C. HPGL Document Scaling and Coordinate System

HPGL Documents use integer coordinates based on a 25µm grid in the printing space – i.e. the paper to print on – rather than the object space. HPGL Document Scaling (0068,62F2) is used to scale the printed dimensions measured in millimeters to match the real dimensions of the implant measured in millimeters.

Notes: 1. For example, if HPGL Document Scaling is 2.5, then a line in HPGL that goes from (0,0) to (0,500) that is 12.5 mm long when printed represents 31.25 mm in the real world.

2. In HPGL, the origin of the printing space is placed in the lower left corner with the x-axis pointing to the right. No negative coordinates are allowed.

This Attribute does not compensate for any radiographic geometric magnification effect caused by the diverging X-ray beam in the projection patient images used for planning. Such compensation is the responsibility of the application based on calibration of the imaging process.