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Diffstat (limited to 'src/3rdparty/libwebp/README')
| -rw-r--r-- | src/3rdparty/libwebp/README | 58 |
1 files changed, 46 insertions, 12 deletions
diff --git a/src/3rdparty/libwebp/README b/src/3rdparty/libwebp/README index 90f8f10..4c15c4a 100644 --- a/src/3rdparty/libwebp/README +++ b/src/3rdparty/libwebp/README @@ -4,7 +4,7 @@ \__\__/\____/\_____/__/ ____ ___ / _/ / \ \ / _ \/ _/ / \_/ / / \ \ __/ \__ - \____/____/\_____/_____/____/v0.5.1 + \____/____/\_____/_____/____/v0.6.0 Description: ============ @@ -220,8 +220,9 @@ assumed to be a PNG, JPEG, TIFF or WebP file. Options: -h / -help ............. short help -H / -longhelp ......... long help - -q <float> ............. quality factor (0:small..100:big) - -alpha_q <int> ......... transparency-compression quality (0..100) + -q <float> ............. quality factor (0:small..100:big), default=75 + -alpha_q <int> ......... transparency-compression quality (0..100), + default=100 -preset <string> ....... preset setting, one of: default, photo, picture, drawing, icon, text @@ -229,17 +230,18 @@ Options: -z <int> ............... activates lossless preset with given level in [0:fast, ..., 9:slowest] - -m <int> ............... compression method (0=fast, 6=slowest) - -segments <int> ........ number of segments to use (1..4) + -m <int> ............... compression method (0=fast, 6=slowest), default=4 + -segments <int> ........ number of segments to use (1..4), default=4 -size <int> ............ target size (in bytes) -psnr <float> .......... target PSNR (in dB. typically: 42) -s <int> <int> ......... input size (width x height) for YUV - -sns <int> ............. spatial noise shaping (0:off, 100:max) - -f <int> ............... filter strength (0=off..100) - -sharpness <int> ....... filter sharpness (0:most .. 7:least sharp) + -sns <int> ............. spatial noise shaping (0:off, 100:max), default=50 + -f <int> ............... filter strength (0=off..100), default=60 + -sharpness <int> ....... filter sharpness (0:most .. 7:least sharp), default=0 -strong ................ use strong filter instead of simple (default) -nostrong .............. use simple filter instead of strong + -sharp_yuv ............. use sharper (and slower) RGB->YUV conversion -partition_limit <int> . limit quality to fit the 512k limit on the first partition (0=no degradation ... 100=full) -pass <int> ............ analysis pass number (1..10) @@ -252,18 +254,18 @@ Options: -print_ssim ............ prints averaged SSIM distortion -print_lsim ............ prints local-similarity distortion -d <file.pgm> .......... dump the compressed output (PGM file) - -alpha_method <int> .... transparency-compression method (0..1) + -alpha_method <int> .... transparency-compression method (0..1), default=1 -alpha_filter <string> . predictive filtering for alpha plane, one of: none, fast (default) or best - -exact ................. preserve RGB values in transparent area + -exact ................. preserve RGB values in transparent area, default=off -blend_alpha <hex> ..... blend colors against background color expressed as RGB values written in hexadecimal, e.g. 0xc0e0d0 for red=0xc0 green=0xe0 and blue=0xd0 -noalpha ............... discard any transparency information - -lossless .............. encode image losslessly + -lossless .............. encode image losslessly, default=off -near_lossless <int> ... use near-lossless image - preprocessing (0..100=off) + preprocessing (0..100=off), default=100 -hint <string> ......... specify image characteristics hint, one of: photo, picture or graph @@ -383,6 +385,7 @@ Options are: Keyboard shortcuts: 'c' ................ toggle use of color profile 'i' ................ overlay file information + 'd' ................ disable blending & disposal (debug) 'q' / 'Q' / ESC .... quit Building: @@ -411,6 +414,37 @@ $ make -f makefile.unix examples/vwebp > nmake /f Makefile.vc CFG=release-static \ ../obj/x64/release-static/bin/vwebp.exe +Animation creation tool: +======================== +The utility 'img2webp' can turn a sequence of input images (PNG, JPEG, ...) +into an animated WebP file. It offers fine control over duration, encoding +modes, etc. + +Usage: + + img2webp [file-level options] [image files...] [per-frame options...] + +File-level options (only used at the start of compression): + -min_size ............ minimize size + -loop <int> .......... loop count (default: 0, = infinite loop) + -kmax <int> .......... maximum number of frame between key-frames + (0=only keyframes) + -kmin <int> .......... minimum number of frame between key-frames + (0=disable key-frames altogether) + -mixed ............... use mixed lossy/lossless automatic mode + -v ................... verbose mode + -h ................... this help + +Per-frame options (only used for subsequent images input): + -d <int> ............. frame duration in ms (default: 100) + -lossless ........... use lossless mode (default) + -lossy ... ........... use lossy mode + -q <float> ........... quality + -m <int> ............. method to use + +example: img2webp -loop 2 in0.png -lossy in1.jpg + -d 80 in2.tiff -o out.webp + Animated GIF conversion: ======================== Animated GIF files can be converted to WebP files with animation using the |