Document scanner

[arunitasahu]

closes : #766 The document scanning process involves several key steps:

1. Image Loading: Load the input image containing the documents to be scanned.
2. Preprocessing: Preprocess the image by converting it to grayscale, applying Gaussian blur to reduce noise, and performing edge detection to detect document contours.
3. Contour Detection: Identify contours in the edge-detected image to locate the boundaries of the document(s).
4. Perspective Transformation: Apply perspective transformation to obtain a top-down view of the document(s) by correcting for perspective distortion.
5. Displaying the Result: Display the original image and the scanned documents side by side for visual comparison.