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University Library, University of Illinois at Urbana-Champaign

Unwarping images using ArcMap

This guide shows how to use ArcMap to transform an image of a curled book into a flat picture. Scanned images of books are often distorted near the binding. This process can correct that.

Add a Grid

A grid can be used to help align the curled image in ArcMap.

  • Don't worry if the grid is larger than your curled image.  
  • While handy, using a grid is not absolutely necessary.  You can “eyeball” the transformation instead.
  1. Right click on the grid image at the bottom of this page and select "Save image as..." or "Save Picture As..." and save the file to your computer.  

    Save Image As

  2. From a file browser, drag the grid file into the ArcMap table of contents and place it above the image you want to uncurl.   
  3. A window will pop up asking if you want to build pyramids. Respond “Yes”.

    Build Pyramids?
  4. If a window pops up saying that the data source has an unknown or missing spatial reference, click “OK”.

  5. Double click on the grid image name.  

    Double Click the graph/grid to open Layer Properties
  6. Go to the "Display" tab in "Layer Properties" and set the transparency anywhere from 50% to 90%, depending on your preference, and press "OK".

    Set Transparency
  7. When zoomed out, some of the grid lines may disappear; don't worry they will show up when you zoom in to look at the text.

Below is a grid image you may use: