If you are about to embark on a project to scan aperture cards, make sure you have considered all of the steps necessary for a successful aperture card scanning project. There are six important steps to be considered and acted upon when converting aperture cards to digital images in order to create usable images within a realistic budget.
Steps to Completing a Successful Aperture Card Scanning Project
One of the most basic tasks is often forgotten: pulling aperture cards from their storage location and moving them to the scanning station or sending them to an outside service provider in an organized manner. It is amazing how many projects don’t get started simply because the labor to accomplish this task was overlooked and was not available. Make sure you have the labor available to gather the cards to be scanned.
2. Evaluate the condition of the aperture cards for batch or automated scanning.
Theoretically if your aperture cards were made in accordance with ANSI Standards, they could be scanned in an automated method which would provide high quality results at the rated throughput of the scanner. Unfortunately, in the many years of working with aperture cards, I have found relatively few cards that actually were made 100% to industry standards. Typically, cards from different periods of time would be made to different loosely interpreted variations of the ANSI, (American National Standards Institute), AIIM, (Association for Image and Information Management), or NMA, National Microfilm Association) Standards.
Issues that will affect automated scanning include:
- Magnification ratios for specific document sizes
- Film density
- Image contrast
- Hollerith encoding of index
- Hollerith encoding of document size
- Image centering
To determine the degree of automated scanning that can be performed, all of these factors must be taken into account. In addition, as previously stated, even within a library of aperture cards from a single organization these factors can vary in accordance with the time frame in which the aperture cards were produced.
3. Evaluate Post Processing, Quality Review and Enhancement Steps required to assure high quality usable digital images.
After the aperture cards are scanned, additional steps may be necessary to assure that the digital images are of the quality necessary for viewing and printing. Consideration of factors such as deskewing or straightening the images, cropping or sizing the images to the original document size, splitting images for documents filmed with multiple pages in a single frame, and removing excessive speckles caused by dirt or other film issues.
4. Index images in accordance with a structure that will assure the ability to retrieve images as needed.
This step is very important if you want to find your images later in a sea of digital data.
Questions to consider include:
- Is the data contained on the aperture card in the form of the hollerith code?
- Will the index information require entering data?
- Where will the index information come from? From a database? From information on the document or other source?
5. Output images and index or metadata to a specific file format that will support use of the documents.
In this step you should consider:
- If the documents will consist of a single page or multiple pages
- What will the file format will be? (Usually PDF or TIFF)
- Will the index data and/or other metadata be embedded in the image file to facilitate importing into a database?
6. Store or dispose of aperture cards.
What will happen to the aperture cards after they have been scanned? If discarding, how and where will this be accomplished? If you are going to continue to store the aperture cards, do you have a storage facility that will provide the proper environmental storage and security? If you are going to destroy the aperture cards, you will want to consider the time frame, method of destruction, and how this will be accomplished.
As you probably have observed, each of these steps requires a thoughtful decision process along with the commitment of a budget, both in terms of expenditures and labor to complete the project. Shortcuts may save a little time or dollars, but they will most likely also significantly impact the ability to use the data which of course is the primary reason to embark on a scanning project in the first place.