Re: [filter-effects] feImage with missing image resource

On Mon, Nov 3, 2014 at 9:38 AM, Paul LeBeau <paul.lebeau@gmail.com> wrote:

> The Error Processing section of the SVG spec says: "The document shall be
> rendered up to, but not including, the first element which has an error."
>
> Would not a bad input, such as a bad URL reference be counted as an
> error?  If so, processing should(?) stop at the filter primitive before the
> <feImage>.  Which to me sounds exactly like option 3.
>

If we define that a missing image is allowed, it wouldn't be an error any
more :-)
Moving forward I believe we should make things more permissive.


> On 4 November 2014 06:25, Rik Cabanier <cabanier@gmail.com> wrote:
>
>>
>>
>> On Mon, Nov 3, 2014 at 6:14 AM, Dirk Schulze <dschulze@adobe.com> wrote:
>>
>>> Hi,
>>>
>>> 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.
>>>
>>
>> I agree that 1) is the most reasonable option.
>> Can you break out which browser does what option?
>>
>
>