comp = cv2.compareHist(H1, H2, cv2.HISTCMP_CHISQR)

        height, width = gray_image.shape
        while comp >= maxDist:
            for x in range(height):
                gray_image[x,0] = 255
                gray_image[x, width-1] = 255

            for y in range(width):
                gray_image[0,y] = 255
                gray_image[height-1, y] = 255

            cv2.imshow("image",  gray_image)

            H1 = cv2.calcHist( gray_image, [0], None, [256], [0,256])
            H2 = cv2.calcHist(gray_image, [0], None, [256], [0,256])
            comp = cv2.compareHist(H1, H2, cv2.HISTCMP_CHISQR)
            print(comp)

        cv2.waitKey(0)
        camera.release()
        cv2.destroyAllWindows()
    else:
        camera.release()
        break