Can I upload RLE encoded TGA files?

I've some things in mind which will need textures to be uploaded in a lossless way and I'll create them using self created tools. Given the simplicity of TGA I'd use it as my output format. Now some of those textures will greatly benefit from RLE encoding and it would save considerable diskspace and upload time but I wonder whether this is supported.

Has anybody tried this out?

All uploaded images are automatically translated to SL's native image format, JPEG2000: Uploading a lossless format is moot, as it'll get "lossified" to JPEG2000 on the way to the server.

I believe that somebody did post a thread where they'd successfully uploaded RLE compressed TGAs, but IIRC from that thread, it doesn't save upload time - the client does the decompression and as pointed out it's not stored as TGA anyway.

If the client decompresses it before sending that's quite annoying and inefficient. If it does they might as well just let the client convert it to JPEG2000. As to lossless and JPEG2000, do they use a lossy or lossless JPEG2000 variant? Both can be used. Guess I'll have to spend some L$ just testing what they do.

Don't bother, I have already tested it. The loss is actually quite significant, although not too visible in most cases unless the information discrepancy is isolated with filters.

Saving a .TGA in the GIMP has RLE compression ticked off as a default option when you have. I've never had problems with uploading those files into SL, Course, the only thing I thought RLE affected was size, so I'm ignorant of any other effects you may be talking about. But like other people said, it all comes out as JPEG2000 on the other end.

Not really. If you recompress a lossy image with another lossy format, it will just get more and more lossy. Do it several times and you'll notice a difference. The average person probably won't know or care if they're looking at a twice-compressed file however.