REQUEST: Select specific RGB channel to pull greyscale image

[chupinsky27]

It would be great to have the option to select which RGBA channel to pull a float value from in the image texture node. It would be great to be able to work with packed textures without having to save them individually into greyscale images. Currently you can pull a float image from either the Alpha or an arbitrary channel (Red maybe? I haven't thoroughly tested this.).

I would love to see the image mode drop down to read:
-RGB
-Float - R
-Float - G
-Float - B
-Float - A

Is this something that could be implemented?... without having to wait for OSL?

-Craig