CodecCompTesting: Difference between revisions

(Created page with "= Code Compression Testing = == High Level Goal == The goal is to create a framework for testing image compression. We should be able to create data sets for any given codec...")
 
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== Planned Work (specific) ==
== Planned Work (specific) ==


* coming soon
Methodology
 
* [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.
* 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.
** https://news.ycombinator.com/item?id=6581827
 
 
Quality Tests to Add
 
*
 
Quality Tests to Port to C
 
*
 
Data Output
 
* Output RD curve result data to format that is easily human and machine readable (e.g. CSV)
 
Graphing Capabilities
 
* Add ability to create a graph with one or more sets of RD curve results.
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