check https://gist.github.com/farukcankaya/b1a461c0f269a7c8ae57dcf702b0da4c for VisualizationHook

detectron2_visuzalization.py

def do_train_visualization(visualizer, model, inputs):
    training_mode = model.training
    model.eval()

    outputs = visualizer.inference(model, inputs)
    visualizer.process(inputs, outputs)

    model.train(training_mode)
    
with EventStorage(start_iter) as storage:
    train_visualizer = VisualizationHook(cfg.DATASETS.TRAIN[0], storage=storage) # ADDED NEW
    
    for data, iteration in zip(data_loader, range(start_iter, max_iter)):
        storage.iter = iteration
        ...
        # ADDED NEW #############################################
        if iteration % 20 == 0: # log predictions every 20 iteration
            do_train_visualization(train_visualizer, model, inputs)
        ##########################################################
        ...