[daip] Re: Help me track down a problem

[Eric Greisen]

Kristy Dyer writes:
 > I'm working with some 74 MHz images that were made a long time ago
 > (31DEC99 on 22-Oct-1999) that seem to have "steps" in the transfer
 > function -- that is the shades of gray don't change evenly, they seem
 > to go in steps.
 > 
 > Do you know why this would be? I've written them out to FITS and then
 > read them back in -- did I do this to them?

I suppose that you could have done this in one of 2 ways:

1. Use 16-bit output with a rather large dynamic range in the image

2. Use FITAB with QUANTIZE set too high.

Eric Greisen