I have a 1-bit deep 9135px x 6655px @ 240ppi. I used WinTopo to convert it to a dxf. When I open the dxf in LibreCAD it looks fine. I then inserted the TIFF image so that I could overlay and compare the two. However the inserted TIFF image isn't at the right scale. LibreCAD maps it at approximately 1" per pixel! How do I get the bitmap image to scale properly?
When importing an image you can set either a factor or a dpi value in the Tool Options bar:
With Factor 1 it will show up with 1 unit per pixel.
You can also scale the imported image afterwards with Tools -Modify - Scale like any other object.
If you are on LC 2.1.3 it will seem to be disappeared afterwards. Do an Auto Zoom to bring it back.