• Digital Image Processing: A Practical Introduction Using Java, by Nick Efford
• Digital Image Processing, by Gonzalez and Woods
• Ken Castleman's Pixel Page

File formats:

• PNG - Portable Network Graphics
• Graphics file formats

Organizations:

• The Society for Imaging Science and Technology
• MPEG.org

• OpenCV - Intel's open source computer vision library
• Mathematics of the Discrete Fourier Transform - from Stanford
• Digital Image Processing (DIP) with Khoros Pro 2001
• Mathematics Experiences Through Image Processing (METIP)
• A nice set of lecture sides from St. Mary's
• Andrew Barclay's Medical Imaging Pages
• Amara's Wavelet Page
• GIMP - GNU Image Manipulation Program
• Snagit - nice software for grabbing screen shots, a free trial version is available

Images:

• Images
• NASA JSC Digital Image Collection