Method and apparatus for pattern recognition and detection

A method of detecting patterns in an image consisting of a matrix of multivalued digital data signals, said method comprising:

• (a) electronically dilating the image matrix with a structuring element of a particular configuration to form a first transformation matrix;
• (b) electronically eroding the first transformation matrix by the same structuring element used in step (a) to form a second transformation matrix;
• and
• (c) comparing said first and second transformation matrices to detect patterns in the original image matrix.

A method of detecting patterns of a particular configuration in a three-dimensionally sensed scene represented by a matrix of data points in the form of multivalued digital data signals having values corresponding to the relative distances between points in the scene and a sensor, said method comprising:

• (a) electronically eroding the original scene matrix with a structuring element of a particular configuration to form an erosion transformation matrix;
• (b) electronically dilating the erosion transformation matrix by the same structuring element used in step (a) to form a ground plane estimated transformation matrix;
• and
• (c) comparing said ground plane estimated matrix with the original scene matrix to form a ground plane normalized matrix to detect the location of the desired object in the original scene.

A method of detecting pattern configurations in a three-dimensional scene represented by stream of multivalued digital data signals having values corresponding to points in a matrix constituting the scene, said method comprising:

• (a) repetitively loading said signals into a plurality of storage devices in a transformation stage to sequentially access substantially each neighborhood of points in the matrix, said neighborhood including a central data point and its surrounding points in the matrix;
• (b) modifying the values of selected data points in the storage devices to provide new values for particular data points;
• (c) comparing the modified data point values to select the maximum value thereof;
• (d) supplying said maximum value to a chain of subsequent substantially identical stages;
• (e) repeating steps (a)-(d) in said subsequent stages to form a transformed ground plane estimated matrix devoid of the pattern to be detected;
• and
• (f) subtracting in a digital circuit network each data point of the ground plane estimated matrix from each data point in the original scene matrix, with the remaining data points representing the location of the desired pattern configuration in the original scene.

A method of analyzing an image having points therein represented by digital data signals, said method comprising:

• (a) serially feeding said digital data signals to an input of at least one programmable neighborhood transformation stage;
• (b) sequentially accessing a plurality of said signals corresponding to a neighborhood of points in the image, with said neighborhood including a central point and its surrounding points in the image;
• (c) programming the stage with contribution values, each contribution value being associated with a point in the neighborhood;
• (d) selectively modifying the values of the data signals in the neighborhood with their associated contribution value to form modified digital data signals;
• (e) comparing the values of the modified digital data signals;
• and
• (f) providing the maximum value of the signals associated with the neighborhood of points as a transformation output signal for each of the neighborhood of points in the image.

Apparatus for analyzing an image represented by digitial data signals whose values represent characteristics of particular points in the image, said apparatus comprising:

• a digital controller, and at least one programmable transformation stage coupled to the controller, said stage including:
• neighborhood extraction means for sequentially accessing a plurality of said signals corresponding to a neighborhood including a central point and its surrounding points in the image;
• programmable contribution circuit means having means for receiving contribution values from the controller, each contribution value being associated with a given point in the neighborhood, said circuit means further including means for selectively modifying the values of the signals associated with the neighborhood of points with their associated contribution value to form modified digital data signals;
• and
• transformation generator means for comparing the values of the modified digital data signals and selecting extreme values thereof as an output signal of the stage.

Apparatus for analyzing an image represented by multivalued digital data signals having values associated with points in a matrix constituting the image, said apparatus comprising:

• a chain of substantially identical neighborhood transformation stages, each stage having a data input for receiving the digital data signals from a preliminary stage, neighborhood extraction means including a plurality of storage devices for temporarily storing values of said data signals associated with a neighborhood in the matrix comprised of a central point and its surrounding points in the matrix, means for loading the data signals into the storage devices to sequentially access substantially all of the neighborhoods in the matrix, a transformation generator portion including neighborhood contribution circuit means coupled to the neighborhood extraction means for operating on the values of the data signals associated with the points in the neighborhood when they are loaded into the storage devices, operative to modify the values of the data signals associated with the accessed neighborhood and maximum value selection means coupled to said neighborhood contribution circuit means for selecting the maximum value associated with the modified values and providing said maximum value as the transformation output signal to the next stage;
• and
• central controller means coupled to the neighborhood contribution circuit means of each stage for selectively altering the operation on the neighborhood of points in each stage.