Re: Studying Lossy Image Compression Efficiency
HDR-VDP-2 is relatively recent metric that produces predictions for difference visibility and quality degradation. http://sourceforge.net/apps/mediawiki/hdrvdp/index.php?title=Main_Page It could been interesting to add this metric in future studies. Rafał Mantiuk (the guy behind HDR-VDP-2) also worked on this paper: "New Measurements Reveal Weaknesses of Image Quality Metrics in Evaluating Graphics Artifacts" http://www.mpi-inf.mpg.de/resources/hdr/iqm-evaluation/ Which leads to think that doing some blinded experiment (real people evaluating the images) to compare compressed images has still some value. It could be fun to conduct such an experience, presenting 2 or 3 versions of the same image compressed with different methods and asking a wide panel (could be open to anyone on the web) to pick their favorite one. ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Studying Lossy Image Compression Efficiency
Thank you for publishing this study, here are my first questions: - Why didn't you include JPEG 2000? - Correct me if I'm wrong but JPEG-XR native color space is not Y'CbCr this means that this format had to perform an extra (possibly lossy) color space conversion. - I suppose that the final lossless step used for JPEGs was the usual Huffman encoding and not arithmetic coding, have you considered testing the later one independently? - The image set is some what biased toward outdoor photographic images and highly contrasted artificial black and white ones, what about fractal renderings, operating systems and 2D/3D games screen-shots, blurry, out of frame or night shots? - I've found only two cats and not a single human face in the Tecnick image set, no fancy à la Instagram filters, this can't be seriously representative of web images, a larger image corpus would be welcome. ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
