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Diffstat (limited to 'gs/jpeg/jdsample.c')
| -rw-r--r-- | gs/jpeg/jdsample.c | 478 |
1 files changed, 0 insertions, 478 deletions
diff --git a/gs/jpeg/jdsample.c b/gs/jpeg/jdsample.c deleted file mode 100644 index 80ffefb2a..000000000 --- a/gs/jpeg/jdsample.c +++ /dev/null @@ -1,478 +0,0 @@ -/* - * jdsample.c - * - * Copyright (C) 1991-1996, 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. - * - * This file contains upsampling routines. - * - * Upsampling input data is counted in "row groups". A row group - * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size) - * sample rows of each component. Upsampling will normally produce - * max_v_samp_factor pixel rows from each row group (but this could vary - * if the upsampler is applying a scale factor of its own). - * - * An excellent reference for image resampling is - * Digital Image Warping, George Wolberg, 1990. - * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" - - -/* Pointer to routine to upsample a single component */ -typedef JMETHOD(void, upsample1_ptr, - (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)); - -/* Private subobject */ - -typedef struct { - struct jpeg_upsampler pub; /* public fields */ - - /* Color conversion buffer. When using separate upsampling and color - * conversion steps, this buffer holds one upsampled row group until it - * has been color converted and output. - * Note: we do not allocate any storage for component(s) which are full-size, - * ie do not need rescaling. The corresponding entry of color_buf[] is - * simply set to point to the input data array, thereby avoiding copying. - */ - JSAMPARRAY color_buf[MAX_COMPONENTS]; - - /* Per-component upsampling method pointers */ - upsample1_ptr methods[MAX_COMPONENTS]; - - int next_row_out; /* counts rows emitted from color_buf */ - JDIMENSION rows_to_go; /* counts rows remaining in image */ - - /* Height of an input row group for each component. */ - int rowgroup_height[MAX_COMPONENTS]; - - /* These arrays save pixel expansion factors so that int_expand need not - * recompute them each time. They are unused for other upsampling methods. - */ - UINT8 h_expand[MAX_COMPONENTS]; - UINT8 v_expand[MAX_COMPONENTS]; -} my_upsampler; - -typedef my_upsampler * my_upsample_ptr; - - -/* - * Initialize for an upsampling pass. - */ - -METHODDEF(void) -start_pass_upsample (j_decompress_ptr cinfo) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - - /* Mark the conversion buffer empty */ - upsample->next_row_out = cinfo->max_v_samp_factor; - /* Initialize total-height counter for detecting bottom of image */ - upsample->rows_to_go = cinfo->output_height; -} - - -/* - * Control routine to do upsampling (and color conversion). - * - * In this version we upsample each component independently. - * We upsample one row group into the conversion buffer, then apply - * color conversion a row at a time. - */ - -METHODDEF(void) -sep_upsample (j_decompress_ptr cinfo, - JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, - JDIMENSION in_row_groups_avail, - JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, - JDIMENSION out_rows_avail) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - int ci; - jpeg_component_info * compptr; - JDIMENSION num_rows; - - /* Fill the conversion buffer, if it's empty */ - if (upsample->next_row_out >= cinfo->max_v_samp_factor) { - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - /* Invoke per-component upsample method. Notice we pass a POINTER - * to color_buf[ci], so that fullsize_upsample can change it. - */ - (*upsample->methods[ci]) (cinfo, compptr, - input_buf[ci] + (*in_row_group_ctr * upsample->rowgroup_height[ci]), - upsample->color_buf + ci); - } - upsample->next_row_out = 0; - } - - /* Color-convert and emit rows */ - - /* How many we have in the buffer: */ - num_rows = (JDIMENSION) (cinfo->max_v_samp_factor - upsample->next_row_out); - /* Not more than the distance to the end of the image. Need this test - * in case the image height is not a multiple of max_v_samp_factor: - */ - if (num_rows > upsample->rows_to_go) - num_rows = upsample->rows_to_go; - /* And not more than what the client can accept: */ - out_rows_avail -= *out_row_ctr; - if (num_rows > out_rows_avail) - num_rows = out_rows_avail; - - (*cinfo->cconvert->color_convert) (cinfo, upsample->color_buf, - (JDIMENSION) upsample->next_row_out, - output_buf + *out_row_ctr, - (int) num_rows); - - /* Adjust counts */ - *out_row_ctr += num_rows; - upsample->rows_to_go -= num_rows; - upsample->next_row_out += num_rows; - /* When the buffer is emptied, declare this input row group consumed */ - if (upsample->next_row_out >= cinfo->max_v_samp_factor) - (*in_row_group_ctr)++; -} - - -/* - * These are the routines invoked by sep_upsample to upsample pixel values - * of a single component. One row group is processed per call. - */ - - -/* - * For full-size components, we just make color_buf[ci] point at the - * input buffer, and thus avoid copying any data. Note that this is - * safe only because sep_upsample doesn't declare the input row group - * "consumed" until we are done color converting