On the ribbon, click
Raster Tools tab Edit panel Cleanup drop-down menu Bias.
If you have not already selected an image, select the image you want to correct, and then press Enter.
Note: You can select your image or images before you select the Bias command.
Specify a point in the drawing to use as a base point, or press Enter to use the origin as the base point.
Enter a calibration distance for the X direction by selecting two points to represent the distance, or enter the distance in AutoCAD units at the Command prompt. Then enter a desired distance for the X direction using one of the two methods, or press Enter to leave the X direction unchanged.
Enter a calibration distance for the Y direction by selecting two points to represent the distance, or enter the distance in AutoCAD units at the Command prompt. Then enter a desired distance for the Y direction using one of the two methods, or press Enter to leave the Y direction unchanged.