Talk:Riven tBMP resources

Aaron, I'm not entirely clear on your recent additions to the tBMP decode algorithms. Are you aware of specific images that exhibit the behaviors you describe to use a test cases, or a decoder implementation which respects those details?

[Tito] I think I've seen Aaron's effects in some compressed tBMPs. In particular, I recall being surprised by observing duplets repeating themselves, though I don't remember which tBMPs I was inspecting at the time.

[ agrif 06:55, 23 February 2009 (CET) ] I mean to go back and check specifically for this, but I'm almost completely certain that this is true. Initially, in my algorithm, I used an unsigned integer to represent the number of pixels to look back from where I started, and decremented it each time I copied a pixel. This crippled all my images, and caused weird segfaults when it rolled over after 0. This was fixed when I used a signed integer type (ie let the command copy into newly-written pixels). This is basically an implementation detail, most people would do it a different way where this doesn't matter, or use a signed integer to begin with. [also, I think that pixel-based lookbacks ignore the extra space off the edge, while duplet-based ones do not, but I'm not certain on that. I'll verify that too, but it's too late now.] I didn't realize this was new information, I just thought it was left out.