Microfilm has long served as an archival cornerstone for preserving historical records, newspapers, government documents, financial transactions, and other valuable data. But digitizing these reels of information is no small feat. Converting microfilm to digital files involves far more than pushing a button—it requires precision, patience, and the right technology to ensure the integrity of the source material is maintained while making it digitally accessible.
Evaluation of Content
Before the conversion process can begin, the media must be reviewed and evaluated. What is contained in the archives, 16mm, 35mm, microfiche, or aperture cards? Are they damaged, fading, or emitting a vinegar-type odor? If so, these files need to be digitized immediately for preservation purposes.
Each roll of microfilm can contain more than a thousand frames of information. Properly indexing the documents is an essential step for easy search and retrieval after the images have been scanned.
Scanning Equipment
Once these considerations have been addressed, the crucial decision is to select the appropriate scanner for your digital conversion. In today’s microfilm scanner market the customer has a choice between two kinds of capture technology, Line Scanning or Area Scanning.
Line Scanning technology, like that used on nextScan’s Eclipse 2000 and FlexScan+ microfilm conversion scanner, is designed specifically for high-speed digital capture. The linear array of sensors in nextScan’s stroboscopic lighting technology allows microfilm to be continuously streamed through the scanner with one pixel line of information being captured at a time. This ensures that every piece of data has been captured from the film.
Area Scanning technology, like that used on ST Imaging’s ViewScan line of microfilm scanners, is designed to capture one image at a time, of either the entire frame or a portion of it. Not unlike a stop-and-shoot digital camera you are familiar with today.
As you can see, while both processes create digital images, they approach it in two radically different ways. The line scanning sensor allows for high-speed capture, optimal for large-scale archival projects. The area scanner, is best suited for research and on-demand retrieval of information from microfilm, instead of having to scan the entire roll.
Complexity of Line Scanning Technology
The line scanning process requires precision from all components. First, there is mechanical precision. The film must move smoothly at a consistent speed. Any slight movement or slippage will result in a distorted image. The tension on the film must also remain consistent, especially with older or fragile film that has experienced vinegar syndrome. The second consideration is the optical alignment. The line scanner must be perfectly aligned with the film path, and the focal plane must remain consistent across the width of the film. Slight misalignments can create distorted images. The third part of the line scanning process involves combining all the captured data into a usable image by stitching the thousands of lines of data together seamlessly. With the dozens of moving parts and precision required, the line-scanning capture process, while more complex, can deliver astonishingly fast results.
Workflow
Once the scanning technology has been selected and the physical media evaluated, the next phase is executing the conversion itself. This is where planning meets precision. A successful microfilm digitization project hinges on a well-defined workflow—one that ensures every frame is captured, verified, and delivered in a usable format. The following three-step process outlines how raw microfilm is transformed into accessible digital assets, ready for integration into modern document management systems.
- Scan or Capture – During this step we are digitizing a roll of film or microfiche into a lossless file format called a Ribbon. That ribbon is essentially a single continuous copy of the entire roll of film or microfiche. There is not strip capture, or image stitching occurring to display/output our ribbon data. This ensures that during the scanning step, we capture 100% of the image data that was on film.
- Audit or QC – During this step, we open the Ribbon file and preform two main tasks: 1) Verify that our frame detection algorithm successfully identified every individual frame in that ribbon using software tools to make this a quick and efficient process and 2) Doing any type of image processing (ie: Contrast/Brightness, bitonal thresholding, etc…). At this step, you can also input any additional metadata for indexing that may not have been possible to capture during the scan step.
- Output – After the Audit has been finalized, this unattended step will convert the image data from our proprietary ribbon format, to a common file type such as as TIFF, JPEG, PDF, PDF/A, BMP, and more. This output can be saved to a local disk or network attached storage to be imported into the document management system of your choosing.
The full conversion process, and the data contained within your microfilm archive, deserve the very best considerations when considering creating a digital replacement. Understanding the steps from initially inspecting your film, to uploading your digital files, is imperative for a successful conversion project. Learn more at www.nextScan.com, reaching out to sales@nextscan.com or calling 208-514-4000.