Constant value components

Two small requests:

1. Green -> Gray
With all the new math stuff it would be extremely useful if there was a way going from green to gray inputs. I'm not talking about converting all grey constant inputs to sampler inputs. I'm talking about taking one sample from a fixed position (say 0,0 or 0.5, 0.5) and use that as value in a constant grey output type.

2. Image Constants
All bitmap based components use a specific samplerate (related to the size of the image). Controlling their radius input on a pixel level is currently only possible if your filter only support a specific input image size and calculate the value manually.
It is quite difficult "extracting" the percentage value equivalent to the width of one pixel. It is possible due to a shift in the motion blur, but you're limited to using this in green inputs. So it is not much help anyways.

I suggest a grey output component where you can choose to output image width, height and perhaps native bitrange (i.e. for 8 bpp, the value is 256)