Selection locking

[Sjef]

It's a nice tip. Though the only benefit I could think of is to divide a picture in exactly 4 parts, as one can drag a selection with the Ctrl-key pressed (see attachment). Why would a user need a selection round the edges otherwise? The user can drag any selection with the mouse, doesn't he?

[Mij]

The issue arose previously when I had to crop a small amount off one edge of a number of images. I posted to complain that you could not drag a selection starting from outside the image, so as to ensure that you included the area right up to the 3 other edges. This tip was my eventual solution to that problem. After drawing a box around the image edges using this method, all I needed to do was drag one side in a little.
In fact you are right. It is not as useful as I thought. I could have drawn a box completely within the image and then dragged 3 of the sides out to the edges because, unlike dragging the whole box, you cannot drag a side beyond the image boundary. Actually I did spend a considerable time imitating Jokale's Chinese miniaturist, trying to set the sides exactly onto the image boundary. It does show how complex and inconsistent this subject that the OP calls Selection locking turns out to be.

[Sjef]

You talked about cropping a small amount along the edge of an image. I ones cursed IV for throwing away my image when I deleted such a small region. I used the Delete key, because in most progs you can. That was years ago. To-day I use other graphical programs to apply those tasks. IV is in essence a viewer/converter with some basic graphical tools. As a viewer there's very little competition, but one cannot demand strong graphical possibilities from IV. To practise miniaturistm, the selections of IV are a good start though (so the Chinese Jokale assured us).