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Wall Drawer

A Simple Solution to Traditional Drawing and Photographic Recording of Archaeological Features;
a joint work with Amanda Henry.


The search for novel methods to record excavated features in archaeological sites has led to the invention or adaptation of many technological tools, ranging from photogrammetry to 3D reconstruction. Unfortunately, many of these methods require more training, more preparation and more expense than the traditional method of handing a measuring tape, plumb bob and graph paper to a volunteer. While the traditional method is the most convenient for many field directors, it is often subject to inaccuracy and can be very time consuming.

In contrast to both the traditional and the more expensive methods, we have developed a simple protocol using a computer program which can process digital photographs to remove parallax problems and find the edges (e.g. boundaries between blocks in a wall) in the resulting image. The end result is a properly scaled, un-warped image, with or without highlighted edges, which can be printed or stored electronically. This method requires the time of only one operator with minimal training in digital photography and a brief introduction to the program. It has been successfully employed at the Brown University Excavation of the Petra Great Temple, Jordan.

the original picture of the wall to draw	the un-warped and scaled image	the computer-generated drawing

Acknowledgements
This work has been realized within the SHAPE Lab at Brown University, under the NSF grants ITR # 0205477 and KDI #BCS-9980091.

We would like to thank Martha S. Joukowsky, Artemis Joukowsky, David B. Cooper, the SHAPE Lab, Brown University, Andrew Willis, Sara Reid and the 2002 Petra team, for their help and support at different stages of the project.

Further information
Wall Drawer: A Simple Solution to Traditional Drawing and Photographic Recording of Archaeological Features - P. L. Bazin and A. Henry, submited to the Journal of Field Archaeology.

Get the program!

A short tutorial

1. Install the program: download the software and extract the program (using Winzip). The Wall Drawer program is the file walldrawer.exe (on Windows).
   
   
2. Launch the program: execute walldrawer.exe (double-click on the program icon). A command line window and the regular window of the program should appear (the command line window just displays extra information).
   
   
3. Set the preferences to the desired settings (File -> Preferences) and save them (File -> Save Preferences). A text file walldrawer-prefs.txt should appear in the program directory. Important settings to fix are the desired output scale (1:10, 1:20, ...) and the resolution of your printer
(warning! if you have a very fine printer resolution like 1200dpi, the images will be huge. You can adapt the resolution of the printer too (I recommend 300dpi), so the images will remain of decent size in pixels. Also note that the output drawing must fit on the paper size used in the printer, i.e. mostly letter or tabloid).
Take some time to review the important keys you will need to manipulate the selection region, the checkerboard and the ruler (Help menu).
   
   
4. Load the picture you want to process (File -> Open Image).
   
   
5. Select the region of interest in the picture (Processing -> Select Region). By default, the entire image is selected.
   
   
6. Place the checkerboard outline to coincide with the image (Un-warping -> Draw Checkerboard, then use the mouse to drag the outline on the checkerboard image).
   
   
7. Un-warp the image (Un-warping -> Un-warp Image). The new image is automatically scaled in the process.
   
   
8. Draw the edges (Un-warping -> Draw Edges).
   
   
9. Post-process the edge image to the desired quality (Processing -> Magnify to darken the edges, Threshold to remove weak edges, Thicken to broaden the edges). At any time, the original, un-warped, edge and processed image are available (Display menu) and can be saved (File -> Save will save the displayed image).
   
   
10. Finally, you can store the digital image, take direct measurements with a metric ruler (Ruler menu) and print the edges to obtain a drawing at the specified scale.

News & Updates

07 - 03 : Initial release.

Further details

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