123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150 |
- // Copyright 2014 Google Inc. All Rights Reserved.
- //
- // Use of this source code is governed by a BSD-style license
- // that can be found in the COPYING file in the root of the source
- // tree. An additional intellectual property rights grant can be found
- // in the file PATENTS. All contributing project authors may
- // be found in the AUTHORS file in the root of the source tree.
- // -----------------------------------------------------------------------------
- //
- // WebPPicture tools for measuring distortion
- //
- // Author: Skal (pascal.massimino@gmail.com)
- #include <math.h>
- #include "./vp8enci.h"
- //------------------------------------------------------------------------------
- // local-min distortion
- //
- // For every pixel in the *reference* picture, we search for the local best
- // match in the compressed image. This is not a symmetrical measure.
- #define RADIUS 2 // search radius. Shouldn't be too large.
- static float AccumulateLSIM(const uint8_t* src, int src_stride,
- const uint8_t* ref, int ref_stride,
- int w, int h) {
- int x, y;
- double total_sse = 0.;
- for (y = 0; y < h; ++y) {
- const int y_0 = (y - RADIUS < 0) ? 0 : y - RADIUS;
- const int y_1 = (y + RADIUS + 1 >= h) ? h : y + RADIUS + 1;
- for (x = 0; x < w; ++x) {
- const int x_0 = (x - RADIUS < 0) ? 0 : x - RADIUS;
- const int x_1 = (x + RADIUS + 1 >= w) ? w : x + RADIUS + 1;
- double best_sse = 255. * 255.;
- const double value = (double)ref[y * ref_stride + x];
- int i, j;
- for (j = y_0; j < y_1; ++j) {
- const uint8_t* s = src + j * src_stride;
- for (i = x_0; i < x_1; ++i) {
- const double sse = (double)(s[i] - value) * (s[i] - value);
- if (sse < best_sse) best_sse = sse;
- }
- }
- total_sse += best_sse;
- }
- }
- return (float)total_sse;
- }
- #undef RADIUS
- //------------------------------------------------------------------------------
- // Distortion
- // Max value returned in case of exact similarity.
- static const double kMinDistortion_dB = 99.;
- static float GetPSNR(const double v) {
- return (float)((v > 0.) ? -4.3429448 * log(v / (255 * 255.))
- : kMinDistortion_dB);
- }
- int WebPPictureDistortion(const WebPPicture* src, const WebPPicture* ref,
- int type, float result[5]) {
- DistoStats stats[5];
- int has_alpha;
- int uv_w, uv_h;
- if (src == NULL || ref == NULL ||
- src->width != ref->width || src->height != ref->height ||
- src->y == NULL || ref->y == NULL ||
- src->u == NULL || ref->u == NULL ||
- src->v == NULL || ref->v == NULL ||
- result == NULL) {
- return 0;
- }
- // TODO(skal): provide distortion for ARGB too.
- if (src->use_argb == 1 || src->use_argb != ref->use_argb) {
- return 0;
- }
- has_alpha = !!(src->colorspace & WEBP_CSP_ALPHA_BIT);
- if (has_alpha != !!(ref->colorspace & WEBP_CSP_ALPHA_BIT) ||
- (has_alpha && (src->a == NULL || ref->a == NULL))) {
- return 0;
- }
- memset(stats, 0, sizeof(stats));
- uv_w = (src->width + 1) >> 1;
- uv_h = (src->height + 1) >> 1;
- if (type >= 2) {
- float sse[4];
- sse[0] = AccumulateLSIM(src->y, src->y_stride,
- ref->y, ref->y_stride, src->width, src->height);
- sse[1] = AccumulateLSIM(src->u, src->uv_stride,
- ref->u, ref->uv_stride, uv_w, uv_h);
- sse[2] = AccumulateLSIM(src->v, src->uv_stride,
- ref->v, ref->uv_stride, uv_w, uv_h);
- sse[3] = has_alpha ? AccumulateLSIM(src->a, src->a_stride,
- ref->a, ref->a_stride,
- src->width, src->height)
- : 0.f;
- result[0] = GetPSNR(sse[0] / (src->width * src->height));
- result[1] = GetPSNR(sse[1] / (uv_w * uv_h));
- result[2] = GetPSNR(sse[2] / (uv_w * uv_h));
- result[3] = GetPSNR(sse[3] / (src->width * src->height));
- {
- double total_sse = sse[0] + sse[1] + sse[2];
- int total_pixels = src->width * src->height + 2 * uv_w * uv_h;
- if (has_alpha) {
- total_pixels += src->width * src->height;
- total_sse += sse[3];
- }
- result[4] = GetPSNR(total_sse / total_pixels);
- }
- } else {
- int c;
- VP8SSIMAccumulatePlane(src->y, src->y_stride,
- ref->y, ref->y_stride,
- src->width, src->height, &stats[0]);
- VP8SSIMAccumulatePlane(src->u, src->uv_stride,
- ref->u, ref->uv_stride,
- uv_w, uv_h, &stats[1]);
- VP8SSIMAccumulatePlane(src->v, src->uv_stride,
- ref->v, ref->uv_stride,
- uv_w, uv_h, &stats[2]);
- if (has_alpha) {
- VP8SSIMAccumulatePlane(src->a, src->a_stride,
- ref->a, ref->a_stride,
- src->width, src->height, &stats[3]);
- }
- for (c = 0; c <= 4; ++c) {
- if (type == 1) {
- const double v = VP8SSIMGet(&stats[c]);
- result[c] = (float)((v < 1.) ? -10.0 * log10(1. - v)
- : kMinDistortion_dB);
- } else {
- const double v = VP8SSIMGetSquaredError(&stats[c]);
- result[c] = GetPSNR(v);
- }
- // Accumulate forward
- if (c < 4) VP8SSIMAddStats(&stats[c], &stats[4]);
- }
- }
- return 1;
- }
- //------------------------------------------------------------------------------
|