IMAGING TERMINAL HAVING COLOR CORRECTION

• US 20100259638A1
• Filed: 04/09/2009
• Published: 10/14/2010
• Est. Priority Date: 04/09/2009
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Wang, Ynjiun P.
• Granted Patent: US 8,218,027 B2
• Time in Patent Office: Days
• US Class Current: 348/223.100
• CPC Class Codes: H04N 23/12 with one sensor only
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

There is provided an imaging terminal comprising a hybrid monochrome and color image sensor pixel array having a first subset of pixels provided by color pixels having color filter elements and a second subset of pixels provided by monochrome pixels without color filter elements. The terminal can be operative to capture a frame of image data including monochrome image data representative of light incident on the monochrome pixels and color image data representative of light incident on the color pixels. The terminal can be operative to activate a color correction processing module that utilizes the monochrome color image data.

Claims

1. An imaging terminal comprising:

a hybrid monochrome and color image sensor pixel array having a first subset of pixels and a second subset of pixels, the first subset of pixels being a monochrome subset of pixels devoid of color filter elements and a second subset of pixels being a color sensitive subset of pixels including color filter elements;

a lens assembly for use in focusing an image of a target scene onto the hybrid monochrome and color image sensor array; and

a hand held housing, wherein the hybrid monochrome and color image sensor pixel array is disposed in the hand held housing;

wherein the imaging terminal is operative, in response to an operator initiated command, to capture a raw frame of image data, the raw frame of image data having a first subset of pixel values and a second subset of pixel values, the first subset of pixel values being monochrome pixel values representing light incident at the first subset of pixels, the second subset of pixel values being color pixel values representing light incident at the second subset of pixels;

wherein the imaging terminal is further operative to process the raw frame of image data for providing a demosaicized frame of image data;

wherein the imaging terminal includes a color correction processing module that utilizes pixel values of the first subset of pixel values, the color correction processing module being operative for color correction of the demosaicized frame of image data.

2. The imaging terminal of claim 1, wherein the color correction processing module has an active state and an inactive state and wherein the imaging terminal is operative so that in a first operating mode of the imaging terminal, the color correction processing module is active to process a frame of image data and further so that in a second operating mode of the imaging terminal, the color correction processing module is maintained in an inactive state so that a captured frame of image data is not subject to processing by the color correction processing module.

3. The imaging terminal of claim 1, wherein the imaging terminal is operative to output a visual display frame of image data by one or more of (a) displaying the visual display frame of image data on a display, (b) writing the visual display frame of image data to a memory of the imaging terminal, or (c) transmitting the visual display frame of image data to an external device for display and/or storage.

4. The imaging terminal of claim 1, wherein the color correction processing module is operative to utilize pixel values of the first set of pixel values for determining whether to apply a white balancing algorithm to the demosaicized frame of image data.

5. The imaging terminal of claim 1, wherein the color correction processing module is operative to utilize pixel values of the first set of pixel values by examination of the vector quantities M/R, M/G, M/B, where M is the average monochrome pixel value for a brightest predetermined percentage of pixel positions of the raw frame and R, G, B, are respective average red, green, and blue pixel values for the brightest predetermined percentage of pixel positions of the raw frame.

6. The imaging terminal of claim 1, wherein the color correction processing module is operative to avoid application of a white balancing algorithm to the demosaicized frame if examination of one of the vector quantities M/R, M/G or M/B indicates that a frame currently being subject to processing represents a color imbalanced scene.

7. The imaging terminal of claim 1, wherein the color pixels of the image sensor pixel array include red, green, and blue pixels uniformly or substantially uniformly distributed at spaced apart positions of the image sensor pixel array.

8. The imaging terminal of claim 1, wherein the color correction module is operative to determine a brightest predetermined percentage of pixel positions of the raw frame and wherein the color correction processing module is further operative to calculate an average M value for the brightest predetermined percentage of pixel positions.

9. The imaging terminal of claim 1, wherein the imaging terminal is operative in an indicia decode mode in which the imaging terminal attempts to decode a decodable indicia represented in a frame of image data captured during operation of the imaging terminal in the indicia decode mode, the color correction processing module having an active state and an inactive state, the imaging terminal being operative to maintain the color correction processing module in an inactive state when the imaging terminal is operated in an indicia decode mode of operation.

10. An imaging terminal comprising:

a hybrid monochrome and color image sensor pixel array having a first subset of pixels and a second subset of pixels, the first subset of pixels being a monochrome subset of pixels devoid of color filter elements and a second subset of pixels being a color sensitive subset of pixels including color filter elements;

a lens assembly for use in focusing an image of a target scene onto the hybrid monochrome and color image sensor array; and

a hand held housing, wherein the hybrid monochrome and color image sensor pixel array is disposed in the hand held housing;

wherein the imaging terminal is operative, in response to an operator initiated command, to capture a raw frame of image data, the raw frame of image data having a first subset of pixel values and a second subset of pixel values, the first subset of pixel values being monochrome pixel values representing light incident at the first subset of pixels, the second subset of pixel values being color pixel values representing light incident at the second subset of pixels;

wherein the imaging terminal further includes a color correction processing module that utilizes pixel values of the first subset of pixel values, the color correction processing module being operative for color correction of a frame of image data for output by the imaging terminal;

wherein the imaging terminal is operative in an operator selectable picture taking mode of operation and an operator selectable indicia decode mode of operation;

wherein the color correction processing module includes an active state and an inactive state;

wherein the imaging terminal is operative so that when the imaging terminal is operated in the picture taking mode the color correction processing module is active so a frame captured in response to an operator initiated command to capture and process a frame of image data when the imaging terminal is operated in the picture taking mode is subject to color correction by the color correction processing module; and

wherein the imaging terminal is further operative so that when the imaging terminal is operated in the indicia decode mode the color correction processing module is maintained in the inactive state so that frames of image data captured in response to an operator initiated command to capture and process frames of image data when the imaging terminal is operated in the indicia decode mode are not subject to color correction by the color correction processing module.

11. The imaging terminal of claim 10, wherein the imaging terminal attempts to decode a decodable indicia represented in captured image data when operated in the indicia decode mode.

12. The imaging terminal of claim 10, wherein the imaging terminal when operated in the indicia decode mode is operative to output a decoded message by one or more of writing the decoded message to a memory of the terminal or by transmitting the decoded message to an external device.

13. The imaging terminal of claim 10, wherein the imaging terminal when operated in the picture taking mode is operative to process the raw frame of image data to provide a demosaicized frame, and wherein the color correction processing module is operative to process the demosaicized frame.

14. The imaging terminal of claim 10, wherein the color pixels of the image sensor pixel array include red, green, and blue pixels uniformly or substantially uniformly distributed at spaced apart positions of the image sensor pixel array.

15. The imaging terminal of claim 10, wherein the color correction module is operative to determine a brightest predetermined percentage of pixel positions of the raw frame and wherein the color correction processing module is further operative to calculate an average M value for the brightest predetermined percentage of pixel positions.

16. The imaging terminal of claim 10, wherein the color correction processing module is operative to utilize pixel values of the first set of pixel values for determining whether to apply a white balancing algorithm to the demosaicized frame of image data.