Grid Scanner

This notebooks implements a simple grid scanner that scans a photo of a 2d grid where some cells of the grid are hashed(colored).

Input Image

from tsoding daily youtube channel

1. Finding Corners

Via mouse clicks using a GUI tool

2. Perspective Transform

cv2.getPerspectiveTransform() and cv2.warpPerspective()

3. Grid lines

4. Processenig the Image

• Grayscale
• CLAHE contrast enhancement
• Erode (15,15) for 5 iterations
• Median Blur (ksize=31)

5. Visualizing Seperation

The processing has distributed the centers of our cells like this (y axis is just the index of the cell in a given value bucket):

As you can see they're very seperable by thresholding the value of each cell. nice!

Note: value of each cell is the average of a small region in that cell(near the center of the cell)

Let's use a value like 119.

6. Filled/Empty Estimation

and Done.