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Image Comparisons: PNG, WebP, and HIPIX

by on October 7, 2010

So based on all this, what have we learned:

From what I’ve seen so far, I have to say that WebP is the best ‘all around’ format.  The image quality is pretty good no matter the compression settings, and the filesize is a nice improvement over JPG in some situations.  In the photo case, the high quality WebP was actually larger than the JPEG, but of higher quality.  Here’s a good way to look at the quality RMSE numbers:

You can see some interesting trends across everything.  Green tends to the be most “accurate” channel, while Blue is the least accurate.  Red tends to fall in the middle.  The high error of normal quality HIPIX is plain to see, and the low error of the High quality is as well.

So, if you really must have the smallest filesize, then HIPIX seems to win.  At the highest quality settings, the files are of better quality than the highest quality WebP’s and smaller in size by around 30%. I found it faster to encode than WebP (and I did this on a laptop with no real H264 encoding acceleration hardware), and visually I think the high-quality HIPIX images look better.  Also, HIPIX already has software out for Windows, Mac, Linux, and Android.  Currently, the WebP software only runs on Linux (not even on Mac).

Which will win is anybody’s guess.  Both formats have their benefits:  HIPIX has the established H264 industry to accelerate the compression and decompression, and the smaller filesizes at maximum quality, however WebP has the power of Google and open source behind it. However, based on the filesize and image quality metrics I ran, I cast my vote for HIPIX being the best of the lossly compression image formats available right now.

However, until one of the two formats appears in FireFox and Photoshop, I doubt we’ll see much of either.  What do you think?