1e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#if !defined(_FX_JPEG_TURBO_) 2e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 3e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * jcsample.c 4e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 5e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Copyright (C) 1991-1996, Thomas G. Lane. 6e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This file is part of the Independent JPEG Group's software. 7e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * For conditions of distribution and use, see the accompanying README file. 8e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 9e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This file contains downsampling routines. 10e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 11e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsampling input data is counted in "row groups". A row group 12e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * is defined to be max_v_samp_factor pixel rows of each component, 13e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * from which the downsampler produces v_samp_factor sample rows. 14e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * A single row group is processed in each call to the downsampler module. 15e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 16e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The downsampler is responsible for edge-expansion of its output data 17e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * to fill an integral number of DCT blocks horizontally. The source buffer 18e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * may be modified if it is helpful for this purpose (the source buffer is 19e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * allocated wide enough to correspond to the desired output width). 20e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The caller (the prep controller) is responsible for vertical padding. 21e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 22e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The downsampler may request "context rows" by setting need_context_rows 23e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * during startup. In this case, the input arrays will contain at least 24e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * one row group's worth of pixels above and below the passed-in data; 25e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * the caller will create dummy rows at image top and bottom by replicating 26e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * the first or last real pixel row. 27e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 28e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * An excellent reference for image resampling is 29e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Digital Image Warping, George Wolberg, 1990. 30e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7. 31e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 32e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The downsampling algorithm used here is a simple average of the source 33e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * pixels covered by the output pixel. The hi-falutin sampling literature 34e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * refers to this as a "box filter". In general the characteristics of a box 35e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * filter are not very good, but for the specific cases we normally use (1:1 36e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * and 2:1 ratios) the box is equivalent to a "triangle filter" which is not 37e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * nearly so bad. If you intend to use other sampling ratios, you'd be well 38e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * advised to improve this code. 39e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 40e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * A simple input-smoothing capability is provided. This is mainly intended 41e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * for cleaning up color-dithered GIF input files (if you find it inadequate, 42e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * we suggest using an external filtering program such as pnmconvol). When 43e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * enabled, each input pixel P is replaced by a weighted sum of itself and its 44e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * eight neighbors. P's weight is 1-8*SF and each neighbor's weight is SF, 45e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * where SF = (smoothing_factor / 1024). 46e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Currently, smoothing is only supported for 2h2v sampling factors. 47e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 48e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 49e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define JPEG_INTERNALS 50e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jinclude.h" 51e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jpeglib.h" 52e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 53e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 54e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Pointer to routine to downsample a single component */ 55e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef JMETHOD(void, downsample1_ptr, 56e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (j_compress_ptr cinfo, jpeg_component_info * compptr, 57e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data)); 58e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 59e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Private subobject */ 60e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 61e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef struct { 62e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov struct jpeg_downsampler pub; /* public fields */ 63e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 64e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Downsampling method pointers, one per component */ 65e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample1_ptr methods[MAX_COMPONENTS]; 66e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} my_downsampler; 67e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 68e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef my_downsampler * my_downsample_ptr; 69e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 70e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 71e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 72e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Initialize for a downsampling pass. 73e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 74e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 75e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 76e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovstart_pass_downsample (j_compress_ptr cinfo) 77e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 78e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* no work for now */ 79e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 80e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 81e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 82e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 83e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Expand a component horizontally from width input_cols to width output_cols, 84e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * by duplicating the rightmost samples. 85e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 86e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 87e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 88e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovexpand_right_edge (JSAMPARRAY image_data, int num_rows, 89e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION input_cols, JDIMENSION output_cols) 90e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 91e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register JSAMPROW ptr; 92e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register JSAMPLE pixval; 93e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int count; 94e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int row; 95e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int numcols = (int) (output_cols - input_cols); 96e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 97e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (numcols > 0) { 98e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (row = 0; row < num_rows; row++) { 99e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ptr = image_data[row] + input_cols; 100e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov pixval = ptr[-1]; /* don't need GETJSAMPLE() here */ 101e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (count = numcols; count > 0; count--) 102e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *ptr++ = pixval; 103e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 104e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 105e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 106e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 107e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 108e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 109e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Do downsampling for a whole row group (all components). 110e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 111e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * In this version we simply downsample each component independently. 