Trans-illuminated image restoration of Nevoscope

Nevoscope is an optical imaging device to obtain images of skin-lesions through back-scattered diffused light using trans-illumination to determine abnormalities such as skin-cancers. Due to the nature of the process of transillumination, images obtained from Nevoscope suffer from a dark-field effect. We proposed a two-step algorithm to restore Nevoscope images under the trans-illumination mode. First, a background attenuation matrix was extracted from an image of normal skin close to the suspicious abnormality. This matrix was then applied to the trans-illuminated image to correct background. Second, the background corrected image was decomposed using wavelet transform. By adjusting the wavelet coefficients judiciously, a denoised and feature enhanced image was obtained.