US 8,800,874 B2 · Systems and methods of optical code reading using a color imager

Abstract

Systems and methods of optical code reading include production of image data by a color image sensor array and processing of the image data to decode an optical code. In one configuration, the color image sensor array includes first and second sets of sensor pixels sensitive to light having wavelengths within, respectively, first and second wavelength bands, reflected light is focused by an optical system to form an image of an optical code on the color image sensor array, first and second sets of image data representing light intensity levels sensed by, respectively, the first and second sets of sensor pixels are produced, and the first set of image data is processed to determine whether the second set of image data is to be used in combination with the first set of image data to decode the optical code.

Claims37

Dependent claims

A method of data reading comprising the steps of:

illuminating a field of view of an optical code reader to produce light reflected from an optical code toward an optical system of the optical code reader;
focusing with the optical system the reflected light to form an image of the optical code on a color image sensor array of the optical code reader, the color image sensor array including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band, and
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band;
producing multiple sets of image data including a first set of image data representing light intensity values of light sensed by the first set of sensor pixels and a second set of image data representing light intensity values of light sensed by the second set of sensor pixels;
selecting a target set of image data from the multiple sets of image data by evaluating statistical characteristics of the light intensity values of the first and second sets of image data, the statistical characteristics corresponding to intensity variations of the light intensity values;
and
processing the target set of image data to attempt to decode the optical code.

5 more elements

A method of data reading, comprising:

illuminating a field of view of an optical code reader to produce light reflected from an optical code toward an optical system of the optical code reader;
focusing with the optical system the reflected light to form an image on an array of sensor pixels of a color image sensor array positioned in the optical code reader, the image including an image of the optical code, and the array of sensor pixels including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band,
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band, and
a third set of sensor pixels sensitive to light having a wavelength within a third wavelength band different from the first and second wavelength bands;
producing first, second, and third sets of image data representing light intensity values sensed by, respectively, the first, second, and third sets of sensor pixels;
processing the first set of image data to identify a feature of the optical code that enables categorization of the optical code into one of a number of symbology types;
estimating a size of an image of the feature representing a number of sensor pixels of the first, second, and third sets on which the image of the feature is formed to thereby determine whether the image of the optical code is sufficiently large relative to the array of sensor pixels to enable decoding of the optical code using a combination of the first, second, and third sets of image data.

5 more elements

A method of data reading, comprising:

illuminating a field of view of an optical code reader to produce light reflected from an optical code toward an optical system of the optical code reader;
focusing with the optical system the reflected light to form an image of the optical code on a color image sensor array of the optical code reader, the color image sensor array including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band,
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band, and
a third set of sensor pixels sensitive to light having a wavelength within a third wavelength band different from the first and second wavelength bands;
producing image data representing light intensity values sensed by at least one of the first, second, or third sets of sensor pixels;
determining from the image data a percentage of the light intensity values that are below a selected light intensity threshold value;
comparing the determined percentage to a selected percentage;
and
processing the image data to attempt to decode the optical code in response to the determined percentage being less than the selected percentage.

7 more elements

An optical code reader, comprising:

a color image sensor array including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band, the first set of sensor pixels configured to produce a first set of image data representing sensed light intensity values, and
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band, the second set of sensor pixels configured to produce a second set of image data representing sensed light intensity values;
an optical system configured to direct light on the color image sensor array to form an image of an optical code on the color image sensor array;
a data processing system configured to receive the first and second sets of image data, the data processing system including:
a calculation unit configured to determine a first statistical characteristic of the intensity values of the first set of image data and a second statistical characteristic of the intensity values of the second set of image data,
a comparison unit configured to compare the first and second statistical characteristics and identify a highest intensity variation among the first and second statistical characteristics,
a data set selection unit configured to select as a target set of image data one of the first or second sets of image data based on the comparison performed by the comparison unit, the target set of image data having the highest intensity variation among the first and second statistical characteristics, and
a low-resolution decoding unit configured to receive the target set of image data and process the target set of image data to thereby attempt to decode the optical code using the target set of image data.

