New Submission Automatic Classification of Severity Stages of Plaque Psoriasis by Using Image Processing

Psoriasis is a common skin disease affecting all ages and sexes. The most common type is plaque psoriasis, which causes raised, red patches on the skin that are covered with a silvery-white buildup of dead skin cells, based on its severity which has three stages: mild, moderate, and severe. The severity stages of plaque psoriasis have different shapes, sizes, and symptoms and various types of medication and treatment. Accurate visual diagnosis is time-consuming, leading to unnecessary suffering due to incorrect or delayed diagnosis, inadequate treatment options, and insufficient access to care. Thus, this study aims to automatically classify the severity stages of plaque psoriasis using an image processing technique. In total, 200 sample plaque psoriasis images were taken from Bisidimo General Hospital, Oromia region, and Yem Dermatology and Venereology clinic, Harar. The sample images were acquired using a Samsung Galaxy A14 mobile camera with (1080 × 2408) resolution and loaded or imported to a computer. The imported images were pre-processed converted from Red Green Blue to gray-scale images and enhanced using Contrast Limit Adaptive Histogram Equalization to increase the visibility of the plaque psoriasis images. Then, thresholding was used to segment the plaque psoriasis-diseased images, and the morphological feature was extracted from each image. Based on the morphological feature, the arrangement for the input is carefully divided so that 70% for training 15% for validation, and 15% for testing sets. Artificial Neural Network was used to classify plaque psoriasis skin disease severity stages as mild, moderate, and severe. The performance measure of the classifier accuracy was computed. It was observed that the proposed scheme with the Artificial Neural Network classifier outperformed by giving 90% accuracy and a 10% probability of misclassification error to classify plaque psoriasis as mild, moderate, or severe. All the techniques were implemented through MATLAB(MatrixLaboratory) R2018a platform and the design and implementation of these image processing techniques help easy classification of severity stages of plaque psoriasis skin diseases.

Keywords: Accuracy, Artificial Neural Network, Enhancement, Features, Segmentation, Severity, Skin diseases