Some of the features:

• Reads/writes BMP, ICO, CUR, WMF, EMF, JPEG, TIFF, PNG, MNG, GIF, PCX and JPEG2000 images.
• Reads PNM, PGM, PPM, HIPS and Matlab files.
• Scanner and printer support.
• Built-in conventional and adaptive filters.
• User specifided filters in spatial and frequency domain.
• Retinex filter for reducing shadows and increasing local contrast
• Distance, Fourier and discrete cosine transformation.
• Color model conversion: RGB, CMY, HSI, YCbCr and YIQ.
• Morpheological operations.
• Resize, rotate, crop and warping.
• Math expression module for creating and transforming images.
• Easy red-eye removal.
• Noise reduction.
• Automatic brightness, contrast, gamma and saturation adjustment.
• Test of methods for automatic image processing.
• Plugins available - see the programs website.
• Download includes a simple 3D modelling plugin.