Hand-supportable digital imaging-based bar code symbol reading system automatically processing captured images along parallel virtual scan lines based on the maximum pixel height of the region of interest (ROI)
First Claim
1. A hand-supportable digital imaging-based bar code symbol reading system, comprising:
- a hand-supportable housing;
an image formation and detection subsystem having image formation optics for producing a field of view (FOV) upon an object to be imaged and an area-type image sensing array for detecting imaged light reflected off the object during illumination operations in an image-capture mode in which substantially all rows of said area-type image sensing array are enabled;
a LED-based illumination subsystem having an LED illumination array for producing a field of narrow-band illumination within said FOV during said image-capture mode;
an image capturing and buffering subsystem for capturing and buffering a digital image of the object detected by said image formation and detection subsystem;
an image-processing based bar code symbol reading subsystem for processing said digital image by a method of reading 1D or 2D bar code symbols graphically represented in said captured digital image, wherein said method comprises the steps of;
(1) processing said captured digital image along a set of parallel virtual scan lines spaced-apart by a number of pixel-offset distances, said processing involving(i) determining a region of interest (ROI) in said digital image containing a bar code symbol, and(ii) determining the maximum pixel height of said ROI, and(iii) computing the number of pixel-offset distances that is proportional to the maximum pixel height of said ROI;
(2) detecting and examining the zero-crossings along the virtual scan lines;
(3) creating bar and space patterns from detected zero-crossings; and
(4) decoding the bar and space patterns using one or more decoding algorithms; and
a system control subsystem for controlling and coordinating said subsystems.
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Accused Products
Abstract
A hand-supportable digital imaging-based bar code symbol reading system comprises: an automatic object presence detection subsystem; an image formation and detection subsystem having an area-type image sensing array with a field of view (FOV); a LED-based illumination subsystem having an LED illumination array for producing a field of narrow-band illumination within the FOV; an automatic light exposure measurement and illumination control subsystem; an image capturing and buffering subsystem; an image-processing bar code symbol reading subsystem; an input/output subsystem; and a system control subsystem for controlling the subsystems. The image-processing bar code symbol reading subsystem has a mode of image processing, wherein a captured digital image is automatically processed along a set of parallel virtual scan lines spaced-apart by a number of pixel-offset distances proportional to the maximum pixel height of the region of interest (ROI) in the captured digital image containing a bar code symbol.
155 Citations
8 Claims
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1. A hand-supportable digital imaging-based bar code symbol reading system, comprising:
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a hand-supportable housing; an image formation and detection subsystem having image formation optics for producing a field of view (FOV) upon an object to be imaged and an area-type image sensing array for detecting imaged light reflected off the object during illumination operations in an image-capture mode in which substantially all rows of said area-type image sensing array are enabled; a LED-based illumination subsystem having an LED illumination array for producing a field of narrow-band illumination within said FOV during said image-capture mode; an image capturing and buffering subsystem for capturing and buffering a digital image of the object detected by said image formation and detection subsystem; an image-processing based bar code symbol reading subsystem for processing said digital image by a method of reading 1D or 2D bar code symbols graphically represented in said captured digital image, wherein said method comprises the steps of; (1) processing said captured digital image along a set of parallel virtual scan lines spaced-apart by a number of pixel-offset distances, said processing involving (i) determining a region of interest (ROI) in said digital image containing a bar code symbol, and (ii) determining the maximum pixel height of said ROI, and (iii) computing the number of pixel-offset distances that is proportional to the maximum pixel height of said ROI; (2) detecting and examining the zero-crossings along the virtual scan lines; (3) creating bar and space patterns from detected zero-crossings; and (4) decoding the bar and space patterns using one or more decoding algorithms; and a system control subsystem for controlling and coordinating said subsystems. - View Dependent Claims (2, 3, 4, 5)
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6. A method of processing captured digital images within a hand-supportable digital imaging-based bar code symbol reader in order to decode bar code symbols graphically represented in a captured digital image, said method comprising the steps of:
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(a) providing a hand-supportable imaging-based bar code symbol reader having an area-type image sensing array with a field of view (FOV); (b) positioning an object to be imaged within the FOV of said hand-supportable imaging-based bar code symbol reader; (c) producing a field of LED-based illumination from said hand-supportable imaging-based bar code symbol reader, and illuminating said object within said FOV; (d) within said hand-supportable digital imaging-based bar code symbol reader, forming and detecting a digital image of the object illuminated during step (c); (e) within said hand-supportable digital imaging-based bar code symbol reader, capturing and buffering said digital image formed and detected in step (d); (f) within said hand-supportable digital imaging-based bar code symbol reader, processing said captured digital image along a set of parallel virtual scan lines spaced-apart by a number of pixel-offset distances, said processing involving comprising the steps (1) determining a region of interest (ROI) in said digital image containing a bar code symbol, and (2) determining the maximum pixel height of said ROI, and (3) computing the number of pixel-offset distances that is proportional to the maximum pixel height of said ROI; (g) detecting and examining the zero-crossings along said set of parallel virtual scan lines; (h) creating bar and space patterns from the detected zero-crossings; and (i) decoding the bar and space patterns using conventional decoding algorithms. - View Dependent Claims (7, 8)
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Specification