In this introductory talk, we will discuss some classical image processing techniques for denoising, segmentation, edge-detection, and inpainting. We will try to see how to implement some of these imaging algorithms, and how to make them faster. We will discuss isotropic denoising using heat equation, and its fast implementation. We will then look at some anisotropic variations of this such as Perona-Malik diffusion, and bilateral filter. The talk should be accessible to undergraduate mathematics, and Physics students.