Method of image background replacement

• US 6,950,130 B1
• Filed: 01/05/1999
• Issued: 09/27/2005
• Est. Priority Date: 01/05/1999
• Status: Expired due to Term

• Current Assignee: Rakuten, Inc. (Rakuten Group, Inc.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Qian, Richard J.
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Hannett, James M.
• Application Number:
  US09/225,189
• Time in Patent Office: 2,457 Days
• Field of Search: 348/586, 348/239
• US Class Current: 348/239
• CPC Class Codes: H04N 5/272 Means for inserting a foreground image in a background image, i.e. inlay, outlay
• CPC Class Codes: H04N 7/141 between two video terminals, e.g. videophone telephonic communication systems combined with television receiver for reception of entertainment or information matter H04M11/085
• CPC Class Codes: H04N 9/74 for obtaining special effects H04N9/65 - H04N9/73 take precedence
• CPC Class Codes: H04N 9/75 Chroma key

Abstract

A method for background replacement. The method takes an input image of one or more frames of video, or a still image, and performs an initial classification of the pixels (14) as foreground or background pixels. The classification is refined (16) using one of several techniques, including anisotropic diffusion or morphological filtering. After the refined classification is completed, a feathering process (18) is used to overlay the foreground pixels from the original image on the pixels of the new background, resulting in a new output image (20).

Claims

1. A method for background replacement in image capture systems, the method comprising:

recording a background of an image with no foreground object with an image capture device, wherein the background is used as an input to a probability function;

using said image capture device to capture an input image having a foreground object;

classifying each pixel in said input image as a foreground pixel or a background pixel wherein classification results from calculating the probability function directly from a formula using chromatic component values and intensity values in the probability function for each pixel in the input image producing a classification and a probability map simultaneously;

refining said classification and probability map to ensure proper classification;

replacing said background pixels with pixels from a different background, wherein said replacing is performed with feathering using weighted values for pixel values of the input image and the different background determined by the probability map; and

producing an output image comprised of said foreground pixels and said pixels from a different background.

2. The method as claimed in claim 1 where refining is performed in the normalized RGB chromatic color space.

3. The method as claimed in claim 1 wherein refining is performed in YCbCr color space.

4. The method as claimed in claim 1 wherein said input image comprises one frame of video data.

5. The method as claimed in claim 1 wherein said input image comprises more than one frame of video data.

6. The method as claimed in claim 1 wherein said input image comprises a still image.

7. The method as claimed in claim 1, wherein said refining is performed with anisotropic diffusion.

8. The method as claimed in claim 1, wherein said refining is performed with morphological filtering.

9. The method as claimed in claim 1, wherein said output image is a video image.

10. The method as claimed in claim 1, wherein said output image is a still image.