Image Analysis for the Biological Sciences (online)
An excellent book on Image Analysis applied to Biological Sciences: 'Image Analysis for the Biological Sciences' - Glasbey, C.A. and Horgan, G.W. (published by Wiley in 1995, but now out of press)
Image Analysis Cookboook
An online resource with lots of imaging examples, by Reindeer Graphics.
Computer Vision books
A collection of online books on Computer Vision (and related subjects).
Lectures on Image Processing
Lectures on Image Processing: A collection of 18 lectures in pdf format from Alan Peters at Vanderbilt University.
Morphology Digest
The Morphology Digest list provides a communication channel between people interested in mathematical morphology and morphological image analysis.
Spectral imaging
Fluorescent Spectra Interactive Database
An excellent interactive site to combine and compare any and all combinations of fluorescent molecules, filters, mirrors and excitation sources.
PubSpectra
PubSpectra has links to files containing dye/protein, filters and light sources/other spectra. The non-spectral section contains links and information on over 5000 dyes, over 1000 fluorescent proteins and specifications on hundreds of objective lenses.
Graphic Image formats
A programmer's file and data format resource. The site contains information on hundreds of different file types, data types, hardware interface details and other useful programming information; algorithms, source code, specifications, etc.