A canvas is an element of the website that can be drawn to from javascript. The result of some drawing operations can have subtle differences between devices which can aid in fingerprinting your specific device. (e.g. because of different fonts, gpu’s and gpu drivers) To do so the tracking script has to read the current raw-pixel content of the canvas to evaluate it. Reading the raw image data is what this permission (should) block, so websites can still use canvas, but not fingerprint your device with it.
Legit applications for reading from the canvas could be games, simulations, and other computing stuff which your average website is unlikely to need to do.
A canvas is an element of the website that can be drawn to from javascript. The result of some drawing operations can have subtle differences between devices which can aid in fingerprinting your specific device. (e.g. because of different fonts, gpu’s and gpu drivers) To do so the tracking script has to read the current raw-pixel content of the canvas to evaluate it. Reading the raw image data is what this permission (should) block, so websites can still use canvas, but not fingerprint your device with it.
Legit applications for reading from the canvas could be games, simulations, and other computing stuff which your average website is unlikely to need to do.
Thank you for you explanation!