Check your original map bmp. There's a glitch in DF's bmp-writing algorithm that causes it to sometimes write out bmps with those black vertical bars. (This has been reported before, and when I asked the person to turn their bmp into a png and upload it so I could try to find the problem, they said "Oh wait, it's in the bmp too...")
(But if the black bars aren't in the bmp, then yes, it would be the fault of the compressor, and if so I would like you to convert the bmp into a png using an image editing program, and then upload the png somewhere and link to it (after making sure whereever you uploaded it didn't resize it) so I can do tests with it.)
Assuming that the bands are in the bmp too, meaning it isn't the compressor's fault:
If DF isn't destroying any image data (and it doesn't look like it is), then in theory I could make the map compressor try to look for this kind of thing and strip out the black bands. But right now, I don't know whether the black bands are always the same size in pixels, or in tiles, or whether DF always adds the bands if the map is a certain width in tiles, or if the tile size is a certain value, and so on.
From looking at that map, it looks like your tiles are 10x16, the valid area between black bands is 800 pixels wide (or 80 tiles), and the black bands are 320 pixels wide (or 32 tiles). (I only measured one section each, and I'm assuming that the width doesn't vary)
I have a couple questions:
1. Do all your bmps from that fort have banding? (and how many bmps from that fort do you have, from different years)
2. Do you have multiple forts, and if so, do all your fort bmps have banding?
3. Did you make those bmps from windowed or fullscreen mode?
4. If you have more than one bmp with banding, could you check the width of one of the valid areas and the width of one of the black bands, in each image, to see if they are always 800 pixels and 320 pixels for you?
If anyone else has a bmp written by DF with black bands in it, can you report what your tile size was, what the width of the valid areas and of the black bands were for you, and whether you exported the images from windowed or fullscreen?
(As a side note, the map compressor already checks for and works around one or two other oddities in map bmps written by DF, one of which is that DF sometimes writes map bmps whose width is not a multiple of the tile width)
[ June 22, 2007: Message edited by: Shadowlord ]
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Topic: The DF Map Archive (Read 78241 times)