112e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 113e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 114e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 115e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovsep_downsample (j_compress_ptr cinfo, 116e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPIMAGE input_buf, JDIMENSION in_row_index, 117e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPIMAGE output_buf, JDIMENSION out_row_group_index) 118e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 119e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample; 120e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci; 121e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info * compptr; 122e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY in_ptr, out_ptr; 123e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 124e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 125e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ci++, compptr++) { 126e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov in_ptr = input_buf[ci] + in_row_index; 127e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor); 128e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr); 129e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 130e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 131e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 132e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 133e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 134e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsample pixel values of a single component. 135e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * One row group is processed per call. 136e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This version handles arbitrary integral sampling ratios, without smoothing. 137e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Note that this version is not actually used for customary sampling ratios. 138e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 139e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 140e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 141e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovint_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 142e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 143e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 144e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v; 145e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */ 146e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 147e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPROW inptr, outptr; 148e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov INT32 outvalue; 149e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 150e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor; 151e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor; 152e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov numpix = h_expand * v_expand; 153e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov numpix2 = numpix/2; 154e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 155e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Expand input data enough to let all the output samples be generated 156e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * by the standard loop. Special-casing padded output would be more 157e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * efficient. 158e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 159e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov expand_right_edge(input_data, cinfo->max_v_samp_factor, 160e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->image_width, output_cols * h_expand); 161e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 162e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inrow = 0; 163e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 164e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outptr = output_data[outrow]; 165e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outcol = 0, outcol_h = 0; outcol < output_cols; 166e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outcol++, outcol_h += h_expand) { 167e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outvalue = 0; 168e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (v = 0; v < v_expand; v++) { 169e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr = input_data[inrow+v] + outcol_h; 170e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (h = 0; h < h_expand; h++) { 171e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outvalue += (INT32) GETJSAMPLE(*inptr++); 172e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 173e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 174e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix); 175e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 176e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inrow += v_expand; 177e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 178e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 179e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 180e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 181e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 182e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsample pixel values of a single component. 183e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This version handles the special case of a full-size component, 184e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * without smoothing. 185e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 186e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 187e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 188e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovfullsize_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 189e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 190e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 191e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Copy the data */ 192e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jcopy_sample_rows(input_data, 0, output_data, 0, 193e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->max_v_samp_factor, cinfo->image_width); 194e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Edge-expand */ 195e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov expand_right_edge(output_data, cinfo->max_v_samp_factor, 196e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->image_width, compptr->width_in_blocks * DCTSIZE); 197e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 198e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 199e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 200e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 201e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsample pixel values of a single component. 202e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This version handles the common case of 2:1 horizontal and 1:1 vertical, 203e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * without smoothing. 204e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 205e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * A note about the "bias" calculations: when rounding fractional values to 206e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * integer, we do not want to always round 0.5 up to the next integer. 207e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * If we did that, we'd introduce a noticeable bias towards larger values. 208e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Instead, this code is arranged so that 0.5 will be rounded up or down at 209e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * alternate pixel locations (a simple ordered dither pattern). 210e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 211e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 212e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 213e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovh2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 214e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 215e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 216e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int outrow; 217e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION outcol; 218e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 219e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register JSAMPROW inptr, outptr; 220e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int bias; 221e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 222e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Expand input data enough to let all the output samples be generated 223e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * by the standard loop. Special-casing padded output would be more 224e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * efficient. 225e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 226e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov expand_right_edge(input_data, cinfo->max_v_samp_factor, 227e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->image_width, output_cols * 2); 228e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 229e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 230e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outptr = output_data[outrow]; 231e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr = input_data[outrow]; 232e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov bias = 0; /* bias = 0,1,0,1,... for successive samples */ 233e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outcol = 0; outcol < output_cols; outcol++) { 234e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1]) 235e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov + bias) >> 1); 236e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov bias ^= 1; /* 0=>1, 1=>0 */ 237e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr += 2; 238e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 239e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 240e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 241e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 242e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 243e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 244e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsample pixel values of a single component. 245e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This version handles the standard case of 2:1 horizontal and 2:1 vertical, 246e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * without smoothing. 