1ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#if !defined(_FX_JPEG_TURBO_) 2ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 3ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * jcsample.c 4ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 5ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Copyright (C) 1991-1996, Thomas G. Lane. 6ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This file is part of the Independent JPEG Group's software. 7ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * For conditions of distribution and use, see the accompanying README file. 8ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 9ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This file contains downsampling routines. 10ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 11ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsampling input data is counted in "row groups". A row group 12ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * is defined to be max_v_samp_factor pixel rows of each component, 13ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * from which the downsampler produces v_samp_factor sample rows. 14ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * A single row group is processed in each call to the downsampler module. 15ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 16ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * The downsampler is responsible for edge-expansion of its output data 17ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * to fill an integral number of DCT blocks horizontally. The source buffer 18ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * may be modified if it is helpful for this purpose (the source buffer is 19ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * allocated wide enough to correspond to the desired output width). 20ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * The caller (the prep controller) is responsible for vertical padding. 21ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 22ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * The downsampler may request "context rows" by setting need_context_rows 23ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * during startup. In this case, the input arrays will contain at least 24ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * one row group's worth of pixels above and below the passed-in data; 25ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * the caller will create dummy rows at image top and bottom by replicating 26ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * the first or last real pixel row. 27ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 28ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * An excellent reference for image resampling is 29ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Digital Image Warping, George Wolberg, 1990. 30ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7. 31ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 32ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * The downsampling algorithm used here is a simple average of the source 33ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * pixels covered by the output pixel. The hi-falutin sampling literature 34ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * refers to this as a "box filter". In general the characteristics of a box 35ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * filter are not very good, but for the specific cases we normally use (1:1 36ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * and 2:1 ratios) the box is equivalent to a "triangle filter" which is not 37ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * nearly so bad. If you intend to use other sampling ratios, you'd be well 38ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * advised to improve this code. 39ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 40ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * A simple input-smoothing capability is provided. This is mainly intended 41ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * for cleaning up color-dithered GIF input files (if you find it inadequate, 42ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * we suggest using an external filtering program such as pnmconvol). When 43ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * enabled, each input pixel P is replaced by a weighted sum of itself and its 44ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * eight neighbors. P's weight is 1-8*SF and each neighbor's weight is SF, 45ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * where SF = (smoothing_factor / 1024). 46ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Currently, smoothing is only supported for 2h2v sampling factors. 47ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 48ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 49ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define JPEG_INTERNALS 50ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#include "jinclude.h" 51ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#include "jpeglib.h" 52ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 53ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 54ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* Pointer to routine to downsample a single component */ 55ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovtypedef JMETHOD(void, downsample1_ptr, 56ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov (j_compress_ptr cinfo, jpeg_component_info * compptr, 57ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data)); 58ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 59ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* Private subobject */ 60ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 61ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovtypedef struct { 62ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov struct jpeg_downsampler pub; /* public fields */ 63ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 64ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Downsampling method pointers, one per component */ 65ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample1_ptr methods[MAX_COMPONENTS]; 66ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} my_downsampler; 67ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 68ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovtypedef my_downsampler * my_downsample_ptr; 69ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 70ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 71ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 72ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Initialize for a downsampling pass. 73ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 74ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 75ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 76ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovstart_pass_downsample (j_compress_ptr cinfo) 77ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 78ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* no work for now */ 79ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 80ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 81ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 82ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 83ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Expand a component horizontally from width input_cols to width output_cols, 84ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * by duplicating the rightmost samples. 85ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 86ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 87ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovLOCAL(void) 88ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovexpand_right_edge (JSAMPARRAY image_data, int num_rows, 89ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION input_cols, JDIMENSION output_cols) 90ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 91ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register JSAMPROW ptr; 92ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register JSAMPLE pixval; 93ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register int count; 94ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int row; 95ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int numcols = (int) (output_cols - input_cols); 96ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 97ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (numcols > 0) { 98ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (row = 0; row < num_rows; row++) { 99ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ptr = image_data[row] + input_cols; 100ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov pixval = ptr[-1]; /* don't need GETJSAMPLE() here */ 101ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (count = numcols; count > 0; count--) 102ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *ptr++ = pixval; 103ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 104ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 105ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 106ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 107ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 108ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 109ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Do downsampling for a whole row group (all components). 110ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 111ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * In this version we simply downsample each component independently. 112ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 113ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 114ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 115ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovsep_downsample (j_compress_ptr cinfo, 116ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPIMAGE input_buf, JDIMENSION in_row_index, 117ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPIMAGE output_buf, JDIMENSION out_row_group_index) 118ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 119ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample; 120ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int ci; 121ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov jpeg_component_info * compptr; 122ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY in_ptr, out_ptr; 123ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 124ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 125ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ci++, compptr++) { 126ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov in_ptr = input_buf[ci] + in_row_index; 127ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor); 128ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr); 129ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 130ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 131ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 132ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 133ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 134ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsample pixel values of a single component. 135ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * One row group is processed per call. 136ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This version handles arbitrary integral sampling ratios, without smoothing. 137ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Note that this version is not actually used for customary sampling ratios. 138ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 139ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 140ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 141ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovint_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 142ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 143ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 144ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v; 145ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */ 146ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 147ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPROW inptr, outptr; 148ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov INT32 outvalue; 149ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 150ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor; 151ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor; 152ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov numpix = h_expand * v_expand; 153ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov numpix2 = numpix/2; 154ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 155ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Expand input data enough to let all the output samples be generated 156ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * by the standard loop. Special-casing padded output would be more 157ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * efficient. 158ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 159ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov expand_right_edge(input_data, cinfo->max_v_samp_factor, 160ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->image_width, output_cols * h_expand); 161ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 162ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inrow = 0; 163ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 164ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_data[outrow]; 165ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outcol = 0, outcol_h = 0; outcol < output_cols; 166ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outcol++, outcol_h += h_expand) { 167ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outvalue = 0; 168ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (v = 0; v < v_expand; v++) { 169ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr = input_data[inrow+v] + outcol_h; 170ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (h = 0; h < h_expand; h++) { 171ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outvalue += (INT32) GETJSAMPLE(*inptr++); 172ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 173ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 174ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix); 175ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 176ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inrow += v_expand; 177ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 178ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 179ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 180ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 181ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 182ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsample pixel values of a single component. 183ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This version handles the special case of a full-size component, 184ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * without smoothing. 185ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 186ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 187ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 188ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovfullsize_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 189ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 190ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 191ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Copy the data */ 192ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov jcopy_sample_rows(input_data, 0, output_data, 0, 193ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->max_v_samp_factor, cinfo->image_width); 194ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Edge-expand */ 195ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov expand_right_edge(output_data, cinfo->max_v_samp_factor, 196ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->image_width, compptr->width_in_blocks * DCTSIZE); 197ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 198ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 199ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 200ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 201ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsample pixel values of a single component. 202ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This version handles the common case of 2:1 horizontal and 1:1 vertical, 203ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * without smoothing. 204ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 205ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * A note about the "bias" calculations: when rounding fractional values to 206ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * integer, we do not want to always round 0.5 up to the next integer. 207ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * If we did that, we'd introduce a noticeable bias towards larger values. 208ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Instead, this code is arranged so that 0.5 will be rounded up or down at 209ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * alternate pixel locations (a simple ordered dither pattern). 210ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 211ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 212ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 213ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovh2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 214ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 215ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 216ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int outrow; 217ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION outcol; 218ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 219ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register JSAMPROW inptr, outptr; 220ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register int bias; 221ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 222ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Expand input data enough to let all the output samples be generated 223ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * by the standard loop. Special-casing padded output would be more 224ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * efficient. 225ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 226ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov expand_right_edge(input_data, cinfo->max_v_samp_factor, 227ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->image_width, output_cols * 2); 228ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 229ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 230ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_data[outrow]; 231ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr = input_data[outrow]; 232ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov bias = 0; /* bias = 0,1,0,1,... for successive samples */ 233ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outcol = 0; outcol < output_cols; outcol++) { 234ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1]) 235ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + bias) >> 1); 236ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov bias ^= 1; /* 0=>1, 1=>0 */ 237ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr += 2; 238ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 239ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 240ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 241ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 242ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 243ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 244ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsample pixel values of a single component. 245ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This version handles the standard case of 2:1 horizontal and 2:1 vertical, 246ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * without smoothing. 247ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 248ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 249ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 250ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovh2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 251ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 252ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 253ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int inrow, outrow; 254ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION outcol; 255ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 256ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register JSAMPROW inptr0, inptr1, outptr; 257ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register int bias; 258ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 259ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Expand input data enough to let all the output samples be generated 260ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * by the standard loop. Special-casing padded output would be more 261ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * efficient. 262ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 263ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov expand_right_edge(input_data, cinfo->max_v_samp_factor, 264ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->image_width, output_cols * 2); 265ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 266ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inrow = 0; 267ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 268ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_data[outrow]; 269ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr0 = input_data[inrow]; 270ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr1 = input_data[inrow+1]; 271ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov bias = 1; /* bias = 1,2,1,2,... for successive samples */ 272ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outcol = 0; outcol < output_cols; outcol++) { 273ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 274ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]) 275ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + bias) >> 2); 276ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov bias ^= 3; /* 1=>2, 2=>1 */ 277ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr0 += 2; inptr1 += 2; 278ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 279ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inrow += 2; 280ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 281ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 282ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 283ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 284ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 285ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 286ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 287ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsample pixel values of a single component. 288ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This version handles the standard case of 2:1 horizontal and 2:1 vertical, 289ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * with smoothing. One row of context is required. 290ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 291ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 292ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 293ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovh2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, 294ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 295ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 296ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int inrow, outrow; 297ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION colctr; 298ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 299ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr; 300ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov INT32 membersum, neighsum, memberscale, neighscale; 301ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 302ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Expand input data enough to let all the output samples be generated 303ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * by the standard loop. Special-casing padded output would be more 304ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * efficient. 305ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 306ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2, 307ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->image_width, output_cols * 2); 308ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 309ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* We don't bother to form the individual "smoothed" input pixel values; 310ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * we can directly compute the output which is the average of the four 311ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * smoothed values. Each of the four member pixels contributes a fraction 312ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * (1-8*SF) to its own smoothed image and a fraction SF to each of the three 313ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final 314ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * output. The four corner-adjacent neighbor pixels contribute a fraction 315ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * SF to just one smoothed pixel, or SF/4 to the final output; while the 316ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * eight edge-adjacent neighbors contribute SF to each of two smoothed 317ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * pixels, or SF/2 overall. In order to use integer arithmetic, these 318ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * factors are scaled by 2^16 = 65536. 319ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Also recall that SF = smoothing_factor / 1024. 320ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 321ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 322ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */ 323ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */ 324ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 325ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inrow = 0; 326ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 327ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_data[outrow]; 328ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr0 = input_data[inrow]; 329ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr1 = input_data[inrow+1]; 330ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov above_ptr = input_data[inrow-1]; 331ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov below_ptr = input_data[inrow+2]; 332ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 333ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Special case for first column: pretend column -1 is same as column 0 */ 334ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 335ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]); 336ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) + 337ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) + 338ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[2]) + 339ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[2]); 340ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum += neighsum; 341ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum += GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[2]) + 342ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[2]); 343ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 344ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 345ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2; 346ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 347ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (colctr = output_cols - 2; colctr > 0; colctr--) { 348ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* sum of pixels directly mapped to this output element */ 349ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 350ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]); 351ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* sum of edge-neighbor pixels */ 352ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) + 353ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) + 354ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[2]) + 355ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[2]); 356ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* The edge-neighbors count twice as much as corner-neighbors */ 357ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum += neighsum; 358ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Add in the corner-neighbors */ 359ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[2]) + 360ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[2]); 361ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* form final output scaled up by 2^16 */ 362ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 363ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* round, descale and output it */ 364ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 365ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2; 366ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 367ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 368ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Special case for last column */ 369ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) + 370ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]); 371ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) + 372ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) + 373ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[1]) + 374ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[1]); 375ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum += neighsum; 376ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[1]) + 377ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[1]); 378ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 379ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr = (JSAMPLE) ((membersum + 32768) >> 16); 380ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 381ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inrow += 2; 382ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 383ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 384ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 385ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 386ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 387ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Downsample pixel values of a single component. 388ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This version handles the special case of a full-size component, 389ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * with smoothing. One row of context is required. 390ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 391ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 392ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovMETHODDEF(void) 393ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovfullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr, 394ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY input_data, JSAMPARRAY output_data) 395ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 396ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int outrow; 397ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION colctr; 398ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; 399ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov register JSAMPROW inptr, above_ptr, below_ptr, outptr; 400ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov INT32 membersum, neighsum, memberscale, neighscale; 401ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int colsum, lastcolsum, nextcolsum; 402ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 403ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Expand input data enough to let all the output samples be generated 404ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * by the standard loop. Special-casing padded output would be more 405ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * efficient. 406ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 407ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2, 408ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->image_width, output_cols); 409ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 410ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Each of the eight neighbor pixels contributes a fraction SF to the 411ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * smoothed pixel, while the main pixel contributes (1-8*SF). In order 412ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * to use integer arithmetic, these factors are multiplied by 2^16 = 65536. 413ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Also recall that SF = smoothing_factor / 1024. 414ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 415ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 416ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */ 417ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighscale = cinfo->smoothing_factor * 64; /* scaled SF */ 418ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 419ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { 420ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_data[outrow]; 421ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr = input_data[outrow]; 422ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov above_ptr = input_data[outrow-1]; 423ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov below_ptr = input_data[outrow+1]; 424ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 425ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Special case for first column */ 426ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov colsum = GETJSAMPLE(*above_ptr++) + GETJSAMPLE(*below_ptr++) + 427ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr); 428ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = GETJSAMPLE(*inptr++); 429ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) + 430ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr); 431ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum = colsum + (colsum - membersum) + nextcolsum; 432ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 433ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 434ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov lastcolsum = colsum; colsum = nextcolsum; 435ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 436ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (colctr = output_cols - 2; colctr > 0; colctr--) { 437ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = GETJSAMPLE(*inptr++); 438ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov above_ptr++; below_ptr++; 439ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) + 440ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov GETJSAMPLE(*inptr); 441ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum = lastcolsum + (colsum - membersum) + nextcolsum; 442ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 443ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16); 444ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov lastcolsum = colsum; colsum = nextcolsum; 445ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 446ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 447ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Special case for last column */ 448ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = GETJSAMPLE(*inptr); 449ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov neighsum = lastcolsum + (colsum - membersum) + colsum; 450ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov membersum = membersum * memberscale + neighsum * neighscale; 451ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov *outptr = (JSAMPLE) ((membersum + 32768) >> 16); 452ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 453ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 454ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 455ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 456ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif /* INPUT_SMOOTHING_SUPPORTED */ 457ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 458ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 459ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 460ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Module initialization routine for downsampling. 461ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Note that we must select a routine for each component. 462ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 463ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 464ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovGLOBAL(void) 465ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovjinit_downsampler (j_compress_ptr cinfo) 466ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 467ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov my_downsample_ptr downsample; 468ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int ci; 469ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov jpeg_component_info * compptr; 470ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov boolean smoothok = TRUE; 471ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 472ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample = (my_downsample_ptr) 473ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 474ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov SIZEOF(my_downsampler)); 475ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov cinfo->downsample = (struct jpeg_downsampler *) downsample; 476ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->pub.start_pass = start_pass_downsample; 477ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->pub.downsample = sep_downsample; 478ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->pub.need_context_rows = FALSE; 479ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 480ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (cinfo->CCIR601_sampling) 481ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ERREXIT(cinfo, JERR_CCIR601_NOTIMPL); 482ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 483ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Verify we can handle the sampling factors, and set up method pointers */ 484ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 485ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ci++, compptr++) { 486ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (compptr->h_samp_factor == cinfo->max_h_samp_factor && 487ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov compptr->v_samp_factor == cinfo->max_v_samp_factor) { 488ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 489ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (cinfo->smoothing_factor) { 490ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->methods[ci] = fullsize_smooth_downsample; 491ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->pub.need_context_rows = TRUE; 492ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } else 493ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 494ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->methods[ci] = fullsize_downsample; 495ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor && 496ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov compptr->v_samp_factor == cinfo->max_v_samp_factor) { 497ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov smoothok = FALSE; 498ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->methods[ci] = h2v1_downsample; 499ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor && 500ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) { 501ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 502ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (cinfo->smoothing_factor) { 503ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->methods[ci] = h2v2_smooth_downsample; 504ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->pub.need_context_rows = TRUE; 505ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } else 506ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 507ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->methods[ci] = h2v2_downsample; 508ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 && 509ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) { 510ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov smoothok = FALSE; 511ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov downsample->methods[ci] = int_downsample; 512ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } else 513ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL); 514ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 515ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 516ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifdef INPUT_SMOOTHING_SUPPORTED 517ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (cinfo->smoothing_factor && !smoothok) 518ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL); 519ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 520ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 521ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 522ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif //_FX_JPEG_TURBO_ 523