dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-12 22:14:29 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

add a WebPCleanupTransparentArea() method

Browse Source 
to 'clean up' the fully-transparent area and make it more compressible
new cwebp flags: -alpha_cleanup (off by default, since gain is not 100% guaranteed)

Change-Id: I74d77e1915eee146584cd61c9c1132a41db922eb
This commit is contained in:
Pascal Massimino
2012-01-17 08:18:22 +00:00
committed by James Zern
parent 552c121715
commit 2e3e8b2ef5
5 changed files with 93 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
examples/cwebp.c
View File

@ -206,6 +206,11 @@ static HRESULT ReadPictureWithWIC(const char* filename,
if (!ok)
hr = E_FAIL;
}
if (SUCCEEDED(hr)) {
if (has_alpha && keep_alpha == 2) {
WebPCleanupTransparentArea(pic);
}
}
// Cleanup.
if (pConverter != NULL) IUnknown_Release(pConverter);
@ -416,6 +421,10 @@ static int ReadPNG(FILE* in_file, WebPPicture* const pic, int keep_alpha) {
: WebPPictureImportRGB(pic, rgb, stride);
free(rgb);
if (ok && has_alpha && keep_alpha == 2) {
WebPCleanupTransparentArea(pic);
}
End:
return ok;
}
@ -702,6 +711,7 @@ static void HelpLong(void) {
printf(" -alpha_method <int> .... Transparency-compression method (0..1)\n");
printf(" -alpha_filter <string> . predictive filtering for alpha plane.\n");
printf(" One of: none, fast (default) or best.\n");
printf(" -alpha_cleanup ......... Clean RGB values in transparent area.\n");
printf(" -noalpha ............... discard any transparency information.\n");
printf("\n");
@ -795,6 +805,8 @@ int main(int argc, const char *argv[]) {
config.alpha_quality = strtol(argv[++c], NULL, 0);
} else if (!strcmp(argv[c], "-alpha_method") && c < argc - 1) {
config.alpha_compression = strtol(argv[++c], NULL, 0);
} else if (!strcmp(argv[c], "-alpha_cleanup")) {
keep_alpha = keep_alpha ? 2 : 0;
} else if (!strcmp(argv[c], "-alpha_filter") && c < argc - 1) {
++c;
if (!strcmp(argv[c], "none")) {