how to convert a rgbaImage to opencv's Mat?

[ProgramAPE]

I want to use the image to take screencapture and then send the pic to opencv to analysis.
and the opencv use Mat data type. so i want to turn the image to Mat.
Did anyone can help me? ths!

[ProgramAPE]

after some research i find a way to do it .
But i am not sure if this is the best way to do it.
unsafe {
src = Mat::new_rows_cols_with_data_unsafe_def(height as i32, width as i32, core::CV_8UC3, buffer.as_mut_ptr() as *mut _, )?;
}

[HeroicKatora]

This is a good way to reference external data in cv. However, care must be taken:

Matrix constructors that take data and step parameters do not allocate matrix data. Instead, they just initialize the matrix header that points to the specified data, which means that no data is copied. This operation is very efficient and can be used to process external data using OpenCV functions. The external data is not automatically deallocated, so you should take care of it.

This means the matrix must not be used after the image's buffer is deallocated. You can call cv::Mat::clone to take an owning copy of the created matrix that lives independently from the buffer, and so does not require it to stay alive.

[konstantinzolotarev]

First of all, big thank you @ProgramAPE and @HeroicKatora, spent almost an hour on trying to convert image into Mat unless found this discussion.
Just in case if somebody will search for a working code in future:

Note: I'm using RGBa with alpha layer. If you wouldn't need it, you will have to switch core::CV_8UC4 to correct type.

// Converts rawImage into opencv::Mat
fn into_mat(image: &RgbaImage) -> Mat {
    unsafe {
        Mat::new_rows_cols_with_data_unsafe_def(
            image.height() as i32,
            image.width() as i32,
            core::CV_8UC4,
            image.as_raw().clone().as_mut_ptr() as *mut _,
        )
        .unwrap()
    }
}