Classic Computer Magazine Archive COMPUTE! ISSUE 125 / JANUARY 1991 / PAGE 94

Migraph Hand Scanner and Touch-up. (evaluation)
by Morton A. Kevelson

Migraph has teamed the Omron hand-held scanner with its Touch-Up software to create an excellent low-cost scanning solution for Amiga users. The scanner can be conveniently operated with either hand, although its activating push button is located on the left side. In fact, based on the size and shape of the scanner, operating it is like handling a large mouse, except that the tail is at the wrong end. The scanner can be positioned prior to the scan, and the object can be viewed during the scan be peering through a green-tinted window at the front of the scanner while the scanner light is on. The scanner light is controlled by Migraph's Touch-Up software. The light stays on during the scan and shuts off automatically after the scan buffer has been filled or within ten seconds after the scan button has been released.

The scanner offers hardware-switchable resolutions of 100, 200, 300 and 400 dots per inch. A second four-position switch lets you choose between Line-Art mode and three photo settings. Since the Line-Art mode generates a pure black-and-white image, it's suitable for text, engravings, and, of course, line art. The three photo settings are used when scanning photographs and continuous-tone graphics that you wish to represent with some tonal gradation. The scanner uses a 6 X 6 dot dither pattern to simulate 31 gray levels. As a result, the effective resolution in the Photo mode is about 66 lines per inch. A rotary control lets you set the threshold for the Line-Art mode and the middle gray for the Photo mode.

The active width of the scan head is 4.08 inches, which generates an image with a maximum width of 1632 dots. The length of the scan can be 2, 4, 6, 8, 10, or 14 inches. You connect the scanner to the Amiga's parallel port with a custom interface. The scanner and interface are powered from a power supply that plugs into the interface.

The underside of the scanner has one large roller toward the front and two small rollers toward the rear for stability. The forward roller is used to measure the distance and speed the scanner has moved. Since the scanner has limited on-board storage, the scanned data has to be transferred to the computer while the scan is being made. A steadily glowing green light, located on top of the scanner, indicates that all is well during the scan. Scanning speeds range from about three inches per second at 100 dots per inch to a bit less than one inch per second at 400 dots per inch. At these rates, a typical scan takes no more than a few seconds.

The Touch-Up software does far more than control the scanner and store the digitized image data. Touch-Up is also a full-featured bitmapped paint program. The size of the bitmaps Touch-Up can handle is limited only by the available memory. Page sizes can be specified in pixels, inches, or centimeters. As a bitmapped drawing program, Touch-Up is limited to black-and-white images or images with a single bit plane. This makes sense because the scanner can only generate single bit-plane image data. Nevertheless, Touch-Up can import any color or monochrome IFF image. Color images are converted as they're loaded in. The conversion can be to black-and-white, or it can utilize a variety of dithering modes and patterns to simulate the original colors as a gray scale.

Scanned images tend to be larger than the Amiga's display screen. As a result, Touch-Up will look best on a hi-res interlaced screen. Since Touch-Up runs on the Workbench screen, you'll have to set Interlace mode from Preferences. An option to have Touch-Up run from its own screen would've been more convenient. The Workbench screen will let Touch-Up run on a megapixel display device, such as a Viking or 2024 monitor.

Touch-Up operates in one of three modes: Paint, Clip, or Scan. Drawing tools include spray, box, circle, b-spline, and Bezier curves. Touch-Up also includes 36 predefined fill patterns, including pure black and pure white, which are used with the drawing tools.

The Clip mode is used to perform operations on the entire image, such as cut, paste, flip, mirror, rotate, stretch, compress, and distort. The Paint mode performs operations at a pixel-by-pixel level.

You use Scan mode to interact with the scanning hardware. You can scan images directly onto the page or into a predefined clip box. This lets you combine a series of scans into one image. Touch-Up has four writing modes that determine how subsequent operations will interact with the existing image. In the Replace mode, the latest image or operation takes precedence. In Transparent mode, the white parts of the overlay do not affect the existing image. The XOR (eXclusive OR) mode writes only where one of the images is black; it generates white when both are black. Reverse Transparent is like Transparent with black and white reversed.

Scan mode also lets you convert a dithered photo scan into a true 16-level Amiga gray-scale image. This operation takes each 6 X 6 dot area of the scanned image and converts it into a single pixel of the appropriate shade of gray. The resulting image is 272 dots wide. Touch-Up can also generate a 544-pixel-wide image, with 31 gray levels, by dithering image data.

In addition to the Amiga's standard IFF-image file format, Touch-Up can also load images in IMG, PCX, TIFF, MacPaint, and PrintMaster file formats. Touch-Up will save files in these formats as well as EPS, Degas, and GIF. You'll have to use a program such as CrossDOS to exchange files with PCs, or A-Max II or Mac-2-DOS to transfer files to and from Macintosh disks. A modem will work as well.

At a fraction of the cost of a full-size desktop scanner, the Migraph Hand Scanner with Touch-Up is well worth considering if your scanning needs can be met with a hand-held unit.

Ease of Use/Installation [star][star][star][star]

Documentation [star][star][star]

Features [star][star][star]

Compatibility [star][star][star][star]

Amiga with 1MB--$399.95 MIGRAPH 200 S. 333rd, Ste. 220 Federal Way, WA 98003 (800) 223-3729 (206) 838-4677 (in Washington)