OpenCV

Question

我正在尝试使用蒙版计算两个图像的绝对差异，因此在计算差异时只考虑图像的一个区域。但是 OpenCV 在 its function. I saw this question 中没有掩码部分，但对我不起作用。我正在尝试将蒙版中的结果相乘，以便只保留指定的区域。

代码：

Mat region = //a grayscale image containing a region of 255 and the rest is zero
Mat img1, img2 = //two images of the same size as the region image and of type CV_8UC1
Mat mask = region / 255; //to make a binary mask
Mat difference = Mat::zeros(region .rows, region .cols, CV_8UC1);

cv::absdiff(img1, img2, difference);
difference = difference * mask;
if (!difference.empty()) imshow("difference", difference);

当我尝试这个时，出现错误。

错误：

Error: Assertion failed (a_size.width == len) in cv::gemm

发生在这里：

inline
Mat& Mat::operator = (const MatExpr& e)
{
    e.op->assign(e, *this);
    return *this;
}

Answer 1

difference * mask 表示您正在执行 Matrix multiplication, in this case the height of difference must be the same as width of mask, if you want to perform an Element wise multiplication 您应该调用 difference.mul(mask)

OpenCV - 带有掩码的 absdiff

OpenCV - absdiff with a mask

c++

mask

mat

代码：

错误：