Color Fourier orthoscopic holography with laser capture and an LED display

Abstract

We present an end-to-end full color Fourier holographic imaging approach, which involves standard holographic recording with three wavelengths and an improved LED-driven display. It provides almost undistorted orthoscopic reconstruction of large objects in full color, which can be viewed with a naked eye. High quality reconstruction is preserved across large object depths, measured in meters, as shown theoretically and experimentally. Our imaging approach is based on capture, processing and display of the object wave fields without spherical phase factors. This efficient convention combined with a novel numerical propagator for confocal fields enables complete axial decoupling of both ends of the imaging chain, and consequently, free manipulation of axial position as well as size of the image without visible deformations and with minimal computation effort.

Visual perception of Fourier rainbow holographic display

“…All holograms are generated for λ 0 = 540 nm. The first test object is “wolf” figurine with dimensions of 80 mm width, 60 mm height, and 30 mm depth, captured in the lensless Fourier capture system with the following parameters: camera resolution 2,448 × 2,050; camera pixel pitch 3.45 μm; object distance from the camera 790 mm; registration wavelength 540 nm. The second object is a “dog” model represented by a cloud of points.…”

“…First, the distribution of the complex object wave is calculated or captured at the VW plane of the display. For the generation of holograms of a 3D object, the 3D point‐based CGH method is used , and for capturing of holograms of real object, the lensless Fourier hologram capture system is utilized . Then, to reduce the spatial frequency content in vertical direction, the numerical slit is applied to the complex object wave field.…”

Wave atoms for digital hologram compression

“…For Fourier holograms, that have been recorded with respect to a spherical reference point source in the objects middle plane, this assessment is not true anymore. The spherical, or in the near-field approximation quadratic, phase shift typically introduced by propagation is largely annihilated by the curvature of the reference wave, as only differences with respect to the reference are encoded in the hologram [27]. This is the idea of the compact space-bandwidth representation (CSBP) proposed in [26].…”

“…The "Sphere" hologram was captured from a 6.5cm object using the green channel of a Basler piA2400-12gm with 3.45µm pixel-pitch in an off-axis lens-less synthetic aperture Fourier holography setup as described in [7,27]. It was then converted to an on-axis geometry by numerical filtering of the +1 diffraction order.…”

Detection and Analysis of LED Display System in Large Stadiums

“…It has the following advantages: long life cycle, less energy consumption, large visibility range, long viewing distance, etc. [1]. At present, it has a wide range of use, for example, securities trading, finance, stations, stadiums, road traffic, airport flights, dispatching command centres, and shopping malls, advertising media and other public places.…”