and emitting it. - */ - -METHODDEF(void) -fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - *output_data_ptr = input_data; -} - - -/* - * This is a no-op version used for "uninteresting" components. - * These components will not be referenced by color conversion. - */ - -METHODDEF(void) -noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - *output_data_ptr = NULL; /* safety check */ -} - - -/* - * This version handles any integral sampling ratios. - * This is not used for typical JPEG files, so it need not be fast. - * Nor, for that matter, is it particularly accurate: the algorithm is - * simple replication of the input pixel onto the corresponding output - * pixels. The hi-falutin sampling literature refers to this as a - * "box filter". A box filter tends to introduce visible artifacts, - * so if you are actually going to use 3:1 or 4:1 sampling ratios - * you would be well advised to improve this code. - */ - -METHODDEF(void) -int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - JSAMPARRAY output_data = *output_data_ptr; - register JSAMPROW inptr, outptr; - register JSAMPLE invalue; - register int h; - JSAMPROW outend; - int h_expand, v_expand; - int inrow, outrow; - - h_expand = upsample->h_expand[compptr->component_index]; - v_expand = upsample->v_expand[compptr->component_index]; - - inrow = outrow = 0; - while (outrow < cinfo->max_v_samp_factor) { - /* Generate one output row with proper horizontal expansion */ - inptr = input_data[inrow]; - outptr = output_data[outrow]; - outend = outptr + cinfo->output_width; - while (outptr < outend) { - invalue = *inptr++; /* don't need GETJSAMPLE() here */ - for (h = h_expand; h > 0; h--) { - *outptr++ = invalue; - } - } - /* Generate any additional output rows by duplicating the first one */ - if (v_expand > 1) { - jcopy_sample_rows(output_data, outrow, output_data, outrow+1, - v_expand-1, cinfo->output_width); - } - inrow++; - outrow += v_expand; - } -} - - -/* - * Fast processing for the common case of 2:1 horizontal and 1:1 vertical. - * It's still a box filter. - */ - -METHODDEF(void) -h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - JSAMPARRAY output_data = *output_data_ptr; - register JSAMPROW inptr, outptr; - register JSAMPLE invalue; - JSAMPROW outend; - int inrow; - - for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) { - inptr = input_data[inrow]; - outptr = output_data[inrow]; - outend = outptr + cinfo->output_width; - while (outptr < outend) { - invalue = *inptr++; /* don't need GETJSAMPLE() here */ - *outptr++ = invalue; - *outptr++ = invalue; - } - } -} - - -/* - * Fast processing for the common case of 2:1 horizontal and 2:1 vertical. - * It's still a box filter. - */ - -METHODDEF(void) -h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - JSAMPARRAY output_data = *output_data_ptr; - register JSAMPROW inptr, outptr; - register JSAMPLE invalue; - JSAMPROW outend; - int inrow, outrow; - - inrow = outrow = 0; - while (outrow < cinfo->max_v_samp_factor) { - inptr = input_data[inrow]; - outptr = output_data[outrow]; - outend = outptr + cinfo->output_width; - while (outptr < outend) { - invalue = *inptr++; /* don't need GETJSAMPLE() here */ - *outptr++ = invalue; - *outptr++ = invalue; - } - jcopy_sample_rows(output_data, outrow, output_data, outrow+1, - 1, cinfo->output_width); - inrow++; - outrow += 2; - } -} - - -/* - * Fancy processing for the common case of 2:1 horizontal and 1:1 vertical. - * - * The upsampling algorithm is linear interpolation between pixel centers, - * also known as a "triangle filter". This is a good compromise between - * speed and visual quality. The centers of the output pixels are 1/4 and 3/4 - * of the way between input pixel centers. - * - * A note about the "bias" calculations: when rounding fractional values to - * integer, we do not want to always round 0.5 up to the next integer. - * If we did that, we'd introduce a noticeable bias towards larger values. - * Instead, this code is arranged so that 0.5 will be rounded up or down at - * alternate pixel locations (a simple ordered dither pattern). - */ - -METHODDEF(void) -h2v1_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - JSAMPARRAY output_data = *output_data_ptr; - register JSAMPROW inptr, outptr; - register int invalue; - register JDIMENSION colctr; - int inrow; - - for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) { - inptr = input_data[inrow]; - outptr = output_data[inrow]; - /* Special case for first column */ - invalue = GETJSAMPLE(*inptr++); - *outptr++ = (JSAMPLE) invalue; - *outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(*inptr) + 2) >> 2); - - for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) { - /* General case: 3/4 * nearer pixel + 1/4 * further pixel */ - invalue = GETJSAMPLE(*inptr++) * 3; - *outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(inptr[-2]) + 1) >> 2); - *outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(*inptr) + 2) >> 2); - } - - /* Special case for last column */ - invalue = GETJSAMPLE(*inptr); - *outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(inptr[-1]) + 1) >> 2); - *outptr++ = (JSAMPLE) invalue; - } -} - - -/* - * Fancy