247e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 248e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 249e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 250e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovh2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 251e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 252e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 253e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int inrow, outrow; 254e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION outcol; 255e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 256e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register JSAMPROW inptr0, inptr1, outptr; 257e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int bias; 258e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 259e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Expand input data enough to let all the output samples be generated 260e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * by the standard loop. Special-casing padded output would be more 261e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * efficient. 262e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 263e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov expand_right_edge(input_data, cinfo->max_v_samp_factor, 264e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->image_width, output_cols * 2); 265e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 266e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inrow = 0; 267e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 268e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outptr = output_data[outrow]; 269e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr0 = input_data[inrow]; 270e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr1 = input_data[inrow+1]; 271e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov bias = 1; /* bias = 1,2,1,2,... for successive samples */ 272e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outcol = 0; outcol < output_cols; outcol++) { 273e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 274e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]) 275e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov + bias) >> 2); 276e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov bias ^= 3; /* 1=>2, 2=>1 */ 277e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr0 += 2; inptr1 += 2; 278e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 279e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inrow += 2; 280e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 281e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 282e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 283e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 284e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 285e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 286e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 287e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsample pixel values of a single component. 288e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This version handles the standard case of 2:1 horizontal and 2:1 vertical, 289e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * with smoothing. One row of context is required. 290e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 291e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 292e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 293e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovh2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 294e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 295e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 296e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int inrow, outrow; 297e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION colctr; 298e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 299e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr; 300e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov INT32 membersum, neighsum, memberscale, neighscale; 301e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 302e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Expand input data enough to let all the output samples be generated 303e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * by the standard loop. Special-casing padded output would be more 304e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * efficient. 305e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 306e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2, 307e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->image_width, output_cols * 2); 308e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 309e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We don't bother to form the individual "smoothed" input pixel values; 310e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * we can directly compute the output which is the average of the four 311e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * smoothed values. Each of the four member pixels contributes a fraction 312e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * (1-8*SF) to its own smoothed image and a fraction SF to each of the three 313e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final 314e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * output. The four corner-adjacent neighbor pixels contribute a fraction 315e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * SF to just one smoothed pixel, or SF/4 to the final output; while the 316e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * eight edge-adjacent neighbors contribute SF to each of two smoothed 317e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * pixels, or SF/2 overall. In order to use integer arithmetic, these 318e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * factors are scaled by 2^16 = 65536. 319e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Also recall that SF = smoothing_factor / 1024. 320e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 321e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 322e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */ 323e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */ 324e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 325e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inrow = 0; 326e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 327e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outptr = output_data[outrow]; 328e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr0 = input_data[inrow]; 329e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr1 = input_data[inrow+1]; 330e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov above_ptr = input_data[inrow-1]; 331e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov below_ptr = input_data[inrow+2]; 332e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 333e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Special case for first column: pretend column -1 is same as column 0 */ 334e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 335e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]); 336e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) + 337e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) + 338e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[2]) + 339e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[2]); 340e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum += neighsum; 341e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum += GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[2]) + 342e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[2]); 343e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 344e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 345e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2; 346e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 347e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (colctr = output_cols - 2; colctr > 0; colctr--) { 348e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* sum of pixels directly mapped to this output element */ 349e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 350e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]); 351e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* sum of edge-neighbor pixels */ 352e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) + 353e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) + 354e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[2]) + 355e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[2]); 356e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* The edge-neighbors count twice as much as corner-neighbors */ 357e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum += neighsum; 358e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Add in the corner-neighbors */ 359e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[2]) + 360e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[2]); 361e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* form final output scaled up by 2^16 */ 362e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 363e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* round, descale and output it */ 364e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 365e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2; 366e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 367e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 368e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Special case for last column */ 369e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 370e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]); 371e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) + 372e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) + 373e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[1]) + 374e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[1]); 375e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum += neighsum; 376e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[1]) + 377e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[1]); 378e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 379e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr = (JSAMPLE) ((membersum + 32768) >> 16); 380e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 381e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inrow += 2; 382e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 383e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 384e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 385e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 386e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 387e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Downsample pixel values of a single component. 388e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This version handles the special case of a full-size component, 389e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * with smoothing. One row of context is required. 