Image Retrieval-Based Decision Support System for Dermatoscopic Images

This paper presents a content-based image retrieval system for dermatoscopic images as a diagnostic aid to the dermatologists for skin cancer recognition. In this context, the ultimate aim is to support decision making by locating, retrieving and displaying relevant past cases along with diagnostic reports. However, most challenging aspect in this domain is to extract local lesion specific image features and define the relevance between query and database images for retrieval. A fast and automatic segmentation method to detect the lesion from background healthy skin is proposed. This method first transforms a color image into an intensity image by utilizing domain specific image properties and NBS color distance in HVC color space. Lesion mask is detected by fusing individually segmented images based on iterative thresholding. Lesion specific local color and texture features are extracted and represented in the form of mean and variance-covariance of color channels and in a reduced PCA sub-space. Finally, for effective image retrieval, a similarity matching function is defined based on the fusion of a Bhattacharyya and Euclidean distance metric. The performance of the retrieval system is evaluated using average precision on a collection of 358 images, which demonstrates effectiveness of the proposed approach