+/*
+ * qscale: Quick, high-quality JPEG-to-JPEG scaler.
+ * Copyright (C) 2008 Steinar H. Gunderson <sgunderson@bigfoot.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
#include <stdio.h>
-#include <math.h>
-#include <string.h>
#include <stdlib.h>
-#include "jpeglib.h"
-
-#define CACHE_LINE_FACTOR 8
-
-double sinc(double x)
-{
- // This is bad for very small x, should use power series instead.
- if (x == 0.0)
- return 1.0;
- else
- return sin(x) / x;
-}
-
-double lanczos_tap(double x)
-{
- if (x < -3.0 || x > 3.0)
- return 0.0;
- if (x < 0.0)
- return sinc(-x*M_PI) * sinc(-x*M_PI / 3.0);
- else
- return sinc(x*M_PI) * sinc(x*M_PI / 3.0);
-}
-
-struct filter {
- struct pix_desc *pd;
- float *coeffs;
-};
-struct pix_desc {
- unsigned start, end;
- unsigned startcoeff;
-};
-
-void hscale_calc_filter(struct filter *filter, unsigned w, unsigned h, unsigned nw)
-{
- struct pix_desc *pd = (struct pix_desc *)malloc(nw * sizeof(struct pix_desc));
- int size_coeffs = 8;
- float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
- int num_coeffs = 0;
- int x, sx;
- double sf = (double)w / (double)nw;
- double support = (w > nw) ? (3.0 * sf) : (3.0 / sf);
-
- /* calculate the filter */
- for (x = 0; x < nw; ++x) {
- int start = ceil(x * sf - support);
- int end = floor(x * sf + support);
- double sum = 0.0;
-
- if (start < 0) {
- start = 0;
- }
- if (end > w - 1) {
- end = w - 1;
- }
-
- pd[x].start = start;
- pd[x].end = end;
- pd[x].startcoeff = num_coeffs;
-
- for (sx = start; sx <= end; ++sx) {
- double nd = (w > nw) ? (sx/sf - x) : (sx - x*sf);
- double f = lanczos_tap(nd);
- if (num_coeffs == size_coeffs) {
- size_coeffs <<= 1;
- coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
- }
-
- coeffs[num_coeffs++] = f;
- sum += f;
- }
-
- for (sx = start; sx <= end; ++sx) {
- coeffs[pd[x].startcoeff + sx - start] /= sum;
- }
- }
-
- filter->pd = pd;
- filter->coeffs = coeffs;
-}
-
-void hscale(struct filter *filter, unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nw, unsigned sstride, unsigned dstride)
-{
- struct pix_desc *pd = filter->pd;
- float *coeffs = filter->coeffs;
- int y;
-
- for (y = 0; y < h; ++y) {
- unsigned char *sptr = pix + y*sstride;
- float *dptr = npix + y*dstride;
- float acc = 0.0;
- int x;
- for (x = 0; x < nw; ++x) {
- float *cf = &coeffs[pd[x].startcoeff];
- unsigned sx;
- acc = 0.0;
-
- for (sx = pd[x].start; sx <= pd[x].end; ++sx) {
- acc += sptr[sx] * *cf++;
- }
- *dptr++ = acc;
- }
- for ( ; x < dstride; ++x) {
- *dptr++ = acc;
- }
- }
-}
-
-void vscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nh, unsigned dstride)
-{
- struct pix_desc *pd = (struct pix_desc *)malloc(nh * sizeof(struct pix_desc));
- int size_coeffs = 8;
- float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
- int num_coeffs = 0;
- int x, y, sy;
- double sf = (double)h / (double)nh;
- double support = (h > nh) ? (3.0 * sf) : (3.0 / sf);
-
- /* calculate the filter */
- for (y = 0; y < nh; ++y) {
- int start = ceil(y * sf - support);
- int end = floor(y * sf + support);
- double sum = 0.0;
-
- if (start < 0) {
- start = 0;
- }
- if (end > h - 1) {
