Image Filtering and Transformations in OpenCV

In this chapter, you will learn the basic building blocks for computer vision applications. We are already familiar with digital cameras and smartphone devices with auto image enhancement or color adjustments to make our photographs more pleasing. The techniques behind these originated long ago and have come through several iterations to become better and faster. Many of the techniques explained in this chapter also become major preprocessing techniques for object detection and object classification tasks introduced later. Hence, it is very important to study these techniques and understand their applications.

You will study the basis for these applications with several techniques for filtering an image linearly as well as non-linearly.

Later in the chapter, you will also study transformation techniques and downsampling techniques. A code is provided together with explanations and sample output. Readers are encouraged to write the code and experiment with changing parameters to understand several concepts. There are several colored image results in this chapter, for an effective understanding download the images from book's website. 

In this chapter, we will learn the following topics:

• Datasets and libraries required
• Image manipulation
• Introduction to filters
• Transformations on an image
• Image pyramids