Vectorizing and raster to vector line conversion are achieved with a set of tools and function keys, together with special features to control the automatic line conversion: the nodes. This chapter explains all of these features and their properties, as well as the behavior of the vector data which is generated.

The conversion functions can work with gray scale or color images, as well as with binary or two-color images. When gray scale or color images are digitized, a color mask has to be used in order to determine the lines to be converted.

Automatic line conversion consists of following lines and outlines, or following the boundaries between a mass of pixels belonging to a given color mask and the rest of the image.

None of the functions need a file to be selected. If a function needs to edit an unselected image, an Alert message appears giving you the option to automatically select the file. This also means that a function, such as Convert Lines, will be able to follow a line that continues over several images, because the function runs on any image displayed in the view.

This chapter first presents the concepts utilized in heads-up digitizing or line conversion operations, and then describes a set of enhanced MicroStation line editing tools, with integrated automatic line conversion and raster snap functions and zoom capabilities.