Alternatives to Matlab's Image Processing Toolkit

Question

Are there any comprehensive open-source alternatives to Matlab\'s Image Processing Toolkit?

Answer 1

As suggested above:Octave and ImageJ

If you do have Matlab there is an open source Image Processing toolbox: http://www.cb.uu.se/~cris/blog/index.php/archives/456

For raster check Gimp: http://www.gimp.org/ And Inagemagik http://www.imagemagick.org/script/index.php