The key concepts of transform mat to qimage are brief copy qimage into cv mat struct mat to qimage cpy policy static qimage start cv mat const mat qimage format format the fourth parameters mat step is crucial because opencv may do padding on every row you need to tell the qimage how many bytes per row the.
Copy mat opencv.
Whenever a header is cleaned this counter is decreased.
Quite a few.
So mat dims is always 2 can also be 0 when the array is empty.
Opencv data type change copy vector to mat mat to vector.
What most of opencv functions do is to copy a given image onto another slightly larger image and then automatically pads the boundary by any of the methods explained in the sample code just below.
Use a copy constructor or assignment operator where there can be an array or expression on the right side see below.
This way the convolution can be performed over the needed pixels without problems the extra padding is cut after the operation is done.
If the memory of the mat mat is continuous all its data is continuous you can directly get its data to a 1d array.
The next stop on our journey brings us to the large array types.
Dynamic and variable storage.
Whenever somebody copies a header of a mat object a counter is increased for the matrix.
Reference this example source code.
Sometimes you will want to copy the matrix itself too so opencv provides the cv mat clone and cv mat copyto functions.
When the counter reaches zero the matrix too is freed.
Making borders for images padding if you want to create a border around the image something like a photo frame you can use cv copymakeborder function.
Chief among these is cv mat which could be considered the epicenter of the entire c implementation of the opencv library.
The overwhelming majority of functions in the opencv library are members of the cv mat class take a cv mat as an argument or return cv mat as a return value.
I would like to have direct conversion from mat to array if available if not to vector.
It passes the number of dimensions 1 to the mat constructor but the created array will be 2 dimensional with the number of columns set to 1.
I need opencv functions because the code has to be undergo high level synthesis in vivado hls.