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Image enhancement is used to improve the visual effects and the clarity of image or to make the original image more beneficial for computer to process. Uneven illumination always affects image quality serious in practice. To weaken illumination effect on image quality, local gamma correction with adaptive threshold is used to improve the visual appearance of the image or to provide better transform representation for future automated image processing. In proposed method, whole image has been divided into two levels having low and high contrast values and low contrast regions are enhanced by large gamma values and high contrast regions are enhanced by low gamma value. Therefore gamma correction has been applied locally on separate regions. Results are measured by finding mean, standard deviation, average gradient and entropy values and are compared with existed techniques.