May 6

More Scanning Tips
Sun Review May 6, 2000

Many people own scanners yet are not entirely sure how to use them. Here are some tips and links to help you get the most out of your scanner.

A flatbed scanner is similar to a copy machine with a glass plate under a lid and a moving light that scans across under it. The scanner can convert your photo, paper document, book or magazine into a digital image that you can view on a monitor, save to a file, e-mail or print on your colour printer. The scanner itself does not usually have any fancy controls, so instead we must use software to control the scanner. Your choice of software will make a huge difference. As I have mentioned in previous columns, my favourite program by far is Adobe PhotoDeluxe, which has intuitive controls, plain English help files and handy tutorial style projects that will walk you through every step of the process.

If you want to scan a photo or document, you must place it face down on the glass of the scanner, and then start your favourite scanning or image-editing program (or just use the program that came with the scanner). Now, what resolution should you use? Depending on how you intend to use your scanned image, you must choose an appropriate resolution. A good rule of thumb for images that you will view on a monitor is to scan them at twice the resolution, or select a scanning resolution to get the desired image size.

Since you need only 70-80dpi for viewing images on a monitor, you can scan your originals at 150dpi. Scan colour photos or documents at millions of colours, scan black and white drawings as "grayscale". If you want to zoom in on a photo and crop out only a small portion of the original, you could scan it at a slightly higher resolution (200-300dpi) so that when you zoom in, you still have enough information to display a relatively clear image. That said, most photos have a natural resolution no higher than 200-300dpi, so there's not much point in scanning at greater than 300dpi.

If you want to print your scanned images, it's a good idea to do some experimenting first to find out the resolution of your printer. Scan your image at 100dpi and print it out. Now compare the printed version of an image scanned at 200dpi. The size of the printed image should not change (like it did on the monitor), but if there is no appreciable difference in the quality of the image, you can determine whether it is worthwhile scanning your original in at a higher resolution. Remember that scanning at a higher resolution generates much larger files, which can clog up your hard drive and make your printer choke!

Once you have scanned your image, you can use your image editing software to improve the quality. This is the fun part! Make a copy of your original scan, so you can safely play with the copy and keep your original stored somewhere else on your hard drive. Try the brightness/contrast controls, sharpen or blur the image, apply special effects or give yourself a moustache with the paint brush tool. Every image editing program is slightly different, so don’t be afraid to experiment.