Comment 2 for bug 472978

Juho Vepsäläinen (bebraw) wrote :

Apparently PIL saves PGM internally as PPM unless you convert the image to grayscale first. Add proper check for format to fix the issue (perhaps to imtools save?).

Here's a test case I used to verify this behavior:
from Image import open

im = open('Lenna.png')

gim = im.convert('L')
gim.save('Lenna1.pgm')
im.save('Lenna2.pgm')
im.save('Lenna3.ppm')