291 research outputs found
The Facts of Light
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-70-A-0362-0005.This is a random collection of facts about radiant and luminous energy. Some of this information may be useful in the design of photo-diode image sensors, in the set-up of lighting for television microscopes and the understanding of the characteristics of photographic image output devices. A definition of the units of measurement and the properties of lambertian surfaces is included.MIT Artificial Intelligence Laboratory
Department of Defense Advanced Research Projects Agenc
Notes Relating to the Design of a High Quality Image Sensor
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-70-A-0362-0005.Some of the information that as used in arriving at a design for a high quality image input device is documented. The device uses a PIN photo-diode directly coupled to an FET-input op-amp as the sensor and two moving-iron galvanometer-driven mirrors as the deflection system. The disadvantages of a system like this are its long random access time (about 4 milli-seconds) and the long settling time of the diode-amplifier system (about 1 milli-seconds). In almost all other respects such a sensor is superior to other known image sensors. Pictures taken with this device have shown that some of the difficulties experienced in image analysis can be directly traced to the low quality of images read in through vidicons and image dissectors.MIT Artificial Intelligence Laborator
Kinematics, Statics, and Dynamics of Two-D Manipulators
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-70-A-0362-0005.In order to get some feeling for the kinematics, statics, and dynamics of manipulators, it is useful to separate the problem of visualizing linkages in three-space from the basic mechanics. The general-purpose two-dimensional manipulator is analyzed in this paper in order to gain a basic understanding of the issues without the complications of three-dimensional geometry.MIT Artificial Intelligence Laborator
The Binford-Horn LINEFINDER
This paper briefly describes the processing performed in the course of producing a line drawing from vidisector information.MIT Artificial Intelligence Laboratory Vision Grou
What is Delaying the Manipulator Revolution?
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory's artificial intelligence research is provided in part by the Office of Naval Research of the Department of Defense under ONR contract N00014-77-C-0389.Despite two decades of work on mechanical manipulators and their associated controls, we do not see wide-spread application of these devices to many of the tasks to which they seem so obviously suited. Somehow, a variety of interacting causes has conspired to prevent them from fulfilling their much talked about potential. In part, this appears to be the result of a research effort that was too small, too fragmented, and too discontinuous in time.MIT Artificial Intelligence Laboratory
Department of Defense Office of Naval Researc
Vision Review
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-75-C-0643.MIT Artificial Intelligence Laboratory
Department of Defense Advanced Research Projects Agenc
Kinematics of the MIT-AI-VICARM Manipulator
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-70-A-0362-0005.This paper describes the basic geometry of the electric manipulator designed for the Artificial Intelligence Laboratory by Victor Scheinman while on leave from Stanford University. The procedure for finding a set of joint angles that will place the terminal device in a desired position and orientation is developed in detail. This is on of the basic primitives that an arm controller should have. The orientation is specified in terms of Euler-angles. Typically eight sets of joint angles will produce the same terminal device position and orientation.MIT Artificial Intelligence Laborator
Looking in the Shadows
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-75-C-0643.The registration of an image with a model of the surface being imaged is an important prerequisite to many image understanding tasks. Once registration is achieved, new image analysis techniques can be explored. One approach is to compare the real image with an image synthesized from the surface model. But, accurate comparison requires and accurate synthetic image.
More realistic synthetic images can be obtained once shadow information is included. Accurate shadow regions can be determined when a hidden-surface algorithm is applied to the surface model in order to calculate which surface elements can be seen from the light source. We illustrate this technique using LANDSAT imagery registered with digital terrain models. Once shadow information is included, the effect of sky illumination and atmospheric haze can be measured.MIT Artificial Intelligence Laborator
The Application of Linear Systems Analysis to Image Processing. Some Notes.
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-70-A-0362-0005.The Fourier transform is a convenient tool for analyzing the performance of an image-forming system, but must be treated with caution. One of its major uses is turning convolutions into products. It is also used to transform a problem that is more naturally thought of in terms of frequency than time or space. We define the point-spread function and modulation transfer function in a two-dimensional linear system as analogues of the one-dimensional impulse response and its Fourier transform, the frequency response, respectively. For many imagine devices, the point-spread function is rotationally symmeteric. Useful tranforms developed for the special cases of a "pill box,", a gaussian blob, and an inverse scatter function.
Fourier methods are appropriate in the analysis of a defocused imaging system. We define a focus function as a weighted sum of high frequency terms in the spectrum of the system. This function will be a maximum when the image is in focus, and we can hill-climb on it to determine the best focus. We compare this function against two others, the sum of squares of intensities, and the sum of square of first differences, and show it to be superior.
Another use of the Fourier transform is in optimal filtering, that is, of filtering to separate additive noise from a desired signal. We discuss the theory for the two-dimensional case, which is actually easier than for a single dimension since causality is not an issue. We show how to consumerist a linear, shift-invariant filter for imaging systems given only the input power spectrum and cross-power spectrum of input versus desired output.
Finally, we present two ways to calculate the line-spread function given the point-spread function.MIT Artificial Intelligence Laborator
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