Feature extraction through median-split algorithm segmentation for melanoma detection

Detection of melanoma remains an empirical clinical science. New tools for automatic discrimination of melanoma from benign lesions in digitized dermoscopy images may allow an improvement in early detection of melanoma. This research implements a fast version of the median split algorithm in an open source format and applied to four-color splitting of the lesion area to capture the architectural disorder apparent in melanoma colors. This version of the median split algorithm splits colors along the color axis with maximum range . For a dermoscopy set of 888 images, K-means clustering algorithm is compared with a median split algorithm to find which model is performing better according to logistic regression analysis from SAS. For images with the median split algorithm, a full model of 208 features and a robust model of 45 features were developed for an 837 dermoscopy image set and a threshold was selected using logistic regression analysis that shows the most important features in both the models. Using this threshold, we checked the robustness and accuracy on a test model of 78 dermoscopy images with full and robust model. The median split algorithm is fast, requiring less than one second per image and only a four-color splitting, but it captures sufficient critical information regarding color disorder, with peripheral inter-color boundaries showing the highest significance for melanoma discrimination --Abstract, page iii

The Median Split Algorithm for Detection of Critical Melanoma Color Features

Detection of melanoma remains an empirical clinical science. New tools for automatic discrimination of melanoma from benign lesions in digitized dermoscopy images may allow an improvement in early detection of melanoma. This research implements a fast version of the median split algorithm in an open source format and applied to four-color splitting of the lesion area to capture the architectural disorder apparent in melanoma colors. Our version of the median split algorithm splits colors along the color axis with maximum Range. For a set of 888 dermoscopy images, the best model for discrimination produces an area under the receiver operating characteristic curve of 0.821. Logistic regression analysis of 242 parameter variables obtained from 888 images shows that the most important features in the final model, measured by Wald Chi-square significance, are the lengths of two peripheral inter-color boundaries and one measure of boundary overlay by different colors. The median split algorithm is fast, requiring less than one second per image and only a four-color splitting, but it captures sufficient critical information regarding color disorder, with peripheral inter-color boundaries showing the highest significance for melanoma discrimination