Large Format Scanners

In almost every office throughout the world, people use scanners without even being aware of the fact. These scanners are better known as - fax machines. When you feed a document or a picture into a fax machine, it initially converts the information into a digital, compressed "raster" file and then transfers this file via the telephone system to the receiving fax machine, when then decompresses and reads the raster file before printing it out on the built-in printer.

Using a small format scanner - either hand-held or A4 size - is the same thing; - scan in and print out. This occurs locally, without the intermediate of the telephone transmission system. Frankly speaking, users are really interested in what technology is used in the scanning process, just as long as the fax goes through to the right destination, or the small scanner provides the images for their graphics applications or identifiable text for their OCR applications.

BUT, there's a difference in the expectations of a fax user and that of a large format scanner user.

This is because for the above tasks nice, clean white paper with clear black letters from a good quality printer tends to be used. Thus, the difference between the actual information (whether image of text) and the background level (i.e. the signal to noise ratio) is very significant.

Technical drawings are frequently a totally different matter. First of all, different types of media such as paper, vellum, sepia, transparency etc. are used, and many of the drawings are old and therefore often in a very poor condition. This means that the media has faded, and there are also unwanted data on the paper such as coffee stains, fingerprints etc.

With drawings the main task in the scanning process is to extract the original information (signal) from the background (noise) and for very old drawings the difference between the two is frequently very small. Consider for example blueprints or brown prints where the human can hardly distinguish text, arcs and lines from the background. Similarly, with contour maps or seismographic data from oil well exploration, where the human eye is unable to separate the very closely-spaced narrow lines from each other. These are the type of demands that users of large format scanners expect manufacturers to meet. They are quite different from the demands of the office environment and, therefore, different technologies and processes tend to be used. This is where CDSS comes in with our range of scanners from Industry leader…..Contex Inc.