Abstract: Noise is one of the main problems of digital image processing. The noise in an image is a disturbance while performing operations in the image processing. Medical images plays vital role in digital image processing. In dermoscopic images, the unwanted hairs on skin lesion, air bublles etc., are considered as noise. Noise can be removed in the preprocessing stage through filtering. Filtering is the technique used in preprocessing to make the image a clear and eligible manner so that other process can be further continued without any disturbances. This paper mainly focuses on the noise in an image and filtering used to remove the noise.

Keywords: Noise, Filtering, Images, Pixels, Preprocessing.