The Next Best Thing To Being There

Albrecht Dürer, Artist Drawing A Lute, woodcut from Unterweysung der Messung mit dem Zyrkel und Rychtscheyd, 1525, (The Metropolitan Museaum of Art, Harris Brisbane Dick Fund, 1941).

During the 16th century, the most widely read discourse on the science of perspective was written by Albrecht Dürer (1471-1528). Dürer describes both mathematical and mechanical methods for drawing perspective in his work, Unterweysung der Messung mit dem Zyrkel und Rychtscheyd. One of the mechanical methods for constructing a perspective view of an object is depicted in his woodcut , Artist Drawing A Lute.

Change your perspective on any imagery-based scene; rural, urban or industrial; exterior and/or interior.

Diverse Content

Thus you are not restricted to the position and orientation of the camera at the time a photograph is collected.

What you get are photo-truthful pictures synthesized - not merely simulated - from photographs, terrain data and three-dimensional (3-D) feature models.

For example, from one or more aerial photographs, it is possible to create a combined imagery and 3-D geometry data base and then generate an unlimited number of new snapshots from arbitrary vantage points, even ground level, looking in any direction. Using animation techniques, IPT allows you to simulate driving down the streets of the city. Furthermore, if hand-held photographs of the interiors of some of the buildings are added to the data base, then it is also possible to enter the buildings, go up stairs, enter offices, etc. The possibilities are unlimited.

Technology Fusion

IPT provides this flexible-viewpoint photography through a functional merging of photogrammetry, computer graphics, 3-D modeling and image processing technologies. Photography is first collected and digitized and then calibrated using photogrammetric techniques. The digital imagery is then decomposed into its basic geometric and textural components through the use of a three-dimensional, photogrammetry-based CAD/CAM tool. This tool has the unique characteristic that it allows the construction of three-dimensional objects directly on the source photographs. No blue-prints or other drawings are required. The shape, orientation, position, and size of the modeled object is then stored in the data base along with the visual components of each of its surfaces. Furthermore, attribute information corresponding to the modeled feature geometry can be added and saved in a relational data base for SQL-type queries. The generation of output images involves the projection of elements of the model data base into the desired perspective using standard computer graphics techniques, followed by the rendering of each of the surfaces of the output scene with imagery from the visual data base. Preprocessing is not required to orthorectify and mosaic oblique source images into a vertical format or to cut out and rectify the component faces of man-made objects, although the latter is an option.





Applications

Military Mission Planning create 3-D data bases for aircraft/vehicle visual simulators generate new views from arbitrary vantage points for navigation points

Urban Planning create 3-D data bases for urban renovation planning generate visualizations of hypothetical renovations in existing surroundings

Transportation Analysis create 3-D data bases for traffic network analysis generate visualizations of traffic conditions create 3-D data bases for driving trainers in actual cities

Telecommunications Analysis create 3-D data bases for RF transmission analysis of cellular telephone communications lines generate line-of-sight visualizations of obscuration conditions from arbitrary vantage points

Security Analysis and Training create 3-D data bases for analysis of urban/facility security generate new views from arbitrary vantage points for line of sight analysis of key security areas create 3-D data bases for virtual reality play-out of hypothetical high security risk situations and response training

Rapid Response Analysis and Training create 3-D data bases for analysis of urban rapid response emergency situations generate new views from arbitrary vantage points for line of sight analysis create 3-D data bases for virtual reality play-out of hypothetical rapid response situations and training

Industrial Facility Characterization create 3-D data bases of environmentally denied facilities, e.g. nuclear, chemical, biological create 3-D data bases for virtual reality worker training of facility dismantlement procedures generate visualizations for public awareness briefings

Internet/World Wide Web VRML Models create virtual reality 3-D data bases of urban areas create virtual reality 3-D data bases of industrial facilities







Example Images

Rendered Output Image For A Rural Area (Monterey,CA) Source data included a single aircraft collected nadir photograph at about 10 ft resolution and a 93 m resolution USGS Digital Elevation Model (DEM). (21.8 Kbytes)



Rendered Output Image For Another Rural Area (Irish Canyon, CO) Source data included a subsection of a SPOT multi-spectral digital image at 20 m resolution and a corresponding 10 m SPOT Digital Terrain Model (DTM). (48.6 Kbytes)



3-D Modeling Tool For An Urban Area (San Jose, CA) (151.8 Kbytes)



Rendered Output Image For An Urban Area (San Jose, CA) Source data included two aircraft collected oblique photographs at about 1 ft resolution and a 93 m resolution USGS Digital Elevation Model (DEM). (30.2 Kbytes)



Processing Mosaic For An Urban Area (San Jose, CA) Same source data as above. Upper Left - Source image. Upper Right - Source image with 3-D wire frame models. Lower Left - Wire frame output at a new perspective. Lower Right - Rendered output at a new perspective. (215.0 Kbytes)



Rendered Output Image For Another Urban Area (San Jose, CA) Source data included two aircraft collected oblique photographs at about 1 ft resolution, one aircraft collected nadir photograph at about 1 ft resolution and a 93 m resolution USGS Digital Elevation Model (DEM). (44.4 Kbytes)



Partial 3D Model And Rendered Output Images For Another Urban Area (San Francisco, CA) Source data included many aircraft collected oblique photographs at about 1 ft resolution and a 93 m resolution USGS Digital Elevation Model (DEM).



3-D Modeling Tool For A Facility Interior (TRW Loading Dock) (100.0 Kbytes)



Rendered Output Image For A Facility Interior (TRW Loading Dock) Source data included 18 hand-held 35 mm camera photographs. (49.3 Kbytes)



Wire-frame Output Image Of A Motor Generator In A Facility (TRW Loading Dock) Same source data as above. (8.6 Kbytes)



Rendered Output Image For A Facility Interior (TRW Loading Dock) Same source data as above. (16.8 Kbytes)





Example Animations

A low altitude fly-around of downtown San Jose, CA

(1220 Kbytes, 160 x 120 pixels)

(1220 Kbytes, 160 x 120 pixels) A low altitude fly-over of Irish Canyon, CO

(1290 Kbytes, 160 x 120 pixels)

(1290 Kbytes, 160 x 120 pixels) Moving around a TRW Loading Dock

(974 Kbytes, 160 x 120 pixels)





Fred Weinhaus

fmw@alink.net