processing for the common case of 2:1 horizontal and 2:1 vertical. - * Again a triangle filter; see comments for h2v1 case, above. - * - * It is OK for us to reference the adjacent input rows because we demanded - * context from the main buffer controller (see initialization code). - */ - -METHODDEF(void) -h2v2_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - JSAMPARRAY output_data = *output_data_ptr; - register JSAMPROW inptr0, inptr1, outptr; -#if BITS_IN_JSAMPLE == 8 - register int thiscolsum, lastcolsum, nextcolsum; -#else - register INT32 thiscolsum, lastcolsum, nextcolsum; -#endif - register JDIMENSION colctr; - int inrow, outrow, v; - - inrow = outrow = 0; - while (outrow < cinfo->max_v_samp_factor) { - for (v = 0; v < 2; v++) { - /* inptr0 points to nearest input row, inptr1 points to next nearest */ - inptr0 = input_data[inrow]; - if (v == 0) /* next nearest is row above */ - inptr1 = input_data[inrow-1]; - else /* next nearest is row below */ - inptr1 = input_data[inrow+1]; - outptr = output_data[outrow++]; - - /* Special case for first column */ - thiscolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++); - nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++); - *outptr++ = (JSAMPLE) ((thiscolsum * 4 + 8) >> 4); - *outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4); - lastcolsum = thiscolsum; thiscolsum = nextcolsum; - - for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) { - /* General case: 3/4 * nearer pixel + 1/4 * further pixel in each */ - /* dimension, thus 9/16, 3/16, 3/16, 1/16 overall */ - nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++); - *outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4); - *outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4); - lastcolsum = thiscolsum; thiscolsum = nextcolsum; - } - - /* Special case for last column */ - *outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4); - *outptr++ = (JSAMPLE) ((thiscolsum * 4 + 7) >> 4); - } - inrow++; - } -} - - -/* - * Module initialization routine for upsampling. - */ - -GLOBAL(void) -jinit_upsampler (j_decompress_ptr cinfo) -{ - my_upsample_ptr upsample; - int ci; - jpeg_component_info * compptr; - boolean need_buffer, do_fancy; - int h_in_group, v_in_group, h_out_group, v_out_group; - - upsample = (my_upsample_ptr) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - SIZEOF(my_upsampler)); - cinfo->upsample = (struct jpeg_upsampler *) upsample; - upsample->pub.start_pass = start_pass_upsample; - upsample->pub.upsample = sep_upsample; - upsample->pub.need_context_rows = FALSE; /* until we find out differently */ - - if (cinfo->CCIR601_sampling) /* this isn't supported */ - ERREXIT(cinfo, JERR_CCIR601_NOTIMPL); - - /* jdmainct.c doesn't support context rows when min_DCT_scaled_size = 1, - * so don't ask for it. - */ - do_fancy = cinfo->do_fancy_upsampling && cinfo->min_DCT_scaled_size > 1; - - /* Verify we can handle the sampling factors, select per-component methods, - * and create storage as needed. - */ - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - /* Compute size of an "input group" after IDCT scaling. This many samples - * are to be converted to max_h_samp_factor * max_v_samp_factor pixels. - */ - h_in_group = (compptr->h_samp_factor * compptr->DCT_scaled_size) / - cinfo->min_DCT_scaled_size; - v_in_group = (compptr->v_samp_factor * compptr->DCT_scaled_size) / - cinfo->min_DCT_scaled_size; - h_out_group = cinfo->max_h_samp_factor; - v_out_group = cinfo->max_v_samp_factor; - upsample->rowgroup_height[ci] = v_in_group; /* save for use later */ - need_buffer = TRUE; - if (! compptr->component_needed) { - /* Don't bother to upsample an uninteresting component. */ - upsample->methods[ci] = noop_upsample; - need_buffer = FALSE; - } else if (h_in_group == h_out_group && v_in_group == v_out_group) { - /* Fullsize components can be processed without any work. */ - upsample->methods[ci] = fullsize_upsample; - need_buffer = FALSE; - } else if (h_in_group * 2 == h_out_group && - v_in_group == v_out_group) { - /* Special cases for 2h1v upsampling */ - if (do_fancy && compptr->downsampled_width > 2) - upsample->methods[ci] = h2v1_fancy_upsample; - else - upsample->methods[ci] = h2v1_upsample; - } else if (h_in_group * 2 == h_out_group && - v_in_group * 2 == v_out_group) { - /* Special cases for 2h2v upsampling */ - if (do_fancy && compptr->downsampled_width > 2) { - upsample->methods[ci] = h2v2_fancy_upsample; - upsample->pub.need_context_rows = TRUE; - } else - upsample->methods[ci] = h2v2_upsample; - } else if ((h_out_group % h_in_group) == 0 && - (v_out_group % v_in_group) == 0) { - /* Generic integral-factors upsampling method */ - upsample->methods[ci] = int_upsample; - upsample->h_expand[ci] = (UINT8) (h_out_group / h_in_group); - upsample->v_expand[ci] = (UINT8) (v_out_group / v_in_group); - } else - ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL); - if (need_buffer) { - upsample->color_buf[ci] = (*cinfo->mem->alloc_sarray) - ((j_common_ptr) cinfo, JPOOL_IMAGE, - (JDIMENSION) jround_up((long) cinfo->output_width, - (long) cinfo->max_h_samp_factor), - (JDIMENSION) cinfo->max_v_samp_factor); - } - } -} |