[PATCH] 100_crop.dpatch

Lossless-crop patch from <http://sylvana.net/jpegcrop/croppatch.tar.gz>

4 files changed, 987 insertions, 273 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.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 */