Enhancing Skin Disease Diagnosis Through Deep Learning: A Comprehensive Study on Dermoscopic Image Preprocessing and Classification

Skin cancer occurs when abnormal cells in the top layer of the skin, known as the epidermis, undergo uncontrolled growth due to unrepaired DNA damage, leading to the development of mutations. These mutations lead to rapid cell growth and development of cancerous tumors. The type of cancerous tumor depends on the cells of origin. Overexposure to ultraviolet rays from the sun, tanning beds, or sunlamps is a primary factor in the occurrence of skin cancer. Since skin cancer is one of the most common types of cancer and has a high mortality, early diagnosis is extremely important. The dermatology literature has many studies of computer-aided diagnosis for early and highly accurate skin cancer detection. In this study, the classification of skin cancer was provided by Regnet x006, EfficientNetv2 B0, and InceptionResnetv2 deep learning methods. To increase the classification performance, hairs and black pixels in the corners due to the nature of dermoscopic images, which could create noise for deep learning, were eliminated in the preprocessing step. Preprocessing was done by hair removal, cropping, segmentation, and applying a median filter to dermoscopic images. To measure the performance of the proposed preprocessing technique, the results were obtained with both raw images and preprocessed images. The model developed to provide a solution to the classification problem is based on deep learning architectures. In the four experiments carried out within the scope of the study, classification was made for the eight classes in the dataset, squamous cell carcinoma and basal cell carcinoma classification, benign keratosis and actinic keratosis classification, and finally benign and malignant disease classification. According to the results obtained, the best accuracy values of the experiments were obtained as 0.858, 0.929, 0.917, and 0.906, respectively. The study underscores the significance of early and accurate diagnosis in addressing skin cancer, a prevalent and potentially fatal condition. The primary aim of the preprocessing procedures was to attain enhanced performance results by concentrating solely on the area spanning the lesion instead of analyzing the complete image. Combining the suggested preprocessing strategy with deep learning techniques shows potential for enhancing skin cancer diagnosis, particularly in terms of sensitivity and specificity.