Image display apparatus and method

• US 20070229557A1
• Filed: 03/06/2007
• Published: 10/04/2007
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sasaki, Takashi, Okumura, Haruhiko, Hotta, Aira
• Granted Patent: US 7,777,766 B2
• Time in Patent Office: Days
• US Class Current: 345/698
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: H04N 9/3188 Scale or resolution adjustment scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391

Abstract

An image display unit has a display region with a higher resolution than a number of pixels of an image. A base information storage unit stores viewing position information of a viewer and size information of the display region. A wide-angle transformation unit calculates a central area including a viewing center of the viewer of the display region using the viewing position information and the size information, divides the image into a first pixel area corresponding to the central area and a second pixel area corresponding to a peripheral area other than the central area, and transforms the first pixel area and the second pixel area by magnifying. A magnification ratio of the first pixel area is less than a magnification ratio of the second pixel area. The image display unit displays an image including the transformed first pixel area and the transformed second pixel area.

Claims

1. An apparatus for displaying an image, comprising:

an image display unit including a display region having a higher resolution than a number of pixels of the image;

a base information storage unit configured to store viewing position information of a viewer, and size information of the display region; and

a wide-angle transformation unit configured to calculate a central area including a viewing center of the viewer of the display region using the viewing position information and the size information, to divide the image into a first pixel area corresponding to the central area and a second pixel area corresponding to a peripheral area other than the central area, and to transform the first pixel area and the second pixel area by magnifying, a magnification ratio of the first pixel area being less than a magnification ratio of the second pixel area;

wherein the image display unit displays an image including the transformed first pixel area and the transformed second pixel area.

2. The apparatus according to claim 1, further comprising:

an image storage unit configured to store a plurality of images each corresponding to a frame;

a first image memory and a second image memory, each configured to alternatively store images from the plurality of images in the image storage unit in order of frame sequence by the wide-angle transformation unit.

3. The apparatus according to claim 2, further comprising:

a first switch to connect one of the first image memory and the second image memory to the wide-angle transformation unit; and

a second switch to connect the other of the first image memory and the second image memory to the image display unit;

wherein the first switch and the second switch change over in order of frame sequence.

4. The apparatus according to claim 1, wherein

the viewing position information includes a viewing point of the viewer based on the origin of the display region, and

the size information includes the resolution, and a horizontal length and a vertical length of the display region.

5. The apparatus according to claim 4, wherein

the wide-angle transformation unit calculates the viewing center on the display region using the viewing point, and the horizontal length and the vertical length of the display region, and calculates a left side length, a right side length, a top side length, and a bottom side length from the viewing center on the display region.

6. The apparatus according to claim 5, wherein

the wide-angle transformation unit respectively calculates a left side field of view, a right side field of view, a top side field of view, and a bottom side field of view using the left side length, the right side length, the top side length, the bottom side length, and a distance between the viewing point and the display region.

7. The apparatus according to claim 6, wherein,

if at least one of the left side field of view, the right side field of view, the top side field of view, and the bottom side field of view is above 30°

,

the wide-angle transformation unit sets the central area centered around the viewing center within a radius of 30°

on the display region.

8. The apparatus according to claim 7, wherein

the wide-angle transformation unit sets the magnification ratio of the first pixel area corresponding to the central area as a first value not above 1.

9. The apparatus according to claim 8, wherein

the wide-angle transformation unit sets the magnification ratio of the second pixel area corresponding to the peripheral area as a second value not below 1.4 times the first value.

10. The apparatus according to claim 9, wherein,

when the wide-angle transformation unit magnifies each pixel position of the second pixel area,

the wide-angle transformation unit interpolates a new pixel between each pixel of the second pixel area based on the magnification ratio.

11. The apparatus according to claim 9, wherein

a ratio of a transformed pixel area of the first pixel area to the display region is less than a ratio of the first pixel area to the image.

12. The apparatus according to claim 2, wherein

the image display unit includes a source of light to radiate a light, a display element to display the image by the light, a wobbling element to wobble the image from the display element, a projection lens to project the image from the wobbling element, and a screen to display a projected image from the projection lens.

13. The apparatus according to claim 12, further comprising:

a field subsample unit configured to divide each frame image into a first field image and a second field image, the first field image being odd numbered scan lines of pixels, and the second field image being even numbered scan lines of pixels.

14. The apparatus according to claim 13, wherein

the wobbling element periodically shifts an optical path of each pixel of the first field image and each pixel of the second field image at a half frame interval.

15. The apparatus according to claim 14, wherein

a shift quantity of each pixel is a half space between neighboring pixels of scan lines along a diagonal direction on the frame.

16. The apparatus according to claim 15, further comprising:

an aliasing prevention unit configured to calculate an average of two pixel values of a first pixel on a scan line of the frame, and a second pixel vertically adjacent to the first pixel on a next scan line of the frame before subsample processing of the field subsample unit.

17. The apparatus according to claim 16, wherein

the aliasing prevention unit calculates an average of two pixel values of a third pixel on a frame and a fourth pixel at the same position as the third pixel on a previous frame before subsample processing of the field subsample unit.

18. The apparatus according to claim 17, wherein

the aliasing prevention unit calculate an average of four pixel values of the first pixel on the scan line of the frame, the second pixel vertically adjacent to the first pixel on the next scan line of the frame, a fifth pixel at the same position as the first pixel on a previous frame, and a sixth pixel at the same position as the second pixel on the previous frame before subsample processing of the field subsumple unit.

19. A method for displaying an image on a display region having a higher resolution than a number of pixels of the image, comprising:

storing viewing position information of a viewer, and size information of the display region;

calculating a central area including a viewing center of the viewer of the display region using the viewing position information and the size information;

dividing the image into a first pixel area corresponding to the central area and a second pixel area corresponding to a peripheral area other than the central area;

transforming the first pixel area and the second pixel area by magnifying, a magnification ratio of the first pixel area being less than a magnification ratio of the second pixel area; and

displaying an image including the transformed first pixel area and the transformed second pixel area.

20. A computer readable medium that stores a computer program for causing a computer to display an image on a display region having a higher resolution than a number of pixels of the image, the computer program comprising:

a first program code to store viewing position information of a viewer, and size information of the display region;

a second program code to calculate a central area including a viewing center of the viewer of the display region using the viewing position information and the size information;

a third program code to divide the image into a first pixel area corresponding to the central area and a second pixel area corresponding to a peripheral area other than the central area;

a fourth program code to transform the first pixel area and the second pixel area by magnifying, a magnification ratio of the first pixel area being less than a magnification ratio of the second pixel area; and

a fifth program code to display an image including the transformed first pixel area and the transformed second pixel area.