Convert screenshot to OpenCV Mat

[rxerox]

Hi,

First, many thanks for this code/project.

Do you have a sample code to convert the screencapture to an OpenCV image ? Or a link to do this ?

Thanks.

[DarthAffe]

hey, this is just based on the docs and not tested. it assumes that emgu.cv is used and opencv has BGRA as internal color format (I couldn't verify that).

IImage image = default; // get your image here
Mat material = new Mat(image.Height, image.Width, DepthType.Cv8U, image.ColorFormat.BytesPerPixel);
image.CopyTo(new Span<byte>((void*)material.DataPointer, image.Width * image.Height * image.ColorFormat.BytesPerPixel));

or

RefImage<ColorBGRA> image = default; // get your image here
Mat material = new Mat(image.Height, image.Width, DepthType.Cv8U, ColorBGRA.ColorFormat.BytesPerPixel);
image.CopyTo(new Span<ColorBGRA>((void*)material.DataPointer, image.Width * image.Height));

I'm currently working on abstracting this kind of conversion a bit more to make it easier in the future.

[rxerox]

Hi, nice and quick answer. Your right, I'am using emgu.cv, and I try your 2nd sample code : it's work fine.

Again, many thanks ;)

[glasscake]

hey, this is just based on the docs and not tested. it assumes that emgu.cv is used and opencv has BGRA as internal color format (I couldn't verify that).

IImage image = default; // get your image here
Mat material = new Mat(image.Height, image.Width, DepthType.Cv8U, image.ColorFormat.BytesPerPixel);
image.CopyTo(new Span((void*)material.DataPointer, image.Width * image.Height * image.ColorFormat.BytesPerPixel));
or

RefImage image = default; // get your image here
Mat material = new Mat(image.Height, image.Width, DepthType.Cv8U, ColorBGRA.ColorFormat.BytesPerPixel);
image.CopyTo(new Span((void*)material.DataPointer, image.Width * image.Height));
I'm currently working on abstracting this kind of conversion a bit more to make it easier in the future.

Just for reference I got this code working with OpenCVSharp using the following:

IImage<ColorBGRA> image = fullscreen.Image;
Mat material = new Mat(image.Height, image.Width, MatType.CV_8UC4);
image.CopyTo(new Span<ColorBGRA>((void*)material.DataPointer, image.Width * image.Height));