Chapter 4. App 2 - Applying Perspective Correction

In this chapter, we will continue building on the application that we started in Chapter 3, App 2 - Software Scanner.

We will use the concepts that we've discussed, namely, the edge detection and Hough line transform to do perspective correction to a quadrilateral object. Applying perspective transformation to an object will change the way we see it; this idea will come in handy when you take pictures of documents, receipts, and so on and you want to have a better view of the captured image or a scan-like copy.

We will see how to implement this idea using three different flavors:

• Rigid perspective correction
• Flexible perspective correction
• Manual perspective correction