How do I convert a cv::Mat to a cv::Rect

Question

我在cv :: Mat中有一个图像作为面部，我在cv :: Rect对象中需要整个图像，但我找不到它的完成方式，或者可能的话，从目录中的图像创建Rect

Answer 1

you don't convert a cv::Mat to a cv::Rect.

you want the part of the image inside that Rect ?

Mat roi = Mat(img,rect);

will give you the cropped region

Answer 2

cv :: Mat无法直接给您一个cv :: Rect，但您可以使用cv :: Mat的size（）方法并假设cv :: Rect的起点是（0 ，0）

cv::Mat image; // load your image into the cv::Mat ... // now create the cv::Rect from the cv::Mat cv::Rect rect = cv::Rect(0, 0, image.size().width, image.size().height);

Answer 3

Although, as @berak says, you can't convert a cv::Mat to a cv::Rect, I am guessing you want something like this (untested).

cv::Mat face;   // you already have this with some data in it
cv::Mat image;  // you already have this with some data in it
cv::Rect rect(x, y, w, h); // some place in image where you want face

// copy face into rectange within image
cv::resize(face, image(rect), cv::Size(rect.width, rect.height));