There is no doubt that many microfiche definitions online and everyday usage of "fiche" is just wrong. When it comes to microfiche scanning and actually converting the microfiche to digital images (TIFF, JPEG, PDF, etc.) the differences are paramount.
COM fiche
COM fiche uses a grid set up with coordinates, such as A1, A2, B1, B2, and so on. The majority of microfiche scanners, such as Mekel, Sunrise, Wicks & Wilson, and others use the fixed grid overlay, and it is up to the scanner operator to "center" the grid overlay over the microfiche card.
Some scanners boast that there are different methods to scan COM fiche but it should be noted that those methods are still in the testing stages, and require deep post-processing to create a final product, while scanning COM in the traditional grid set-up is still the industry norm, and quite effective.
Jacketed fiche
Jackets are scanned using edge detection, with the same detection algorithms as roll film scanning. That means that the scanner "sees" white and black pixels and analyzes the edge of a white document to see if that is where an image begins and ends. 16mm and 35mm fiche use the same edge detection parameters, the only difference is the reduction ratio and document size.
Step-and-repeat fiche
One might be inclined to scan step-and-repeat fiche using a fixed grid, however, if there are different size documents on a card or improper spacing, edge detection is the way to go.
AB/Dick or Microx fiche
These rewritable fiche may look like positive duplicated jacket fiche, but have fun trying to get them to edge detect. These fiche are usually faded and beat up, with little edge to work on. Thankfully, Scanning Depot has the hardware and technical experience to scan rewritable microfiche using advanced settings.
