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add LSIM metric to WebPPictureDistortion()

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LSIM stands for "local similarity": before matching
a compressed pixel to the source, we search around in the source
and minimise the squared error. So, this is close to PSNR calculation,
but mitigates some of its limitations (pure translation and noise for instance).

There's a new -print_lsim option to cwebp too.

Change-Id: Ia38561034c7a90e71d2ea0f55bb1de527eda245b
This commit is contained in:
Pascal Massimino
2012-10-18 08:26:40 -07:00
parent c3aa215afa
commit f86e6abe1f
5 changed files with 129 additions and 52 deletions
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23
examples/cwebp.c
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@ -833,8 +833,9 @@ static void HelpLong(void) {
printf(" -444 / -422 / -gray ..... Change colorspace\n");
#endif
printf(" -map <int> ............. print map of extra info.\n");
printf(" -print_ssim ............ prints averaged SSIM distortion.\n");
printf(" -print_psnr ............ prints averaged PSNR distortion.\n");
printf(" -print_ssim ............ prints averaged SSIM distortion.\n");
printf(" -print_lsim ............ prints local-similarity distortion.\n");
printf(" -d <file.pgm> .......... dump the compressed output (PGM file).\n");
printf(" -alpha_method <int> .... Transparency-compression method (0..1)\n");
printf(" -alpha_filter <string> . predictive filtering for alpha plane.\n");
@ -898,7 +899,7 @@ int main(int argc, const char *argv[]) {
int resize_w = 0, resize_h = 0;
int show_progress = 0;
WebPPicture picture;
int print_distortion = 0; // 1=PSNR, 2=SSIM
int print_distortion = -1; // -1=off, 0=PSNR, 1=SSIM, 2=LSIM
WebPPicture original_picture; // when PSNR or SSIM is requested
WebPConfig config;
WebPAuxStats stats;
@ -928,12 +929,15 @@ int main(int argc, const char *argv[]) {
} else if (!strcmp(argv[c], "-d") && c < argc - 1) {
dump_file = argv[++c];
config.show_compressed = 1;
} else if (!strcmp(argv[c], "-print_ssim")) {
config.show_compressed = 1;
print_distortion = 2;
} else if (!strcmp(argv[c], "-print_psnr")) {
config.show_compressed = 1;
print_distortion = 0;
} else if (!strcmp(argv[c], "-print_ssim")) {
config.show_compressed = 1;
print_distortion = 1;
} else if (!strcmp(argv[c], "-print_lsim")) {
config.show_compressed = 1;
print_distortion = 2;
} else if (!strcmp(argv[c], "-short")) {
short_output++;
} else if (!strcmp(argv[c], "-s") && c < argc - 2) {
@ -1149,7 +1153,7 @@ int main(int argc, const char *argv[]) {
if (picture.extra_info_type > 0) {
AllocExtraInfo(&picture);
}
if (print_distortion > 0) { // Save original picture for later comparison
if (print_distortion >= 0) { // Save original picture for later comparison
WebPPictureCopy(&picture, &original_picture);
}
if (!WebPEncode(&config, &picture)) {
@ -1179,12 +1183,13 @@ int main(int argc, const char *argv[]) {
PrintExtraInfoLossy(&picture, short_output, in_file);
}
}
if (!quiet && !short_output && print_distortion > 0) { // print distortion
if (!quiet && !short_output && print_distortion >= 0) { // print distortion
static const char* distortion_names[] = { "PSNR", "SSIM", "LSIM" };
float values[5];
WebPPictureDistortion(&picture, &original_picture,
(print_distortion == 1) ? 0 : 1, values);
print_distortion, values);
fprintf(stderr, "%s: Y:%.2f U:%.2f V:%.2f A:%.2f Total:%.2f\n",
(print_distortion == 1) ? "PSNR" : "SSIM",
distortion_names[print_distortion],
values[0], values[1], values[2], values[3], values[4]);
}
return_value = 0;