addendum Re: working with images (PIL ?)

[Ivan Illarionov]

On Mon, 19 May 2008 10:18:00 -0400, Poppy wrote:

> Thanks, since posting I  figured out how to interpret the histogram
> results, which seems to be the consensus in responses. I wrote a check
> image program and have been periodically calling it against a folder
> where I make a copy of our images used for production. My method right
> now is to check what we send for errors, but is not preventive.
> 
> Also I determined whitespace is not the only issue, any color that
> dominates. I'm considering rewriting this code below to setup bins, so
> if combined neighboring colors exceeds the threshold then reject the
> image. I have examples where half the image appears black, but actually
> varies throughout.
> 
> Since my image is RGB I'm looping through a 768 element list.

I suggest:
1. convert to greyscale
2. posterize
3. check the max(im.histogram())

-- Ivan