Realtime construction and reconstruction of fresnel holograms is demonstrated using an opticallyaddressable ferroelectric liquidcrystal spatial light modulator. This technique achieves 3d reconstruction of objects from a 2d hologram image and reaches accuracies in the range of or smaller than the wavelength. May 30, 2011 categories laser tags diagram or figure of recording process in holography, diagram or fogure or picture of reconstruction process in holography, how 3 dimensional picture is recored in holography, how hologram is made, how hologram records complete picture, how hologram works, recording and reconstruction process in holography, what is gabor. There exist several methods for hologram reconstruction. Jan 18, 2018 in this paper, a digital hologram reconstruction process is investigated. A laser light hologram is recorded and reconstructed by using the same laser light as for recording. Holography 1 holography introduction and background the aesthetic appeal and commercial usefulness of holography are both related to the ability of a hologram to store a threedimensional image. Optics for reflection holographic stereogram systems core. A laser beam identical to the reference beam is used for reconstruction of the object. Inline hologram reconstruction with sparsity constraints.
Other possibilities for reconstructing images on arbitrary curved surfaces are discussed herein. Jul 31, 2012 construction and reconstruction of image on hologram in holography the process of image formatter consist of two types. This conjugate wave which appears during reconstruction, is not seen when we focus on the primary reconstruction. Image reconstruction from acoustical holograms using. The most important methods for reconstruction of holograms, recorded in fresnel zone, are fourier reconstruction algorithm and convolutional reconstruction algorithm 1. Recording and reconstruction process in holography. The relationship between the quality of holograms and some parameters was obtained by comparing the images of reconstruction at different distances. Reconstruction of the hologram generated by spherical wave. However, its presence degrades the primary wave and prevents getting a high quality hologram. The discussion in this chapter will also make clear the need for a cylindrical shaped hologram, and explain its advantages and disadvantages. Digital reconstruction of a hologram recorded using partially. Inline hologram reconstruction with sparsity constraints lo c denis,1. Schnars and juptner applied their method to interferome.
In the current paper we present a totally new algorithm also based on the two hologram technique. Computergenerated holograms of images reconstructed on. Because phase is a relative property, construction of a. Pdf 3d volume reconstruction using hologram researchgate. Pdf holography is the science of making holograms which are usually intended for displaying three dimensional images. In digital holography, where the hologram is recorded using partially coherent illumination, to reconstruct the object information from holographic fringes term i or, the conventional optical reconstruction process is replaced by a computer algorithm see fig. When the hologram is illuminated by the reconstruction wave,2waves are produced. Here we describe a new method for numerically reconstructing an object with variable viewing angles. Construction and reconstruction of image on hologram in holography the process of image formatter consist of two types. Therefore, reconstruction of the image occurs when the reference beam diffracts off the interference pattern. The magnification image can be obtained by two methods based on convolution method and fresnel method. Review of digital holography reconstruction methods.
This framework is much more flexible than existing work, in the sense that it can handle objects with multiple sections. Numerical reconstruction of images from digital holograms is a fundamental task in digital holography. Digital holography became feasible since charged coupled devices ccds with suitable numbers and sizes of pixels and computers with suf. As 3d information coded in a digital hologram can be recorded in one shot, this technique can be used with high speed cameras to perform timeresolved 3d reconstructions of high speed phenomena. A real image of the object is reconstructed from the digitally sampled hologram by means of numerical methods. In digital holography in particular the downscaling causes high spatial frequencies to be cut from the reconstruction.
Unlike ordinary photographs, holograms record both phase and amplitude information. Pdf 3d volume reconstruction technology is the new sign of future technology and communications. Recording and reconstruction of holograms phywe series of publications laboratory experiments physics phywe systeme gmbh 37070 gottingen, germany 22603 3 index phase hologram. This paper discusses the reconstruction of sectional images from a hologram generated by optical scanning holography. Computer generated holograms generated by using three different numerical techniques are reconstructed optically by spatial light modulators. A bright holographic image is read out due to the optical separation between the write and read sides by a dielectric mirror. Construction of whitelight holographic screens arxiv. For a fair comparison, the reconstruction parameters for both spatial. Introduction first experiments in numerical reconstruction of optical holograms date back to 196070th. Second, we read the created hologram by illuminating it with a suitable reference beam.
