Digital Light & Color

The following is a feature request:
I normally start my mat and framing process as follows.
I have a collection of frames of fixed size, i.e. 40 x 50 cm, or 50 x 70 cm
I have to find out, at which size an image would nicely fit to these frames.
So my starting point is normally not the images size, but the size of the frame/mat.

It is quite the opposite to how it is now implemented within the transformation.
But, I can more easy print an image at a new size than building a new frame. Cutting mats is also not problem.
So please consider whether it is possible to have the mat size as a starting point.

Thanks

There is already a feature that deals with this issue:

In the Image tab, set Base Size On to Mat Opening Size. Then enter the mat opening sizes for your different standard frames to see the framed image. You can fine tune image cropping using the crop rectangle overlay on the input image. If your mat widths are all the same, set Base Size On to Frame Opening Size or Frame Outside Size.

Thanks Jonathan for hinting me into the right direction.
I will use this.
But I still have a little problem:
With the Outer Mat the border setting "Unequal" does not work as I expexct.
Although I specify four values, just the values for Left and Buttom are used. The values for Right and Top are replaced by the value for Left. So there is no difference between "Unequal" and "Unequal Buttom".
With the Inner Mat all four values work fine with "Unequal".

Thanks - this is fixed in the next release.