Create Mat from vector

Question

I am extremely new to computer vision and the opencv library.

I\'ve done some googling around to try to find how to make a new image from a vector of Point2fs and ha

Answer 1

Should be as simple as

std::vector points;
cv::Mat image(points);
//or
cv::Mat image = cv::Mat(points) 

The probably confusion is that a cv::Mat is an image width*height*number of channels but it also a mathematical matrix , rows*columns*other dimension.

If you make a Mat from a vector of 'n' 2D points it will create a 2 column by 'n' rows matrix. You are passing this to a function which expects an image.

If you just have a scattered set of 2D points and want to display them as an image you need to make an empty cv::Mat of large enough size (whatever your maximum x,y point is) and then draw the dots using the drawing functions http://docs.opencv.org/doc/tutorials/core/basic_geometric_drawing/basic_geometric_drawing.html

If you just want to set the pixel values at those point coordinates search SO for opencv setting pixel values, there are lots of answers