Re: [FreeWRL-develop] Testing > linux > .rgb

[doug s. <hig...@ho...>]

>> I haven't got the .rgb file naming worked out yet - I did it wrong in win32, and I want to get them harmonized.
>>
> I made changes to avoid converting the .rgb to .png for testing on linux.
> But it looks like there's no widthxheight header information being written, and graphicsmagick installed on ubuntu asks for that information if I go
> gm display 1_wrl.0001.rgb
> (whereas gm display 1_wrl.0001.png displays the image without having to ask)
> When I look for an .rgb format, SGI has a .rgb format, and they specify a header.
> ftp://ftp.sgi.com/graphics/grafica/sgiimage.html
> http://www.fileformat.info/format/sgiimage/egff.htm
> and the Snapshot.c code doesn't write a header - just the body, and looks like not in the byte order of the .sgi format.
> freewrl linux uses imlib2 for reading images. Perhaps imlib2 could be used to save the snapshot images directly to .png, and in such a way that there's no compression, if compression is a problem.
> http://docs.enlightenment.org/api/imlib2/html/index.html
> Or during the current image conversion method, specify no compression, if compression is a problem.
.
I'm finding the .pngs show different when using perl compare, but show identical when using the graphicsmagick compare function:
.
gm compare -metric mse fixture/1_wrl.0001.png playback/1_wrl.0001.png
(shows a statistical table with 0.00000 difference)
gm compare fixture/1_wrl.0001.png playback/1_wrl.0001.png -file diff.png -highlight-color purple -highlight-style Assign
# win32: gm convert diff.bmp win:
# linux: gm display diff.png
gm display diff.png
(shows a .png snapshot image with any different pixels highlighted in purple - no differences)
.
Hypothesis: the difference is in the .png header information, which may include things like date stamp or name of file, and would show different in a perl file binary compare(,) but not in a gm image compare that compares just the pixel data.
.
So I'll leave the linux code as it was - converting .rgb to .png.
-Doug