OpenCV 3 Computer Vision Application Programming Cookbook - Third Edition

Chapter 6. Filtering the Images

In this chapter, we will cover the following recipes:

• Filtering images using low-pass filters
• Downsampling images with filters
• Filtering images using a median filter
• Applying directional filters to detect edges
• Computing the Laplacian of an image

Introduction

Filtering is one of the fundamental tasks in signal and image processing. It is a process aimed at selectively extracting certain aspects of an image that are considered to convey important information in the context of a given application. Filtering removes noise in images, extracts interesting visual features, allows image resampling, and so on. It finds its roots in the general Signals and Systems theory. We will not cover this theory in detail here. However, this ...