Text extraction and skewing adjustment

Now, all we must do is extract the text and adjust the text skew. This is done by the deskewAndCrop function, as follows:

Mat deskewAndCrop(Mat input, const RotatedRect& box) 
   double angle = box.angle;      
   auto size = box.size; 
   //Adjust the box angle 
   if (angle -45.0)  
        angle += 90.0;         std::swap(size.width, size.height);         
   //Rotate the text according to the angle 
   auto transform = getRotationMatrix2D(box.center, angle, 1.0); 
   Mat rotated; 
   warpAffine(input, rotated, transform, input.size(), INTER_CUBIC); 
   //Crop the result 
   Mat cropped; 
   getRectSubPix(rotated, size, box.center, cropped); 
   return cropped; 

First, we start by reading the desired ...

Get Building Computer Vision Projects with OpenCV 4 and C++ now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.