{1}Scanners capture images and translate them into a form which can be interpreted by a computer - beyond that the applications for scanned images are as diverse as the imagination permits. Some typical scanner applications are summarised here - more details are presented later in the Using applications section.
Image-editing and retouching
One of the main uses of scanners is to scan colour and monochrome originals to produce reproductions of those originals in a format suitable for subsequent editing. Image-editing software can be used either to clean up or to make deliberate modifications to the resulting images.
For example, perhaps you are considering replacement windows for your house and want to see how the various design options will look in situ as opposed to in the salesman's catalogue. Editing a scanned colour photograph of your house can produce a very convincing impression of the desired effects.
{2}Creative design
Scanners and image-editing software provide enormous flexibility in the field of creative design. You can experiment by scanning three-dimensional objects or reflective materials. You do not even have to start with a scanned image - you can use image-editing software to draw and paint onto a 'bare canvas'.
Scanners have found a useful niche in textile and wallpaper design: image-editing software seems to lend itself well to the production of intricate, colourful and repetitive designs. We can thank scanning technology for the recent electronic restoration of the rare Creselli Star carpet pattern - an event which may have passed the uninitiated by, but was, to international carpet experts, an event as significant as the splitting of the atom.
{3}Desktop Publishing (DTP)
Before the advent of desktop scanners, most 'Desktop Publishers' had to rely on outside agencies to supply and incorporate much of the artwork. Now scanned images can be incorporated easily into page layouts, enabling the whole job to be created from scratch in-house. As well as providing greater autonomy within the DTP process, the advent of scanners has also encouraged increased use and experimentation with graphic material at both the professional and non-professional level.
One has to acknowledge the sheer practicality of being able to scan a signature for subsequent use wherever the 'personal touch' is required.
{4}Optical Character Recognition (OCR)
It is not surprising that personal computer software is still largely unable to decipher the complex and varied scrawls and scribbles of handwritten text.
You may, however, be pleasantly surprised by the great strides which have been made in the ability of OCR software to read printed text. It is now possible to scan and decipher the contents of letters, memos and other printed papers at a high level of accuracy. The resulting files can then be edited for subsequent incorporation into other documents.
{5}Document Image Processing (DIP)
Document Image Processing systems can be thought of as an 'intelligent computerised microfiche'. Whole pages can be scanned in, usually as greyscale images rather than in the usual black and white OCR format.
Complete libraries of documents can thus be held on file and searched at high speed using computerised indexing. Documents can then be viewed on-screen or printed as required.
Combining the DIP and OCR elements can automate the process still further. For example, the scanned page can be processed by an OCR routine to extract appropriate keywords for indexing automatically. Readers can, if they wish, obtain a copy of pages in the form of a word-processing file instead of on paper.
{6}Presentation graphics
Most presentation graphics packages can now incorporate images into presentation slides, so you are no longer restricted to the graphics and clip-art supplied with the package. Scanned images are even used in video applications to produce animated presentations.
{7}CAD / Technical Drawing
A major obstacle facing architects and other users of Computer Aided Design (CAD) systems is how to import existing line drawings into the CAD system without having to redraw from scratch. With a scanner, a drawing can be scanned and saved as an image file. A tracing program can then be used to convert the 'bitmap' image to a 'vector' image - one composed of line segments instead of individual pixels - the required format for the CAD software.
Some CAD software packages now incorporate their own scanning and vectorising facilities. In a more creative vein, some architects now use scanners and associated software to create and superimpose complex images onto technical line drawings.
For example they may scan photographs of trees or areas of water and include these in their plans in order to demonstrate their design concepts more definitively.
