HumbleSoftware/js-imagediff — Issue #7: Lossy Tolerance
Author: cesutherland
Created: 2012-02-20 14:56:54+00:00
State: open

When diffing PNGs or other lossy items the API provides a tolerance parameter. Sometimes canvas is lossy when we don't expect it to be. Writing / reading imagedata with an alpha layer is lossy (see http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#pixel-manipulation).

Can we encapsulate this away from the user?
Or can our matchers intelligently suggest this is the issue when a test has failed?