Vector file with linework only, edited by CAD technician

Level 4

Partially Edited Vector files are created by operator-assisted conversion, also known as heads-up digitization. We start either with a Level 2 gray scale or a full-color image (when color makes more sense), and create the vector data on-screen by using our specialized interactive tracing routines to draw by following the raster data. During this operation, our operators make all pertinent decisions concerning the meaning of each piece of linework being captured. This way, the software does what it is best at, but the intelligence comes from a trained professional with full knowledge of the contents of the map or engineering document.

These files are saved as standard AutoCAD, Microstation or Arc/Info documents delivered in their native formats or in industry-standard DXF format. The original document geometry is identified, extracted and fully cleaned-up. Text, dimensions and hatches are removed. This option is useful when the base document is needed in properly edited vector format, but text information is either obsolete or unnecessary. These files are composed of edited lines, including full-size scaling, separation into intelligent layers and object geometric correction (orthogonal, perpendicular and endpoint adjustment). Object integrity (no overlapping or broken lines) is preserved as well.

Level 4 introduces a major advantage over previous conversion levels: Geometric Accuracy. We correct them by a process of matching or “biasing” the scanned raster image to corresponding vector-accurate known points. Biasing starts by creating vector-based monument points entered by operator key-in into a master file. Known dimensions and angles taken from the original drawing annotation are used to construct this accurate vector frame, which is then matched to any corresponding points on the raster image. Rubbersheeting the scanned image creates a geometrically accurate raster file.

Then, the high-quality line conversion process takes place, driven by GIS and CAD technicians, not just software. This is an intelligent, operator-driven process based on computer-assisted line following and heads-up line construction. The resulting product is a fully layered, geometrically accurate and completely clean vector file. Accurate, line endpoint termination is assured by our experienced operators. The use of industry-standard layering simplifies the incorporation of Level 4 files into your workflow.

Since Level 4 conversions require measurable amounts of time and effort to complete, pricing is dependent on the actual graphics complexity of each original. Of course, it will take considerably longer to convert a very complex drawing than a simple one, so the actual cost is directly influenced by this factor. Although the evaluation of drawing complexity is a relatively abstract exercise, the following descriptions attempt to illustrate the appearance of originals in each one of these categories. Of course, the only way to correctly evaluate your design documents will be by direct inspection of the entire set, or at least a representative sample.