使用Objective-C,有没有办法比较两个图像并返回%差值？

- (CGFloat)compareImages:(UIImage *)image1 withImage:(UIImage *)image2 {
    // 将图像转换为灰度图像
    UIGraphicsBeginImageContext(image1.size);
    [image1 drawAtPoint:CGPointZero];
    UIImage *grayImage1 = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UIGraphicsBeginImageContext(image2.size);
    [image2 drawAtPoint:CGPointZero];
    UIImage *grayImage2 = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    // 获取图像的像素数据
    CFDataRef pixelData1 = CGDataProviderCopyData(CGImageGetDataProvider(grayImage1.CGImage));
    CFDataRef pixelData2 = CGDataProviderCopyData(CGImageGetDataProvider(grayImage2.CGImage));
    const UInt8 *data1 = CFDataGetBytePtr(pixelData1);
    const UInt8 *data2 = CFDataGetBytePtr(pixelData2);

    // 计算像素差值
    NSInteger totalPixels = image1.size.width * image1.size.height;
    NSInteger differentPixels = 0;
    for (int i = 0; i< totalPixels; i++) {
        differentPixels += abs(data1[i] - data2[i]);
    }

    // 计算差异百分比
    CGFloat differencePercentage = (CGFloat)differentPixels / (CGFloat)totalPixels * 100.0;

    // 释放内存
    CFRelease(pixelData1);
    CFRelease(pixelData2);

    return differencePercentage;
}