. Lane.
+ * Copyright (C) 1997-2001, Thomas G. Lane.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
@@ -22,32 +22,6 @@
 #define TRANSFORMS_SUPPORTED 1		/* 0 disables transform code */
 #endif
 
-/* Short forms of external names for systems with brain-damaged linkers. */
-
-#ifdef NEED_SHORT_EXTERNAL_NAMES
-#define jtransform_request_workspace		jTrRequest
-#define jtransform_adjust_parameters		jTrAdjust
-#define jtransform_execute_transformation	jTrExec
-#define jcopy_markers_setup			jCMrkSetup
-#define jcopy_markers_execute			jCMrkExec
-#endif /* NEED_SHORT_EXTERNAL_NAMES */
-
-
-/*
- * Codes for supported types of image transformations.
- */
-
-typedef enum {
-	JXFORM_NONE,		/* no transformation */
-	JXFORM_FLIP_H,		/* horizontal flip */
-	JXFORM_FLIP_V,		/* vertical flip */
-	JXFORM_TRANSPOSE,	/* transpose across UL-to-LR axis */
-	JXFORM_TRANSVERSE,	/* transpose across UR-to-LL axis */
-	JXFORM_ROT_90,		/* 90-degree clockwise rotation */
-	JXFORM_ROT_180,		/* 180-degree rotation */
-	JXFORM_ROT_270		/* 270-degree clockwise (or 90 ccw) */
-} JXFORM_CODE;
-
 /*
  * Although rotating and flipping data expressed as DCT coefficients is not
  * hard, there is an asymmetry in the JPEG format specification for images
@@ -75,6 +49,19 @@ typedef enum {
  * (For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim
  * followed by -rot 180 -trim trims both edges.)
  *
+ * We also offer a lossless-crop option, which discards data outside a given
+ * image region but losslessly preserves what is inside.  Like the rotate and
+ * flip transforms, lossless crop is restricted by the JPEG format: the upper
+ * left corner of the selected region must fall on an iMCU boundary.  If this
+ * does not hold for the given crop parameters, we silently move the upper left
+ * corner up and/or left to make it so, simultaneously increasing the region
+ * dimensions to keep the lower right crop corner unchanged.  (Thus, the
+ * output image covers at least the requested region, but may cover more.)
+ *
+ * If both crop and a rotate/flip transform are requested, the crop is applied
+ * last --- that is, the crop region is specified in terms of the destination
+ * image.
+ *
  * We also offer a "force to grayscale" option, which simply discards the
  * chrominance channels of a YCbCr image.  This is lossless in the sense that
  * the luminance channel is preserved exactly.  It's not the same kind of
@@ -83,20 +70,89 @@ typedef enum {
  * be aware of the option to know how many components to work on.
  */
 
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jtransform_parse_crop_spec	jTrParCrop
+#define jtransform_request_workspace	jTrRequest
+#define jtransform_adjust_parameters	jTrAdjust
+#define jtransform_execute_transform	jTrExec
+#define jtransform_perfect_transform	jTrPerfect
+#define jcopy_markers_setup		jCMrkSetup
+#define jcopy_markers_execute		jCMrkExec
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/*
+ * Codes for supported types of image transformations.
+ */
+
+typedef enum {
+	JXFORM_NONE,		/* no transformation */
+	JXFORM_FLIP_H,		/* horizontal flip */
+	JXFORM_FLIP_V,		/* vertical flip */
+	JXFORM_TRANSPOSE,	/* transpose across UL-to-LR axis */
+	JXFORM_TRANSVERSE,	/* transpose across UR-to-LL axis */
+	JXFORM_ROT_90,		/* 90-degree clockwise rotation */
+	JXFORM_ROT_180,		/* 180-degree rotation */
+	JXFORM_ROT_270		/* 270-degree clockwise (or 90 ccw) */
+} JXFORM_CODE;
+
+/*
+ * Codes for crop parameters, which can individually be unspecified,
+ * positive, or negative.  (Negative width or height makes no sense, though.)
+ */
+
+typedef enum {
+	JCROP_UNSET,
+	JCROP_POS,
+	JCROP_NEG
+} JCROP_CODE;
+
+/*
+ * Transform parameters struct.
+ * NB: application must not change any elements of this struct after
+ * calling jtransform_request_workspace.
+ */
+
 typedef struct {
   /* Options: set by caller */
   JXFORM_CODE transform;	/* image transform operator */
+  boolean perfect;		/* if TRUE, fail if partial MCUs are requested */
   boolean trim;			/* if TRUE, trim partial MCUs as needed */
   boolean force_grayscale;	/* if TRUE, convert color image to grayscale */
+  boolean crop;			/* if TRUE, crop source image */
+
+  /* Crop parameters: application need not set these unless crop is TRUE.
+   * These can be filled in by jtransform_parse_crop_spec().
+   */
+  JDIMENSION crop_width;	/* Width of selected region */
+  JCROP_CODE crop_width_set;
+  JDIMENSION crop_height;	/* Height of selected region */
+  JCROP_CODE crop_height_set;
+  JDIMENSION crop_xoffset;	/* X offset of selected region */
+  JCROP_CODE crop_xoffset_set;	/* (negative measures from right edge) */
+  JDIMENSION crop_yoffset;	/* Y offset of selected region */
+  JCROP_CODE crop_yoffset_set;	/* (negative measures from bottom edge) */
 
   /* Internal workspace: caller should not touch these */
   int num_components;		/* # of components in workspace */
   jvirt_barray_ptr * workspace_coef_arrays; /* workspace for transformations */
+  JDIMENSION output_width;	/* cropped destination dimensions */
+  JDIMENSION output_height;
+  JDIMENSION x_crop_offset;	/* destination crop offsets measured in iMCUs */
+  JDIMENSION y_crop_offset;
+  int max_h_samp_factor;	/* destination iMCU size */
+  int max_v_samp_factor;
 } jpeg_transform_info;
 
 
 #if TRANSFORMS_SUPPORTED
 
+/* Parse a crop specification (written in X11 geometry style) */
+EXTERN(boolean) jtransform_parse_crop_spec
+	JPP((jpeg_transform_info *info, const char *spec));
 /* Request any required workspace */
 EXTERN(void) jtransform_request_workspace
 	JPP((j_decompress_ptr srcinfo, jpeg_transform_info *info));
@@ -106,10 +162,24 @@ EXTERN(jvirt_barray_ptr *) jtransform_adjust_parameters
 	     jvirt_barray_ptr *src_coef_arrays,
 	     jpeg_transform_info *info));
 /* Execute the actual transformation, if any */
-EXTERN(void) jtransform_execute_transformation
+EXTERN(void) jtransform_execute_transform
 	JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 	     jvirt_barray_ptr *src_coef_arrays,
 	     jpeg_transform_info *info));
+/* Determine whether lossless transformation is perfectly
+ * possible for a specified image and transformation.
+ */
+EXTERN(boolean) jtransform_perfect_transform
+	JPP((JDIMENSION image_width, JDIMENSION image_height,
+	     int MCU_width, int MCU_height,
+	     JXFORM_CODE transform));
+
+/* jtransform_execute_transform used to be called
+ * jtransform_execute_transformation, but some compilers complain about
+ * routine names that long.  This macro is here to avoid breaking any
+ * old source code that uses the original name...
+ */
+#define jtransform_execute_transformation	jtransform_execute_transform
 
 #endif /* TRANSFORMS_SUPPORTED */