Abstract: A system for locating at least one object within an intensity image is disclosed. The system includes means for analyzing the intensity image with at least two different edge detectors to detect a multiplicity of edges oriented in at least two directional ranges. First comparing means is provided for comparing information representative of detected edges angularly oriented in a first directional range and information representative of detected edges angularly oriented in a second directional range. Means for selecting at least one foreground region in the intensity image is also included. The detected edges in the selected foreground region are angularly oriented substantially in accordance with a target orientation.

Abstract: A system for determining the fine angular orientation of a bar code symbol in a two-dimensional pixel image. A window is selected from the two-dimensional image for processing. Edge magnitude information and edge direction information are determined for a plurality of pixels in the selected window. For each pixel in the plurality of pixels, the edge magnitude and the edge direction of each pixel is associated with at least one of a plurality of directional ranges if the edge magnitude associated with the pixel exceeds a threshold. For each directional range in the plurality of directional ranges, a density value associated with each directional range is determined in accordance with the number of pixels associated with the directional range, an angular mean value is determined in accordance with the edge directions associated with the directional range, and a noise value is determined in accordance with the edge directions associated with the directional range.

Abstract: A system for simultaneously convolving first and second digital binary images in parallel with a single convolver having a binary mask. A first window is selected from the first digital binary image and a second window is selected from the second digital binary image. A first binary pixel is selected from the first window and a second binary pixel is selected from the second window. The first binary pixel is bit-shifted by concatenating a plurality of trailing zero bits to the first binary pixel. A multi-bit input pixel is formed by combining the bit-shifted first binary pixel and the second binary pixel. A single multi-bit output value is generated by simultaneously applying a plurality of multi-bit input pixels to a single convolver.

Abstract: A method and apparatus for decoding a pixel image representative of a bar code symbol. A bar code symbol is scanned along a first scan line to determine a first set of candidate character values, each candidate character value of this first set having an error value associated therewith. If the scanning along the first scan line results in an unsuccessful reading of the bar code symbol, then the bar code symbol is scanned along a second differing scan line to determine a second set of candidate character values, each candidate character value of this second set having an error value associated therewith. Corresponding error values associated with the first and second sets of candidate character values are next compared. For each corresponding pair of candidate character values from the first and second sets, the candidate character value having the smallest associated error value is selected.

Abstract: A method and apparatus for decoding a pixel image representative of a bar code symbol. The bar code symbol is comprised of a plurality of encoded character values each of which corresponds to one of a plurality of prototype bar patterns, wherein each of the prototype bar patterns has a set of predetermined bar width feature values associated therewith. A set of bar width information estimates is determined from the pixel image. The set of bar width information estimates being representative of a character value stored in the bar code symbol. The set of bar width estimates is compared to a selected set of predetermined bar width feature values. Based on this comparison, it is determined whether the character value stored in the bar code symbol corresponds to the selected set of predetermined bar width information values.

Abstract: A method for determining the displacement in six degrees of freedom of a rectangular planar surface with respect to a reference position includes providing a reference image having projections of a defined lighting pattern having at least six points on a reference rectangular planar surface in the reference position, the six points including first, second and third points on the reference surface, fourth and fifth points at the intersections of a first edge of the reference surface, and, respectively, first and second parallel lines in the plane of the reference surface and perpendicular to the first edge, and a sixth point at the intersection of a second edge of the reference surface and a third line in the plane of the reference surface and perpendicular to the second edge, the first edge being perpendicular to the second edge, and the first and second points being in known relationship with the first, second and third lines.

Abstract: A system is disclosed for processing a two dimensional digital image representative of a bar code symbol. The bar code symbol is oriented in a bar direction. The system includes means for dividing the two dimensional image into a plurality of two dimensional sections perpendicular to the bar direction. Means for determining information representative of the intensity of a plurality of such sections is also provided. A one dimensional intensity projection signal is formed from the determined information. The system also includes means for calculating the areas of a plurality of regions described by the projection signal. The widths of a plurality of bars in the bar code symbol are determined from the calculated areas.