Computer-implemented system and method for color sensing, storage and comparison

• US 10,057,549 B2
• Filed: 05/01/2015
• Issued: 08/21/2018
• Est. Priority Date: 11/02/2012
• Status: Active Grant

• Current Assignee: Variable Inc.
• Original Assignee: Variable Inc.
• Inventors: Yu, George Yang, Temple, Andrew Richard, Gasior, Wade
• Primary Examiner(s): Chen, Chia-Wei A
• Application Number:
  US14/702,236
• Publication Number:
  US 20150296189A1
• Time in Patent Office: 1,208 Days
• Field of Search: 348263, 3482231, 3482271
• CPC Class Codes: G01J 3/0262 Constructional arrangements for removing stray light
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0275 making use of sensor-related data, e.g. for identification of sensor parts or optical elements
• CPC Class Codes: G01J 3/0286 Constructional arrangements for compensating for fluctuations caused by temperature, humidity or pressure, or using cooling or temperature stabilization of parts of the device; Controlling the atmosphere inside a spectrometer, e.g. vacuum
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: H04N 23/12 with one sensor only
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/52 Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 23/631 Graphical user interfaces [GUI] specially adapted for controlling image capture or setting capture parameters

Abstract

A modular device includes base and color sensing portions. The color sensing portion has a face, a controlled light source offset from the face to define an interior, the face configured to engage a target surface about a perimeter of the device housing wherein ambient light is restricted from entering the interior. A color sensor receives light reflected from the target surface and generates output signals representative of a surface color. The base portion communicates with the color sensor and a user device having a hosted program which generates a user interface enabling users to provide control input for the color sensor. The program further receives the output signals from the color sensing device and displays a first image of the detected color, and displays a second image of a user-selected color beside the first image. Color data values are further displayed corresponding to the difference between displayed colors.

Claims

1. A color sensing system comprising:

a color sensing device further comprising

a housing having an external perimeter about a length thereof, and a face defining a plane perpendicular to said length,

a substrate residing within the housing, oriented in parallel with and offset from the plane defined by the face to define an interior within the perimeter of the housing, the face configured to engage a target surface about the perimeter of the housing wherein ambient light is substantially restricted from entering the interior,

a controlled light source and a color sensor mounted to the substrate, wherein the controlled light source comprises a plurality of light-emitting diodes circumferentially disposed about the color sensor and configured to collectively emit light having a common color temperature,

a controller configured to control the plurality of light-emitting diodes to be turned off or on across a plurality of lighting power levels in response to an input control signal,

the color sensor arranged to receive light radiated by the controlled light source and reflected from the target surface when the face of the color sensing device engages the target surface, the sensor further effective to generate output signals representative of a color of the target surface, and

a memory storing a matrix of device-specific calibration values, wherein the controller is further effective to convert output from the color sensor to tristimulus values using a priori estimation with respect to the calibration values;

a computing device having a display unit and a computer program product residing thereon, the computer program product executable to direct the performance of operations comprising

generating a user interface via the display unit enabling a user to select from a plurality of available lighting conditions for the color sensing device,

transmitting control signals to the color sensing device corresponding to the selected lighting condition,

receiving the output signals from the color sensing device,

generating a first image comprising the color represented by said output signals on the display unit of the computing device,

enabling a user to select one or more of a plurality of colors stored in a database, and

generating at least a second image comprising the selected one or more colors alongside the first image.

2. The system of claim 1, wherein the matrix of device-specific calibration values is generated via a series of operations comprising:

converting known MacBeth CIE Lab values to CIE XYZ tristimulus values based on d50 light,

performing chromatic adaptation of the tristimulus values using a Bradford transform,

providing raw sensor calibration measurements from the color sensing device with respect to a color reference, and

generating a sensor to CIE tristimulus matrix based on the tristimulus values and the raw sensor calibration measurements.

3. The system of claim 1, wherein the plurality of light-emitting diodes are configured to collectively define a controlled 6500 Kelvin light source.

4. The system of claim 1, further comprising a cover mounted to the substrate and about the color sensor, wherein the plurality of light-emitting diodes are circumferentially arranged about the cover, the cover further comprising an aperture between the color sensor and the face of the housing whereby reflected light from a color sample is passed through the cover and to the color sensor.

5. A color sensing device comprising:

a housing having an external perimeter about a length thereof, and a face defining a plane perpendicular to said length;

a substrate residing within the housing, oriented in parallel with and offset from the plane defined by the face to define an interior within the perimeter of the housing, the face configured to engage a target surface about the perimeter of the housing wherein ambient light is substantially restricted from entering the interior;

a controlled light source and a color sensor mounted to the substrate, wherein the controlled light source comprises a plurality of light-emitting diodes circumferentially disposed about the color sensor and configured to collectively emit light having a common color temperature;

a controller configured to control the plurality of light-emitting diodes to be turned off or on across a plurality of lighting power levels in response to an input control signal,

the color sensor arranged to receive light radiated by the controlled light source and reflected from the target surface when the face of the color sensing device engages the target surface, the sensor further effective to generate output signals representative of a color of the target surface;

a memory storing a matrix of device-specific calibration values, wherein the controller is further effective to convert output from the color sensor to tristimulus values using a priori estimation with respect to the calibration values; and

a cover mounted to the substrate and about the color sensor, wherein the plurality of light-emitting diodes are circumferentially arranged about the cover, the cover further comprising an aperture between the color sensor and the face of the housing whereby reflected light from a color sample is passed through the cover and to the color sensor.

6. The color sensing device of claim 5, wherein the matrix of device-specific calibration values is generated via a series of operations comprising:

converting known MacBeth CIE Lab values to CIE XYZ tristimulus values based on d50 light,

performing chromatic adaptation of the tristimulus values using a Bradford transform,

providing raw sensor calibration measurements from the color sensing device with respect to a color reference, and

generating a sensor to CIE tristimulus matrix based on the tristimulus values and the raw sensor calibration measurements.

7. The color sensing device of claim 5, wherein the plurality of light-emitting diodes are configured to collectively define a controlled 6500 Kelvin light source.

8. A color sensing method comprising:

transmitting raw sensor calibration measurements with respect to a color reference from a color sensing device to a user computing device;

generating a sensor to CIE tristimulus matrix of device-specific calibration values based on the raw sensor calibration measurements;

storing the generated matrix of device-specific calibration values in memory on the color sensing device;

transmitting control signals to the color sensing device corresponding to a selected lighting condition;

controlling a light source within the color sensing device to be turned on at one of a plurality of lighting power levels as corresponding to the control signals;

receiving at a color sensor light radiated by the controlled light source and reflected from a target surface when a face of the color sensing device engages the target surface;

converting output from the color sensor to tristimulus values using a priori estimation with respect to the device-specific calibration values; and

generating output signals to a display on the user computing device representative of a color of the target surface in association with the selected lighting condition.