Clean up scripts in image directory. Use Octave coding conventions. Redo docstrings. Add %!tests. * brighten.m: Put input validation first. Use iscolormap to simplify input checking. * cmunique.m: Use faster method of validating input class. * colormap.m: Tweak docstring. Improve input validation. * contrast.m: Tweak docstring. Use cmap instead of map as variable name for clarity. * gray2ind.m: Wrap long lines. Use faster method of validating input class. Delete unreachable code for n>65536. * hsv2rgb.m: Use faster method of validating input class. * imwrite.m: Tweak FIXME notes. * ind2gray.m: Use correct caller name for ind2x. Update %!tests with new 2-input calling convention. * ind2rgb.m: Tweak docstring. Update %!tests with new 2-input calling convention. * iscolormap.m: Tweak docstring. Re-order validation tests. * ntsc2rgb.m: Use faster method of validating input class. Better input validation. Add %!tests. * private/ind2x.m: Use more descriptive variable names. * rgb2hsv.m: Tweak docstring. Use faster method of validating input class. * rgb2ind.m: Tweak docstring. Wrap long lines. * rgb2ntsc.m: Use faster method of validating input class. Improve input validation. Add %!tests. * rgbplot.m: Match variable names in docstring to those in function prototype.

--- a/scripts/image/cmunique.m	Sun Dec 02 17:29:47 2012 +0100
+++ b/scripts/image/cmunique.m	Sun Dec 02 10:02:57 2012 -0800
@@ -62,7 +62,7 @@
 
   cls = class (X);
   ## FIXME: Documentation accepts only 3 classes.  Could easily add 'single'.
-  if (! any (isa (X, {"uint8", "uint16", "double"})))
+  if (! any (strcmp (cls, {"uint8", "uint16", "double"})))
     error ("cmunique: X is of invalid data type '%s'", cls);
   endif