390e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 391e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 392e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 393e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovfullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr, 394e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 395e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 396e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int outrow; 397e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION colctr; 398e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 399e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register JSAMPROW inptr, above_ptr, below_ptr, outptr; 400e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov INT32 membersum, neighsum, memberscale, neighscale; 401e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int colsum, lastcolsum, nextcolsum; 402e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 403e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Expand input data enough to let all the output samples be generated 404e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * by the standard loop. Special-casing padded output would be more 405e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * efficient. 406e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 407e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2, 408e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->image_width, output_cols); 409e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 410e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Each of the eight neighbor pixels contributes a fraction SF to the 411e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * smoothed pixel, while the main pixel contributes (1-8*SF). In order 412e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * to use integer arithmetic, these factors are multiplied by 2^16 = 65536. 413e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Also recall that SF = smoothing_factor / 1024. 414e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 415e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 416e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */ 417e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighscale = cinfo->smoothing_factor * 64; /* scaled SF */ 418e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 419e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 420e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov outptr = output_data[outrow]; 421e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inptr = input_data[outrow]; 422e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov above_ptr = input_data[outrow-1]; 423e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov below_ptr = input_data[outrow+1]; 424e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 425e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Special case for first column */ 426e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov colsum = GETJSAMPLE(*above_ptr++) + GETJSAMPLE(*below_ptr++) + 427e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr); 428e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = GETJSAMPLE(*inptr++); 429e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) + 430e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr); 431e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum = colsum + (colsum - membersum) + nextcolsum; 432e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 433e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 434e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov lastcolsum = colsum; colsum = nextcolsum; 435e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 436e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (colctr = output_cols - 2; colctr > 0; colctr--) { 437e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = GETJSAMPLE(*inptr++); 438e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov above_ptr++; below_ptr++; 439e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) + 440e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov GETJSAMPLE(*inptr); 441e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum = lastcolsum + (colsum - membersum) + nextcolsum; 442e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 443e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 444e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov lastcolsum = colsum; colsum = nextcolsum; 445e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 446e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 447e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Special case for last column */ 448e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = GETJSAMPLE(*inptr); 449e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov neighsum = lastcolsum + (colsum - membersum) + colsum; 450e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 451e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *outptr = (JSAMPLE) ((membersum + 32768) >> 16); 452e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 453e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 454e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 455e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 456e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif /* INPUT_SMOOTHING_SUPPORTED */ 457e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 458e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 459e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 460e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Module initialization routine for downsampling. 461e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Note that we must select a routine for each component. 462e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 463e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 464e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovGLOBAL(void) 465e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovjinit_downsampler (j_compress_ptr cinfo) 466e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 467e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov my_downsample_ptr downsample; 468e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci; 469e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info * compptr; 470e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov boolean smoothok = TRUE; 471e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 472e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample = (my_downsample_ptr) 473e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 474e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov SIZEOF(my_downsampler)); 475e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->downsample = (struct jpeg_downsampler *) downsample; 476e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->pub.start_pass = start_pass_downsample; 477e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->pub.downsample = sep_downsample; 478e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->pub.need_context_rows = FALSE; 479e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 480e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->CCIR601_sampling) 481e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_CCIR601_NOTIMPL); 482e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 483e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Verify we can handle the sampling factors, and set up method pointers */ 484e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 485e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ci++, compptr++) { 486e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (compptr->h_samp_factor == cinfo->max_h_samp_factor && 487e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->v_samp_factor == cinfo->max_v_samp_factor) { 488e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 489e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->smoothing_factor) { 490e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->methods[ci] = fullsize_smooth_downsample; 491e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->pub.need_context_rows = TRUE; 492e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else 493e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif 494e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->methods[ci] = fullsize_downsample; 495e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor && 496e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->v_samp_factor == cinfo->max_v_samp_factor) { 497e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov smoothok = FALSE; 498e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->methods[ci] = h2v1_downsample; 499e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor && 500e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) { 501e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 502e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->smoothing_factor) { 503e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->methods[ci] = h2v2_smooth_downsample; 504e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->pub.need_context_rows = TRUE; 505e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else 506e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif 507e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->methods[ci] = h2v2_downsample; 508e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 && 509e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) { 510e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov smoothok = FALSE; 511e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov downsample->methods[ci] = int_downsample; 512e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else 513e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL); 514e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 515e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 516e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 517e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->smoothing_factor && !smoothok) 518e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL); 519e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif 520e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 521e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 522e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif //_FX_JPEG_TURBO_ 523