[Image-SIG] RGB conversion to CMKY gives strange results

[Ray Pasco]

I'm using the im.convert() from RGB to CMYK and am getting very strange 
results.
First, the K value is stuck at zero no matter what the RGB values are.
Next, the C, M and Y values are integers and not in the value range 0.0 
- 1.0.
I have no idea what they mean. They seem to bear no relationship at all 
to the
proper CMYK values.

I coded an RGB to CMY to CMYK algorithm derived from the formulas
found at http://www.easyrgb.com/math.php?MATH=M2#text2 , which
seem to be correct.

Is im.convert ('CMYK') broken ? I'd like to use it since this is the only
colorspace conversion available in PIL.

Is there any particular reason why conversions to HSV and/or HSL don't 
exist ?
It would really useful to work with brightness or luminosity directly.

(1.1.5b1 on XP)