Image enhancement using piecewise linear contrast stretch methods based on unsharp masking algorithms for leather image processing

This research work proposes a novel method to improve quality of animal leather images using digital image processing approach. In this work, piecewise linear contrast stretch based on unsharp masking algorithm is employed for image enhancement. The proposed method minimizes contrast problem. Experiments had been done on four categories of animal leather images namely crocodile leather, monitor lizard leather, cow leather and goat leather. The proposed method was then compared with other piecewise linear transforms based image enhancement techniques including intensity level slicing, bit plane slicing and contrast stretching methods. PSNR, MSE and SSIM values were obtained by using our proposed method and our proposed method produced better result. The values of PSNR when using piecewise linear contrast stretch unsharp masking (PLCSUS) respectively for crocodile leather, monitor lizard leather, cow leather and goat leather are 30.06 dB, 18.97 dB, 20.66 dB and 14.73 dB. This value is higher when compared to using other methods on the same image. Experiments show that our proposed method is better compared to conventional methods with respect to special characteristics of animal leather to be used as raw materials of artworks.