Method for creating brightness filter and virtual space creation system

A virtual space creation system, said system comprising:

• a curved screen offering a wide field of view;
• an image creation module, said image creation module dividing a single seamless image into a plurality of divided images which are intended to be projected on said curved screen;
• a plurality of projectors, said projectors project said divided images respectively on said curved screen in a partially overlapping relation with each other;
• wherein said image creation module has a brightness filter for each of said divided images, said brightness filters being prepared by the steps of;
• (a) producing a screen model reflecting a shape of said curved screen;
• (b) setting projection points respectively for projecting therefrom said divided images on said screen model, said projection points being different from each other in conformity with said projectors, respectively;
• (c) allocating one of said divided images to a reference image and allocating each of the adjacent divided images to a peripheral image;
• (d) setting a view point that is coincident with the projection point of said reference image;
• (e) obtaining a 2-dimensional reference area of said reference image that is rendered on said screen model and is viewed from said view point;
• (f) obtaining a 2-dimensional, peripheral area of said peripheral image that is rendered on said screen model and is viewed from said view point;
• (g) extracting an overlapping area of said 2-dimensional reference area that overlaps with the 2-dimensional peripheral area;
• (h) making a brightness correction for either said overlapping area or said non-overlapping area with regard to said 2-dimensional reference area;
• (i) providing a brightness filter for said reference image that realizes said brightness correction;
• (j) allocating another divided image to said reference image and repeating the steps of (d) to (i) for providing said brightness filter for each of said divided images.

A set of projectors adapted in use for a virtual space creation system which combines a plurality of divided images into a single image to be rendered on a curved screen, said projectors projecting said divided images respectively on said curved screen in a partially overlapping relation with each other, and being equipped with filters for adjusting brightness of said divided images for harmonizing the brightness of overlapping areas with the brightness of non-overlapping areas to make said single image seamless,

• said filters being prepared by the steps of;
• (a) producing a screen model reflecting a shape of said curved screen;
• (b) setting projection points respectively for projecting therefrom said divided images on said screen model, said projection points being different from each other in conformity with said projectors, respectively;
• (c) allocating one of said divided image to a reference image and allocating each of the adjacent divided images to a peripheral image;
• (d) setting a view point that is coincident with the projection point of said reference image;
• (e) obtaining a 2-dimensional reference area of said reference image that is rendered on said screen model and is viewed from said view point;
• (f) obtaining a 2-dimensional peripheral area of said peripheral image that is rendered on said screen model and is viewed from said view point;
• (g) extracting an overlapping area of said 2-dimensional reference area that overlaps with the 2-dimensional peripheral area;
• (h) making a brightness correction for either said overlapping area or said non-overlapping area with regard to said 2-dimensional reference area;
• (i) providing a brightness filter for said reference image that realizes said brightness correction;
• (j) allocating another divided image to said reference image and repeating the steps of (d) to (i) for providing said brightness filter for each of said divided images.

A program for preparing brightness filters:

• said brightness filters being adapted in use for an image projection system which projects divided images on a curved screen respectively from a plurality of projectors with adjacent ones of said divided images partially overlapped to reproduce a combined image, said filter being given a brightness correction for adjusting the brightness of said divided images for harmonizing the brightness of the overlapping areas with the brightness of non-overlapping areas to make said combined image seamless, said program comprising:
• (a) a screen model creation module for producing screen model reflecting a shape of said curved screen;
• (b) a projection point setting module for setting projection points that project therefrom said divided images on said screen model, said projection points being different from each other in conformity with said projectors, respectively;
• (c) a view point setting module which allocates one of said divided images to a reference image and allocates each of the adjacent divided images to a peripheral image, said view point setting module setting a view point that is coincident with the projection point of said reference image;
• (d) a reference area capturing module that obtains a 2-dimensional reference area of said reference image that is rendered on said screen model and is viewed from said view point;
• (e) a peripheral area capturing module that obtains a 2-dimensional peripheral area of said peripheral image that is rendered on said screen model and is viewed from said view point;
• (f) an extracting module that extracts an overlapping area of said 2-dimensional reference area that overlaps with the 2-dimensional peripheral area;
• (g) a brightness correction module that gives said brightness correction for either said overlapping area or said non-overlapping area with regard to said 2-dimensional reference area;
• (h) a brightness filter creation module that provides a brightness filter for said reference image that realizes said brightness correction;
• (i) a repeater module that allocates another divided image sequentially to said reference image and operating said modules for providing the brightness filter for each of the divided images.