System Information

OpenCV python version: 4.6.0.66
Operating System / Platform: Ubuntu 20.04
Python version: 3.9.6

Detailed description

The image provided for calibration (https://github.com/opencv/opencv/tree/4.x/samples/data/chessboard.png) is not right. The image are supposed to contain 8X8 grid of perfect squares but the chessboard is made up of squares with one side longer than the other. This will introduce errors in calibration.

Steps to reproduce

Just open the file and use any image viewer to calculate the height and width of the calibration image

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues, forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files (videos, images, onnx, etc)