Fix image conversion when both format and pitch are specified.
Fix image conversion when both format and pitch are specified.

oktayacikalin/pyglet,oktayacikalin/pyglet,theblacklion/pyglet,mammadori/pyglet,theblacklion/pyglet,oktayacikalin/pyglet,theblacklion/pyglet,theblacklion/pyglet,oktayacikalin/pyglet,mammadori/pyglet,mammadori/pyglet,mammadori/pyglet,theblacklion/pyglet,oktayacikalin/pyglet