[Image-SIG] dithered display

[William Baxter]

How come on the SGI, my black & white images look dithered and low-grade
when using im.show? In xv they look crisp and sharp. (SGI, IRIX64,
Imaging-1.1.4, Python-2.2.3) They also look fine on my linux computer.

They start out as floating point images, then I rescale them to 0..255,
and convert to grayscale im.convert("L")

Nothing shows up if I use ImageOps.grayscale().