The optical design and construction of a reflection holographic stereogram. Reconstruction of image in the reconstruction process, the hologram is illuminated by laser beam and this beam is called reconstruction beam. Reconstruction depth adaptive coding of digital holograms. The hologram in figure 22 was used to illustrate reconstruction by convolution. Reconstruction of a complex object from two inline holograms. Many methods exist for the recording and playback of a hologram, and a simple apparatus is shown in figure 1 and figure 2. One more thing to note, the type of holograms made here are referred to as transmission. The positive print is only a 2d record of light intensity.
A new dctbased algorithm for numerical reconstruction of. Recording and reconstruction process in holography winner. In this process,a wave identical to reference beam is used. Signal processing 5 1983 531540 531 northholland image reconstruction from acoustical holograms using microprocessors b. The main restriction on the use of a twobeam scanning arrangement as outlined above, is the requirement for there to be significant overlap of the two beams at the hologram plate at all points over the hologram aperture. The object is stored in the hologram in the form of interference pattern. The reproduction of the image from the hologram is known as reconstruction of the hologram. Jeong lake forest college lake forest, illinois holography is a much broader field than most people have perceived. Holography holography mathematics proposed by dennis gabor 1948. T1 reconstruction depth adaptive coding of digital holograms. May 04, 1993 furthermore, each point on the hologram should receive the same amount of exposure thereby improving uniformity of exposure. We developed an experimental setup that allowed the optical recording construction of dynamic digital holograms dhs from real threedimensional objects in. Posso department of electrical and electronic engineering, the merz laboratories, university of newcastleupontyne, newcastle upon tyne.
We present a mathematical model for the holographic image capture, which facilitates the use of inverse imaging techniques to recover individual sections. Explain the construction and reconstruction of hologram. More complete discussions of the theory are in references 1, 2, 3. Reconstruction of computer generated holograms by spatial. Dynamic digital holography for recording and reconstruction of 3d. This beam is identical to reference beam used in construction of hologram. Dec 05, 2017 this is small topic of engineering physics. The reconstruction of the object field encoded within the hologram is based on the principle of light diffraction.
Ideally, the reconstruction procedure should give back the original point object in our. First, we create the hologram of the point object using a reference beam and an object beam. This article describes the principles and major applications of digital recording and numerical reconstruction of holograms digital holography. N2 we propose an adaptive coding algorithm for digital hologram transmission based on serverclient interaction. When the developed hologram is illuminated by the same reference wave, the reconstructed object wave as was previously emitted from the actual object. According to the sampling theorem downsampling works like a lowpass. At that time, scanning devices that could be used for digitizing holograms, had low resolution, which required optical magnification of holograms to. Image is seen in the same side of viewer after illuminating light gets reflected from the hologram can be viewed by white light also.
The details of a software implementation of a digital hologram reconstruction methods are presented. Osa direct recording of holograms by a ccd target and. The hologram was also reconstructed using the cepstrum technique proposed in this paper. One wave appears to diverge from the object and provides the virtual image of the object. The classical computer reconstruction method kir offaxis holograms is to compute the 2d fit of the measured hologram. If the holographic plate is illuminated after its development using the same reference wave used in the recording process, the light will diffract into three orders of diffraction if the diffraction network is sinusoidal. Reconstruction from digital holograms by statistical methods. Construction and reconstruction of image on hologram for. Image is seen after light passedtransmitted through the holographic plate reflection hologram recording. Nov 15, 2011 the superposition of the two beams creates an interference pattern on the ccd sensor. Computergenerated holograms of images reconstructed on curved surfaces joseph rosen when one illuminates a computergenerated hologram by a plane wave, the obtained twodimensional image is usually displayed on a planar plane. Whenever required the object can be viewed by illuminating the hologram as shown in the figure below 2.
In conventional photography, a negative is made first and using it a positive print is produced later. It is shown that images reconstructed from a digital hologram in a fresnel region at a distance matching a distance from the object to the hologram consist of two parts, one of which is a clear. Holography is a technique that enables a light field, which is generally the product of a light source scattered off objects, to be recorded and later reconstructed when the original light field is no longer present, due to the absence of the original objects. Osa reconstruction of sectional images in holography using. Recorded hologram with the reconstruction area of the lcos highlighted. The principle of recording holograms directly on a ccd target is described. Reconstruction from digital holograms by statistical methods saowapak sotthivirat and jeffrey a.
Resolution enhancement in digital holography by self. Construction and reconstruction of image on hologram. The phases of the stored light waves can be calculateddirectly from the digital holograms, without. The advantages and limitations of common wave propagation methods are discussed. Such a reconstruction algorithm simulates the coherent reconstruction. Numerical reconstruction of digital holograms with variable. Digital recording and numerical reconstruction of holograms.
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