[filter-effects] feImage with missing image resource


I checked the behavior of different SVG viewers on <feImage>[1] with a missing image resource. It appears that we have three behavior categories across 7 different SVG viewers (6 if you still count WebKit and Blink as one). Tested: Safari, Chrome, IE, Firefox, Opera (presto), Illustrator, InkScape (no result), Batik.

All viewers apply an SVG filter on content even if <feImage> has a missing resource. Other then that, viewers either:

1) treat <feImage> as a transparent black image taking all primitive regions into account,
2) replace the missing image with a “missing image” icon and take all primitive regions into account or
3) treat <feImage> and all successor color manipulating primitives as null filter.

Example: https://www.w3.org/Bugs/Public/attachment.cgi?id=1531
Description: https://www.w3.org/Bugs/Public/show_bug.cgi?id=27221#c0

Option 1) looks reasonable for me and is easy to implement/specify. Option 2) looks strange but at least gives authors feedback of what is going on. I am unsure how to specify 3) and how it actually is implemented. Maybe someone from Mozilla could clarify.


[1] http://dev.w3.org/fxtf/filters/#feImageElement

Received on Monday, 3 November 2014 14:15:21 UTC