A typical problem when using DXT compression is that it's not possible to obtain pure greys. This is usually a problem when compressing lightmaps, since white light produces results in colored patches. That can be avoided using the YCoCg-R color space:
A typical problem when using DXT compression is that it's not possible to obtain pure greys (the same applies to any format that stores RGB colors in 565 bits). This is usually a problem when compressing lightmaps, since white light results in colored patches. However, that can be avoided transforming the colors to YCoCg-R color space as follows:
{{{
Co = R-B;
@ -50,19 +50,14 @@ for(int i = 0; i < 256; i++)
}
}}}
In order to obtain better results you should adjust the color weights used to measure the error, so that you get higher accuracy in the luminance component.
In order to obtain best results you should adjust the color weights used to measure the error in your compressor, so that you get higher accuracy in the luminance component.
=== Higher Quality Compression ===
A simple way of obtaining higher quality compression is using the YCoCg color space and DXT5 to encode the Y in the alpha channel and the CoCg components in the RGB channels.
A simple way of obtaining higher quality compression is also using the YCoCg color space, but encoding the Y component in the in the alpha channel of a DXT5 block, and the CoCg components in the RGB channels. That was originally suggested in the following document:
castano
17 years ago