Screenshotting a small region of the screen to test grim with a minimum delay turned out to be not robust, because a pre-defined region might not be part of the display.
Therefor we switched to grab the whole screen for testing, but scale the result to a tiny picture to keep the delay low.
Screenshotting a small region of the screen to test grim with a minimum delay turned out to be not robust, because a pre-defined region might not be part of the display.
Therefor we switched to grab the whole screen for testing, but scale the result to a tiny picture to keep the delay low.