The tool described here will allow you to scale an inserted image so that the scale of the image matches the active drawing scale. This will allow you to trace the image using the Design tools, obtaining exact measurements where possible and very close estimates otherwise. To resize an image to match the drawing scale:
Click the Resize an Existing Raster Image to Active Drawing Scale icon in the Imaging Tab
From the drop‐down list that appears, select the raster name corresponding to the raster image you wish to scale
Note: After a PDF is inserted the file will be shown as a series of numbers NOT the file name.
Enter a known length of a line on the raster (e.g. a property line) in the modifier box that appears. Use the longest known line on the raster for the greatest accuracy.
Click on each end of the line with the known length and the image will resize to the drawing scale.
Tip: In step 4 above, use the zoom tools get in closer to select the endpoints with greater accuracy.
Make sure your constraints are set to None.
Once step 4 is completed, verify the accuracy of the new image scale by using the Measure the Distance Between 2 Locations tool in the Edit toolbox and click on each end of the known line on the drawing.
Detailed instructions with screen captures can be found in the Design User Manual or by opening Design, going to the ‘pull-down’ menus Help > Online User Manual, section entitled Resizing an Image to the Drawing Scale.