Wigner inverse transform based computer generated hologram for large object at far field from its perspective light field

A hologram synthesis method, comprising:

• a) obtaining perspective views Ptx,ty(u, v) for a three dimensional object by capturing light field data at spatial coordinates along (tx, ty) axes and angular coordinates expressed as spatial frequencies (u, v) of light ray angles (θx, θy) in a front focal plane at a focal length (f) in front of a lens;
• b) synthesizing an intermediate hologram by using the obtained perspective views Ptx,ty(u,v) as an orthographic view array Ou′,v′(t′x, t′y) in a back focal plane at the focal length (f) behind the lens and performing a Wigner inverse Fourier transform on the orthographic view array,
• wherein u=sin θx/λ and v=sin θy/λ,
• wherein u′=−tx/λf and v′=−ty/λf,
• wherein t′x=uλf and t′y=vλf, and
• wherein λ is a wavelength;
• and
• c) synthesizing a final hologram in the front focal plane by performing a Fourier transform of the synthesized intermediate hologram with spatial frequencies x/λf and y/λf.

A hologram synthesis system, comprising:

• a collecting unit configured to collect perspective views in a front focal plane;
• and
• a hologram synthesizing unit configured to:
• obtain perspective views for a three dimensional object at a distance by capturing light field data at spatial coordinates and angular coordinates expressed as spatial frequencies of light ray angles in a front focal plane at a focal length in front of a lens;
• synthesize an intermediate hologram by using the obtained perspective views as an orthographic view array in a back focal plane at the focal length behind the lens and performing in a Wigner inverse Fourier transform on the orthographic view array to obtain an orthographic light field;
• and
• synthesize a final hologram in the front focal plane by performing a Fourier transform using a spatial frequency for the synthesized intermediate hologram.