ela.py 文件源码

def cv2_ELA(name):
    input_image = cv2.imread(name)

    scale = 15
    quality = 75

    cv2.imwrite(base+'ELA/temp.jpg', input_image, [cv2.IMWRITE_JPEG_QUALITY, quality])

    compressed_image = cv2.imread(base+'ELA/temp.jpg')

    output_image = (input_image - compressed_image) * scale

    gray_image = cv2.cvtColor(output_image, cv2.COLOR_BGR2GRAY)

    nonzero = cv2.countNonZero(gray_image)
    total = output_image.shape[0] * output_image.shape[1]
    zero = total - nonzero
    ratio = zero * 100 / float(total)

    cv2.imwrite(base+'ELA/results/{}_results.png'.format(name), output_image)
    return ratio, output_image