We sit and watch as developers race each other against the clock to be the first to develop a new feature, the best feature, the fastest feature or the most feature packed product for the best price. Companies have to adapt or face the consequences of their own indifference. Technology is cruel and will not wait for anyone.

In many companies engineering drawings are not entered into the financial reports as being assets of any tangible value. Yet should these very same drawings miraculously disappear, it would be a catastrophe and great costs would be incurred in recovering at least some of the information that those drawings contained.

The challenge for most companies is how do they modernise their hardcopy drawings to protect their assets in the most cost-effective manner? It has been said that there are 3,5 billion engineering drawings already produced and this figure is growing by 26 million new drawings each year.

There are two processes that can be considered in the modernising process:

* Converting drawings from paper to a scan file that is stored in a graphical database.

* Converting drawings from paper to a CAD file using a raster-to-vector conversion technique.

Both these processes will be discussed, with the aim of equipping the reader to make informed choices, when the need arises. Both of these processes have their place, and both may also be used together within the same organisation - or even within the same department.

The first imperative is to build a good team of enthusiastic people who will have the insight to want to see the project succeed. Looking at the quantity of hardcopy drawings needed to modernise is probably a good foundation for them to build on. The next imperative is deciding how much intelligence is needed from the drawings, as this will determine how much time is required and what resources are needed to be employed to get the drawings into a workable state. This will make it clear whether there is sufficient expertise within the company to perform the task.

The raster process

Running a paper drawing or microfilmed aperture card through the scanner produces a raster file. Today, this may take seconds, depending on the method of scanning used. Once the drawing is saved to the desired media (CD, hard drive, etc) it is a digital, raster-based file. A raster file is a series of dotted pixels grouped together to form a digital representation of entities, such as lines, circles or text, which in turn represents your engineering drawing. Editing the raster file is the simplest and most productive method of modifying designs provided you have a competent raster editor. A raster editor, which incorporates the familiar vector (CAD) feel, allows the user to be comfortable in his environment.

Initially the world was impressed with the fact that it was possible to take a hardcopy drawing, run it through a scanner and within 30 min it was a digital file. This introduced the first generation of raster editors. We could look, but not much could be done with the drawing. It did not take long for the next generation to be developed. These were hybrid systems, which emerged from the leading CAD and imaging developers. These hybrid systems allowed conventional CAD users to adapt to the raster environment with ease. They enjoyed the familiar vector entities that took advantage of CAD geometry construction and combined it with raster paint techniques to further improve drawing productivity.

The third generation of raster editors has taken an even bigger step. Raster entities can now be treated as if they were CAD objects. Rasterex says that it is presently offering the market leading Windows-based raster editing applications on the market.

Today, scanning bureaus are able to offer service solutions enabling companies to reduce overall capital expenditure, while speeding up the overall time to project completion. Aperture card scanning is currently in the spotlight, since the throughput is high and resources required are minimal. The cost to capture an A0 drawing on an aperture card into a raster format is on average R4. This cost is significantly lower than it would be for a company to retrieve a hardcopy drawing from a cabinet in the paper document department. Electronic distribution of engineering documents and drawings is fast becoming a company necessity, in order to restore some control over the masses of drawings currently been produced in the race against time. This method of information exchange enables a quicker flow of work and thus an increase in productivity. Communication is improved tenfold resulting in quicker decision making and departments are made more efficient.

Like the CAD standard of vector file, namely the drawing exchange file (.DXF), people in the know who have been through the process of enterprise re-engineering and implementing systems for data control, are looking for an industry standard. This has given rise to the Department of Defence's mandated computer-aided logistic support (CALS) initiative. This initiative bundles networking, scanning, database management and viewing/redlining in a variety of price ranges and solutions, the purpose of which is to find an industry standard for the raster-focused market to adopt. Today the industry standard file format seems to have rested on the targeted image file format group 4 (TIF grp4) also known as CCITT.

Implementing raster editors allows companies to support their drawings at a minimal cost for capturing the data. They are also ideal for restoring old and worn drawings, as various clean up filters can be used to improve image quality. This means that the constant deterioration of the hardcopy file has ended and instead of getting worse the file can finally be restored to its original quality through raster/hybrid editing techniques.

One of the most critical considerations when considering any raster editing process is turnaround of revisions. Cost of personnel, rentals of space and storage services is minimal compared to the cost savings a company will achieve in the revision, editing and retrieval of correct information. The immediate savings can not be seen, but once the process of information flow is in operation, and efficiency can be monitored, the real saving will be measured by the time taken to get the goods to the market.

Working with hybrid data is in no way designed to eliminate the CAD system. It is purely a method of performing speedy revisions. For parametric design, manufacturing or analysis a high-end CAD system together with the recommended application for the industry is the answer, and to get hardcopy drawings to a state for such work to be undertaken, a raster-to-vector converter should be considered. The raster-based approaches have proven to be best suited for large volumes of archive-type data (drawings) in a technical data management situation.

