Brad's Blog

Published: 2010-02-25

Building PIL on OS X: Snow Leopard

Mac OS PIL Python X homebrew virtualenv

There are several places online that discuss problems installing PIL on Mac OS X Snow LeopardThis is how I got it to work.Install lib jpeg using homebrew (which is super-aweseome!) brew intall jpeg.This installs the library into /usr/local/Cellar/jpeg/7Install libfreetype the old-fashioned way (./configure, make, sudo make install). I used freetype-2.1.10.pre-20050511.Download, unpack PIL (I used Imaging-1.1.6). I had to make the following changes to setup.pyFREETYPE_ROOT = "/usr/local"JPEG_ROOT ...

Published: 2007-12-05

Computing Correlation Coefficients in Python

Image Python numpy pil

A useful technique for matching objects in images is to compute the images' Correlation Coefficients. Essentially, you take any image and compute the correlation between it and another, smaller image containing ONLY the object that you want to identify. The resulting correlation image should contain bright spots where there is a high correlation (or match) between the two images. Here's a simple python script to compute the correlation between two images: It requires PIL ...