Article by Kevin Savetz

First Published:
Date Published:
Copyright © by Kevin Savetz


Adding a scanner to your computing arsenal is a fairly cheap affair these days, with decent flatbed models costing less than $100. A scanner lets you put all those photos stuffed in your closet on CDs or turn them into digital images you can post to the Web to share with family and friends.

Buying Advice

1. Choose the right scanner. There are several types of scanners, so select a model that's suited to the work you need it to do. A flatbed scanner works much like a photocopier: You place a page, photo, or object (such as a book) on a glass surface. Sheet-fed scanners feed one page at a time through the scanning mechanism, so these scanners won't work with books or magazines. Some sheet-fed scanners include an ADF (automatic document feeder) that can automatically scan a pile of loose-leaf papers one sheet after another.

2. Scanning film. Film scanners, sometimes called transparency scanners, scan film negatives or slides rather than paper. Optimized for making high-resolution digital images from 35mm film, transparency scanners shine light through the film rather than onto it. Film scanners are generally expensive, but film adapters are readily available to add the capability to many flatbed models.

3. Multifunction devices save space. If desktop real estate is at a premium, save space by buying an MFD (multifunction device). These devices typically give you a printer, scanner, copier, and fax machine one device. MFDs are perfect for small or home offices, and save you on buying consumables for several machines. Many models cost less than $300. However, if one component fails, the entire machine may not function until it's fixed.

4. More resolution means more detail. A scanner's resolution, measured in dpi (dots per inch), is an important specification to consider. A higher resolution means the scanner can capture more detail. A low-end scanner might have a maximum of 1,200 x 600 dpi, which is more than enough for scanning images for the Web. More expensive scanners can handle 4,800 x 2,400 dpi, which is better for digitally preserving treasured family photos.

5. Color depth. A scanner's color depth, measured in bits per pixel, is the number of distinct colors the scanner can recognize. For general use, 24-bit color depth is usually sufficient.

6. Make sure the scanner is compatible with your computer. When choosing a scanner, make sure it's compatible with your current hardware and OS (operating system). For example, your PC needs the appropriate port. Scanners typically connect to a PC's USB (Universal Serial Bus) or parallel port. SCSI (Small Computer System Interface) scanners are also available. These are typically faster but more expensive. Also be sure the scanner includes drivers (small programs that allow the computer and scanner to communicate) for your OS. You may have to download updated drivers that are more current from the manufacturer's Web site after purchasing your model.

7. Consider an ultra-portable scanner. A pen scanner is a different animal. About the size of a pen, it doesn't require a computer to scan text and is portable enough to take to the library for research. As you pass it over typewritten text, a tiny digital camera captures the words and stores the data in memory. Later, you can transfer the text to your PC. Pen scanners (typically starting at $100) are available from such companies as C-Pen (http://www.cpen.com) and WizCom (http://www.wizcomtech.com).

Scanning Basics

8. Put it in easy reach. If you use a flatbed scanner, place it within easy reach of your mouse and keyboard so you can swap documents without constantly getting up.

9. Get a graphics application. After you scan your documents or photos, you'll probably want to alter them to improve the quality. This doesn't mean you need to buy an expensive graphics application, such as Photoshop (around $600), that contains more tools than you'll probably ever use. A good free or shareware image-editing app such as IrnfanView (free; http://www.irfanview.com), or Paint Shop Pro ($99 download, $109 box; http://www.jasc.com), will do the job.

10. Keep it straight. When you scan, make sure the original document is aligned straight in the scanner. If the document is skewed, you can correct it with graphics software, but the results may not look as good as if the original were straight in the first place.

11. Preview before you scan. Most scanning software provides a preview mode that lets you look at the image before scanning. This lets you do such things as check the alignment and crop the image before you scan.

12. Crop your images. Cropping involves selecting the exact image portion you want to scan, which results in faster scans, smaller files, better color, and usually better images.

