Image enhancement with mean brightness preservation based on multiscale top-hat transform

Multiscale mathematical morphology is a technique used to improve the visual quality of images. These techniques generally introduce distortions in the process of im- provement that cause loss of brightness in the images. In this work a method of contrast improvement and brightness preservation is presented. The method is based on the mul- tiescale top-hat transform. In the top-hat transform two structuring elements of different areas are used, but of similar and flat structures. The evaluation of the proposed method was carried out using 200 images from a public database. The comparison of the proposal was made with other state of the art methods. Numerical and visual results show images with contrast enhancement, natural brightness and moderate distortions.