Image histogram

Gary Herron gherron at
Tue Aug 10 03:23:38 CEST 2010

On 08/09/2010 05:02 PM, Paul Rubin wrote:
> Gary Herron<gherron at>  writes:
>> This is a Python newsgroup, not an image processing news group.
>> If you are asking for an algorithm to modify an image....
> I saw it as a question of how to do something using PIL.  Seems ok to me.

A quote from the OP:
   "however I dont know how to apply the new histogram to the image"

PIL has no such operation.  I have no knowledge of any such operation.  
And frankly, I'm having a hard time imagining what "apply a histogram to 
the image" even means.  (For instance if the original histogram says 
there are 30 pixels with some value, and the new histogram says there 
should be 20 pixels with that value -- which 10 do I replace, and with 
what do I replace them?)

We can help him use PIL to read, manipulate, and write an image.  But 
the actual manipulation he is requesting is so far unspecified.  So I'll 
repeat: If he is looking for an algorithm -- I haven't got one.  If he 
has an algorithm -- tell us about it, and we'll discuss implementing it 
in Python.

Gary Herron

More information about the Python-list mailing list