Decapod is a project focused on building a low-cost digitization solution that will allow for rare materials, materials held in collections without large budgets, and other scholarly content to be digitized into a high-quality PDF format. This project will work to incorporate the off-the-shelf hardware and open source software necessary to accomplish this goal.
This guide provides information on how to set up equipment and how to work through a Decapod workflow.
Tethered: Decapod controls the cameras using USB cables. With tethered capturing:
Decapod manages all the filenames to ensure they are the proper format if shooting in stereo 3D.
Both cameras can be triggered simultaneously which can speed up work.
No need for memory cards and all files are transferred directly to the system.
Not all cameras are supported by tethering.
Unetethered: The cameras are used independently of a computer and the images are stored locally on the camera using a memory card. With untethered capture:
The hardware is more portable and any camera hardware can be used.
If capturing images in stereo 3D, the user will have to manually change the filenames to follow the expected stereo 3D filename format.
User will need to manually trigger cameras.
Stereo 3D Capture: Two cameras are mounted side-by-side and used to create a stereo image of the book content. With the Decapod Stereo 3D Dewarp application, stereo images of books can be flattened to remove distortions caused by page curl.
Specific conditions need to be met in order for stereo images to be dewarped.
Calibration must be performed on the cameras first before dewarping can proceed.
The dewarping software expects files to follow a particular format so it knows which camera is left and which is right.
Conventional Capture: One or two cameras are used to simply capture images of a book. With two cameras, one camera would take a picture of one page, with the other camera capturing the opposite page.
Conventional capture is the traditional method of capture and no special processing is done by Decapod.
Page flattening by software dewarping is not performed (only available in stereo 3D capture). Page flattening in the conventional method will have to be done manually by pressing down on the pages.