- end = h - 1;
- }
-
- pd[y].start = start;
- pd[y].end = end;
- pd[y].startcoeff = num_coeffs;
-
- for (sy = start; sy <= end; ++sy) {
- double nd = (h > nh) ? (sy/sf - y) : (sy - y*sf);
- double f = lanczos_tap(nd);
- if (num_coeffs == size_coeffs) {
- size_coeffs <<= 1;
- coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
- }
-
- coeffs[num_coeffs++] = f;
- sum += f;
- }
-
- for (sy = start; sy <= end; ++sy) {
- coeffs[pd[y].startcoeff + sy - start] /= sum;
- }
- }
-
-#if CACHE_LINE_FACTOR > 1
- for (x = 0; x < w; x += CACHE_LINE_FACTOR) {
- float *sptr = pix + x;
- unsigned char *dptr = npix + x;
- for (y = 0; y < nh; ++y) {
- int i;
- float acc[CACHE_LINE_FACTOR];
- for (i = 0; i < CACHE_LINE_FACTOR; ++i)
- acc[i] = 0.0;
- float *cf = &coeffs[pd[y].startcoeff];
- unsigned sy;
-
- for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
- for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
- acc[i] += sptr[sy * w + i] * *cf;
- }
- ++cf;
- }
-
- for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
- unsigned char ch;
- if (acc[i] < 0.0)
- ch = 0;
- else if (acc[i] > 255.0)
- ch = 255;
- else
- ch = (unsigned char)acc[i];
- dptr[i] = ch;
- }
- dptr += dstride;
- }
- }
- for (x = (x/CACHE_LINE_FACTOR)*CACHE_LINE_FACTOR; x < w; ++x) {
-#else
- for (x = 0; x < w; ++x) {
-#endif
- float *sptr = pix + x;
- unsigned char *dptr = npix + x;
- for (y = 0; y < nh; ++y) {
- float acc = 0.0;
- float *cf = &coeffs[pd[y].startcoeff];
- unsigned sy;
-
- for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
- acc += sptr[sy * w] * *cf++;
- }
-
- unsigned char ch;
- if (acc < 0.0)
- ch = 0;
- else if (acc > 255.0)
- ch = 255;
- else
- ch = (unsigned char)acc;
- *dptr = ch;
- dptr += dstride;
- }
- }
-}
+#include "libqscale.h"
int main(int argc, char **argv)
{
+ /* user-settable parameters */
unsigned nominal_w = atoi(argv[1]);
unsigned nominal_h = atoi(argv[2]);
-
unsigned samp_h0 = 2, samp_v0 = 2;
unsigned samp_h1 = 1, samp_v1 = 1;
unsigned samp_h2 = 1, samp_v2 = 1;
- unsigned max_samp_h = 2, max_samp_v = 2;
-
- unsigned nw0 = nominal_w * samp_h0 / max_samp_h, nh0 = nominal_h * samp_v0 / max_samp_v;
- unsigned nw1 = nominal_w * samp_h1 / max_samp_h, nh1 = nominal_h * samp_v1 / max_samp_v;
- unsigned nw2 = nominal_w * samp_h2 / max_samp_h, nh2 = nominal_h * samp_v2 / max_samp_v;
-
- unsigned stride0 = (nw0 + DCTSIZE-1) & ~(DCTSIZE-1);
- unsigned stride1 = (nw1 + DCTSIZE-1) & ~(DCTSIZE-1);
- unsigned stride2 = (nw2 + DCTSIZE-1) & ~(DCTSIZE-1);
-
- struct jpeg_decompress_struct dinfo;
- struct jpeg_error_mgr jerr;
- dinfo.err = jpeg_std_error(&jerr);
- jpeg_create_decompress(&dinfo);
- jpeg_stdio_src(&dinfo, stdin);
- jpeg_read_header(&dinfo, TRUE);
- dinfo.raw_data_out = TRUE;
- jpeg_start_decompress(&dinfo);
-
- fprintf(stderr, "Scaling using Lanczos filter:\n");
- fprintf(stderr, " Y component: %ux%u -> %ux%u\n", dinfo.comp_info[0].width_in_blocks * DCTSIZE, dinfo.comp_info[0].height_in_blocks * DCTSIZE, nw0, nh0);
- fprintf(stderr, " Cb component: %ux%u -> %ux%u\n", dinfo.comp_info[1].width_in_blocks * DCTSIZE, dinfo.comp_info[1].height_in_blocks * DCTSIZE, nw1, nh1);
