Patent ID: 7573622

Claim:
A method for creating a computer hologram, which is supposed to be observed in a lighting environment of the real world where a multiple of light sources exist, by forming interference fringes on a predetermined recording surface by a computer-aided operation, said method comprising the steps of: defining a predetermined original image in a three-dimensional coordinate system, a recording surface placed in the coordinate system for recording the original image, and a reference light to be irradiated onto the recording surface; defining a large number of calculation points on the recording surface, and calculating, in terms of the individual calculation points, intensity of an interference wave formed by an object light emitted from a light source defined on the original image and the reference light; defining a plurality of types of binary patterns each defined by dividing a unit area having a fixed form and size into a first area having a first pixel value and a second area having a second pixel value by changing an occupancy ratio of the first area relative to the unit area; allocating, at positions of the respective calculation points, binary patterns having occupancy ratios corresponding to interference wave intensities in terms of the respective calculation points, respectively; and creating physical fringes on a medium based on a binary image formed from an assembly of the binary patterns allocated onto the recording surfacer, wherein a rectangle is used as the unit area, and the binary pattern is formed by arranging the first area formed of a rectangle having a vertical width equal to a vertical width of the unit area and having a horizontal width according to a predetermined occupancy ratio at an approximately center position with respect to a horizontal width of the unit area and providing a remaining part as the second area, and wherein a horizontal pitch of the calculation points defined on the recording surface is set equal to or less than a minimum wavelength of a visible light.