Image analysis in the RGB and HS colour planes for a computer-assisted diagnosis of cutaneous pigmented lesions

Aims and background: A study was carried out to evaluate the effectiveness of image analysis performed by the two color representation models when a computer-assisted diagnosis of melanoma is involved. Methods: Color images of 40 skin pigmented lesions, which included 12 melanomas, were acquired by a standard color RGB video camera and stored in a PC for off-line processing. Image analysis was performed in the red green and blue color representation model and using hue and saturation color components. To describe shape and color characteristics of each lesion, including area, roundness and color variegation, 16 parameters were derived from red, green, blue, hue and saturation color planes and tested as possible variables useful to differentiate melanomas from benign nevi. Results: The test gave a result of significance for six of the 16 derived image descriptors. The general trend of our data was in agreement with clinical observations according to Which melanoma is usually darker, more variegated and round than a benign nevus, whereas lesion dimension of melanomas and benign lesions was not significantly different. Conclusions: Our preliminary results suggested that image analysis performed on hue and saturation-derived and red green and blue-derived data could better discriminate melanoma from nevi than separately using the two color representation models.