In this chapter, we have continued our journey from the previous one. Filtering operations have been the primary focus of our study. The chapter started off by describing an image averaging operation and then went on to explain how such an operation may be conceptualized by visualizing the same in terms of filters. We then continued to generalize our concept of filters by demonstrating the basics of how any form of filtering is performed on images. By now, you must have realized that we are no longer dealing with simple pixel transformations similar to the ones that we discussed in the last chapter (grayscale transformations). When we talk of filtering operations, the computations at each pixel become much more sophisticated and involve a neighborhood around the pixel.
We learnt about a couple of different filtering techniques: box filtering and Gaussian filtering. Box filtering assumes an equal contribution from all the neighboring pixels in computing the weighted average. This assumption...