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IMAGE SCANNING

The digital age has brought many improvements to the process of photography, the best of which is the digital camera. Images captured with a digital camera may be downloaded directly to any computer with the proper connector, then resized and manipulated with a wide range of applications specifically designed for image enhancement.

However, digital cameras were not available when our ancestors were creating visual records of their lives and times. For them, photography was a process of taking pictures with film cameras, and having the film processed and prints created from negatives. Even earlier, photography involved the transfer of images onto chemically-treated metal plates or sheets of glass. These processes produced images that were state-of-the-art for the day, but have not held up well over time. Old photographs may fade, lose color, and generally succumb to exposure to the elements.

Although preserving these precious family heirlooms has become a priority for many family historians, they may lack the necessary skills and tools for converting the old photos to digital. The popularity of personal computers and technology has created a consumer market of affordable digital imaging equipment. Now, anyone with a computer at home can create digital versions of their own family photos, often with minimal investment on equipment upgrades.

Digital image technology varies among each type of equipment. But they all have some basic operations in common. Here are some helpful tips for creating digital versions of your valuable family photos.
 

GOING DIGITAL

Photographs are what is known as continuous-tone images -- each area of color blends seamlessly into the next. When photos are scanned, they are converted to digital images that are called halftones. The color blends are no longer continuous, but consist of dots of various color shades. They are too small to be easily seen, and appear visually to "run together" to create the overall image. It is this characteristic that allows digital images to be changed, using image-editing applications on the computer.
 

RESOLUTION AND FILE SIZE

Knowing how a digital image will be used is the key to successful scanning. The number of dots in a digital image can be changed to increase or decrease the overall quality of that image. The measurement of image dots is called resolution, and is measured in dots per inch or DPI. Resolution is set when the image is scanned. Higher image resolution means higher quality image. But sometimes higher is not better.

If the scanned image you are making is intended to be emailed and viewed on the Internet, then a resolution of 72 dpi is sufficient. This keeps the image file size small, and allows it to be transferred quickly as an email attachment. Most of the images you see on the Internet are 72 dpi. However, if you require an image that will print with good quality, then a higher resolution is needed. A value of 150 to 200 dpi will work for this purpose, and will create an image that looks good when printed from an inkjet or laser printer. If a high-quality print is necessary, then set the resolution at 300 dpi or greater. Keep in mind that the higher the resolution, the larger the image file size (measured in bytes on the hard drive).
 

COLOR

Choosing the right color format will also affect the quality of the scanned image. All colors viewed on the Internet are RGB, referring to the three primary colors in every computer monitor, red-green-blue, that combine to create every other color. If your scanned image is intended for viewing on the Internet or as an email attachment, then you should scan and save the photo in RGB format.

For images that will be printed, choose the CMYK color format. It stands for Cyan, Magenta, Yellow and Black -- the four colors that all inkjet and laser printers combine to create every other color. Scanned images are typically RGB by default, and can be changed to CMYK afterwards. Black-and-white photos are scanned as grayscale. Typed or handwritten pages should be scanned as line art.

These color formats were developed for very specific purposes. When RGB images are printed on inkjet and laser printers, the color quality may not appear as expected. The same holds true for CMYK images that are used on the Internet. They will not look right on your computer monitor.
 

CHANGING IMAGE SIZE

A photo may need to be enlarged or reduced to fit a particular need. Changing image dimensions proportionally is referred to as scaling. Image size changes are measured in percentages in the scanning process. The actual dimensions of the original photo are measured at 100%. An image scanned at 200% will be twice as large as the original photo. An image scanned at 50% will be half as large as the original, and so forth. Increasing the width and height of an image by the same amount, say 1 inch, will not produce a scaled version of the original. The result will be a skewed or "stretched" image, and will not look like the original. Width and height must be changed by the same percentage to produce a properly scaled image scan. This can be achieved by choosing "constrain proportions" in the scanning program. The example below illustrates the correct way to scale an image for scanning.

This diagram illustrates
how a photo is scaled
proportionally, following
the dotted line. This applies
also to reducing image size.
Changes in size are
measured in percentages.

Once a digital version of the original photo is created, it can be changed using a photo-editing program on the computer. Programs such as Adobe Photoshop were designed for professionals to enhance digital images. There are other programs that are easier to use (like Photoshop Elements), but may not have all the tools necessary to achieve the enhancements you need in your image. Changes and improvements are limitless -- creases are removed, foxing is blended away, colors restored. Most photo-editing programs take some experience to use effectively, so don't expect miracles if you are a beginner.


PRESERVING DIGITAL VIDEOS

What’s the best digital video file format for preservation? Finding appropriate digital preservation file formats for audiovisual materials is not an easy task.  While much of the recorded sound preservation realm has agreed upon the viability of the Broadcast Wave file format for sound materials, the video realm is still kind of the Wild West in that there is no broad consensus regarding what kinds of file formats or codecs are appropriate for preservation. Many institutions use the AVI container with uncompressed video bit streams as masters. However some institutions prefer QuickTime wrappers for their uncompressed video masters.

See the following link at the Library of Congress website for more information on creating and/or preserving digital videos:
http://blogs.loc.gov/digitalpreservation/2011/07/whither-digital-video-preservation


RECOMMENDED READING

For more infomation about digital documentation and preserving your treasured family photos, read the book titled Digitizing Your Family History by Rhonda R. McClure, published in 2004 by Family Tree Books; library call number 929.1 M.

Real World Scanning and Halftones by David Blatner and Steve Roth, published in 2004 by Peachpit Press (3rd edition), ISBN number 0321241320; contains advanced information for scanning and digitizing images, both documents and photos.


RECOMMENDED WEBSITES

Scanning Basics 101 - the purpose is to offer some scanning tips and to explain the basics for photos and documents.

Scanning - information on scanning family photos from Pastfinders, south Lake County, FL; hosted by RootsWeb.

PhotoTree - a site dedicated to research, dating, and preservation of 19th century photographs.

Federal Agencies Digital Guidelines Initiative, a collaborative effort to define common guidelines, methods, and practices for digitizing historical content:
http://www.digitizationguidelines.gov/

© 2014 Joe Defazio, Uncle Joe's Genealogy


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