# Scrawl-canvas v8 - Filters test 001

## Parameters for: Blur, Gaussianblur filters; filter memoization

### To change image, drag-and-drop an image file over the canvas

Blur
Opacity
Radius
Passes
Step
Exclude transparent pixels
Include red
Include green
Include blue
Include alpha
Process horizontal
Process vertical
Memoize filter

#### Test purpose

- Create a test Picture entity
- Create a blur filter and apply it to the test entity
- Update filter attributes and observe the effect they have on the entity

Known issue: Filter memoization will, sometimes, kill Safari-based browsers for as-yet-unknown reasons - it appears to cause the the getImageData() invocation on line 595 in mixin/entity.js to go from taking a a handful of milliseconds to over 5 seconds, but only after an element's memoizeFilterOutput flag has been set to true.

For now, if Scrawl-canvas detects that the user is viewing the canvas in a Safari-based browser, it will ignore requests to memoize filters. Use cache output functionality instead to improve render speeds.

Touch test: not required

Annotated code