6 more elements

A method of data reading comprising the steps of:

illuminating a field of view of an optical code reader to produce light reflected from an optical code toward an optical system of the optical code reader;
focusing with the optical system the reflected light to form an image of the optical code on a color image sensor array of the optical code reader, the color image sensor array including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band, and
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band;
producing multiple sets of image data including a first set of image data representing light intensity values of light sensed by the first set of sensor pixels and a second set of image data representing light intensity values of light sensed by the second set of sensor pixels;
selecting a target set of image data from the multiple sets of image data by evaluating statistical characteristics of the light intensity values of the first and second sets of image data, the statistical characteristics corresponding to intensity variations of the light intensity values, wherein the statistical characteristics correspond to (a) a first standard deviation of the light intensity values of the first set of image data and (b) a second standard deviation of the light intensity values of the second set of image data;
and
processing the target set of image data to attempt to decode the optical code.

5 more elements

An optical code reader, comprising:

a color image sensor array including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band, the first set of sensor pixels configured to produce a first set of image data representing sensed light intensity values,
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band, the second set of sensor pixels configured to produce a second set of image data representing sensed light intensity values, and
a third set of sensor pixels sensitive to light having a wavelength within a third wavelength band, the third set of sensor pixels configured to produce a third set of image data representing sensed light intensity values;
an optical system configured to direct light on the color image sensor array to form an image of an optical code on the color image sensor array;
a data processing system configured to receive the first, second, and third sets of image data, the data processing system including:
a calculation unit configured to determine a first statistical characteristic of the intensity values of the first set of image data, a second statistical characteristic of the intensity values of the second set of image data, and a third statistical characteristic of the intensity values of the third set of image data, wherein the first, second, and third statistical characteristics are, respectively, first, second, and third standard deviations,
a comparison unit configured to compare at least two of the first, second, and third statistical characteristics and identify a highest intensity variation among the at least two of the first, second, and third statistical characteristics,
a threshold comparison unit configured to compare at least one of the first, second, and third standard deviations to a selected standard deviation threshold value to determine whether said at least one of the first, second, and third standard deviations is greater than the selected standard deviation threshold value,
a data set selection unit configured to select as a target set of image data at least one of the first, second, and third sets of image data based on the comparison performed by the comparison unit, the target set of image data having the highest intensity variation among the first, second, and third statistical characteristics, and
a low-resolution decoding unit configured to receive the target set of image data and process the target set of image data to thereby decode the optical code in response to the threshold comparison unit determining that said at least one of the first, second, and third standard deviations is greater than the selected standard deviation threshold value.

8 more elements

An optical code reader, comprising:

a color image sensor array including:
a first set of sensor pixels sensitive to light having a wavelength within a first wavelength band, the first set of sensor pixels configured to produce a first set of image data representing sensed light intensity values,
a second set of sensor pixels sensitive to light having a wavelength within a second wavelength band different from the first wavelength band, the second set of sensor pixels configured to produce a second set of image data representing sensed light intensity values, and
a third set of sensor pixels sensitive to light having a wavelength within a third wavelength band, the third set of sensor pixels configured to produce a third set of image data representing sensed light intensity values;
an optical system configured to direct light on the color image sensor array to form an image of an optical code on the color image sensor array;
a data processing system configured to receive the first, second, and third sets of image data, the data processing system including:
a calculation unit configured to determine a first statistical characteristic of the intensity values of the first set of image data, a second statistical characteristic of the intensity values of the second set of image data, and a third statistical characteristic of the intensity values of the third set of image data,
a comparison unit configured to compare at least two of the first, second, and third statistical characteristics and identify a highest intensity variation among the at least two of the first, second, and third statistical characteristics,
a histogram comparison unit configured to:
generate a histogram of the light intensity values of at least one of the first, second, and third sets of image data,
determine a percentage of the light intensity values of the at least one of the first, second, and third sets of image data that are below a selected light intensity threshold value, and
compare the determined percentage to a selected percentage,
a data set selection unit configured to select as a target set of image data at least one of the first, second, and third sets of image data based on the comparison performed by the comparison unit, the target set of image data having the highest intensity variation among the first, second, and third statistical characteristics, and
a low-resolution decoding unit configured to receive the target set of image data and process the target set of image data to thereby attempt to decode the optical code using the target set of image data in response to the histogram comparison unit determining that the determined percentage is below the selected percentage.

11 more elements

Dependencies are inferred from the claim text.

Systems and methods of optical code reading using a color imager

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Systems and methods of optical code reading using a color imager

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Abstract

Claims37