Image processing unit and method for executing image processing of a virtual environment

• US 5,442,734 A
• Filed: 03/06/1992
• Issued: 08/15/1995
• Est. Priority Date: 03/06/1991
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Nishiyama, Soichi, Murakami, Koichi, Hirota, Katsuhiko
• Primary Examiner(s): Zimmerman, Mark K.
• Assistant Examiner(s): Smith, Michael
• Application Number:
  US07/845,422
• Time in Patent Office: 1,257 Days
• Field of Search: 395/127,128,129,119,155,158
• US Class Current: 345/427
• CPC Class Codes: G06F 3/012 Head tracking input arrangements
• CPC Class Codes: G09B 9/302 the image being transformed by computer processing, e.g. updating the image to correspond to the changing point of view
• CPC Class Codes: G09B 9/307 by helmet-mounted projector or display G09B9/36 takes precedence; optical parts of head-up displays G02B27/01
• 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

Abstract

An image processing unit generates a virtual environment or an artificial reality by displaying a necessary image in accordance with movement of a view direction of a person on a head mounted display and comprises a sensor, an image processing portion, and a display. The sensor detects a view direction and generates a view vector, and the image processing portion comprises a view direction movement discriminator, a priority degree allocator, and a partial update portion. The view direction movement discriminator calculates a view direction movement vector from the difference from the two fetched view vectors. The priority degree allocator generates a projection vector by projecting the view direction movement, determines a priority degree at each divided section of the display screen to be higher when the projection vector approaches and to withdraw from the center of the display screen to a periphery along the projection vector; and the partial update portion updates the display of the display screen in each divided section in accordance with the priority degree.

Claims

1. An image processing unit comprising:

sensor means for detecting a view direction of a person and for generating a view vector indicative of the view direction;

display means having a display screen for displaying an image on the display screen, said display screen having a center; and

image processing means for generating an image defined by the view vector in accordance with given image data, said image processing means comprising;

view direction movement discrimination means for fetching the view vector at a certain time interval, and for calculating a view direction movement vector designating a moving speed of the view direction based on the difference between the latest two fetched view vectors;

priority degree allocation means for receiving the view direction movement vector and for generating a projection vector by projecting the view direction movement vector on the display screen, setting the center of the display screen as an origin, dividing the display screen into a selected number of sections, each divided section having a priority degree and for determining the priority degree for each divided section of the display screen such that the priority degree is higher when the projection vector approaches the divided section and lower as the projection vector is more distant from the center of the display screen to a periphery of the display screen along the projection vector; and

partial update means for updating the display of the display screen in each divided section by the image defined by the latest view vector, sequentially from the section having a higher priority degree.

2. An image processing unit as set forth in claim 1 wherein

said each divided section of the display screen is a divided rectangle section having the same size and the same shape.

3. An image processing unit as set forth in claim 1, wherein

said generating, dividing and determining in said priority degree allocation means introduce a plurality of isosceles triangles which have respective vertexes on the projection vector, have a base on a line on the display screen, said line being perpendicular to the projection vector at the origin, and have different areas;

said priority degree allocation means further determines a priority degree for each area divided by at least one of the isosceles triangles, and

said priority degree allocation means determines, in accordance with the priority degree determined for the isosceles triangle area, the corresponding priority degree of the divided sections.

4. An image processing unit as set forth in claim 3, wherein:

said partial update means holds a second priority degree in each divided section of the display screen;

when the update of the display screen in each divided section is executed, said partial update means reduces the priority degree of the divided section by a certain value; and

when no movement of the view direction is detected by the view direction movement vector, said partial update means repeatedly updates the image corresponding to the divided section in accordance with the priority degree while no movement of the view direction is detected.

5. An image processing unit as set forth in claim 2, wherein

said generating, dividing and determining in said priority degree allocation means introduce a plurality of isosceles triangles which have respective vertexes on the projection vector, have a base on a line on the display screen, said line being perpendicular to the projection vector at the origin, and have different areas;

said priority degree allocation means further determines a priority degree for each area divided by at least one of the isosceles triangles, and

said priority degree allocation means determines, in accordance with the priority degree determined for the isosceles triangle area, the corresponding priority degree of the divided sections.

6. An image processing unit as set forth in claim 4, wherein:

said partial update means holds a second priority degree in each divided section of the display screen;

when the update of the display screen in each divided section is executed, said partial update means reduces the priority degree of the divided section by a certain value; and

when no movement of the view direction is detected by the view direction movement vector, said partial update means repeatedly updates the image corresponding to the divided section in accordance with the priority degree while no movement of the view direction is detected.

7. An image processing unit as set forth in claim 1, wherein:

said partial update means holds a second priority degree in each divided section of the display screen;

when the update of the display screen in each divided section is executed, said partial update means reduces the priority degree of the divided section by a certain value; and

when no movement of the view direction is detected by the view direction movement vector, said partial update means repeatedly updates the image corresponding to the divided section in accordance with the priority degree while no movement of the view direction is detected.

8. An image processing unit as set forth in claim 2, wherein:

said partial update means holds a second priority degree in each divided section of the display screen;

when the update of the display screen in each divided section is executed, said partial update means reduces the priority degree of the divided section by a certain value; and

when no movement of the view direction is detected by the view direction movement vector, said partial update means repeatedly updates the image corresponding to the divided section in accordance with the priority degree while no movement of the view direction is detected.

9. An image processing method comprising:

a 1st process step for fetching a view vector;

a 2nd process step for calculating a view direction movement vector between a view vector fetched in the 1st process step and a stored view vector fetched, one period before the view vector fetched in the 1st process step;

a 3rd process step for comparing the magnitude of the view direction movement vector calculated at the 2nd process step with a certain value, for determining whether a view direction movement exists and for proceeding to a 4th process step if said view direction movement is determined to exist and to an 11th process step when said view direction movement is determined not to exist,

said 4th process step generating a projection vector projecting the view direction movement vector on a display screen and generating a partial image priority degree for each partial image;

a 5th process step for setting a triangle area on the display screen in accordance with the projection vector generated in the 4th process step;

a 6th process step for calculating an area priority degree in accordance with an overlap area between a triangle area and a divided section of the display screen, and the partial image priority degree calculated in the 4th process step, for each area;

a 7th process step for resetting second priority degrees to initial values;

an 8th process step for determining if a process period has attained a certain time and for proceeding to a 9th process step if said process period has not attained the certain time and to an end process, if said process period has attained a certain time

said 9th process step updating each partial image in accordance with the area priority degree;

a 10th process step for decreasing the partial image priority degree of the updated partial image and for returning to said 8th process step for repeating the process steps of updating and decreasing until the process period attains the certain time;

an 11th process step for determining if a process period has attained the certain time and for proceeding to a 12th process step if said certain time has been attained and proceeding to the end process step if said certain time has not been attained,

said 12th process step updates the partial image having the highest priority degree, said partial image having a corresponding second priority degree;

a 13th process step for decreasing the second priority degree corresponding to partial image updated in the 12th process step; and

a 14th process step for returning to the 11th process step if one of the second priority degrees of the updated partial images is greater than zero as a result of the 13th process step and for proceeding to a 15th process step when all the second priority degrees of the partial images are less than zero as a result of the 13th process step,

said 15th process step resetting all the second priority degrees and returning to the 11th process step,

said end process ending the one process period when said process period attains the certain time in one of said 8th process step and said 11th process step.

10. An image processing method as set forth in claim 9, wherein

said 5th process step for setting a triangle area comprises:

processes introducing a plurality of isosceles triangles which have respective vertexes on the projection vector, have a base on a line on the display screen perpendicular to the projection vector at the origin, and have different areas;

determining a priority degree for each area divided by the triangles; and

determining the corresponding priority degree of the divided sections in accordance with the priority degree of the triangle area.