Typical Image Selection Jennifer Lin, James Gajnak, Robert F. Murphy Cytometry Development Workshop 2000 Background Fluorescence microscopy is commonly used for digital image collection Current analysis on such images is done by visual inspection which is not quantitative, and not feasible for large data sets We have been working on the automated and objective interpretation of fluorescence images Previous work Typical Image Chooser (TypIC) – method for ranking a set of images in order of typicality using Haralick texture features to describe images TypIC1 Uses only 13 texture features to describe images Uses robust estimation of mean and covariance matrix to eliminate outliers Requires a minimum of 35 images TypIC2 Principal components allow the use of more features without requiring an extremely large number of images • Collapses feature set into a smaller number of dimensions Robust or non-robust estimations of mean and covariance matrix also reduces the number of images needed • Non robust estimations assumes there are no outliers Results Compare Results TypIC2 with TypIC1 for mixed sets Stability of rankings for sets of decreasing size Mixed Sets Assembled a biased test set of images from five classes: zero time (30), 10 min (25), 30 min (20), 60 min (15), basal (10) Hypothetically images from the largest (most biased) classes will be ranked as the most typical Results – TypIC1 Correlation coefficient: -0.52708 TypIC1 with 13 Haralick Features (Robust) Typicality 1.0 0.8 0.6 0.4 0.2 0.0 0 1 2 3 Protein Class 4 5 6 Results – TypIC2 Correlation coefficients for varying numbers of principal components (PC): Num. of PC Cor. Coeff. 1 -0.37177 2 -0.30753 3 -0.30598 4 -0.25877 5 -0.28973 Results – TypIC2 Correlation coefficient: -0.37177 TypIC2 with 1 Principal Component (Robust) Typicality 1.0 0.8 0.6 0.4 0.2 0.0 0 1 2 3 Protein Class 4 5 6 Results - Mixed Sets TypIC2 performs best with only 1 principal component (2 and 3 similar) TypIC1 is better at distinguishing between the protein classes than TypIC2 Results - Set Size Use ten classes of images Rank full set with various methods Rank subsets of decreasing size Measure correlation between rankings Results - Set Size