The raster-to-vector process

The raster-to-vector process requires that all raster entities be converted to a vector state, thus producing CAD-type entities that contain useful attributes. These vector entities will allow for analysis and modelling that will give the data asset more worth, as a broader base of qualified users may add value to such vectors by means of CAD design. The raster-to-vector process enjoys benefits from both worlds in so far as original raster information adds a groundwork from which design, construction and analysis may be built on top. Together, the raster and vector information offers a synergy of co-operative entities. Raster entities offer an easy method of archival, restoration of information, editing and distribution, whilst vector entities allows for parametric design and manipulation of CAD constructions. The raster-to-vector conversion process can be undertaken in various methods. At the very end of the scale we have a purely manual method whereby the entire drawing is redrawn using measuring and transcribing methods from paper to computer. The next notch up allows CAD points to be selected one by one using a digitiser, whilst the hardcopy drawing is used as a template on the digitiser board. The specialised software related method would be very similar, in this case the drawing is scanned and a picture is brought into CAD allowing the drawing to be scaled to the correct shape and size before on-screen digitising commences. This process, which is also known as raster overlaying, can be very labour intensive, but does allow the user to have complete control over the vector entities and layering that he uses during the conversion process.

The next approach of raster-to-vector is the semi-automatic or interactive conversion. Such software allows the user to select a raster entity and then automatically trace the raster entity to produce a vector. Each raster object needs to be selected before the software will attempt to recognise it as a vector. This method is exceptionally good for people in the mapping industry, as the software is able to fulfil a line following function for contours.

Further up the scale is the automated conversion approach. This approach implies that the hardcopy drawings are automatically converted from a raster-state to a vector-state, with minimal interference from human-intelligence. A set of parameters are set defining the rules of recognition, such as what type of entities are to be selected, the area of recognition and so on. Artificial intelligence has certainly come a long way, and many times batches of drawings may be left uninterrupted in order to produce a CAD drawing. Results of up to 98% can be achieved using Rasterex' high-end solutions, but very often the results are dependent on the original quality of the drawing and how much has been lost during the scanning process.

You will find that invariably there will be drawings that have been run through the automatic conversion software, which need to be verified and corrected afterwards. Although this process of clean up may take anything from minutes to hours, the time spent converting each drawing is still greatly reduced. See the chart of comparisons below.

To perform an economic feasibility of automated conversion depends on the expected volume, intended use of the converted drawing and the quality of the originals. There are a number of successful scanning and raster-to-vector conversion bureaus presently operating in South Africa. Whether to use these bureaus or not, depends on the urgency of the job and also whether or not a successful operation is already up and running within the company in question.

To enable a potential client to buy into a product that will revolutionise his operation, he must be able to see:

* Proven solutions in a working environment.

* The ease of implementation.

* A return on investment.

* Potential for high rate of efficiency.

It did not take too long, from the onset of the CALS-initiative to present day standing, for developers to produce the range of professional products on the market. The CALS-initiative provided developers with a set of standards with which to work by in their research and development. It has certainly proven to the market that scanning hard copy documents that have been comfortably stored away in heavy cabinets has come of age. Many companies, both large and small, have implemented one scanning solution or another and regardless of size, they have all benefited from these timesaving processes. It has been proven with the growth of the market over the past 15 years that this is the proven solution to work with in every environment.

Easy implementation refers to the ease at which personnel adapt to the product, in other words the length of the learning curve. A product that is too difficult or too advanced will take personnel too long to become productive with. Once they have mastered the software, their position in the company becomes too specialised, and in turn they become too expensive. Some developers have raster-enabled the more popular CAD applications, by developing add-on tools, allowing customers to work within the environment they are familiar with. This lessens the stress of learning a completely new product. Product affordability and high efficiency are paramount ingredients in the acceptance of any new technology. High efficiency means high productivity, high profits and eventually high growth. When first confronted with two products on either end of the scale, one a manual revision process and the other an automatic conversion process, the potential customer is inclined to move towards the cheaper. This is human nature. However when comparing the two processes and seeing the same result within completely different time frames, the savings of electronic revision is extraordinary. The speed and results allow customers to make a choice with impressive efficiency gains and cost savings.

In order to be globally competitive, companies need to adapt to the electronic age. The tremendous time and substantial cost savings that companies realised in the adoption and use of CAD, proves that a change in process is often required to improve levels of manufacturing and design. Surely then it makes perfect sense to look at the process of document and drawing revision, and implement processes to speed up such revisions and information flow within an organisation. Communication of ideas and data, both within an organisation or throughout the world via the Internet, is becoming clearer.

Conversion of hardcopy information to a suitable electronic format can be either through converting directly to a CAD format using an automatic raster-to-vector technique or through a raster database for document and drawing control. The millions being spent on it each year throughout the world indicate that it is proving to make financial sense. The paper process is currently in debate worldwide, with many organisations adopting solutions to suit their environment.

As more and more people demand more and more scanning of drawings and documents, the automation features of raster editing software will also increase. This will make for quicker drawings with more intelligent recognition. However until such a stage is reached hybrid editing will still make more economic sense. Just as CAD developers have responded with better and faster features, so have the developers of raster-based products. The raster editing market is on a definite upswing!

Image Scanning Technology

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