Academic journal article T H E Journal (Technological Horizons In Education)

Scanners Add Art and Color to School Documents

Academic journal article T H E Journal (Technological Horizons In Education)

Scanners Add Art and Color to School Documents

Article excerpt

Scanners Add Art and Color to School Documents

Graphic scanners offer a variety of services for instructors, students and administrators alike. They help incorporate art work such as line drawings, commercial clip art, illustrations or 3D objects into tests, district publications, student newspapers and other documents.

Although the technology has taken off, particularly in the realm of color, other restrictions such as RAM requirements, price and compatibility make choosing scanners a thought-provoking process.

Types of Scanners

There are three types of graphic scanners available--flatbed, hand-held and 35mm slide scanners. Flatbed scanners are well suited for scanning large, page-sized flat art. These units deal in monochrome, black-and-white or color, and can scan from a variety of sources.

A variation on the flatbed scanner design is the overhead flatbed. The difference is that overhead units are "open air" and scan optically. The optical mechanism is located on a tower that passes over the source material. Overheads often offer better resolution and boast higher dot-per-inch ratios, but they rely on ambient light to illuminate originals and may tend to produce uneven contrasts.

Hand-held models are small in design and are therefore most useful in scanning small images from flat originals. Their other benefits include price, ease-of-use and flexibility. Hand scanners can scan books, pamphlets and even wallpaper designs.

One problem inherent to its size is the hand scanner's small scanning width. To scan large images, multiple passes need to be made then "sewn" together. When using the hand scanner, one must be careful to scan straight down without slipping. If the path is curved, the image will be distorted. Software is usually packaged with these scanners to help meld images back into original form.

Slide scanners scan 35mm transparencies. They are ideal for high-end publication purposes but, because of their price and relative scarcity in the educational arena, will not be treated here. While slides are easier to handle, store and transport than print originals, slide scanners are designed mainly for desktop color separation.

The Basics

A few terms must be explained to completely understand how scanners compare to each other. First, there is pixel depth, which is the number of bits assigned to each pixel to define its color or grey level. This attribute is related to resolution, a measurement of dots (pixels) per inch (dpi). The higher the resolution, the better the scanner is at registering detail.

Some scanners can achieve higher resolutions than what the manufacturer states. A method called interpolation averages an image's grey-scale values and puts extra pixels between existing ones to smooth out an image. …

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