Hi,
howe.steven@gmail.com (2009-03-25 at 1353.01 -0700):

Howdy,
I'm making a mosaic. I've used gimp to strip out extraneous background artifacts posterize the picture down to a sixteen colors. separated the colors onto different layers.

Now I'd like to know either by area (cm, or inch) or percentage of the picture each of the colors (so I can figure out how much tile I'll need).

I don't see an obvious function such a calculation tool for this. Is there one and if so, can someone point me to it?

Histogram can be used to count pixels. So make sure the alpha of each layer is sharp, select the alpha channel in histogram drop down and select the right most bar(s). If you have sharp edges, it should be just a spike on the left for all transp pixels and another in the right for opaque ones (play with log vs linear setting if needed), if you have partially transp pixels, they will appear as spikes in the middle of the graph.

GSR

On Wed, Mar 25, 2009 at 3:53 PM, Steven Howe wrote:

Howdy,
I'm making a mosaic. I've used gimp to strip out extraneous background artifacts posterize the picture down to a sixteen colors. separated the colors onto different layers.

Now I'd like to know either by area (cm, or inch) or percentage of the picture each of the colors (so I can figure out how much tile I'll need).

I don't see an obvious function such a calculation tool for this. Is there one and if so, can someone point me to it?

Hi Steven,

I was messing around with python yesterday and wrote a small plug-in that you might find useful:
http://registry.gimp.org/node/15080

I've only tested it on flattened images and a handful of colors, but it seems to be fairly accurate when it picks up the color (I'm still researching why sometimes the colors don't match).

Let me know how it works out...

Chris