To complete my project, I implemented in Java greyscale, Hough transform, perspective transform of given RGB A4 size image.
What I did in the code:
- First, the input image is converted to grayscale.
- Then, Sobel filter is applied to find edges in the image.
- Next, threshold is applied to find strong edges.
- After that, Hough transform is used to find lines in the image.
- Finally, the corners of the paper sheet are found and the image is cropped.
But code output will be black page. output should be

by inputing
