What does the line in feDisplacementMap about color-interpolation filters not applying to in mean?

In http://www.w3.org/TR/SVG/filters.html#feDisplacementMap there is a line

The 'color-interpolation-filters'  property only applies to the in2
source image and does not apply to the in source image.

I'm not really sure what this means.

In gecko we've implemented filters by creating an sRGB bitmap of the
original drawing which we then apply the filters to. Each filter
converts its input bitmap(s) to either LinearRGB or sRGB depending on
the value of color-interpolation-filters and then processes the output
to an output bitmap in the same colour space as its converted input.
The final output is then converted back to sRGB if necessary for
display.

For feDisplacement map we can convert the in2 source image before we
work on it but what are we supposed to do with the in source image?

a) Always convert in to LinearRGB (or sRGB)
b) Convert it based on color-interpolation rather than
color-interpolation-filters
c) Leave it as whatever it happens to be.

If c) then what happens if in and in2 are the same do we need two
copies of the input surface, one for in2 which we convert based on
color-displacement-filters and one for in which we don't. Also if in
is the output of another filter is in whatever
color-interpolation-filters was for that filter?

Best regards

Robert.

Received on Friday, 3 August 2007 16:50:33 UTC