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Yeah, depending on the image putting a bmp into a zip is actually significantly smaller than a png. Well, bmp has no alpha channel, but just as comment to the s
by panzi 12y ago
Yeah, depending on the image putting a bmp into a zip is actually significantly smaller than a png. Well, bmp has no alpha channel, but just as comment to the size of pngs. pngs even uses the zip algorithm in a way that is supposed to be optimized for images, but apparently it is not. E.g. the tiles here are a lot smaller as bmp in a zip: http://panzi.github.io/mandelbrot/ http://panzi.github.io/mandelbrot/
Ok, it put them into one single zip and can't remember if it was solid or not, so it might be the cross-file compression that makes the major difference here.
- FooBarWidget 12y agoWhat? I thought zip and png use the same compression algorithm.
- pornel 12y agoThey do indeed. If you're seeing BMP+ZIP being smaller than PNG it only means your PNG encoder is poor. This can be easily fixed with a PNG optimizer like Zopfli, AdvPNG or OptiPNG.
- Hello71 12y agozopfli: not a png optimizer.
- chadaustin 12y agoWell, zopflipng is! https://code.google.com/p/zopfli/source/browse/README.zopflipng https://code.google.com/p/zopfli/source/browse/README.zopfli...
- ajslater 12y agoI've had the best luck using opitpng and then pngout. https://github.com/ajslater/picopt https://github.com/ajslater/picopt ...will do this automatically for you. Pictopt: A multi-format, recursive, multiprocessor aware, command line image optimizer utility that uses external tools to do the optimizing. For an all in one GUI for Mac approach to this, try ImageOptim
- imaginenore 12y agoPNGOut is definitely better than OptiPNG most of the time: http://www.olegkikin.com/png_optimizers/ http://www.olegkikin.com/png_optimizers/
- jibsen 12y agozopflipng (with -m switch) is close to or better than the best on those five images: 1_zopflipng.png 8.466 2_zopflipng.png 18.739 3_zopflipng.png 8.012 4_zopflipng.png 91.879 5_zopflipng.png 1.117
- panzi 12y agoYes, I even mentioned that.
- DanitaBaires 12y ago> Well, bmp has no alpha channel BMP have formats which support 1-bit and 8-bit alpha channels http://en.wikipedia.org/wiki/BMP_file_format http://en.wikipedia.org/wiki/BMP_file_format. Just open any file in Photoshop and save as BMP then click advanced. Not sure of browser support.