The 15th Conference of ESRI users in Russia and CIS was organized by DATA+ on October 20-23, 2009 in Golitsyno town near Moscow.
At the Conference, Easy Trace Group represented the report "Is it possible to digitize maps and photos automatically?".
Report theses:
Progress in automatic digitization of maps and imageries is far less impressive than in drawing processing. Many companies unsuccessfully attempted to introduce automation into it applying rather expensive digitizing software with a disappointing result – «we tried but have arrived at the conclusion …».
This outcome is easy to predict. Automatic digitizing packages are developed for CADs where they are undoubtedly useful. When applied for map digitization, they bring their use paradigm to cartography – specify numerous (and often obscure) parameters and click “Start”. No other approach is provided by the very conception of automatic digitizing software.
Unfortunately, it does not work in the case of maps and imageries.
So, is it possible to digitize them automatically?
No – if you insist on the one-click approach. Yes – if you understand automation as making data processing several or even several tens times faster. And we have strong reasons for this statement.
"Divide and conquer" is an ancient motto that we use when “take a map to pieces” for separate processing.
Digitization dividing into simple components enables your computer to manifest its abilities in full, i.e. to process vast amounts of data quickly and successfully.
In general, this approach consists of the following stages:
- Image preparation for digitization (extraction of individual components);
- Automatic tracing and filtering of raw vector data;
- Automatic recognition of vector objects;
- Topological matching of vector data and quality control.
Partition into subject components greatly decreases image complexity. Automatic digitization of such components (subject layers) generates vector objects fit for subsequent processing rather than senseless “rubbish”.
Vector filtering and linking of line segments contribute to further data simplification and make the material suitable for object recognition by specialized utilities.
Operations of topological correction are integrators that automatically assemble a complex vector structure out of individual objects.
Utilities for topology and polygonal cover check-up are entrusted with the task of final inspection.
Digitization control and editing of intermediate results remain manual, but the operator is seldom engaged in object tracing.
This method was impossible before complete revision of some utilities and tools. For example, the Topology Correction utility works tens times faster now and has become the connecting-link of the entire process. We run it several times at different stages of data processing to make thousands changes at once instead of long hours of manual editing.
Advanced editing tools are focused on control of line form as a whole rather than dragging of individual vertices. Further still, they correct all topologically connected objects simultaneously.
We understand of course that powerful tools and utilities by themselves do not guarantee excellent results. It is necessary to know the ways and the order of their use, i.e. methods of automatic digitization.
Our company has been developing such tools and methods for more than fifteen years. Video-examples included into our distribution kit demonstrate different aspects of automatic digitization of real materials.
The entire process is subdivided into a series of operations, and some of them do not require highly skilled workers. It helps to deploy working groups quickly as one may engage operators – freelancers.
It should be especially emphasized that techniques integrated into Easy Trace Pro are suitable for images of the lowest quality. That is because the package origin of course.
There are a lot of maps in Russia printed many decades ago. They neither have high printing quality nor were spared by time. And this is exactly the kind of materials we used for check and adjustment of our tools and methods.
If compared with an automobile, Easy Trace is a real off-highway truck rather than a city car. It has stood hard tests and is afraid of dirty image no more than a tank is afraid of dirty road. The harder is the task, the more is advantages of Easy Trace use.
Good luck!