This document presents a dualistic sub-image histogram equalization technique for medical image enhancement and segmentation. The technique divides an image histogram into two parts based on mean and median, then equalizes each sub-histogram independently. It enhances images effectively while constraining average luminance shift. For segmentation, canny edge detection and neural networks are used. The technique is tested on medical images and shows improved completeness and correctness over previous methods, with neural networks increasing accuracy to 98.3257%.