Transitions Research Corporation

Carl F Weiman

John M Evans, Jr

Steven J King

William Pong

Video image compression apparatus and method provides full color, wide field of view, real time imagery having high central resolution. Compression ratios of 1600:1 are achieved thus reducing a required data transmission bandwidth sufficiently to abolish line-of-sight restrictions. Data compression apparatus and method (a) uses a log polar mapper to match the image display to human perceptual resolution to achieve a 25:1 compression ratio with no loss of perceived cues, (b) separates perceptual channels into low resolution, high discrimination level color and high resolution, low discrimination level contrast edges to yield an additional 8:1 compression ratio and (c) applies a data compression technique to yield an additional 8:1 compression ratio. A Gaussian filter is employed in generating a display of the imagery from the compressed data. An operator is provided a capability to rapidly move the high resolution window to any point of interest within the display.

Digital image compression employing a resolution gradient

Image processing method and apparatus wherein candidate points are first selected in a log-polar image domain. The points may be selected by edge detection, thresholding, or any method suitable for identifying image points which are likely to lie on some feature of interest. For every candidate point there is drawn, also in the log-polar domain, a mirror image of a curve that represents the log-polar image of a straight line. There is accumulated a log-polar domain histogram of 'hits' from the drawing process. Finally, a peak bin is selected. The position of the peak bin corresponds to the position of the recognized line.

Method and means for recognizing patterns represented in logarithmic

Apparatus and method which provides for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of a retroreflective ceiling feature. A mobile robot 10 includes a light source 28 and a camera 12 that are pitched up obliquely at an intermediate angle between a horizon and a zenith. The camera views a ceiling having one or more strip-like retroreflective features 16 which are preferably aligned with an axis of the hallway. In that the feature presents a pattern or alignment which is substantially parallel to a long axis of the hallway the pattern is detected and processed to derive robot navigation information therefrom.

Mobile robot navigation employing retroreflective ceiling features

A vision system for a vehicle, such as a mobile robot (10) includes at least one radiation projector (14, 16) which projects a structured beam of radiation into the robot's environment. The structured beam of radiation (14a, 16a) preferably has a substantially planar pattern of sufficient width to encompass the immediate forward path of the robot and also to encompass laterally disposed areas in order to permit turning adjustments. The vision system further includes an imaging (12) sensor such as a CCD imaging device having a two-dimensional field of view which encompasses the immediate forward path of the robot. An image sensor processor (18) includes an image memory (18A) coupled to a device (18D) which is operable for accessing the image memory. Image processing is accomplished in part by triangulating the stored image of the structured beam pattern to derive range and bearing, relative to the robot, of a object being illuminated. A navigation control system (20) of the robot inputs data from at least the vision system and infers therefrom data relating to the configuration of the environment which lies in front of the robot. The navigation control system generates control signals which drive propulsion and steering motors in order to navigate the robot through the perceived environment.

Visual navigation and obstacle avoidance structured light system

A non-linear digital filter system for image data or other signal data suppresses undesirable noise while enhancing significant characteristics of the data. Data elements in a neighborhood (window) defined around and including an input data element are classified into characteristic classes based on their parameter value range. The class with the maximum population is selected as most representative of the neighborhood. A data value associated with that class is chosen as the output of the filter for the input data element around which the neighborhood is defined, to thereby form a plurality filter. As an alternative, the class holding more than half the data elements in the neighborhood is chosen as most representative, to form a majority filter. In case there is no class containing more than half the elements in a neighborhood, the output of the filter equal the value characteristic of the class in which the input pixel itself falls. In a further heterogeneity filter version, a data element for whose neighborhood there is no majority class is replaced by a '1'; a pixel for whose neighborhood there is a majority class is replaced by a '0'. In the case of image data, the '1' value may represent a black intensity or a white intensity, in which case the '0' represents the opposite intensity.

Processing system and method for enhancing image data

A vision system for a vehicle, such as a mobile robot (10) includes at least one radiation projector (14, 16) which projects a structured beam of radiation into the robot's environment. The structured beam of radiation (14a, 16a) preferably has a substantially planar pattern of sufficient width to encompass the immediate forward path of the robot and also to encompass laterally disposed areas in order to permit turning adjustments. The vision system further includes an imaging (12) sensor such as a CCD imaging device having a two-dimensional field of view which encompasses the immediate forward path of the robot. An image sensor processor (18) includes an image memory (18A) coupled to a device (18D) which is operable for accessing the image memory. Image processing is accomplished in part by triangulating the stored image of the structured beam pattern to derive range and bearing, relative to the robot, of an object being illuminated. A navigation control system (20) of the robot inputs data from at least the vision system and infers therefrom data relating to the configuration of the environment which lies in front of the robot. The navigation control system generates control signals which drive propulsion and steering motors in order to navigate the robot through the perceived environment.

Apparatus and method which provides for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of ceiling lights. A mobile robot 10 includes a camera 12 that is pitched up obliquely at an intermediate angle between a horizon and a zenith. The camera views a ceiling having one or more ceiling lights 16 which may be of rectangular shape and which are preferably aligned with an axis of the hallway. In that the lights present a pattern or alignment which is substantially parallel to or perpendicular to a long axis of the hallway the pattern is detected and processed to derive robot navigation information therefrom.

Mobile robot navigation employing ceiling light fixtures

A vision system for a mobile robot 10 comprises an optical sensor subsystem 20 which generates a substantially one dimensional image of an environment, a signal processing subsystem 24 for extracting and enhancing significant vertical visual features from the one dimensional image and a feature processing system 26 which analyses rapidly and in real time the extracted features for use by a control system 28 for navigation of the robot. The optical sensor may be a line scan camera having a plurality of outputs which relate to brightness values received from the environment. Triangulation, optical flow and optical flow with log transforms methods are disclosed for processing the one dimensional image data to yield azimuth and/or distance to an object within the environment. Also disclosed is a binocular vision system which generates two, one dimensional images and a method of processing same.

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Westport, CT, United States of America

Carl F Weiman