The HXC command line tool can now create simple web pages given a set of original and compressed textures. Here are the results for the Kodak test suite:


HX DXT1 Compression

256†† 256_mips

512†† 512_mips

1024†† 1024_mips

2048†† 2048_mips

4096†† 4096_mips

8192†† 8192_mips


Each page includes the decompressed image in PNG format, RGB RMSE and RGB/Luma PSNR error, bits/texel, output file size, and some summary information at the bottom. You can compare sets of images by loading the pages into different tabs. I included results for all practical power of 2 codebook sizes (256-8192), although the compression engine supports non-power of 2 codebooks.


I included results for textures with and without mipmaps, so you can see the quality and file size impact once mipmaps are included in the compressed file. (But you can't see the actual mipmaps on these pages yet, and I only decompress and calculate error statistics on the first mip.) When mipmaps are included the overall quality drops a bit, and the file size increases by around 15-33%. However, the overall bits/texel rate improves because the overhead due to transmitting the compression tables (which are shared by all mip levels/faces) is amortized over more texels.


The unpack rate to raw DXT1 for all mips on a Athlon 64 X2 2.2GHz is currently 180-200 megatexels/sec. for 512,512 codebooks. (Larger codebooks = slower decompression and vice versa.) This is around 15% faster than last week.


The "Raw DXT1 Compression" links show the output of my DXT1 endpoint optimizer vs. squish's and RYG's. These pages are for conventional DXT1 compression - nothing fancy here. I've refined my optimizer to the point where itís just as good (almost always a bit better) than squish.


Raw DXT1 Compression





PSNR Comparison Chart


And here are the original uncompressed images:


Original Images