Hi all,I want to enlarge the white border of a picture (not crop the white border, mind you), what command or code should I use?

Note in this image that the symbol 'Y' is clearly cut off a little and the distance between it and the edge is clearly not the same as the distance between the symbol 'X' and the edge.

Is there any way to freely adjust the white border? And next I need to keep adjusting the position of the symbols 'X' and 'Y'.

Thanks in advance!