A characteristic intensity of a feature in image data generated by scanning a microarray probe is determined (304). A set of pixels of the image data that nominally represent the feature is identified. The pixels each have a value (such as an intensity value) associated therewith. For each of a plurality of subsets of the set of pixels, a variation statistic value is determined that corresponds to a variation in the values associated with the pixels of that subset (Fig.3).
FEATURE EXTRACTION AND NORMALIZATION ALGORITHMS FOR HIGH-DENSITY OLIGONUCLEOTIDE GENE EXPRESSION ARRAY DATA