The dds exporter has options like so for compression for instance,
Advanced Options Menu
NOTE: Use perceptual error metric becomes available when some type of compression method from
main menu (Compression:) is selected.
The Use perceptual error metric is supposed to enhance visual quality. I would suggest experimenting with the texture in a rendering program to see how it affects the model according to the texture type (Compression:) in question.
Doesn’t do anything I can detect though visually.
Then there’s this basically suggesting DXT5 is best for diffuse images,
NOTE 2: When creating and saving textures using the DXT5 format, I think it best to use AExp or, preferably, one of the YCoCg-ttypes over the typical DXT5 format when possible With modern hardware, the performance hit would be negligible.
YCoCg (DXT5) High-quality compression of color images can be achieved by using the DXT5 format after converting the RGB_ data to CoCg_Y. In other words, the luma (Y) is stored in the alpha channel and the chroma (CoCg) is stored in the first two of the 5:6:5 color channels. For color images, this technique
results in a 4:1 compression ratio with very good quality – generally better than 4:2:0 JPEG at the highest quality setting.
But from posts in the forum I see people using DXT1, which is supposedly best for black and white images. I see no quality difference between the two myself.
Edit: No difference between DXT5 and DXT1 in quality(Just file size). YCoCg /dxt5 doesn’t work at all.
Then for mipmaps,
- Default – no filtering is applied to image. Possibly/probably causes visual anomalies such as excessively sharp edges and stair-stepping artifacts.
- Nearest – bilinear filter, sharp switching between mipmaps?
- Box – is a polyphase box filter. Outside of the Lanczos and Kaiser falters, it’s a good choice for most cases. It’s also much faster than the other filters.
- Triangle – uses a triangle filter. The kernel has a larger width and thus produces blurrier results than the box flter.
- Quadratic – gaussian-type filter?
- B-Spline – trilinear filter?
- Mitchell – sync-type filter. Used primarily to reduce loss of detail while upsampling.
- Lanczos – similar to the Kaiser filter, the results are usually indistinguishable between the two.
Lanczos may handle ringing and artifacts better. Can be tuned with Warp filter selections.
- Kaiser - Kaiser-windowed sync filter. It’s generally considered the best choice for downsampling filters, but in order to obtain best results it is advisable to experiment with Warp modes as is done with the Lanczos filter. Otherwise the resulting images could suffer from ringing artifacts or the result may not be as sharp as desired.
Tried Box and triangle as this says there would be a noticeable difference with blur but results were not really perceptible.
This is why I am asking about what options people are using and for what images they use it for.
Edit: Added missing YCoCg (DXT5) info.