“Don't care” pixel interpolation

• US 7,397,952 B2
• Filed: 11/23/2005
• Issued: 07/08/2008
• Est. Priority Date: 04/25/2002
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Malvar, Henrique S., Simard, Patrice Y., Rinker, James Russell
• Primary Examiner(s): Chawan; Sheela C
• Application Number:
  US11/286,622
• Publication Number:
  US 20060083439A1
• Time in Patent Office: 958 Days
• Field of Search: 348/586, 348/587, 348/590, 348/571, 348/584, 348/598, 382/181, 382/190, 382/195, 382/199, 382/128, 382/162, 382/254, 382/266, 382/283, 382/284, 382/264, 358/448, 358/464
• US Class Current: 382/195
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/77 Retouching; Inpainting; Scratch removal
• CPC Class Codes: G06T 7/136 involving thresholding
• CPC Class Codes: G06T 7/194 involving foreground-background segmentation

Abstract

A system and method facilitating image smoothing is provided. The invention includes an image processor having an image receptor and an image smoother. The invention provides for the image smoother to alter the value of a don'"'"'t care pixel based, at least in part, upon a weighted average of care pixels.

Claims

1. An image processor, comprising:

an image receptor to receive an image, the image comprising care pixels and don'"'"'t care pixels, identification of care pixels and don'"'"'t care pixels being based, at least in part, upon a binary mask; and

an image smoother to smooth the image by altering a value of at least one don'"'"'t care pixel based, at least in part, on a weighted average of care pixels;

wherein altering a value of at least one don'"'"'t care pixel based, at least in part, on a weighted average of care pixels comprises;

determining a first distance to a first care pixel and a first value of the first care pixel;

determining a second distance to a second care pixel and a second value of the second care pixel;

calculating a smoothed value for a don'"'"'t care pixel based, at least in part, upon a weighted average of the first distance, the first value, the second distance and the second value, wherein calculation of the smoothed value of the don'"'"'t care pixel is based, at least in part, upon the equation;

$v=\frac{v_1<br><br>e^{-d_1}+v_2<br><br>e^{-d_2}}{e^{-d_1}+e^{-d_2}}$

where v is the smoothed value of the don'"'"'t care pixel,

v₁ is the first value,

v₂ is the second value,

d₁ is the first distance, and

d₂ is the second distance; and

altering the value of the don'"'"'t care pixel based, at least in part, upon the calculated smoothed value.

2. The image processor of claim 1, further comprising an image separator to separate the image into at least one of a background and a foreground.

3. The image processor of claim 2, the binary mask being based, at least in part, upon a partition of the document image based, at least in part, upon minimization of pixel energy of at least one of the foreground and the background.

4. The image processor of claim 2, wherein the image separator stores separation information in the binary mask.

5. The image processor of claim 1, the image smoother providing an output having at least one altered don'"'"'t care pixel.

6. The image processor of claim 1, wherein a photocopier employs the image processor.

7. The image processor of claim 1, wherein a document scanner employs the image processor.

8. The image processor of claim 1, wherein an optical character recognition system employs the image processor.

9. The image processor of claim 1, wherein a personal digital assistant employs the image processor.

10. The image processor of claim 1, wherein a fax machine employs the image processor.

11. The image processor of claim 1, wherein a digital camera employs the image processor.

12. The image processor of claim 1, wherein a digital video camera employs the image processor.

13. The image processor of claim 1, wherein a segmented layered image system employs the image processor.

14. The image processor of claim 1, wherein information is transmitted between the image receptor and the image smoother by a data packet stored on computer-readable media.

15. The image processor of claim 1, wherein the image receptor and the image smoother are stored on computer-readable media.

16. The image processor of claim 1, wherein the image processor is employed in a networked environment.

17. The image processor of claim 16, wherein the networked environment is the Internet.

18. A method for smoothing an image, the method implemented by computer-executable instructions stored on computer-readable media, the method comprising:

scanning the image from top to bottom and from left to right;

determining a horizontal distance to a left care pixel and a value of the left care pixel;

determining a horizontal distance to a right care pixel and a value of the right care pixel;

determining a vertical distance to a top care pixel and a value of the top care pixel;

determining a vertical distance to a bottom care pixel and a value of the bottom care pixel;

calculating a smoothed value for a don'"'"'t care pixel based, at least in part, upon at least one of the horizontal distance to the left care pixel, the value of the left care pixel, the horizontal distance to the right care pixel, the value of the right care pixel, the vertical distance to the top care pixel, the value of the top care pixel, the vertical distance to the bottom care pixel and the value of the bottom care pixel;

scanning the image from bottom to top and from right to left;

determining a horizontal distance to a right care pixel and a value of the right care pixel;

determining a vertical distance to a bottom care pixel and a value of the bottom care pixel;

calculating a second smoothed value for the don'"'"'t care pixel based, at least in part, upon at least one of the horizontal distance to the right care pixel, the value of the right care pixel, the vertical distance to the bottom care pixel and the value of the bottom care pixel, and

altering of the don'"'"'t care pixel value being based, at least in part, upon the equation;

$v_{\mathrm{FINAL}}=\frac{v_{\mathrm{FIRST}<br><br><br><br>\mathrm{PASS}}<br><br>w<br><br>\left(d_{1<br><br>L},d_{2<br><br>T}\right)+v_{\mathrm{SECOND}<br><br><br><br>\mathrm{PASS}}<br><br>w<br><br>\left(d_{1<br><br>R},d_{2<br><br>B}\right)}{w<br><br>\left(d_{1<br><br>L},d_{2<br><br>T}\right)+w<br><br>\left(d_{1<br><br>R},d_{2<br><br>B}\right)}$

where v_FINAL;

is the smoothed value of the don'"'"'t care pixel,

v_{FIRST PASS} is the first smoothed value,

v_{SECOND PASS} is the second smoothed value,

d_1L is the horizontal distance to the left care pixel,

d_2T is the vertical distance to the top care pixel,

w(d_1L,d_2T) is a weight factor computed from the horizontal distance to the left care pixel and the vertical distance to the top care pixel,

d_1R is the horizontal distance to the right care pixel,

d_2B is the vertical distance to the bottom care pixel, and

w(d_1R,d_2B) is a weight factor computed from the two horizontal distance to the right care pixel and the vertical distance to the bottom care pixel.

19. An image processor, comprising:

means for determining a first distance to a first care pixel and a first value of the first care pixel;

means for determining a second distance to a second care pixel and a second value of the second care pixel;

means for calculating a smoothed value for a don'"'"'t care pixel based, at least in part, upon a weighted average of the first distance, the first value, the second distance and the second value; and

means for altering the value of the don'"'"'t care pixel based, at least in part, upon the calculated smoothed value and the equation;

$v=\frac{v_1<br><br>e^{-d_1}+v_2<br><br>e^{-d_2}+v_3<br><br>e^{-d_3}+v_4<br><br>e^{-d_4}}{e^{-d_1}+e^{-d_2}+e^{-d_3}+e^{-d_4}}$

where v is the smoothed value of the at least one don'"'"'t care pixel,

v₁ is the value of a first care pixel,

v₂ is the value of a second care pixel,

v₃ is the value of a third care pixel,

v₄ is the value of a fourth care pixel,

d₁ is the distance from the at least one don'"'"'t care pixel to the first care pixel,

d₂ is the distance from the at least one don'"'"'t care pixel to the second care pixel,

d₃ is the distance from the at least one don'"'"'t care pixel to the third care pixel,

d₄ is the distance from the at least one don'"'"'t care pixel to the fourth care pixel, for alteration of the at least one don'"'"'t care pixel.