Quality Scans

Getting good results from a flatbed scanner can be tricky; we are discussing some important steps to Quality Scans.  Choosing the Right Scan Level for Quality Scans: Quality Scans level refers to the combination of scan resolution and color depth that is right for your purpose. Resolution is the number of dots per inch available from the scanner. Color depth is the range or number of individual colors the scanner can discern and record. By matching the scan level to the type of display or printing you intend to do the process becomes more efficient and can achieve Quality Scans with higher quality results.

The next important step in achieving high Quality Scans, if the picture is for use on a computer screen then the resolution should match the screen's resolution and ability to display colors. This would currently be considered low to medium with a moderate range of colors. If the picture is to be included in a genealogy report the resolution should match the printer and the color range either monotone (black and white), duotone (two color) or matched to the printing process (such as laser, dye sublimation or the like). If the picture is to be stored for archival purposes, the highest Quality Scans level your storage medium can reasonably process and store should be used. The rule is to Quality Scans at the resolution required by your intended output device.

Make a Preview Scan to achieve Quality Scans: Most scanner software allows you to make a preview scan of the image before the real thing. This allows you to position the image, check for any visible dust particles or moiré patterns on the image and select filters, formats or other tools before initiating the scan. To achieve Quality Scans most scanner software allows you to adjust brightness, contrast and do gamma correction while previewing the image. You can make any number of preview scans until you are satisfied. This is the time to make sure the picture is straight (is parallel to the edge of the scanner glass). Straightening it now will save hours of frustration later on after the scan is complete. Most photo editing software can correct misaligned images, but you must be aware that this always introduces some amount of distortion into the image.

Use the Unsharp Mask to achieve Quality Scans: Whenever you sample an image, whether for the first time in the scanner or for a second time in your application, it becomes slightly fuzzy. Just as it's recommend you sharpen an newly scanned image, you should sharpen the image after changing it's dimensions through resampling. Your software may provide several "filters" or tools for making an image sharper. But to take the slight fuzziness out of our picture we need a special kind of sharpening, one provided by what is called an "Unsharp Mask." Any competent image editing application will provide this filter. Without getting technical, this filter can restore a natural appearance to the scanned image. The method is a use imitates a technique used in traditional photography, providing a smooth and even sharpening.

Caution for Quality Scans: Some newer scanners try to help in the scanning process by making decisions for you, such as automatically applying digital sharpening or other corrections. Others may offer a choice of tools in a scanning "wizard" after acquiring the image. Be aware that tools automatically applied can exaggerate the effects of any tools you apply. If the scanning software has applied digital sharpening for you, then you may choose not to do any further sharpening with the Unsharp Mask. Or use the tool carefully to adjust the amount of sharpening you need if the results were not to your satisfaction. This may also be true for other effects like tonal balance and gamma correction, which may be applied without your knowledge by the scanning software.