allow more accurate image scaling in PicLayer

[travelling_salesman]

Images in PicLayer are scaled by moving the mouse vertically. Each pixel movement rescales the image by a given factor. However this factor is rather big so that images will usually not perfectly match the background.

It would be very helpful if the scaling factor was decreased for more accurate scaling, or the scaling would depend on the zoom-level. For example the image pixel where dragging has started could be moved to the position where the dragging stopped while leaving the image center or the furthermost edges unchanged.

Maybe the whole way images are scaled should be changed, since the available seperate x- and y-scaling does not allow for arbitrary stretching (e.g. in (x+y)-direction).

[Zverikk]

Did you try holding Alt while scaling?

[travelling_salesman]

Replying to Zverikk:

Did you try holding Alt while scaling?

Thanks for the hint! "Alt" did have no effect, but "Shift" leads to a much finer scaling. That solves the problem for now.