Incremental crop of a side via keyboard shortcut

[Typothalamus]

I belive there is a keyboard shortcut (once stumbled across before, but now cannot refind)  for moving any one side of a frame over incrementally, with the option to do it in very fine increments, yes? To be clear, it's not scaling and it's not moving the entire image inside the frame. It's moving one side, thus cropping from that side, precisely, without dragging it manually via the mouse. Appreciatively...

[Robert at ID-Tasker]

You can do this in the Control Panel - Width & Heigh. You also need to select reference point.

[Typothalamus]

Sorry, isn't that numerical control? Referring to a keyboard shortcut – selecting an edge handle and then using  arrows to move. 

[Robert at ID-Tasker]

Right, you can use Direct Selection tool, select points of the edge and then move them using arrows. 

[Typothalamus]

By "select points on the edge" does this means to select the small squares with the already engaged direct select tool? To get those handles (small sqares) to appear, I have to click within the frame with the tool. I can't grab the edges though. It moves the whole image within the frame only. Can you discern what's going on? 

[Robert at ID-Tasker]

Hope this will help:

[Typothalamus]

I see that's it's not a matter of selecting the handles by clicking on them, but rather drawing around them. This may be the key. Not working presently for me, as all my images are in frames that themeselves are in text frames, so encircling them with the direct selection tool catches everything, but I'll sort through it. Thank you.

[Robert at ID-Tasker]

You can select point by clicking on it directly. 

Then press Shift and select more points. 

[Robert at ID-Tasker]

Use Direct Selection tool to click on your object first - all the points will be visible - but not selected :

Then you can select any one of them - top-right one here:

[Robert at ID-Tasker]

But you don't even have to select object first - it's enough to hover over the object:

Left one is selected - there is an anchor icon visible and "point" in the center of the object - right one - I just moved mouse over it and points are visible and ready to be selected.