Inserting text notes and dimensions	Notes, labels and images
How to remove the background image
Concepts     Procedure     Commands

Using the menu Format Background Image  Remove background Image     i t is possible to remove the background image from the drawing. 

  Menu :  Format Background Image  Remove background Image

Also see:

How to insert a background image in the drawing

How to calibrate the background image

How to change the line color of the background image