Raw image sequence

Following on from the Raw image example...

# rawimagesequence.py
import struct, sys

width = 320
height = 240
header = struct.pack("<BBBHHBHHHHBB",0,0,2,0,0,8,0,0,width,height,32,1<<5)

totalframes = 25
for frame in xrange(totalframes):
    out = open("frame%04d.tga" % frame, "wb")
    out.write(header)

    for y in xrange(height):
        for x in xrange(width):
            r = (1.0-(float(frame)/totalframes))*255
            g = r
            b = r
            a = 255
     
            out.write(struct.pack('B', b))
            out.write(struct.pack('B', g))
            out.write(struct.pack('B', r))
            out.write(struct.pack('B', a))
    print r
 
    out.close()

python rawimagesequence.py

The outer loop of this script produces each of the 24 individual frames. Each frame has a different brightness calculated from full on (white) to full off (black). The frame variable is used to number the files using the special python string formatting operator (%):

 print "hello%04d" % 23
 ==>
 hello0023

You can use Imagemagick (for instance) to convert this to an animated gif:

convert frame* fadetoblack.gif