etcpak 0.3

New major version, new features:

• Ability to create mipmaps (only POT, not in benchmark mode).
• Optional dithering of input image.
• Small quality improvements at basically no cost.

Image minification algorithm used for generating mipmaps is stupid simple, but it already beats the implementation in PVRTexTool:

Left: PVRTexTool, Right: etcpak

Notice the high frequency artifacts present in the PVRTexTool image, particularly near the eyes of parrots. etcpak generates smoother and more natural look. Further refinements will be able to improve the image quality even more.

Dithering basically improves the appearance of gradients or smooth areas in photos:

Left: no dithering, Right: dithering enabled

It comes at a small cost however. Here are the timings for normal compression:

$ x64/Release/etcpak.exe 8192.png -b
Image load time: 1352.646 ms
Mean compression time for 50 runs: 630.855 ms

And this is the run with dithering enabled:

$ x64/Release/etcpak.exe 8192.png -b -d
Image load time: 1312.084 ms
Mean compression time for 50 runs: 744.394 ms

Download: https://bitbucket.org/wolfpld/etcpak/downloads

etcpak 0.2.2

This version contains some minor performance improvements and a benchmark mode, which can be activated using the -b parameter. It will perform 50 compression passes and print out the average time for one pass. It should provide better environment for measurements, as the PNG decode is the slowest component during normal operation.

I've also made an example 8192x8192 image available for test purposes. It is based on the Carina Nebula shot from Hubble.

For comparison, here's the previous method of speed measurement, heavily influenced by the PNG decoder:

$ time etcpak.exe 8192.png

real    0m1.471s
user    0m0.000s
sys     0m0.030s

And here's the new benchmark mode:

$ etcpak.exe 8192.png -b
Image load time: 1330.949 ms
Mean compression time for 50 runs: 631.308 ms

Download: https://bitbucket.org/wolfpld/etcpak/downloads