Methods and Systems for Determining a Background Color in a Digital Image

• US 20090041344A1
• Filed: 08/08/2007
• Published: 02/12/2009
• Est. Priority Date: 08/08/2007
• Status: Abandoned Application

• Current Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Campbell, Richard John, Speigle, Jon M.
• Application Number:
  US11/835,684
• Publication Number:
  US 20090041344A1
• Time in Patent Office: Days
• US Class Current: 382/164
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06V 10/56 relating to colour
• CPC Class Codes: G06V 30/413 Classification of content, e.g. text, photographs or tables

Abstract

Aspects of the present invention are related to methods and systems for determining a background color in a digital image.

Claims

1. A system for determining a background color in a digital image, said system comprising:

a. a first buffer;

b. a data selector for selecting data, from a digital image, to be entered in said first buffer; and

c. a color-value estimator for estimating a background-color value based on said data in said first buffer.

2. The system of claim 1, wherein said data selector excludes a data from entry in said first buffer when the location of said data in said digital image is substantially near to an edge in said digital image.

3. The system of claim 1, wherein said data selector includes a data for entry into said first buffer when the location of said data in said digital image is in a region of substantially uniform texture.

4. The system of claim 1 further comprising a weight-factor associator for associating a weighting factor with each entry in said first buffer.

5. The system of claim 1, wherein said first buffer is associated with a first peak in a histogram of color values from said digital image.

6. The system of claim 5 further comprising a second buffer, wherein said second buffer is associated with a second peak in said histogram of color values from said digital image.

7. The system of claim 1, wherein said data selector excludes a data from entry in said first buffer when the color value of said data is substantially close to a foreground object color.

8. The system of claim 1, wherein said color-value estimator comprises a summarization calculator for calculating a calculation selected from the group consisting of a mean, a trimmed mean, a weighted average, a median, a maximum and a minimum of said data in said first buffer.

9. A system for determining a background color in a digital image, said system comprising:

a. a first buffer, said first buffer comprising a first entry corresponding to a first pixel location a digital image;

b. a data-weighting determiner for determining a first weighting factor associated with said first entry in said first buffer; and

c. a color-value estimator for estimating a background-color value based on said first entry and said first weighting factor.

10. The system of claim 9, wherein said data-weighting determiner bases said first weighting factor on a measure of the relative location of said first pixel location and a first edge in said digital image.

11. The system of claim 9, wherein said data-weighting determiner bases said first weighting factor on a uniformity measure in a region substantially proximate to said first pixel location.

12. The system of claim 9, wherein said first buffer is associated with a first peak in a histogram of color values from said digital image.

13. The system of claim 12 further comprising a second buffer wherein said second buffer is associated with a second peak in said histogram of color values from said digital image.

14. The system of claim 9, wherein said data-weighting determiner bases said first weighting factor on a similarity measure between said first entry and a foreground object color.

15. The system of claim 14, wherein said similarity measure comprises a distance calculation selected from the group consisting of a Euclidean distance calculation, a city-block distance calculation and a weighted-distance metric calculation.

16. The system of claim 9, wherein said color-value estimator comprises a weighted-average calculator for calculating a weighted average of said first entry and any additional entries in said first buffer.

17. A method for determining a background color in a digital image, said method comprising:

a. determining a pixel of interest in a digital image;

b. selecting a second plurality of pixels from a first plurality of pixels, wherein said first plurality of pixels are from a first region substantially proximate to said pixel of interest and said second plurality of pixels meet a first criterion;

c. calculating a background-color value based on said second plurality of pixels.

18. The method of claim 17, wherein said first criterion is based on a distance to an edge in said digital image.

19. The method of claim 17, wherein said first criterion is based on a uniformity measure.

20. The method of claim 17, wherein said first criterion is based on a color distance from a foreground color.

21. The method of claim 17 further comprising determining a weighting factor for each of said second plurality of pixels, thereby producing a plurality of weighting factors.

22. The method of claim 21, wherein said calculating is based on said plurality of weighting factors.