Cleaning Chart Images with ScanScribe

The instructions below come from David Sibbet of The Grove and were updated by Cynthia Derosier of Good Juju. I’ve just edited them a little and am reposting them for convenience. If you’re looking for another method of cleaning chart images, I have previously posted instructions for cleaning chart images with Photoshop. 

Cleaning Up Your Charts

Once you’ve taken photos of your charts, you can run them through a program called ScanScribe to drop out the shadows and the gray or yellowish background that results from photographing paper charts. It’s quick and easy, once you get ScanScribe set up. It’s not like most applications — it’s really a script, so you have to be prepared to fiddle a little bit, but once it’s working it’s a great tool for the job. Like David, I haven’t used it’s other features, but I know it’s capable of more than just whitening images. ScanScribe is available for Mac and Windows platforms.

David Sibbet says, “The best program [for cleaning chart images] is still ScanScribe, a never-released piece of software from Xerox [now Parc]. The interface isn’t very intuitive, but it does a great job keeping your yellows intact. You can change the exposure settings: 4 or 7 seem to work best. You can also correct for keystoning under the edit function. TIFF files work best. These are the only functions I’ve ever used and it seems to work very well.”

Using ScanScribe

1. Download ScanScribe from the Parc site: http://www2.parc.com/isl/groups/pda/scanscribe/
2. Save it to a spot on your computer where you will be able to find it (perhaps make a ScanScribe folder inside your Applications or Programs folder).
3. Double click on the Scan app. This will launch a terminal program that then opens the software, so don’t be alarmed when the new program opens.
4. Under EXECUTION, open “SCANSCRIBE.” 
5. Go to “Options” set your Automatic FB/BG Color Processing on Image Load/ background sensitivity to 4 (or 7 — you can experiment).
6. Under FILE open the folder where you have your chart pictures. It doesn’t have menus that open automatically so you have to go through each click manually.
7. Open your file. It may take a little while to process, during which time it can look like nothing is happening. After a bit, your photo should open. When it opens, the photo will be magically whitened! (If not, see the notes below).
8. To adjust for keystoning, go to Edit/Keystone Unwarp. This gives you a box that you can change by using your cursor on the corners. Drag corners to where you want them to be on the photos. Then click the button in the window frame that says “run Keystone” and the picture will unwarp.
9. Save As a TIFF file if possible, or a JPG if you can’t work with TIFFs.

Notes

Cynthia reports that she had a very large TIFF file and had to reduce its file size in order for the program to work. If you load the photo and have done all the steps correctly but still see no change, you may need to reduce the file size. Cynthia noticed that the script at the bottom indicated the computer was out of memory for a TIFF file, but did not run out of memory for a JPG of the same size.

I have noticed that ScanScribe can have difficulty opening files if they are too deep in my computer’s file system — that is, if they are inside a lot of nested folders. I think this is because all the folder names get added to the path name for the image, and perhaps the long path name exceeds some limitation in ScanScribe, but that’s just a guess. To get around the issue, I created a folder inside my Pictures folder called “For ScanScribe,” and I just drop all the photos in there that I want to clean up. ScanScribe remembers the last folder it opened images from, so this is a handy way to avoid having to click through your folders to find your images. I just save the edited versions right back into that same folder, and then move everything to where I actually want it when I’m done to keep the folder clean.

If you have additional questions, please check the ScanScribe discussion forum.