Scanning the globe - evaluation of six scanners - includes related articles on choosing scanner type and purchasing scanner - Software Review - Evaluation

Home Office Computing, Feb, 1997 by Joey Latimer

Here Are Six Scanners That Can Put Both Images and Documents Into Your PC

There is a world of images and data you can use to describe and market your business. The problem is, how can you get all of them into your PC for use in your company brochures, marketing presentations, and Web pages? Whether it's a magazine article, poster, or line-art drawing, you need something powerful enough to incorporate a variety of image types that is also flexible enough to perform optical character recognition (OCR) jobs. In short, you need a four-color flatbed scanner. Although sheet-fed scanners work well with paper that can be pulled through a roller, they can't scan books, brochures, or posters. Slide scanner quality is excellent, but they are expensive and only take slides.

Flatbed scanners, on the other hand, accept many different shapes and sizes. Rather than plastic, the scanning surface is made of easy-to-clean glass. The optical scanning resolutions of the flatbed scanners we tested ran as high as 600 by 1,200dpi (dots per inch), which is not as high as the 5,000 lines per inch resolution of some slide scanners, but it's higher than any hand or sheet-fed scanners we've seen. You canuse a flatbed to scan documents and copy them to your printer (a copy machine), fax them (a fax machine), or convert them to files for editing using OCR.

How We Selected We tested six color flatbed scanners to see how well they performed common office tasks. All of the scanners we selected for this review work with both Windows and Macintosh systems (for Windows systems a SCSI interface card is included), and they all come with comparable image editing, OCR, and scanning software packages. One model that should have been included was Epson's Expression 636, but it wasn't ready for evaluation at press time. Look for it in an upcoming New & Noteworthy review.

How We Tested We were looking for excellence in image quality, functionality, ease of use, and speed. To accomplish this we scanned photos, line art, and text documents in various sizes and resolutions. We scanned at eight by 10 inches, five by seven inches, four by six inches, and three by five inches, in monochrome, grayscale, and color, and in resolutions ranging from 75dpi to 1,200dpi. Since there are many settings that can be changed at the time of scanning (such as brightness, contrast, color blend, and so on), we chose to test the scanners using the default settings (the settings we assume most people will end up using). Finally, we used a stopwatch to time scans of 150dpi and above.

We saved 300dpi scans from each photo size as TIF files and printed them using an Alps MD-4000 Photo-Realistic Micro Dry color printer/scanner, color calibrated with Ulead PhotoImpact 3.1. The printer let us see how the scanned images might reproduce. It was set up to print at resolutions of 600dpi in color or grayscale and 600 by 1,200dpi in black and white. We compared the prints of each scan under natural lighting, side-by-side with each other and with the original prints. None of the prints scanned and printed using the MD-4000 perfectly matched the originals, but all were close enough to see patterns of differences between the scans. For scanning and comparing images on the screen, we used a CTX 17-inch color monitor with a Cirrus Logic graphics card set to 16.7 million colors. The monitor gave us an idea how the scanned images might appear when placed on a Web page.

To test OCR, we scanned the same text document with each scanner at 300dpi, saving it as a TIF file, then ran the file through Caere's OmniPage Professional (OCR program). This resulted in a Word for Windows file that we checked for mistakes. All the scanners did well in this category (close to 100 percent accuracy) and the mistakes were usually the same ("ri" interpreted as "n" and "in" changed to "m"). For line art we made test scans from 75dpi up to 1,200dpi and made prints using the MD-4000 printer at 600 by 1,200dpi and the HP LaserJet 6MP at 600dpi. Then we compared the prints for accuracy and clarity.

Our primary test computer, a 75MHz Compaq Pentium system with 56MB of RAM, was set up to run Windows 95. For testing scanners connected to a Mac, we used a Power Mac 7200 with 32MB of RAM and Photoshop 3.0. Mac-compatible scanners hook directly into the Mac's built-in SCSI port and in every case we were scanning within 15 minutes of beginning the installation. This is a credit to the Mac's excellent hardware design and operating system.

All of the scanners we tested scanned at a maximum of either 24- or 30-bit scanning depths for color and either 8- or 10-bit scanning depth for grayscale. Twenty-four-bit scanning translates into a gamut of approximately 16.7 million colors, whereas 30-bit scanning incorporates over 1 billion colors for potentially greater color depth.

Agfa SnapScan

Rating: ** 1/2

The Agfa SnapScan was a snap to hook up and get running. It took less time than all the other flatbeds we tested. Like the other scanners reviewed here, except the ImageReader Elite and the HP ScanJet 5pSE, the SnapScan comes with both 25-and 50-pin SCSI connectors for easy hookup to other SCSI devices. A 24-bit scanner with an optical resolution of 300 by 600dpi and an interpolated resolution of 2,400dpi, the SnapScan has the ability to cover most small-office tasks.