An Image Enhancement Algorithm Based on Retinex Theory

According to the Retinex theory, the color of an object is jointly decided by its reflecting ability to three independent wave-length lights-lights of short, medium, and long wave. The reflecting ability of the object in a certain wave band is an immanence nature which does not rely on lamp-house itself. In the Retinex model, the brightness values of each pixel have been replaced by an ratio of the brightness value to the average value of the neighboring ones. By analyzing the ratios, we can get the shading value of each pixel and obtain an enhanced image. An image obtained in this way is more clearer. The brightness and saturation also changed accordingly.