Dio,
you're probably right about 'out of spec' thing, I get much more consistent results using the Ati tool.
Squeak,
2bit textures are made by interleaving two of them into one 4bit image and use two different 4bit palettes to draw them (each having 2bits of the palette masked out). You can go down to 1bit textures this way too, but so far I haven't found any real use for them in games
And well, quantizing luminance to 2bits is certainly not lossless so technically both components are stored lossy to some degree (how much exactly depends on the type of source image).
you're probably right about 'out of spec' thing, I get much more consistent results using the Ati tool.
Can't say I see it without blowing up the image. But either way, if you think that's 'nasty', you better not look at how the more known tools mangle this imageTo me, the paletted one has some nasty posterisation in places.
It's perhaps where the disparity in MSE comes from also - like Dio said, it may be more wrong but visually noise is noise after all.andy said:Generally speaking the palettised version is probably doing a better job of the background than the DXTC compression, but it's just not very noticable because of the noise.
The image I posted was using another S3 tool, not ATI one (I sent images to Archie before making the latter).Are you sure that you posted the S3 image
Squeak,
2bit textures are made by interleaving two of them into one 4bit image and use two different 4bit palettes to draw them (each having 2bits of the palette masked out). You can go down to 1bit textures this way too, but so far I haven't found any real use for them in games
You can do that, but at the cost of no longer using hardware mip-mapping - hw can't mix different texture formats across mip-levels.Wouldn?t it just be a matter of simply not doing it on lower MIP levels, because colourspace requirements tend to shrink with texturesize?
Actually I don't know if it has official name yetAnother thing, shouldn?t it be called Croma compression instead, because isn?t it the colour information that?s compromised?
And well, quantizing luminance to 2bits is certainly not lossless so technically both components are stored lossy to some degree (how much exactly depends on the type of source image).