What is GradCam in machine learning?

GradCAM, which stands for Gradient-weighted Class Activation Mapping[2], is a technique in machine learning and computer vision used to visualize the areas of an input image that contributed the most to the final decision made by a Convolutional Neural Network[3] (CNN). It works by creating a heat-map to visualize the parts of an image that contributed to a model's prediction, using the gradients of any target concept[5] flowing into the final convolutional layer[3] to create a coarse localization map[2]. This map highlights important regions in the input image that[2] are significant for predicting the target concept and can be used to understand what the model is focusing on when making a prediction. Grad-CAM is more versatile than previous approaches, allowing it to be applicable to a wide variety of CNN model[5] types without necessitating architectural changes or re-training[5]. Additionally, it can be combined with fine-grained visualizations from methods like Guided Backpropagation to create Guided Grad-CAM[5], a visualization that is high-resolution and class-discriminative, making it more informative and interpretable. Overall, Grad-CAM is a crucial tool for debugging deep learning models[3] and ensuring they are performing as expected.