[fitsbits] fits converter -> BMP/JPG code

[Thierry Forveille]

Darrell Porcello writes:
 > I was looking for a source for code that would take most fits images,
 > parse out its header and convert the image into a BMP or JPG format.
 > Freeware of pay, it doesn't matter. I have found lots of fits readers
 > and converters, but none really work for my purposes.
 > 
Just a warning: FITS is a data format, not a picture format like BMP or JPG.
The item at each pixel is (conceptually) a floating point number with units
of photons/s or W/m^2/s/Hz/steradian or whatever, not an RGB or 
Hue-Saturation-Value triplet. There is no canonical transformation from a 
data format to a picture one, just a number of reasonable choices that will 
show some of the information (but by no mean all of it for every possible 
image). If your program is anything but ultracrude you'd want some amount 
of user control on the transformation. SAOIMAGE and ds9 would give you good 
examples of that functionality.