Image color contrast enhancement using multiscale morphology

Contrast enhancement aims to improve color images in terms of human interpretation and further processing in other stages of digital image processing. The multiscale mathematical morphology technique is widely used to enhance contrast in grayscale images. The extention for mathematical morphology for color images is not an easy task, because the images can be defined by different color spaces, which are represented by n-dimensional vectors and there is no single way of ordering vectors. HSI color space is used to represent the color of pixels and a lexicographical order (ISH) is imposed for processing. The fundamental morphological operations will be extended from this ordering to be applied into color images. In this work, a contrast enhancement algorithm is presented using the features extracted from the color image by the transformed multiscale top-hat. To evaluate the proposed method, various tests were performed using different color images. The experimental results show the effectiveness of the method, in which contrast enhancement was evaluated by the color enhancement factor (CEF) Metric. Also the visual inspection was used.