Convert Opengl Texture To Opencv Mat

It s quite easy to find many examples around even among official qt example projects to deal with and learn more about this topic but i figured there are no clear continue reading using opengl in qt for processing images.

Convert opengl texture to opencv mat. The first thing to note is that the cv mat to qpixmap conversion cvmattoqpixmap at the bottom of this section simply relies on cvmattoqimage and uses qt s qpixmap fromimage to return a qpixmap so that s pretty straightforward. Destination array host or device memory can be mat cuda gpumat ogl buffer or ogl texture2d. I perform a render to texture on opengl so i have and fbo texture that then i want to pass it opencv where ideally i will be some gpu stuff with it. Input is qvideoframe and the format i checked is format bgr32.

Enabling texture and loading of an image. Because opencv uses bgr while opengl es uses rgb format we have to convert the color space with cv cvtcolor. Now we show how to call the functions in opencv native cpp and to update a texture with the image returned by these functions. I ve been spending days reading forums and trying to figure out the formats and get my camera work on android.

Generated on wed oct 9 2019 23 25 03 for opencv by. Then return the converted image buffer. I know a naive way would be using glreadpixels but this is obviously way to slow. Copies from opengl texture to host device memory or another opengl texture object.

Scale linearly when image bigger than texture gltexparameteri gl texture 2d gl texture min filter gl linear. Scale linearly when image. Display the loaded image. Converting opencv mat to opengl texture.

So i created a mat with the codes cv mat mbgra cv mat 1080. Utilizing the power of the gpu and opengl in particular for computer vision and image processing purposes has always been a favorite topic of mine. It requires to copy the data from gpu memory to memory and then load it through cvloadimage or similar in opencv. Create texture glgentextures 1 amp texture 0.