What does the 'gimp_histogram' procedure require to work?

Question

I do not understand why my call to pdb.gimp_histogram throws a RuntimeError: execution error.

from gimpfu import *

def plugin_main ( timg, tdrawable ):

    pdb.gimp_histogram( tdrawable, 0, 0, 255 )

According to the docs, the function takes four arguments:

I provide all four in the barebones code above, so why is the error thrown?

score 1 · Accepted Answer · answered Nov 28 '18 at 15:11

1

The code looks correct (I have similar code that works).

However I get the same error if the image is color-indexed, while the doc says "The drawable may not be indexed.", so that could be your problem?

PS: You should use the named constants (HISTOGRAM_{VALUE|RED|BLUE|GREEN|ALPHA})

answered Nov 28 '18 at 15:11

xenoid

Oh wow, thanks! That's exactly the problem. I somehow missed that part when reading. I was using the histogram window for testing and it works with indexed images so I just assumed the procedure would be the same. Is the solution then to create a temporary version of the image that is another format and use that to get the histogram data? (I am trying to count pixels by color). – Jet Blue Nov 28 '18 at 19:31
No better way off the top of my head, but it's getting late here. – xenoid Nov 29 '18 at 00:16

1 Answers1