Scanners Are
Your Friends



The scanner will be your constant companion when preparing graphics for the web; you will come to love and rely on it, and be quite disconsolate when you can't spend time with it. To prevent any broken hearts, herewith is the unofficial list of scanners available on Grounds:

Bryan Hall Computer Lab
(2nd floor)
4 color flatbed (2 Mac, 2 PC); 1st come, 1st served
(easiest to get to before 10 a.m.)
Electronic Text Center
(3rd floor, Alderman Library)
4 color flatbed (all PC); reservations required
Digital Image Center
(Fiske-Kimball Library)
1 color flatbed, 1 color slide, 1 color negative;
Photoshop available; reservations required
Digital Media & Music Center
(3rd floor, Clemons Library)
1 color flatbed, 1 color slide; reservations suggested
Multimedia Resource Center
(2nd floor, Wilson Hall)
1 color flatbed, 1 color slide;
for use only for projects used in teaching a class
or for a professor


So what now?

Now that you know where to go, what the heck do you do with the scanner? For the purposes of this guide, the use of the scanner is for the web. Since the resolution of a computer screen is 72 dpi (dots per inch), the scanning you do should be targeted for this resolution. But, as with most things, there is a catch. Because you'll be touching up the images you scan (preferably in Photoshop, which we'll discuss later), as well as changing their format to .gif or .jpg, you don't want to lose a lot of information or resolution in the process. Therefore, the general rule of thumb is this:

Scan at a resolution 1.5 to 2 times the resolution of the final product.

In our case, it is a computer screen, so scan at 144 dpi. This is to insure that when you change the size of your image in Photoshop to fit appropriately in your design, information (i.e., color and clarity) is not lost. When you are preparing to save your image, it is recommended that you change the dpi back to 72--but only on a final save. Too much switching back and forth between resolution sizes and image sizes will encourage a loss of information and increase pixelation each time. Of course, scanning at this higher dpi will increase your file size, which is the bane of web developers. In graphics, there will always be a trade-off between quality and size. You need to evaluate the purpose of each image, and determine if it is more important that it be crisp and vibrant (and large), or a small file size (with less quality). It is recommended that web graphics be no more than 40K, as most people are still viewing your incredible site on a 14.4 bps modem--or slower.


They may look friendly. . .

Every scanner software interface is different, so you cannot take the controls for granted. Be sure to check that

  1. Your dpi is set to 144 (or 72 if appropriate)
  2. You are scanning in the appropriate mode (i.e., color, line art, or grayscale).

The rest of the process is self-explanatory: prescan, choose the area for scanning by selecting it, scan, and save. Do not attempt to save your image as a .gif or .jpg at this point, but as a .tif (cross-platform), .psd (Photoshop document), or .pct (Macintosh). The compression involved in .gif and .jpg files will immediately reduce your color and clarity before you have a chance to gussy the image up. Bring your .tif, .psd, or .pct files into Photoshop for manipulation, and then save them in the web-friendly dpi and compression modes.


Questions?

If you have specific questions about scanning or resolution issues, the E-Text Center staff are knowledgeable and helpful. E-Text is open 9-5 Monday-Saturday during the semester. Call ahead for vacation hours.

Home Graphics Video Design

Compiled by

Julie K. Rose and Michael R.H. Owens

QUESTIONS AND COMMENTS?
last updated 7.10.96