- fprintf(stderr, " Cr component: %ux%u -> %ux%u\n", dinfo.comp_info[2].width_in_blocks * DCTSIZE, dinfo.comp_info[2].height_in_blocks * DCTSIZE, nw2, nh2);
-
- float *npix_y = (float *)malloc((dinfo.comp_info[0].height_in_blocks + dinfo.comp_info[0].v_samp_factor - 1) * DCTSIZE * stride0 * sizeof(float));
- float *npix_cb = (float *)malloc((dinfo.comp_info[1].height_in_blocks + dinfo.comp_info[1].v_samp_factor - 1) * DCTSIZE * stride1 * sizeof(float));
- float *npix_cr = (float *)malloc((dinfo.comp_info[2].height_in_blocks + dinfo.comp_info[2].v_samp_factor - 1) * DCTSIZE * stride2 * sizeof(float));
- JSAMPLE *data_y = (unsigned char *)malloc(nh0 * stride0);
- JSAMPLE *data_cb = (unsigned char *)malloc(nh1 * stride1);
- JSAMPLE *data_cr = (unsigned char *)malloc(nh2 * stride2);
-
- struct filter filt0, filt1, filt2;
-
- hscale_calc_filter(&filt0,
- /* w= */ dinfo.image_width * dinfo.comp_info[0].h_samp_factor / dinfo.max_h_samp_factor,
- /* h= */ dinfo.comp_info[0].v_samp_factor * DCTSIZE,
- /* nw= */ nw0
- );
- hscale_calc_filter(&filt1,
- /* w= */ dinfo.image_width * dinfo.comp_info[1].h_samp_factor / dinfo.max_h_samp_factor,
- /* h= */ dinfo.comp_info[1].v_samp_factor * DCTSIZE,
- /* nw= */ nw1
- );
- hscale_calc_filter(&filt2,
- /* w= */ dinfo.image_width * dinfo.comp_info[2].h_samp_factor / dinfo.max_h_samp_factor,
- /* h= */ dinfo.comp_info[2].v_samp_factor * DCTSIZE,
- /* nw= */ nw2
- );
-
- int total_lines = 0, blocks = 0;
- while (total_lines < dinfo.comp_info[0].height_in_blocks * DCTSIZE) {
- unsigned max_lines = dinfo.max_v_samp_factor * DCTSIZE;
- JSAMPLE tmp_y [(dinfo.comp_info[0].width_in_blocks * DCTSIZE) * (DCTSIZE * dinfo.comp_info[0].v_samp_factor)];
- JSAMPLE tmp_cb[(dinfo.comp_info[1].width_in_blocks * DCTSIZE) * (DCTSIZE * dinfo.comp_info[1].v_samp_factor)];
- JSAMPLE tmp_cr[(dinfo.comp_info[2].width_in_blocks * DCTSIZE) * (DCTSIZE * dinfo.comp_info[2].v_samp_factor)];
-
- JSAMPROW y_row_ptrs[max_lines];
- JSAMPROW cb_row_ptrs[max_lines];
- JSAMPROW cr_row_ptrs[max_lines];
- JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
- int i;
-
- for (i = 0; i < max_lines; ++i) {
- y_row_ptrs[i] = tmp_y + i * dinfo.comp_info[0].width_in_blocks * DCTSIZE;
- cb_row_ptrs[i] = tmp_cb + i * dinfo.comp_info[1].width_in_blocks * DCTSIZE;
- cr_row_ptrs[i] = tmp_cr + i * dinfo.comp_info[2].width_in_blocks * DCTSIZE;
- }
-
- int lines = jpeg_read_raw_data(&dinfo, ptrs, max_lines);
- if (lines == 0)
- break;
-
- hscale(/* filter= */ &filt0,
- /* from= */ tmp_y,
- /* to= */ npix_y + blocks * DCTSIZE * dinfo.comp_info[0].v_samp_factor * stride0,
- /* w= */ dinfo.image_width * dinfo.comp_info[0].h_samp_factor / dinfo.max_h_samp_factor,
- /* h= */ dinfo.comp_info[0].v_samp_factor * DCTSIZE,
- /* nw= */ nw0,
- /* sstride= */ dinfo.comp_info[0].width_in_blocks * DCTSIZE,
- /* dstride= */ stride0);
-
- hscale(/* filter= */ &filt1,
- /* from= */ tmp_cb,
- /* to= */ npix_cb + blocks * DCTSIZE * dinfo.comp_info[1].v_samp_factor * stride1,
- /* w= */ dinfo.image_width * dinfo.comp_info[1].h_samp_factor / dinfo.max_h_samp_factor,
