ABSTRACT
Restoring information obstructed by hair is one of the main issues for the accurate analysis and segmentation of skin images. For retrieving pixels obstructed by hair, the proposed system converts dermoscopy images into the L*a*b* color space, then principal component analysis (PCA) is applied to produce grayscale images. Afterward, the contrast-limited adaptive histogram equalization (CLAHE) and the average filter are implemented to enhance the grayscale image. Subsequently, the binary image is generated using the iterative thresholding method. After that, the Hough transform (HT) is applied to each image block to generate the hair mask. Finally, the hair pixels are removed by harmonic inpainting. The performance of the proposed automated hair removal was evaluated by applying the proposed system to the International Skin Imaging Collaboration (ISIC) dermoscopy dataset as well as to clinical images. Six performance evaluation metrics were measured, namely the mean squared error (MSE), the peak signal-to-noise ratio (PSNR), the signal-to-noise ratio (SNR), the structural similarity index (SSIM), the universal quality image index (UQI), and the correlation (C). Using the clinical dataset, the system achieved MSE, PSNR, SNR, SSIM, UQI, and C values of 34.7957, 66.98, 42.39, 0.9813, 0.9801, and 0.9985, respectively. The results demonstrated that the proposed system could satisfy the medical diagnostic requirements and achieve the best performance compared to the state-of-art.
ABSTRACT
BACKGROUND AND OBJECTIVES: Teledermoscopy is a promising telemedicine service for remote diagnosis and treatment of skin diseases using dermoscopy images. It requires high quality transmission services, efficient utilization of channel bandwidth, effective storage, and security. Thus, this work develops an improved teledermoscopy system that guarantees the efficient and secure transmission of the dermoscopy images. It proposed a novel feature-based secure diagnostic system that supports the automated classification of malignant melanoma and benign nevus at the receiver side (i.e. medical facility). METHODS: To overcome the transmission of the original dermoscopy images having large size, a novel representation of the dermoscopy images is proposed, namely the compact feature profile (CFP). The proposed CFP represents the dermoscopy image only using its significant features. For security purpose, the CFP is embedded as a watermark in a speech signal using singular value decomposition (SVD) watermarking at the transmitter. Then, the de-embedding/reconstruction process is performed at the receiver end using a proposed modified SVD technique. Finally, the extracted CFP is fed into a classifier for diagnosis at the receiver. To evaluate the robustness of the proposed system, an additive white Gaussian noise (AWGN) attack was employed during the transmission process. To improve the immunity against the AWGN attack, a novel speech signal weight factor is proposed at the watermarking process. Moreover, a compensation factor is calculated at the training phase to compensate the effect of the channel AWGN attack at the receiver. In addition, the superior transform domain and embedding positions of the CFP in the speech signal were studied. RESULTS: The experimental results established that the proposed CFP diagnostic system achieved high classification accuracy, sensitivity, specificity, and F-measure for classifying the two skin cancer classes with the presence of signal-to-noise ratio (SNR) ranging from 10 to 25 dB. CONCLUSION: This work established that the newly proposed CFP watermarked in speech signal using the DWT-based modified SVD followed by single-level decomposition Db1 with hard thresholding wavelet denoising achieved efficient diagnostic teledermoscopy system.
