1. Use PyTorch to implement GPU-accelerated convolutional filtering (such as edge detection)
import torch import as nn import cv2 import numpy as np # Check if the GPU is availabledevice = ("cuda" if .is_available() else "cpu") print(f"Using device: {device}") # Read the image and convert it to PyTorch tensorimage = ("") # Read BGR format imagesimage = (image, cv2.COLOR_BGR2RGB) # Convert to RGBimage_tensor = torch.from_numpy(image).float().permute(2, 0, 1) # HWC -> CHW image_tensor = image_tensor.unsqueeze(0).to(device) # Add batch dimension and move to GPU # Define edge detection convolution kernel (Sobel operator)conv_layer = nn.Conv2d( in_channels=3, out_channels=3, kernel_size=3, bias=False, padding=1 ).to(device) # Set Sobel core weight manually (example, only for horizontal edges)sobel_kernel = ([ [[[-1, 0, 1], [-2, 0, 2], [-1, 0, 1]]], # Red Channel [[[-1, 0, 1], [-2, 0, 2], [-1, 0, 1]]], # Green Channel [[[-1, 0, 1], [-2, 0, 2], [-1, 0, 1]]], # Blue Channel], dtype=torch.float32).repeat(3, 1, 1, 1).to(device) conv_layer. = sobel_kernel # Perform convolution operations (GPU acceleration)with torch.no_grad(): output_tensor = conv_layer(image_tensor) # Convert the result back to numpy and saveoutput = output_tensor.squeeze(0).permute(1, 2, 0).cpu().numpy() output = (output, 0, 255).astype(np.uint8) ("edge_detection_gpu.jpg", (output, cv2.COLOR_RGB2BGR))
2. Accelerate Gaussian Fuzzy with OpenCV's CUDA Module
import cv2 import time # Check whether OpenCV supports CUDAprint("CUDA devices:", ()) # Read the image and upload it to the GPUimage = ("") gpu_image = cv2.cuda_GpuMat() gpu_image.upload(image) # Create a GPU-accelerated Gaussian filtergaussian_filter = ( cv2.CV_8UC3, # Input type (8-bit unsigned, 3 channels) cv2.CV_8UC3, # Output Type (15, 15), # core size 0 # Sigma (automatic calculation)) # Perform filtering (repeat multiple test speed)start_time = () for _ in range(100): # Repeat 100 times to simulate large data volume gpu_blur = gaussian_filter.apply(gpu_image) end_time = () # Download the results to the CPU and saveresult = gpu_blur.download() print(f"GPU Time: {end_time - start_time:.4f} seconds") ("blur_gpu.jpg", result)
3. Accelerate image Fourier transform using CuPy
import cupy as cp import cv2 import numpy as np import time # Read the image and turn it to grayscaleimage = ("", cv2.IMREAD_GRAYSCALE) # Convert numpy array to CuPy array (upload to GPU)image_gpu = (image) # Fast Fourier Transform (FFT) and Inverse Transform (IFFT)start_time = () fft_gpu = .fft2(image_gpu) fft_shift = (fft_gpu) magnitude_spectrum = ((fft_shift)) end_time = () # Turn the result back to the CPUmagnitude_cpu = (magnitude_spectrum) print(f"GPU FFT Time: {end_time - start_time:.4f} seconds") # Normalize and save the spectrummagnitude_cpu = (magnitude_cpu, None, 0, 255, cv2.NORM_MINMAX) ("fft_spectrum_gpu.jpg", magnitude_cpu.astype(np.uint8))
4. Write custom GPU kernel functions using Numba (image inversion)
from numba import cuda import numpy as np import cv2 import time # Read the imageimage = ("") height, width, channels = # Define GPU kernel functions@ def invert_colors_kernel(image): x, y = (2) if x < [0] and y < [1]: for c in range(3): # traverse RGB channels image[x, y, c] = 255 - image[x, y, c] # Upload the image to the GPUimage_gpu = cuda.to_device(image) # Configure threads and blocksthreads_per_block = (16, 16) blocks_per_grid_x = (height + threads_per_block[0] - 1) // threads_per_block[0] blocks_per_grid_y = (width + threads_per_block[1] - 1) // threads_per_block[1] blocks_per_grid = (blocks_per_grid_x, blocks_per_grid_y) # Execute kernel functionsstart_time = () invert_colors_kernel[blocks_per_grid, threads_per_block](image_gpu) () # Wait for the GPU to completeend_time = () # Download the results and saveimage_cpu = image_gpu.copy_to_host() print(f"GPU Invert Time: {end_time - start_time:.6f} seconds") ("inverted_gpu.jpg", image_cpu)
5. Real-time style migration (GPU acceleration) using PyTorch
import torch import as models from torchvision import transforms from PIL import Image # Load the pretrained model to the GPUdevice = ("cuda" if .is_available() else "cpu") model = models.vgg19(pretrained=True).(device).eval() # Image preprocessingpreprocess = ([ (512), (), (mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]), ]) # Load content images and style imagescontent_image = ("") style_image = ("") # Convert the image to a tensor and move it to the GPUcontent_tensor = preprocess(content_image).unsqueeze(0).to(device) style_tensor = preprocess(style_image).unsqueeze(0).to(device) # Define style transfer function (example, complete loss calculation and optimization)def style_transfer(model, content_input, style_input, iterations=500): # Create optimized images input_image = content_input.clone().requires_grad_(True) # Define an optimizer optimizer = ([input_image]) # Style Transfer Loop for i in range(iterations): def closure(): optimizer.zero_grad() # Extract features and calculate losses (requires specific details) # ... return total_loss (closure) return input_image # Perform style migration (requires complete code)output_image = style_transfer(model, content_tensor, style_tensor) # Post-process and save the resultsoutput_image = output_image.squeeze().cpu().detach() output_image = ()(output_image) output_image.save("style_transfer_gpu.jpg")
Key Notes
1. Hardware dependency: Requires NVIDIA GPU and installs the correct version of CUDA and cuDNN.
2. Library installation:
pip install torch torchvision opencv-python-headless cupy numba
3. Performance comparison: GPU acceleration is usually 10-100 times faster than CPU versions (depending on task complexity).
4. Applicable scenarios:
- PyTorch: Suitable for deep learning-related image processing (such as GAN, super resolution).
- OpenCV CUDA: Suitable for traditional image processing acceleration (filtering, feature extraction).
- CuPy/Numba: Suitable for custom numerical calculations or scientific research algorithms.
This is the end of this article about the detailed explanation of the code for Python's implementation of GPU-accelerated image processing. For more related content for Python GPU-accelerated image processing, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!