Thank you. Will try this.After abandoning the old background feature in 2.8 there seems to be no way to set the dimensions of background images directly, at least with the latest release. As a workaround I create a plane of the desired dimensions and set the cursor to one of the vertices. Then I add an image empty, snap one corner to the cursor and resize the background image via 'image size' (x dimension) to match the dimensions of the plane. Unfortunately, you can blow it up only to 1000 meters, so I scale the image up to, say, 100 percent first and set the size to x/100 (if the imagery is smaller than x = 100 kms). After that the plane can be deleted. Of course, that only works if the image already has the correct aspect ratio - otherwise you have to fine-tune the scaling manually. But maybe there is a more 'elegant' and exact way. As far as I see all other current solutions only work in render mode or - in case of simple textured planes - are useless when in wireframe mode.
It mainly talks about Blender 2.79. I need solution for Blender 2.8.save me typing it all out here it is for you
setting background > https://all3dp.com/2/blender-background-image-simply-explained/