Answer by antpaw for Is it possible to animate filter in Fabric.js?

Here is a updated version for the brightness filter

  var brightnessValue = 0.9;  var brightnessFilter = new fabric.Image.filters.Brightness({    brightness: brightnessValue  });  fabricImage.filters.push(brightnessFilter);  fabric.util.requestAnimFrame(function brightnessFilterAnimation() {    brightnessValue = brightnessValue - 0.04;    brightnessFilter.brightness = brightnessValue;    fabricImage.applyFilters();    if (brightnessValue > 0) {      fabric.util.requestAnimFrame(brightnessFilterAnimation);    }  });