mirror of
https://github.com/DrKLO/Telegram.git
synced 2024-12-22 22:45:18 +01:00
150 lines
5.3 KiB
C
150 lines
5.3 KiB
C
// 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;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|