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CodecCompTesting: Difference between revisions
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* [Fixed by moving to RD Curves] The current test suite uses linear interpolation to match quality between the codec being tested and the JPEG baseline. The curve isn't linear, so there is some minor error introduced. This is resolved by switching to RD curves, which don't require quality matching or interpolation. | * [Fixed by moving to RD Curves] The current test suite uses linear interpolation to match quality between the codec being tested and the JPEG baseline. The curve isn't linear, so there is some minor error introduced. This is resolved by switching to RD curves, which don't require quality matching or interpolation. | ||
* Currently we run the Y-SSIM quality score on PNG images, which are using the RGB colorspace. The input and output images (after encode/decode cycle) are available in YUV image format. Evaluating Y-SSIM quality score (SSIM on the Luma channel Y) on YUV image makes more sense than computing it over RGB colorspace. Solution is to make quality metric programs take YUV input. | * [Fixed] Currently we run the Y-SSIM quality score on PNG images, which are using the RGB colorspace. The input and output images (after encode/decode cycle) are available in YUV image format. Evaluating Y-SSIM quality score (SSIM on the Luma channel Y) on YUV image makes more sense than computing it over RGB colorspace. Solution is to make quality metric programs take YUV input. | ||
* Currently, the matlab implementation of Y-SSIM (ssim.m) down-scales the images to a normalized dimension of 256. The downscale transformation will smooth out the image feature details and can bump up SSIM quality score evaluated on the Luma channel. | * [Fixed] Currently, the matlab implementation of Y-SSIM (ssim.m) down-scales the images to a normalized dimension of 256. The downscale transformation will smooth out the image feature details and can bump up SSIM quality score evaluated on the Luma channel. | ||
* Investigate the following feedback from Hacker News. | * Investigate the following feedback from Hacker News. | ||
** https://news.ycombinator.com/item?id=6581827 | ** https://news.ycombinator.com/item?id=6581827 | ||