Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Get the Coordinate of a Pixle/Point on an Image

Most image editing software (e.g., GIMP) can tell you the coordinate of a point on an image.

Get the Coordinate of a Pixle/Point on the Screen in macOS

Shift + Command + 4 shows the coordinate of the current position of the mouse point. Notice that the coordinate shown by Shift + Command + 4 need to be multiplied by 2 if you use Python packages (Pillow, pyscreenshot, etc.) to take screenshots.