cv::Mat img=[self cvMatFromUIImage:image];

cv::Rect rectangle(10,10,300,150);

cv::Mat result; // segmentation (4 possible values)
cv::Mat bgModel,fgModel; // the models (internally used)
// GrabCut segmentation
cv::grabCut(img,// input image
            result,// segmentation result
            rectangle,// rectangle containing foreground
            bgModel,fgModel,// models
            3,// number of iterations
            cv::GC_INIT_WITH_RECT); // use rectangle
// Get the pixels marked as likely foreground
cv::compare(result,cv::GC_PR_FGD,result,cv::CMP_EQ);
// Generate output image
cv::Mat foreground(img.size(),CV_8UC3,cv::Scalar(255,255,255));
result=result&1;
img.copyTo(foreground,result);
            result);

image=[self UIImageFromCVMat:foreground];
ImgView.image=image;

将UIImage转换为Mat图像的代码如下所示

- (cv::Mat)cvMatFromUIImage:(UIImage *)imge
{
    CGColorSpaceRef colorSpace = CGImageGetColorSpace(imge.CGImage);
    CGFloat cols = imge.size.width;
    CGFloat rows = imge.size.height;

    cv::Mat cvMat(rows,cols,CV_8UC4); // 8 bits per component,4 channels

    CGContextRef contextRef = CGBitmapContextCreate(
                                        cvMat.data,// Pointer to  data
                                        cols,// Width of bitmap
                                        rows,// Height of bitmap
                                        8,// Bits per component
                                        cvMat.step[0],// Bytes per row
                                        colorSpace,// Colorspace
                                        kCGImageAlphaNoneSkipLast |
                                        kCGBitmapByteOrderDefault); 
                                               // Bitmap info flags

    CGContextDrawImage(contextRef,CGRectMake(0,rows),imge.CGImage);
    CGContextRelease(contextRef);
    CGColorSpaceRelease(colorSpace);

    return cvMat;
}

但我得到了错误

OpenCV Error: Bad argument (image must have CV_8UC3 type) in grabCut.

如果我改变
cv :: Mat cvMat(rows,CV_8UC4); line to cv :: Mat cvMat(rows,CV_8UC3);
然后我得到<错误>：CGBitmapContextCreate：不支持的参数组合：8个整数位/组件; 32位/像素; 3组分色彩空间; kCGImageAlphaNoneSkipLast; 342字节/行..

我在这里感到很困惑.

请帮忙