Principles
There are many brands of scanners available today. They do a nice job of
digitizing images. Using them is a bit like using a copier. You must make settings,
though, that will determine the resolution, file size, and screen size of you
image.
Each scanner comes with software to control the scanning process. There are many control programs. Many programs are activated as Photoshop plug-ins. To run these pull down under File in Photoshop to Import. This will activate the scanning software. The final scanned image will be dumped into Photoshop.
Whatever scanning program you use, save your original in an uncompressed format
to avoid loosing detail. Load the original into Photoshop and adjust or compress
into JPEG or GIF as needed. (In almost all cases, use JPEG. This format is more suitable for continuous tone images. The only exeptions would be for animated GIFs or for images with transparant backgrounds.
Scanning using a Photoshop Plug-in (UMAX Magic Scan for example)
From inside Photoshop, pull down under File to Import and select the type of scanner you are connected to. (We use a UMAX Magicscan in our example). You'll see a new program load with its own windows. The folowing shows the windows after you've put a document in the bed of the scanner and hit the Preview button. This scans everything in the bed. Drag a box with the rectangle selection tool.
Before scanning make sure you set the resolution and other settings as shown in the example.
Settings
The following settings are critical:
Scale: This is the pair of numbers labeled 1 in the example. Make sure they are on 100 and the units are percent.
Resolution: This is labeled 2 below. Normally use 75 dpi for web work. If you want to enlarge the image, scan at a higher dpi. For printing, normally use 300 dpi. If you wish to print and to double the final size, use 600 dpi, etc.
Descreening: If you are scanning from a magazine or newspaper, change the item in 3 below. This will help reduce grainy patterns that appear becuase of the technique called half-toning used often in printing.
Doing the scanning
Click Preview to scan the whole bed. Be patient. This takes awhile. Then use
the rectangle selection tool 4
to mark what you want in the final scan. Adjust the rectangle by dragging the
boundary lines up/down or left/right. Finally, click Scan and be even more patient.
Thne better the scanner, the longer this takes. Eventually, the scanned image
appears in normal Photoshop and the scanner software is put away for you.
Page maintained by Dr. Robert Fry. Last updated 27 March 2004.
E-mail comments to:
fry@eve.assumption.edu