Pseudo three dimensional image generating apparatus

• US 20040057613A1
• Filed: 09/17/2003
• Published: 03/25/2004
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Ishigure, Yasuo, Noto, Hajime, Hashimoto, Akihiko
• Granted Patent: US 7,359,547 B2
• Time in Patent Office: Days
• US Class Current: 382/154
• CPC Class Codes: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 7/586 from multiple light sources, e.g. photometric stereo

Abstract

The pseudo depth information of a subject is generated from multiple images of the subject captured with and without illumination or under various illumination intensities. A pseudo 3D image generating apparatus generates a pseudo 3D image. It includes an image storing unit that stores the images, and a depth computing unit that computes pseudo depth values of the subject based on operations between the pixel values of corresponding pixels in the images. A compact and handy 3D image generating apparatus is provided.

Claims

1. A pseudo 3D image generating apparatus that generates a pseudo three dimensional image of a subject from a plurality of images captured in various illumination conditions, comprising:

an image storing unit that stores the images; and

a depth computing unit that computes a pseudo depth value for a plurality of corresponding pixels, each of the stored images containing one of the corresponding pixels, based on an operation between pixel values of the corresponding pixels.

2. The pseudo 3D image generating apparatus as claimed in claim 1, wherein

said depth computing unit reduces the resolution of the images, and computes the pseudo depth value for the corresponding pixels based on an operation between the pixel values of the corresponding pixels of the resolution-reduced images.

3. The pseudo 3D image generating apparatus as claimed in claim 2, wherein

said depth computing unit smoothes the images, and reduces the resolution of the images.

4. The pseudo 3D image generating apparatus as claimed in claim 1, wherein

said depth computing unit assigns a discrete depth value to each pixel by comparing one of the difference and the ratio between the pixel values of the corresponding pixels of the images with a threshold value predetermined for each pixel.

5. The pseudo 3D image generating apparatus as claimed in claim 1, further comprising an object extracting unit that extracts an object of the subject based on the pseudo depth values assigned to the corresponding pixels, the pseudo depth value being computed by said depth computing unit.

6. The pseudo 3D image generating apparatus as claimed in claim 5, wherein

said depth computing unit assigns a discrete depth value to each pixel by comparing one of the difference and the ratio between the pixel values of the corresponding pixels with a threshold value predetermined for each pixel;

and

said object extracting unit extracts adjacent pixels of one of the images as the object, the assigned discrete depth values of the adjacent pixels being equal to each other.

7. The pseudo 3D image generating apparatus as claimed in claim 6, wherein

said depth computing unit fits a depth function to the object based on the discrete depth values.

8. The pseudo 3D image generating apparatus as claimed in claim 6, wherein

said depth computing unit smoothes the discrete depth values of the pixels in a predetermined range in one of the entire image, the peripheral portion of the object, and the object.

9. A method of generating a pseudo 3D image of a subject from a plurality of images captured in various illumination conditions, comprising the steps of:

storing the images; and

computing a pseudo depth value for a plurality of corresponding pixels, each of the stored images containing one of the corresponding pixels, based on an operation between pixel values of the corresponding pixels.

10. The method as claimed in claim 9, wherein the step of computing a pseudo depth value further comprises the steps of:

reducing the resolution of the images; and

computing the pseudo depth value for the corresponding pixels based on an operation between the pixel values of the corresponding pixels of the resolution-reduced images.

11. The method as claimed in claim 10, wherein, when the resolution of the images is reduced, the images are smoothed.

12. The method as claimed in claim 9, wherein a discrete depth value is assigned to each pixel by comparing one of the difference and the ratio between the pixel values of the corresponding pixels with a threshold value predetermined for each pixel.

13. The method as claimed in claim 9, further comprising the step of extracting an object of the subject based on the pseudo depth values assigned to the corresponding pixels.

14. The method as claimed in claim 13, wherein

a discrete depth value is assigned to each pixel by comparing one of the difference and the ratio between the pixel values of the corresponding pixels with a threshold value predetermined for each pixel in the step of computing the depth value;

and

adjacent pixels of one of the images are extracted as an object in the step of extracting the object, the assigned discrete depth values of the adjacent pixels being equal to each other.

15. The method as claimed in claim 14, further comprising the step of fitting a depth function to the object based on the computed discrete depth values.

16. The method as claimed in claim 14, further comprising the step of smoothing the discrete depth values of the pixels in a predetermined range in one of the entire image, the peripheral portion of the object, and the object.

17. A computer program that causes a computer to generate a pseudo 3D image of a subject from a plurality of images captured in various illumination conditions, said computer program comprising the steps of:

storing the images; and

computing a pseudo depth value for a plurality of corresponding pixels, each of the images containing one of the corresponding pixels, based on an operation between pixel values of the corresponding pixels.

18. A computer readable recording medium storing a computer program that causes a computer to generate a pseudo 3D image of a subject from a plurality of images captured in various illumination conditions, said computer program comprising the steps of:

storing the images; and

computing a pseudo depth value for a plurality of corresponding pixels, each of the stored images containing one of the corresponding pixels, based on an operation between pixel values of the corresponding pixels.