WebP Imageplugin
Posted: Sun Sep 02, 2012 11:47 pm
https://developers.google.com/speed/webp/
v0.2.0 seems very mature, and is the one used in Chrome AFAIK.
A image plugin is kind of a must for PureBasic since trying to use libwebp.lib with PB is kinda cumbersome as the image is upside down and a raw bitmap, so you have to use startdrawing() and imageoutput() and drawingbuffer() and a loop to flip the image vertically, while ideally the webp image should just be decoded and written directly to a image bitmap buffer in the right order.
WebP (Lossless) has aprox. 25% better compression than PNG.
WebP (Lossy) has aprox. 25% better compression than JPG.
WebP lossless with alpha takes up around the same size as a PNG without alpha.
WebP can have a lossy image but lossless alpha.
WebP can also have lossy alpha.
Both lossy and lossless have either quality or compression settings.
If a WebP plugin is made loading and saving would be like this:
LoadImage() is the same as the others.
SaveImage(#Image, Filename$ [, ImagePlugin [, Flags [, Depth]]]) ;this one is a little more complex.
New constant #PB_ImagePlugin_WEBP (or #PB_ImagePlugin_WebP ?)
Flags: Quality, a value from 0 to 100, with 100 being the same as WebP lossless mode, 100 to 106 being lossless compression speed 0 to 6 with 100 being fastest and 106 slowest.
Depth: optional, 8, 24, 32 (1 and 4 as well?)
Why this way? Because by the looks of it the webp example tools either use floating point from 0.0 to 1.0 or from 0 to 100 for lossy quality. And Lossless WebP is a different mode and has 7 different compression speeds (and thus compression rates, but they all are lossless) ranging 0 to 6. And this avoids having to change the function params.
And is WebP worth the effort? Absolutely. First of all it's under a similar license to the xml library. (basically it's the BSD license) so it ca be used in closed source/proprietary/commercial projects.
And more importantly the size reduction. A PNG image here that was 219KB (after optimized using 3 different PNG optimizers) became only 167KB with WebP lossless mode, that's around 30% size reduction.
See http://en.wikipedia.org/wiki/WebP#Support for a growing list of what supports WebP. Also lates Firefox releases also support WebP, so the list on wikipedia is a little outdated.
For WebP lossless decoding speed (which is as important as the compression IMO) https://developers.google.com/speed/web ... lpha_study (look at Table 3. Average decoding time).
OK! I'll stop gushing and shut up now... But WebP has really impressed me.
v0.2.0 seems very mature, and is the one used in Chrome AFAIK.
A image plugin is kind of a must for PureBasic since trying to use libwebp.lib with PB is kinda cumbersome as the image is upside down and a raw bitmap, so you have to use startdrawing() and imageoutput() and drawingbuffer() and a loop to flip the image vertically, while ideally the webp image should just be decoded and written directly to a image bitmap buffer in the right order.
WebP (Lossless) has aprox. 25% better compression than PNG.
WebP (Lossy) has aprox. 25% better compression than JPG.
WebP lossless with alpha takes up around the same size as a PNG without alpha.
WebP can have a lossy image but lossless alpha.
WebP can also have lossy alpha.
Both lossy and lossless have either quality or compression settings.
If a WebP plugin is made loading and saving would be like this:
LoadImage() is the same as the others.
SaveImage(#Image, Filename$ [, ImagePlugin [, Flags [, Depth]]]) ;this one is a little more complex.
New constant #PB_ImagePlugin_WEBP (or #PB_ImagePlugin_WebP ?)
Flags: Quality, a value from 0 to 100, with 100 being the same as WebP lossless mode, 100 to 106 being lossless compression speed 0 to 6 with 100 being fastest and 106 slowest.
Depth: optional, 8, 24, 32 (1 and 4 as well?)
Why this way? Because by the looks of it the webp example tools either use floating point from 0.0 to 1.0 or from 0 to 100 for lossy quality. And Lossless WebP is a different mode and has 7 different compression speeds (and thus compression rates, but they all are lossless) ranging 0 to 6. And this avoids having to change the function params.
And is WebP worth the effort? Absolutely. First of all it's under a similar license to the xml library. (basically it's the BSD license) so it ca be used in closed source/proprietary/commercial projects.
And more importantly the size reduction. A PNG image here that was 219KB (after optimized using 3 different PNG optimizers) became only 167KB with WebP lossless mode, that's around 30% size reduction.
See http://en.wikipedia.org/wiki/WebP#Support for a growing list of what supports WebP. Also lates Firefox releases also support WebP, so the list on wikipedia is a little outdated.
For WebP lossless decoding speed (which is as important as the compression IMO) https://developers.google.com/speed/web ... lpha_study (look at Table 3. Average decoding time).
OK! I'll stop gushing and shut up now... But WebP has really impressed me.
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