In the past, high resolution was the trend in the mobile image sensor. Currently, smartphones equipped with 200 million pixel sensor. Recently, efforts have been made to increase profits through miniaturization of pixel size and reduction of chip size by increasing production. The smaller the pixel size, less light is received, with increases noise and deteriorates the image quality. Smartphone manufacturers request specialized features. Therefore, sensor development organization focuses on increasing profits and installing sensors with additional functions such as high sensitivity, high dynamic range, including autofocus pixel. Such efforts do not only bring good results in terms of image quality of the sensor. Inevitably, side effects occur. One of them is maze noise. In this paper, we introduce the image quality performance improved through digital processing of maze noise in CMOS mobile image sensor.