Performing Format context substitution in ImagePlug::image()
Performing Format context substitution in ImagePlug::image()

This fixes an issue during ImageWriter::execute(), because FormatPlug::getValue() currently only performs the context substitution during compute.

boberfly/gaffer,lucienfostier/gaffer,lucienfostier/gaffer,boberfly/gaffer,hradec/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,ivanimanishi/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,chippey/gaffer,GafferHQ/gaffer,chippey/gaffer,boberfly/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,ivanimanishi/gaffer,ivanimanishi/gaffer,hradec/gaffer,lucienfostier/gaffer,chippey/gaffer,johnhaddon/gaffer,lucienfostier/gaffer,hradec/gaffer,boberfly/gaffer,johnhaddon/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,chippey/gaffer,andrewkaufman/gaffer,ivanimanishi/gaffer,hradec/gaffer,ImageEngine/gaffer,hradec/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer