Fundamentals of image gradients and edge detection
Image gradient is nothing but a directional change in image intensity. By computing a gradient for a small area of an image and repeating the process for the entire image, we can detect edges in images. Edge detection is pervasive in several applications, such as fingerprint matching, medical diagnosis, and license plate detection. These applications basically highlight the areas where image intensity changes drastically and ignore everything else.
Gradient computation involves the computation of gradient magnitude and direction. To compute magnitude, we first need to compute gradient in x (Gx) and y(Gy) directions. Consider a rectangle image below. To compute gradient Gx, we move from left to right and highlight the points where image intensity changes drastically. This would give us points along the vertical edges of the rectangle. Similarly to compute…