- /* h= */ dinfo.comp_info[1].v_samp_factor * DCTSIZE,
- /* nw= */ nw1,
- /* sstride= */ dinfo.comp_info[1].width_in_blocks * DCTSIZE,
- /* dstride= */ stride1);
-
- hscale(/* filter= */ &filt2,
- /* from= */ tmp_cr,
- /* to= */ npix_cr + blocks * DCTSIZE * dinfo.comp_info[2].v_samp_factor * stride2,
- /* w= */ dinfo.image_width * dinfo.comp_info[2].h_samp_factor / dinfo.max_h_samp_factor,
- /* h= */ dinfo.comp_info[2].v_samp_factor * DCTSIZE,
- /* nw= */ nw2,
- /* sstride= */ dinfo.comp_info[2].width_in_blocks * DCTSIZE,
- /* dstride= */ stride2);
-
- total_lines += max_lines;
- ++blocks;
- }
-
- vscale(npix_y, data_y, stride0, dinfo.image_height * dinfo.comp_info[0].v_samp_factor / dinfo.max_v_samp_factor, nh0, stride0);
- vscale(npix_cb, data_cb, stride1, dinfo.image_height * dinfo.comp_info[1].v_samp_factor / dinfo.max_v_samp_factor, nh1, stride1);
- vscale(npix_cr, data_cr, stride2, dinfo.image_height * dinfo.comp_info[2].v_samp_factor / dinfo.max_v_samp_factor, nh2, stride2);
- jpeg_destroy_decompress(&dinfo);
-
- struct jpeg_compress_struct cinfo;
- cinfo.err = jpeg_std_error(&jerr);
- jpeg_create_compress(&cinfo);
- jpeg_stdio_dest(&cinfo, stdout);
- cinfo.input_components = 3;
- jpeg_set_defaults(&cinfo);
- jpeg_set_quality(&cinfo, 85, FALSE);
- cinfo.image_width = nominal_w;
- cinfo.image_height = nominal_h;
- cinfo.raw_data_in = TRUE;
- jpeg_set_colorspace(&cinfo, JCS_YCbCr);
- cinfo.comp_info[0].h_samp_factor = samp_h0;
- cinfo.comp_info[0].v_samp_factor = samp_v0;
- cinfo.comp_info[1].h_samp_factor = samp_h1;
- cinfo.comp_info[1].v_samp_factor = samp_v1;
- cinfo.comp_info[2].h_samp_factor = samp_h2;
- cinfo.comp_info[2].v_samp_factor = samp_v2;
- jpeg_start_compress(&cinfo, TRUE);
-
- total_lines = 0;
- blocks = 0;
- while (total_lines < cinfo.comp_info[0].height_in_blocks * DCTSIZE) {
- unsigned max_lines = cinfo.max_v_samp_factor * DCTSIZE;
-
- JSAMPROW y_row_ptrs[max_lines];
- JSAMPROW cb_row_ptrs[max_lines];
- JSAMPROW cr_row_ptrs[max_lines];
- JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
- int i;
-
- for (i = 0; i < max_lines; ++i) {
- // simple edge extension
- int yline = i + blocks*DCTSIZE*cinfo.comp_info[0].v_samp_factor;
- if (yline > nh0 - 1)
- yline = nh0 - 1;
-
- int cbline = i + blocks*DCTSIZE*cinfo.comp_info[1].v_samp_factor;
- if (cbline > nh1 - 1)
- cbline = nh1 - 1;
-
- int crline = i + blocks*DCTSIZE*cinfo.comp_info[2].v_samp_factor;
- if (crline > nh2 - 1)
- crline = nh2 - 1;
-
- y_row_ptrs[i] = data_y + yline * stride0;
- cb_row_ptrs[i] = data_cb + cbline * stride1;
- cr_row_ptrs[i] = data_cr + crline * stride2;
- }
-
- total_lines += max_lines;
- ++blocks;
+ unsigned jpeg_quality = 85;
+ /* end */
- jpeg_write_raw_data(&cinfo, ptrs, max_lines);
- }
- jpeg_finish_compress(&cinfo);
- jpeg_destroy_compress(&cinfo);
+ qscale_img *img = qscale_load_jpeg_from_stdio(stdin);
+ qscale_img *scaled = qscale_scale(img, nominal_w, nominal_h, samp_h0, samp_v0, samp_h1, samp_v1, samp_h2, samp_v2, LANCZOS);
+ qscale_destroy(img);
+ qscale_save_jpeg_to_stdio(scaled, stdout, jpeg_quality, SEQUENTIAL);
return 0;
}
projects / qscale / blobdiff