Scan-Light from Computer Concepts is a system that takes a printed image and reads it into a sprite. This is an integral part of Computer's Concepts Fax system, and the company has decided to release the scanner as a separate product.
Computer Concepts' package consists of a hand-held Mitsubishi scanner, a podule which fits inside the Archimedes, and a user guide. All the software to control the scanner is included in an EPROM on the podule, and therefore no disc-based software is supplied. Obviously, a podule back-plane is necessary to use Scan-Light.
The scanner podule at first sight appears to be a largely unpopulated circuit board. This is because the board is actually a cut down version of the long-awaited Fax podule. CC supply a half width blanking plate to allow the podule to be mounted properly, and installation is a fairly simple process. The podule back-panel carries a socket for connect-ing the scanner, and a couple of unused holes, again a carry over from the Fax system.
When the computer is switched on, the presence of the scanner podule is not announced in any way. It is only when you type *SCAN, or use the RISC OS task manager to start up a task called 'Scan', that the system springs into life. Scan-Light is fully compatible with both Arthur 1.20 and RISC OS, though I shall only deal with RISC OS here. Once started, an icon appears on the icon bar, and a large window is opened that will eventually display the scanned image. This window is peculiar, because clicking on the close box clears the work area of the window, rather than simply closing it. This seems to make the iconbar icon somewhat redundant.
Another novel feature is the inclusion of a menu bar. The software uses a two- level menu structure which can be invoked using the menu button as normal. The purpose of the menu bar is to bypass the first level of the menu tree, which can make the selection of functions much quicker. Keyboard shortcuts exist for many of the menu options. There are three main menus: File, Scan and Edit.
Perhaps the most important item on the menu is Scan. This offers two options, the first to perform a scan, and the second to power down the computer. This latter is another feature aimed at the Fax system, and will only work with a special power switching unit. Once the scan option has been selected, the software waits until the button on the scanner is pressed. The scanner should then be pulled down the page being scanned. The scanning stops when the button is released, although it will also stop when a full A4 page has been read in, or if the scanner is not moved for a couple of seconds or more. A roller on the underside of the scanner detects the speed of movement, and therefore it is not essential to move the scanner at a constant rate. There are limits, however, and a page cannot be scanned in less than about nine seconds. It is also essential not to move the scanner across the page as it is moved, otherwise the image will be distorted. To achieve this, the scanner has graduation marks to line up with the page.
There are two modes of scanning offered - Picture and Text. The text mode creates a simple black and white image of the page at a resolution of 200 dots per inch. The picture mode on the other hand uses a dithering technique to create the appearance of sixteen grey levels. This method, as its names suggests, is best suited to the scanning of pictures and photos.
As the page is scanned, the image is built up in the window, although the scaling applied means that it will look a little strange. Once scanning is completed, the image can be viewed at 25, 50, 100 or 200% scales by selecting options from the Edit menu. A further option allows a scanned picture to be displayed in sixteen grey levels. The scanner assumes that pixels are square in shape, and therefore, scanned images will appear best in mode 9, or ideally mode 20, but this latter requires a multi-sync monitor. Using mode 12 or 15 gives the image an elongated appearance on screen. Other Edit options allow you to edit the image pixel by pixel, and to select an area of the image for future operations.
The File menu allows images to be loaded and saved, and sprites to be included within the image. Rather than follow the standard RISC OS Filer system, Computer Concepts has decided to design their own dialogue box for file operations. In use, I found this was more restricting than having Directory Viewers, and I don't fully agree with CC's departure from the standard which Acorn is eager for developers to follow. Images can be stored in one of two formats. The first is as a normal sprite, in which case the dithered effect is converted to grey levels, and the second as a compressed format which will be compatible with the Fax system. The first method has the advantage that a standard sprite file is produced, so this can subsequently be loaded into ArcPaint and edited, or incorporated into word processor documents etc. The second method saves disc space (an A4 sprite takes up a massive 483K - compression saves about 50%), but for all intents and purposes is useless without the Fax system.
The Scan-Light package reviewed was a pre-release version, and the documentation was in fact the complete manual for the Fax system. However, we understand that the Scan-Light manual will consist of the relevant parts of this, and should end up as a 30-40 page A5 book, which will most likely be wire bound in CC's normal style.
The manual covers the principles behind the scanner, and explains in detail how to scan documents and use the other features of the software. The manual also warns that occasionally the scanner produces slight errors in the image (a fault of the scanner unit), and that red printing is not picked up by the scanner. The reason for this is that the scanner works by bouncing red light off the page as it is scanned. This might sound a bit limiting, but in practice is not too great a problem because much apparently red printing actually contains a fair degree of black, and a brightness control on the scanner allows you to increase the sensitivity to pick this up.
An optional sheet feeder is also available. The scanner clips into this, and can then scan a page fed through automatically. This ensures that the scanner is not moved side to side as the page is scanned. The Scan-Light software includes all the support needed for the sheet feeder, and the unit simply plugs in between the scanner and the computer.
Scan-Light is certainly a very addictive tool, and for the right people it will also have many serious uses. In particular, when desktop publishing packages become available for the Archimedes, it will be a simple matter to include scanned pictures on a page. However, Scan-Light costs £516.35 (inc. VAT), and I feel that this will put many people off. The optional sheet feeder adds another £172.50 to the price, giving a total of nearly £700. This is comparable with a video digitiser and camera - a setup that could in some cases perform a similar function to a scanner. As nice as it is, Scan-Light is very much for the rich Archimedes owner.