Many important historical documents exist only on microfilm and oftentimes it’s challenging to clearly reproduce them. For one, at the time these documents were reduced to film, many already were very old and significantly deteriorated or damaged. Furthermore, the text size on film is extremely small.
Even with the advancements of today’s technologies, reproducing these documents in readable form is difficult. The megapixel size of cameras used in microfilm reader/printer/scanners is a critical element for ensuring that all the detail contained in these documents at the time they were reduced to film, is faithfully reproduced.
Until recently, cameras used in microfilm reader/printer/scanners have been limited by the megapixel size of the image sensor alone. Leading microfilm imaging companies have been able to leverage an imaging method called pixel shifting, allowing microfilm equipment to benefit from what microscopy, astronomy, and other high-end research cameras have employed for years. This method extends camera megapixel size by four or more times that of the image sensor alone, resulting in image clarity never before achieved in microfilm equipment. Film images that previously have been illegible are made readable with pixel shifting.
What is Pixel Shifting?
Pixel shifting is the method of taking four different images of the same document and then integrating those four images into one exceptionally clear, high resolution image. Each time the image is taken, the sensor is shifted just one half of a pixel. A software algorithm integrates the four images into one, extremely high resolution image, resulting in unmatched image clarity.The entire process happens in fractions of a second. The distance the sensor moves is more than 50 times smaller than the thickness of a human hair, yet this small shift makes all the difference.
Imaging advancements continue to raise the bar of what we can capture, not just in photography, but of what is legible and usable from microfilm. Pixel shifting is an exciting advancement in the microfilm equipment industry.
Written by Todd Kahle, VP of Engineering, e-ImageData