| --- |
| license: apache-2.0 |
| language: |
| - en |
| pipeline_tag: text-to-image |
| tags: |
| - pytorch |
| - diffusers |
| - conditional-image-generation |
| - diffusion-models-class |
| datasets: |
| - dpdl-benchmark/caltech_birds2011 |
| library_name: diffusers |
| --- |
| |
| # class-conditional-diffusion-cub-200 |
| |
| A Diffusion model on Cub 200 dataset for generating bird images. |
| |
| ## Usage Predict function to generate images |
| ```python |
| |
| def load_model(model_path, device): |
| # Initialize the same model architecture as during training |
| model = ClassConditionedUnet().to(device) |
| |
| # Load the trained weights |
| model.load_state_dict(torch.load(model_path)) |
| |
| # Set model to evaluation mode |
| model.eval() |
| |
| return model |
| |
| |
| def predict(model, class_label, noise_scheduler, num_samples=8, device='cuda'): |
| model.eval() # Ensure the model is in evaluation mode |
| |
| # Prepare a batch of random noise as input |
| shape = (num_samples, 3, 256, 256) # Input shape: (batch_size, channels, height, width) |
| noisy_image = torch.randn(shape).to(device) |
| |
| # Ensure class_label is a tensor and properly repeated for the batch |
| class_labels = torch.tensor([class_label] * num_samples, dtype=torch.long).to(device) |
| |
| # Reverse the diffusion process step by step |
| for t in tqdm(range(49, -1, -1), desc="Reverse Diffusion Steps"): # Iterate backwards through timesteps |
| t_tensor = torch.tensor([t], dtype=torch.long).to(device) # Single time step for the batch |
| |
| # Predict noise with the model and remove it from the image |
| with torch.no_grad(): |
| noise_pred = model(noisy_image, t_tensor.expand(num_samples), class_labels) # Class conditioning here |
| |
| # Step with the scheduler (model_output, timestep, sample) |
| noisy_image = noise_scheduler.step(noise_pred, t, noisy_image).prev_sample |
| |
| # Post-process the output to get image values between [0, 1] |
| generated_images = (noisy_image + 1) / 2 # Rescale from [-1, 1] to [0, 1] |
| |
| return generated_images |
| |
| |
| def display_images(images, num_rows=2): |
| # Create a grid of images |
| grid = torchvision.utils.make_grid(images, nrow=num_rows) |
| np_grid = grid.permute(1, 2, 0).cpu().numpy() # Convert to (H, W, C) format for visualization |
| |
| # Plot the images |
| plt.figure(figsize=(12, 6)) |
| plt.imshow(np.clip(np_grid, 0, 1)) # Clip values to ensure valid range |
| plt.axis('off') |
| plt.show() |
| ``` |
| |
| # Example of loading a model and generating predictions |
|
|
| ```python |
| model_path = "model_epoch_0.pth" # Path to your saved model |
| device = 'cuda' if torch.cuda.is_available() else 'cpu' |
| model = load_model(model_path, device) |
| noise_scheduler = DDPMScheduler(num_train_timesteps=1000, beta_schedule='squaredcos_cap_v2') |
| class_label = 1 # Example class label, change to your desired class |
| generated_images = predict(model, class_label, noise_scheduler, num_samples=2, device=device) |
| display_images(generated_images) |
| ``` |
