From results of second clustering, what is connected Enzastaurin structure to the lesion border and is not connected to ellipse border is selected as glow mask. At the end, OR combination is applied on lesion and glow masks, and the final binary image is obtained after applying morphological closing and filling operators. Figure 6 shows the results of described sequence for determination of glow mask step by step. Figure 6 (a) A skin lesion with large glow on lesion area and the determined borders by lesion mask, (b) The limited Y channel, (c) The cluster with minimum center value (result

of first run of clustering algorithm), (d) Result of second run of clustering algorithm, … Figure 7 shows the result of applying the described preprocessing step on three different skin lesions characterized by the lack and having a lot of thick hairs and large glows on lesion area. Figure 7 The original (top) and preprocessed (bottom) image of skin lesion (a) Without hairs and large glows, (b) With a lot of thick hairs,

and (c) With large glows on lesion area Feature extraction In this study similar to the traditional process of visual inspection, after determining lesion area, a set of main features is extracted from the area and are combined in order to distinguish between benign and malignant skin lesions. ABCD criteria are selected among methods used to diagnose melanoma because of measurability of its features using the information contained in macroscopic images. These criteria have four features of asymmetry, border irregularity, color variation and diameter.[18] In addition to these features, texture feature plays a decisive role in distinguishing between benign and malignant lesions. Finally, five groups of descriptors which are defined

to measure these features are extracted and combined. Features of asymmetry group are based on characteristics descripting center of gravity and inertia moments Carfilzomib of lesion, which each one tries to measure the lesion asymmetry in the best way. This group includes 32 features such as orientation angle, asymmetry indices,[19,20,21,22,23] mean squared error of nonoverlapping area with the respect to major axes, eccentricity,[6,24] equivalent diameter,[6,8,25] circularity indices,[6,8] excircle and circumcenter index, sphericity index,[6] four features based on areas of both sides of the major axes,[8] normalized contour moments,[24] dimensionless moments,[26] extent index, elongation index[8] and area of bounding box.