Taking a screenshot of a particular area

Question

Looking for a way for taking a screenshot of a particular area on the screen in C++. (So not the whole screen) Then it should save it as .png .jpg whatever to use it with another function afterwards.

Also, I am going to use it, somehow, with openCV. Thought i'd mention that, maybe it's a helpful detail.

Use [this](http://planetsourcecode.com/vb/scripts/ShowCode.asp?txtCodeId=10754&lngWId=3) to take the screen shot then use `OpenCV` to load and crop it. — Fantastic Mr Fox, Jan 23 '15 at 22:44
Which operating system and graphical environment are you using? — crayzeewulf, Jan 23 '15 at 22:50
http://stackoverflow.com/questions/14148758/how-to-capture-the-desktop-in-opencv-ie-turn-a-bitmap-into-a-mat — Playdome.io, Jan 23 '15 at 23:09

score 0 · Answer 1 · answered Jan 24 '15 at 15:51

OpenCV cannot take screenshots from your computer directly. You will need a different framework/method to do this. @Ben is correct, this link would be worth investigating.

Once you have read this image in, you will need to store it into a cv:Mat so that you are able to perform OpenCV operations on it.

In order to crop an image in OpenCV the following code snippet would help.

CVMat * imagesource;

// Transform it into the C++ cv::Mat format
cv::Mat image(imagesource); 

// Setup a rectangle to define your region of interest
cv::Rect myROI(10, 10, 100, 100);

// Crop the full image to that image contained by the rectangle myROI
// Note that this doesn't copy the data
cv::Mat croppedImage = image(myROI);

Taking a screenshot of a particular area

1 Answers1