Page 341 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed

320 Maritime Archaeology: A Technical Handbook, Second Edition
shapes, shades, and anything else are essentially equations. If you double the size of the image the lines will stay smooth and will not pixilate; addi- tionally these image files are relatively small compared to raster images. It is possible to scan an artifact using flatbed scanners. With care and a good quality scanner with a reasonable depth of field, three-dimensional objects can be scanned (the best results are with objects with limited thickness). Given the quality and speed that an object can be scanned, there are very real advantages to this system. Results can be very impressive, although the limitation is obviously the size of the object (it has fit on the bed of the scanner) and the height or thickness of the object.
The table shows a number of choices, all of which need to have a computer-based end product:
Technique
Draw the object conventionally and scan into raster graphics
Draw the object conventionally, scan it and trace drawing with vector graphic
Digital photograph or scan the object, trace scan using vector graphics
Digital photograph or scan the object and keep in raster graphic format
Pro Easy to do
Small file size
Small file size
Easy to do
Con
Large file size, cannot enlarge greatly
Time-consuming, lots of drawing
Difficult with complex three- dimensional objects
Large file size, difficult with complex three-dimensional objects, cannot enlarge greatly
X. THREE-DIMENSIONAL GRAPHICS
The use of three-dimensional graphics to illustrate artifacts is very much in its infancy. Clearly, the use of three-dimensional models of artifacts used in the Tektash survey are particularly interesting, because so many of the objects were identical. The technique was applied essentially to objects with axial symmetry and surface rendering of the wire-frame model was simple shading. As this technology improves, the option of draping a digital image of the surface over the wire frame will be an exciting possibility. Further- more, the development of PhotoModeler as a three-dimensional technique for complex models and with the potential to drape the surface of the object from photographs will present new and interesting options for archaeologi- cal object illustration.