OpenCV乘法标量和矩阵 [英] Opencv multiply scalar and matrix

问题描述

我一直在努力实现一些应该是微不足道的事情，并且在 Matlab 中是不重要的.

I have been trying to achieve something which should pretty trivial and is trivial in Matlab.

我想简单地实现以下目标:

I want to simply achieve something such as:

cv::Mat sample = [4 5 6; 4 2 5; 1 4 2];
sample = 5*sample;

之后应该是以下示例:

[20 24 30; 20 10 25; 5 20 10]

我尝试了scaleAdd，Mul，Multiply，它们都不允许标量乘法器，也不需要相同的大小和类型"矩阵.在这种情况下，我可以创建一个1的矩阵，然后使用scale参数，但这看起来非常多余

I have tried scaleAdd, Mul, Multiply and neither allow a scalar multiplier and require a matrix of the same "size and type". In this scenario I could create a Matrix of Ones and then use the scale parameter but that seems so very extraneous

任何直接的简单方法都很棒！

Any direct simple method would be great!

推荐答案

实际上，OpenCV确实支持标量值与operator*重载相乘.不过，您可能需要正确初始化矩阵.

OpenCV does in fact support multiplication by a scalar value with overloaded operator*. You might need to initialize the matrix correctly, though.

float data[] = {1 ,2, 3,
                4, 5, 6,
                7, 8, 9};
cv::Mat m(3, 3, CV_32FC1, data);
m = 3*m;  // This works just fine

如果您主要对数学运算感兴趣，则cv::Matx会更易于使用:

If you are mainly interested in mathematical operations, cv::Matx is a little easier to work with:

cv::Matx33f mx(1,2,3,
               4,5,6,
               7,8,9);
mx *= 4;  // This works too

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