Using the Opencv GPU module

Third parties such as paddle mediapipe have implemented operations such as uploading and downloading inference of image data from cpu to acceleration devices such as GPU

To use OpenCV's GPU module, first you need to install a version of OpenCV with GPU support. Then, you need to make sure that your computer has an NVIDIA GPU and that the NVIDIA drivers and CUDA toolkit are installed.

In your code, you need to import OpenCV's GPU module first, for example:

import cv2
import cv2.cuda

Then, you can use the cv2.cuda.getCudaEnabledDeviceCount() function to check if there is an available GPU. If so, you can use the cv2.cuda.Device() function to create a GPU device object, and use the cv2.cuda.setDevice() function to set the currently used GPU device.

Then, you can use the cv2.cuda.GpuMat class to create matrices on the GPU, and use the functions in OpenCV's GPU module to operate on these matrices. For example, you can use the cv2.cuda.add() function to add two GPU matrices.

Note that if you need to do something on the CPU, you can use the GpuMat.download() function to copy the GPU matrices to the CPU, and the GpuMat.upload() function to copy the CPU matrices back to the GPU.

One of the OpenCV+CUDA introductory tutorials --- overview