Converting masses of legacy data into geo-relevant digital data can be very time-consuming, yet it represents every scrap of information amassed by generations of local authority planning departments, public utilities, service companies and any other outfit involved in developing and maintaining the country's basic infrastructure.
Because it is spread over thousands, perhaps millions, of hand-drawn plans and documents, converting it into digital information so that it can be used more effectively as part of today's sophisticated GIS solutions involves many man years of patient scrutiny of old maps, land registry documents, sketches and any other arbitrary medium that our ancestors cared to use.
Legacy data is pretty scant information, as well. It merely records the geographical location of a feature, bereft of any other useful information that would benefit the holder of that information. Take street lamps, for instance. Spread over numerous maps for each city, each lamp, which could have been put in place shortly after the introduction of electrical illumination of a city's streets, merely notes the lamp number - if there is one - and where it exists. If that was recorded on a digital map, it could be accompanied by its attributes - the type of lamp, its service history, and the last time the bulb was changed - so that when there is a complaint regarding a street lamp, the relevant service company can pinpoint the problem immediately and send out a van with the necessary tools to solve the problem.
Land boundaries are another case in point. Extracting irregular parcels of land (polylines) from Land Registry records and converting them to digital data is a formidable task. And local authorities that wish to convert a mass of survey data into 3D models of the local terrain - essential for environmental studies and for planning large-scale construction projects - are faced with the tedious task of converting contours into digital vector data. Ordnance Survey sells digital maps that cover every square inch of the country. Great! But these do not include some of the information that the local authorities have in their legacy data. Software is available, however, that simplifies and automates the process - turning a manual task into a smooth operation that can take, literally, years off the process.
Such a solution is WiseImage Geo, developed by Consistent Software and available from Kinetic Distribution in South Africa. WiseImage Geo is a standalone application specifically developed for the cadastral and GIS markets. Cadastrals refer to the depiction of parcels of lands, including buildings used by the Land Registry.
The software is a comprehensive map-processing tool, using unique raster to vector and raster to contour conversion technology, smart object recognition technology and many other features to simplify the task of converting legacy raster data. WiseImage Geo also allows users to set up custom processing scenarios.
Central to the process is the software's ability to convert raster maps to vector-based digital images. WiseObject can be used to separate text areas and symbols from the image using the software's smart tracing function, or the user can elect to go direct for a quick raster to vector conversion.
The software includes an OCR feature that can pick up text strings at any angle in the drawing, and, like symbols, it can also be trained to recognise new text characters.
WiseImage Geo is based on Consistent Software's WiseImage Pro, a versatile tool for manipulating or extracting any type of data from any document. It is this capability that has been enhanced to include geo-related functionality - providing Studio Script with the means to create complex processing scripts for both GIS and cadastral data. In short, whatever data is held on the map as objects, shapes, lines, or text, WiseImage Geo can be set up to extract it, and to convert it into usable digital data. The software is supplemented with performance enhancing tools, such as the ability to load and display multiple raster images simultaneously, so that they can be worked on in tandem, and a batch processing utility, Batch Studio, that can be set up, like Script Studio, using simple drag and drop visual programming tools. Compatibility with multiple images sources is also vital, hence the support for GeoTIFF, AutoCAD's DEG/DXF, LizardTech MrSID, ER Mapper, plot files, ESRI Shape files, DGN and PDF formats.