Apparatus and method for improved-resolution digital zoom in a portable electronic imaging device

• US 20040017491A1
• Filed: 07/29/2002
• Published: 01/29/2004
• Est. Priority Date: 07/29/2002
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Stavely, Donald J.
• Granted Patent: US 7,098,949 B2
• Time in Patent Office: Days
• US Class Current: 348/240.2
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

A portable electronic imaging device, in performing digital zoom, exploits barrel distortion in the original digital image to produce higher quality digitally zoomed images than can be obtained by simple cropping and rescaling. Such a portable electronic imaging device may be implemented using a moderately wide-angle lens of fixed focal length.

Claims

1. A portable electronic imaging device having an improved-resolution digital zoom capability, comprising:

a lens to produce an optical image, the lens having a higher magnification factor in a central region than in an edge region, the lens thereby causing barrel distortion in the optical image;

at least one imaging sensor to convert the optical image to a digital image, the digital image having relatively higher resolution in a first portion corresponding to the central region of the lens than in a second portion corresponding to the edge region of the lens;

first logic to extract a cropped digital image from within the first portion; and

second logic to correct the barrel distortion in the cropped digital image, the portable electronic imaging device thereby producing an improved-resolution digitally zoomed image.

2. The portable electronic imaging device of claim 1, further comprising:

third logic to rescale the improved-resolution digitally zoomed image to a predetermined size.

3. The portable electronic imaging device of claim 1, wherein the lens has a fixed focal length.

4. The portable electronic imaging device of claim 1, wherein the portable electronic imaging device comprises a digital camera.

5. The portable electronic imaging device of claim 1, wherein the portable electronic imaging device comprises a digital video camera.

6. A portable electronic imaging device having an improved-resolution digital zoom capability, comprising:

a lens to produce an optical image, the lens having a higher magnification factor in a central region than in an edge region, the lens thereby causing barrel distortion in the optical image;

at least one imaging sensor to convert the optical image to a digital image;

first logic to correct the barrel distortion in the digital image to produce a corrected digital image, the corrected digital image having relatively higher resolution in a first portion corresponding to the central region of the lens than in a second portion corresponding to the edge region of the lens; and

second logic to extract a cropped digital image from within the first portion, the portable electronic imaging device thereby producing an improved-resolution digitally zoomed image.

7. The portable electronic imaging device of claim 6, further comprising:

third logic to rescale the improved-resolution digitally zoomed image to a predetermined size.

8. The portable electronic imaging device of claim 6, wherein the lens has a fixed focal length.

9. The portable electronic imaging device of claim 6, wherein the portable electronic imaging device comprises a digital camera.

10. The portable electronic imaging device of claim 6, wherein the portable electronic imaging device comprises a digital video camera.

11. A portable electronic imaging device having an improved-resolution digital zoom capability, comprising:

means for producing an optical image, the means for producing an optical image causing barrel distortion in the optical image;

means for converting the optical image to a digital image, the digital image having relatively higher resolution in a first central region than in a second edge region;

first logic means for extracting a cropped digital image from within the first central region; and

second logic means for correcting the barrel distortion in the cropped digital image, the portable electronic imaging device thereby producing an improved-resolution digitally zoomed image.

12. The portable electronic imaging device of claim 11, further comprising:

third logic means for rescaling the improved-resolution digitally zoomed image to a predetermined size.

13. The portable electronic imaging device of claim 11, wherein the means for producing an optical image comprises a lens having a fixed focal length.

14. The portable electronic imaging device of claim 11, wherein the portable electronic imaging device comprises a digital camera.

15. The portable electronic imaging device of claim 11, wherein the portable electronic imaging device comprises a digital video camera.

16. A portable electronic imaging device having an improved-resolution digital zoom capability, comprising:

means for producing an optical image, the means for producing an optical image causing barrel distortion in the optical image;

means for converting the optical image to a digital image;

first logic means for correcting the barrel distortion in the digital image to produce a corrected digital image, the corrected digital image having relatively higher resolution in a first central region than in a second edge region; and

second logic to extract a cropped digital image from within the first central region, the portable electronic imaging device thereby producing an improved-resolution digitally zoomed image.

17. The portable electronic imaging device of claim 16, further comprising:

third logic means for rescaling the improved-resolution digitally zoomed image to a predetermined size.

18. The portable electronic imaging device of claim 16, wherein the means for producing an optical image comprises a lens having a fixed focal length.

19. The portable electronic imaging device of claim 16, wherein the portable electronic imaging device comprises a digital camera.

20. The portable electronic imaging device of claim 16, wherein the portable electronic imaging device comprises a digital video camera.

21. A method for providing an improved-resolution digital zoom feature in a portable electronic imaging device, comprising:

producing an optical image containing barrel distortion;

converting the optical image to a digital image, the digital image having relatively higher resolution in a first central region than in a second edge region;

producing a cropped digital image from within the first central region; and

correcting for the barrel distortion in the cropped digital image to produce an improved-resolution digitally zoomed image.

22. The method of claim 21, wherein producing an optical image containing barrel distortion comprises forming the optical image using a lens that introduces the barrel distortion.

23. The method of claim 22, wherein the lens has a fixed focal length.

24. The method of claim 21, further comprising:

rescaling the improved-resolution digitally zoomed image to a predetermined size.

25. The method of claim 21, wherein the portable electronic imaging device comprises a digital camera.

26. The method of claim 21, wherein the portable electronic imaging device comprises a digital video camera.

27. A method for providing an improved-resolution digital zoom feature in a portable electronic imaging device, comprising:

producing an optical image containing barrel distortion;

converting the optical image to a digital image;

correcting the barrel distortion in the digital image to produce a corrected digital image, the corrected digital image having relatively higher resolution in a first central region than in a second edge region; and

extracting a cropped digital image from within the first central region to produce an improved-resolution digitally zoomed image.

28. The method of claim 27, wherein producing an optical image containing barrel distortion comprises forming the optical image using a lens that introduces the barrel distortion.

29. The method of claim 28, wherein the lens has a fixed focal length.

30. The method of claim 27, further comprising:

resealing the improved-resolution digitally zoomed image to a predetermined size.

31. The method of claim 27, wherein the portable electronic imaging device comprises a digital camera.

32. The method of claim 27, wherein the portable electronic imaging device comprises a digital video camera.