Q18Digital Image Processing

Spatial domain techniques directly manipulate the pixels of an image. They are broadly categorized into point processing (intensity transformations) and spatial filtering (neighborhood processing). Point processing includes contrast stretching, log transformations, and histogram equalization, aiming to improve global contrast. Spatial filtering uses masks (filters) convoluted over the image.

Smoothing filters (like mean and median) reduce noise and blur the image, while sharpening filters (like Laplacian and Gradient) highlight fine details and edges. Median filtering is particularly effective for salt-and-pepper noise. The selection of the technique depends entirely on the specific application and the type of defect in the image.