13. Choose the right file format. Scanning software lets you choose the file format to save images in. A file format specifies the computer's internal rules for storing information, and each format has advantages and disadvantages. The best formats for photographs are JPEG (Joint Photographic Experts Group), PNG (Portable Network Graphics), and TIFF (Tagged Image File Format). JPEG produces smaller files but uses lossy compression, which means the image can lose details during compression. TIFF and PNG are lossless formats; all image data is preserved throughout. TIFF tends to create much larger files than PNG and JPEG, but it's better supported in various software and hardware. For line art and logos, the best file formats are PNG, TIFF, and GIF (Graphics Interchange Format).

14. Higher resolution means bigger files. A scanner measures resolution in dpi. As dpi increases, more details are visible in the image. However, the amount of hard drive space the image requires also increases. Keep files small by using the lowest dpi possible, which depends on how you'll ultimately use the image. For example, if you're using the image in a magazine, 300dpi may be fine. For newspapers, 200dpi may do it. For Web images, 50dpi to 100dpi may be sufficient.

15. Archive your scans. You may want to store large, high-resolution scanned images in a lossless format (such as TIFF or PNG) on removable media (such as CD-R) so they won't take up room on your hard drive. You can use an image-editing application to make smaller versions, but you'll still have the larger version available.

Beyond The Basics

16. Dealing with moire interference. After scanning newspaper or magazine images, the scan-ned image may contain a distracting moire pattern, which is essentially a distortion of the image. Your scanning app or image editor may have a "descreen" filter that can reduce or eliminate the moire interference. If not, try rotating the original slightly when doing the scan.

17. An easy fax machine. If you have a fax modem, your scanner can double as a fax machine. Scan your document in line art mode at 200dpi. Open that image in any viewer application and choose the Print command. When you're asked to choose a printer, select your modem's fax driver.

18. An even easier copier. Your scanner and printer can work as a simple photocopier, too. Scan a page at 300dpi and then print the page. Some scanning software includes a feature to automatically print instead of saving the file after scanning.

19. Software provides room to grow. If the software bundled with your scanner is too limited, you can typically find more advanced software that's compatible with your scanner. VueScan ($39.95 basic; http://www.hamrick.com) works with flatbed, sheet-fed, and transparency scanners from many manufacturers. Your scanner manufacturer's Web site may provide links to other compatible software.

20. Calibrate for consistent color. If your scanned images have one set of colors on-screen but look different printed, you may need to calibrate the monitor. Microsoft has information on color management in Windows 98/2000/Me/XP at http://www.microsoft.com/whdc/hwdev/tech/color/wincolormgmt.mspx.

21. Go online for advanced help. Many Web sites, such as Scan Tips (http://www.scantips.com), provide hints for getting better scans, restoring genealogy photos, and fixing faded originals.

Optical Character Recognition

22. OCR (optical character recognition) turns graphics into text. After scanning a page from a book or other typewritten text, you may want to convert it to a text file you can edit with a word processing app. OCR software does this.

23. You get what you pay for. Most scanners bundle OCR software, but you may want to upgrade. Commercial OCR apps cost more but can create text with fewer errors. Scansoft OmniPage Pro ($500; http://www.scansoft.com) or Presto! OCR Pro ($100; http://www.newsoftinc.com) will provide more accurate OCR. Clara OCR (http://www.claraocr.org) is free for Windows and Linux and worth investigating.

24. OCR software can be picky. No OCR software is perfect: It may mistake a zero for the letter O, for instance. You'll probably have to check OCR text to make sure it's accurate. You can boost accuracy by scanning documents in the resolution and file format your OCR software recommends (grayscale scans at 300dpi or 400dpi, for example).

Maintenance

25. Cleaning advice. If you use a flatbed scanner, you'll need to clean the glass surface. Spray glass cleaner on a soft, lint-free cloth, and rub the cloth gently on the glass. Don't spray or pour liquid directly onto the glass.

Reprinted with permission from Smart Computing magazine.


Articles by Kevin Savetz