Technical Report

Assessment of Original Collection

Out of the 67 German emblem books in the Rare Book and Special Collections Library, 5 were originally selected as samples of "worst case scenario," that is to say, those books that would pose the greatest challenge to digitize. By examining these 5 books we identified five factors that had to be considered before proceeding with the imaging process:

Fragile condition
-- Two of the five books had either loose or detached pages, and/or detached covers. Due to the fragile and rare nature of the books in general, great care must be taken when handling them. Items that have visible damage or deterioration will not be considered for flatbed scanning. Alternatively, they must be digitally photographed.
Tight binding and or inflexible spine
-- Two of the five books would only open partially, making capture on flatbed impossible. Forcing them to open further would have damaged the books, breaking the spine. This was out of the question. Digital photography is preferred in this instance.
Narrow gutters
-- The rebinding process that had been done on some of the items in our selection yielded extremely narrow gutters, again hindering flatbed capture. In order to achieve a full scan of the image, not only would a flexible spine be required but also significant pressure would have to be placed on the item. We were unwilling to test the strength of the binding to that degree. Again, the only alternative would be digital photography.
Thickness of book
-- Consultation with the acting preservation librarian concluded that the only problem caused by this situation is the fact that the lid of the flatbed scanner could not be fully closed. It was determined that as long as the spine was sound and the book could be opened safely a full 180 degrees, flatbed scanning was acceptable.
Natural aging of the paper resulted in a dark, muddy cast
-- Concern was raised for the quality of the original image and the resulting quality in the digital image. The darkened paper reduced the contrast of paper to etched image. This can be corrected in post processing.

Material

The first specific images contained at this website were scanned primarily from Emblemata, by Johann Pfann. This item was selected by the Acting Preservation Librarian, Gene Rinkel. The qualifying features of the book were its excellent condition and its openability. Included with the 16 emblems are an introductory page and two concluding pages for a total of 19 scanned images. Nothing from Emblemata was excluded. However, due to storage limitations, it was decided that for all items only the emblem image itself should be captured by scanning, and that none of the text pages should be captured.

A sample scan was also taken from Joichim Weidner's Die Ehre und Lehre Der Augsprugischen Confession..., which contains approximately 30 images. This book was fully openable and was in very good condition, but had a thickness of approximately 2 inches, necessitating the alteration of the scanning process. Nevertheless, flat bed scanning was successful.

Images from two more books, Nutzliche Anweisung and Himmlischer Liebes... were also sampled using digital photography. These books were decidedly inappropriate for flatbed scanning primarily due either to condition or openability.

Update (Spring 2002):

In 2002, we increased the volume of scanning and digital photography of the German emblem book collection. To see up to date images of those books which have been digitized and for which metadata has been developed, go to our search page. This page is being continually updated, so please check it often.

Equipment

Desktop scanning was conducted on the books which we digitized in the late 1990's using a Hewlett Packard ScanJet 4C Scanner (PC) (Resolution 600 / 2400 dpi; Pixel Depth: 30-bit / 10-bit internal; Scanning Software: HP DeskScan II, managed with Visioneer PaperPort.) Digital Photographic images were produced using a Leaf Digital Camera Back (II) and a Mamiya 2Z67 pd Prismfinder camera front and lens. Maximum image file capture is 16 MB, and resolution is captured from 200 to 450 dpi, depending on the size of the original object. Using a three pass RGB scan, pixel depth can be captured up to 30 bits. Lighting was diffused strobe (2,000 watts, 1/1000th/sec.).

For information about our current digitization process, see the Update further down this page.

Scanning Process

Flatbed:

Books were placed face down on scanner, and a black velvet cover was draped over the books to reduce surrounding light. Light pressure was applied the the lid of the scanner to assure contact with the glass. Images were scanned to capture 24 bit color, 100% scaling, and 150 dpi resolution, resulting in file sizes from 1.7 to 2.3 MB. Although the captured images are suitable for screen delivery, archival quality scans were not captured in this instance. However, all further images will be scanned at a minimum of 300 dpi.

Digital Photography:

Digital photography experimentation was conducted with the cooperation of Scantech Color Systems, 2902 Farber Dr, Champaign, IL 61821-1072, and Thompson-McClellan Photography, 113 N Walnut St, Champaign, IL 61820-4009. Our photographers were significantly impressed by the age and fragility of the books, and great care was taken in their handling. Digital photographing of the images were challenging due to poor openability. Because there were no tools readily available to hold the books open and steady, some inventive ingenuity, a ruler and small books, were used to secure the books. Images were captured in three passes to capture red, green and blue. No filtering was applied to the image.

Post Processing

Post processing on the scanned images was conducted using Adobe Photoshop 4.0 for Macintosh and Debabelizer by Equilibrium for batch processing. All post scanning work was done on either a Macintosh Power PC 8500 and AppleVision 1710AV display or a Umax J700 (Mac Clone) with a Sony sf700 display.

The following tasks were performed on each image:

Rotate 90 degrees from vertical to horizontal alignment, where needed.
Arbitrary rotation of image to straighten image vertically , using text in image as guide. Following arbitrary rotation , the line tool was used to draw a horizontal line beneath the text to test for straightness, then the line was deleted. This process continued until an acceptable match with the line of the text and the added line was met.
Cropping of image -- all emblems in Emblemata were cropped to 5 inches width by 4 inches height (ration of 0.8). Additional images were cropped to within 1/8 inch of the border of the emblem or any other identifying or important marks on the page (i.e, page number, artist, etc.).
Sharpening was kept to a minimum; any sharpening applied to the images was kept to a maximum of 25%.
Images were saved in Tiff format, zero compression.

The following tasks were performed in batch processing:

Images were saved as JPEGs; medium compression, file extension was changed.
Images were saved as JPEGS; medium compression; file extension changed; resolution was reduced to 72 dpi; color was reduced from 24 bit color to 8 bit grayscale.

Update:

(Aug. 30, 2002)

We have started digitizing a larger number of Emblem books from our German Emblem collection. Images are being captured either by digital camera or on a flatbed scanner (depending on the condition of the book).

Digital Camera:

Images are captured using a Nikon D-1 digital camera and Nikon Capture 2.0.0 imaging software. Master images are captured in TIFF format, 24-bit color, using a 28-70 mm Nikkor lens. Image size on average is 2000x1312 pixels (roughly equivalent to 300 DPI). Master image size averages 6.0 MB. Images are optimized using Photoshop 6.0. For this project, image modification is kept to a minimum. Images are rotated, cropped, and light levels are adjusted to reflect the look of the original piece. Access images are created as JPEGS with minimum compression and sized to 1024x768 pixels.

Flatbed Scanner:

Images are captured using an Epson Expression 1640XL flatbed scanner and Silverfast scanning software. Master images are captured in TIFF format, 24-bit color at 600 DPI. Master image size range from 25 to 120 MB. Images are optimized using Photoshop 6.0. For this project, image modification is kept to a minimum. Images are rotated, cropped, and light levels are adjusted to reflect the look of the original piece. Access images are created as JPEGS with minimum compression and sized to 1024x768 pixels.

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