Sometimes, it can be nice to have a dead-simple format for bitmap images. If I'm writing some low level code (say, in C) dealing with graphics, at times I will want a quick way to
quickly output an image file. Let's say that I'm too lazy to bring in a graphics library that can write actual .pngs . The .bmp format, while simple, is a bit more complicated than a list of rgb values, because of alignment.
I wrote a little program that converts ".simple" images (which are a list of R,G,B bytes) into 24 bit .bmp files.
So, your program simply writes a tiny header and three bytes per pixel, and simpletobmp.exe turns this into a .bmp.
This works well from Python, too, when the PIL isn't around.
Here is an example of how to draw a ".simple" image:
fout = open('pyout.simple', 'wb')
chars = array.array('c') #char
ints = array.array('l') #signed long
bytes = array.array('B') #unsigned char
for y in range(HEIGHT):
for x in range(WIDTH):
(This one draws a gradient in red and green. Change the fputc lines in the inner loop to draw the image you want. A common usage is to set up a 2d array of pixels, draw the picture into that array, and then output everything to a file).
Now, one can run
simpletobmp.exe o test.simple test.bmp
to get the image.
This is very similar to how in Linux, one can write a .ppm file, which is, literally, a brief header and list of rgb values.
The .ppm format even accepts pixel information in human-readable ascii digits! Sounds ridiculous, but this type of thing can be useful.