Development of a Stereoscopic Image Processing Software
3. Development of a general purpose stereoscopic image processing software.
A stereoscopic image processing system is very useful in such field that needs topographic information, especially when it has man-machine interface function mentioned above. Since there are now scarcely any stereoscopic image processing systems which have these abilities, it has been planed to develop such a system. Because there was a digital photogrametric system which was already developed using a general purpose stereoscopic image processing programs on this system. The programs were developed on the OS of the personal computer, MS-DOS. The functions of the programs developed on this system were as follows: enlargement and reduction, brightness enhancement, affin transformation, calculation between images, cutting out and displaying a part of a big image, etc. A program which produce stereoscopic images from a digital orthoimage using DEM is also developed.
Photo 4 and 5 show the example of enlargement. Photo 4 is an alternative display of stereo-scopic images, and the operator can get a stereoscopic view through liquid crystal shutter glasses.
Photo 4 Selection of the place to enlarge by a square
Photo 5 Enlarged image of te selected place
A square in the photo, the size of which is determined from the rate of enlargement, is overlayed on one of the stereoscopic images. The operator can move the square in the stereo-scopic view with a mouse, and can select the place to enlarge. Photo 5 in the enlarged image of the place selected in photo 4, and the operator also can get a stereospopic view by looking at the images in photo 5.
A 3D graphic program, which can draw stereoscopic points, lines, circles, etc., has also been developed to serve a tool of man-machine interface to the system using the two dimensional graphic programs provided in the OS, MS-DOS. Photo 1 is an example of writing stereoscopic points on stereoscopic images. Photo 2 is another example of writing stereoscopic lines on stereoscopic images. In this case, stereopair lines are written one by one. Photo 6 is another example of drawing stereoscopic lines. In this case, stereopair lines can be written at one time, but the hight of the line in the 3D image can not be changed. This mode can be used to draw contour lines.
Photo 6 Drawing stereopair lines at one time
4. An example of the utilization of stereoscopic image processing
This stereoscopic image processing software can be used in many fields, such as earth resource exploration, route selection, dam construction, wide area development, etc., The experiments of the utilization of this software have already been done in some fields. Photo 7 is an application example in the field of earth resource exploration. In the photo 7, broken lines are faults, filled dots are hot springs and small marks like eyes are veins. These informations were written of a orthoimage using the calculation program developed in this system, and then transformed to stereoscopic images. The B/H ratio of these stereoscopic images is 0.5, which is the most suitable value in this case. Looking at these stereoscopic images with liquid crystal shutter glasses, observers can t=get a precise topographic information together with images and other important informations, can draw dots and lines on these stereoscopic images to indicate the results of image analysis.
Photo 7 An example of stereoscopic image processing
5. Conclusion
A stereoscopic image processing software has been developed on a PC system which was originally developed as a digital photogrametric system. The system has a special 3D display module which has an ability to display stereoscopic drawings together with stereoscopic images.
Besides usual image processing programs, the functions of which are similar to ordinary ones in a two dimensional image processing system, a 3D graphic program has also been developed. The latter one can be used to draw stereoscopic points, lines, etc., on stereoscopic images. By using this system, many informations about stereoscopic images can be informed from operator to computer. This system has a powerful man-machine interface ability. The usefulness of this ability has been explained in paper in the field of digital photogrametry and earth resource exploration. This system has high application potential in many fields.
Finally I would like to express my appreciation to the members of Murai laboratory in Tokyo university and NEC corporation for their contributions to this research.
Reference
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M. Boulianne, P.A. Gagnon. J.P. Agnard, C. Nolette; Large Scale Map Revision Using a PC-Based Videoplotter; Issprs Com. 4, Tsuduba, May, 1990,pp. 273-279.
- N.Mori, S.Murai, X.Bai; Development of a New Method Attaching precise Topographic Information to Gis by Using 3D Display; ACRS, China, Nov., 1990.pp.H.2.41-H24.6
- N.Mori, T. Tagawa, S.Murai, S.Ito;DTM Extraction and Its Application Using a Digital Stereo-scopic Image Processing System with 3D Display; ACRS, Singapore, Nov., 1991, pp.p.8.1-p.8.6 4.N.Mori, S.Masuda, S.Murai; Development of a PC-Basd Digital Photogrametric System; ISPRS, Washington, Aug., 1992B2-2,pp. 319-322.
