If the image is in linear space, but the composition is in sRGB space. The Colour Filter attribute will be automatically set to Linear to sRGB so that the image displays correctly in the Viewport.
If the image is in sRGB space, but the composition is in Linear space. The Colour Filter attribute will be automatically set to sRGB to Linear so that the image displays correctly in the Viewport.
There is currently no support for rendering to Linear (1.0) Gamma.