Maine Memory Network
Maine's Online Museum

Login · My Account · Show Album


 

 
 

Scanning Standards

These standards and procedures reflect best practices as identified by MHS.

File Formats Used on MMN

Scan Properties

We benchmark by file size, a more comprehensive measurement than resolution. Resolution is only one factor in the quality of a scan. (Resolution x Document size = File size)

File Size

High Resolution Option

When scanning, MMN suggests a high quality image so that it can be printed at 300 dpi up to 11" by 14". To achieve this, you need at least a 40 MB megabyte) file for color images. Even if you don't want to print the image, it is a good idea to scan it at a high resolution so you don't need to rescan it for other purposes later.

Low Resolution Option

The minimum file size for sharing images on the website, and being sufficient size for the zoom feature, is 2.5 MB.

JPG Compression

Save all JPG files at a low (10%) compression value. Using Photoshop, save your JPGs with a quality value of 11 out of 12.

Color Mode

Scan and save all historical items in RGB color mode regardless of whether the item is color or black and white.

Bit Depth

Use 24 bits per pixel (8 bits per color channel).

Saving a Master Scan

At MHS, our scanning philosophy is to scan an item only once, at a high enough quality to accommodate most future uses.

We recommend that all contributing partners save an original, untouched scan as a .TIF file. The original, or master scan, should be saved locally to your computer's harddrive or perhaps to some removable storage system (CD-ROM, etc.). You should make a copy of the master scan to edit for any subsequent use and save as a .JPG to submit to MMN.

Editing and Correcting your Scan

It is the goal of MMN to provide a faithful representation of a historical item at the time it was digitally captured.

For MMN, editing a digital file should be limited to making it look like the original. Editing should not include repairing tears, stains, markings, or any other blemishes on the original.

Monitor Calibration

Color management is a challenging task with the current variety of monitors, scanners, and computers. Different monitors may produce different results. When editing digital files, we suggest you calibrate your monitor to a gamma setting of 2.0 (half way between PC (1.8) and Mac (2.2) standards).

Sharpening

Do not sharpen digital images of photographs or paintings. Manuscripts may have minimal sharpening. We advocate sharpening subsequent copies for individual uses only.

Cleaning scans

Scanners pick up dust, hair, and smudges that result in additional visual elements that were not present on the original. It is acceptable, but not necessary, to clean such marks off a scan and this will make your images more appealing. This process can be time consuming and expensive when dealing with a large volume and, as a practice, the Maine Historical Society does not clean its scans, unless they are to be printed. If cleaned, the old scan is then replaced on the system.

Make sure you clean the glass on the scanner before scanning to prevent unnecessary touchup later.

Rotating

Digital files that are crooked (not aligned square to the edge) will not be accepted in MMN. Make sure you put the image on the scanner as straight as you can. You can always rotate the image after scanning using your image editing software.

Cropping

MMN has specific requirements regarding cropping of images. We think it is important to show the edges of documents and photographs, in most cases. For example, if a photograph, drawing, sketch, etc. is torn, or if the edges are irregular, we scan the image so all edges are showing.

NOTE: If you crop the image, recheck your image size to make sure that it is not below the required file size.

Summary

Technical

Image Quality Benchmarks

Back To Top