Unlike ordinary photographs, holograms record both phase and amplitude information. 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. Numerical reconstruction of digital holograms with variable. Digital reconstruction of a hologram recorded using partially. Schnars and juptner applied their method to interferome.
Image reconstruction from acoustical holograms using. A laser beam identical to the reference beam is used for reconstruction of the object. Review of digital holography reconstruction methods. Pdf 3d volume reconstruction technology is the new sign of future technology and communications. Numerical reconstruction of images from digital holograms is a fundamental task in digital holography.
This technique achieves 3d reconstruction of objects from a 2d hologram image and reaches accuracies in the range of or smaller than the wavelength. However, its presence degrades the primary wave and prevents getting a high quality hologram. Inline hologram reconstruction with sparsity constraints lo c denis,1. The hologram in figure 22 was used to illustrate reconstruction by convolution. Second, we read the created hologram by illuminating it with a suitable reference beam. More complete discussions of the theory are in references 1, 2, 3. Reconstruction from digital holograms by statistical methods saowapak sotthivirat and jeffrey a. Construction of whitelight holographic screens arxiv. Construction and reconstruction of image on hologram for. The positive print is only a 2d record of light intensity. A real image of the object is reconstructed from the digitally sampled hologram by means of numerical methods. According to the sampling theorem downsampling works like a lowpass. A laser light hologram is recorded and reconstructed by using the same laser light as for recording. Construction and reconstruction of image on hologram in holography the process of image formatter consist of two types.
There exist several methods for hologram reconstruction. Because phase is a relative property, construction of a. Reconstruction from digital holograms by statistical methods. A new dctbased algorithm for numerical reconstruction of. Reconstruction of the hologram generated by spherical wave.
The discussion in this chapter will also make clear the need for a cylindrical shaped hologram, and explain its advantages and disadvantages. This conjugate wave which appears during reconstruction, is not seen when we focus on the primary reconstruction. The advantages and limitations of common wave propagation methods are discussed. The magnification image can be obtained by two methods based on convolution method and fresnel method. A bright holographic image is read out due to the optical separation between the write and read sides by a dielectric mirror. This article describes the principles and major applications of digital recording and numerical reconstruction of holograms digital holography. Recorded hologram with the reconstruction area of the lcos highlighted. Reconstruction of a complex object from two inline holograms. In conventional photography, a negative is made first and using it a positive print is produced later. Reconstruction of computer generated holograms by spatial. The relationship between the quality of holograms and some parameters was obtained by comparing the images of reconstruction at different distances.
Inline hologram reconstruction with sparsity constraints. Reconstruction depth adaptive coding of digital holograms. At that time, scanning devices that could be used for digitizing holograms, had low resolution, which required optical magnification of holograms to. Many methods exist for the recording and playback of a hologram, and a simple apparatus is shown in figure 1 and figure 2. In digital holography in particular the downscaling causes high spatial frequencies to be cut from the reconstruction. The hologram was also reconstructed using the cepstrum technique proposed in this paper. The classical computer reconstruction method kir offaxis holograms is to compute the 2d fit of the measured hologram. Computer generated holograms generated by using three different numerical techniques are reconstructed optically by spatial light modulators. When the hologram is illuminated by the reconstruction wave,2waves are produced. Ideally, the reconstruction procedure should give back the original point object in our. Image is seen in the same side of viewer after illuminating light gets reflected from the hologram can be viewed by white light also. N2 we propose an adaptive coding algorithm for digital hologram transmission based on serverclient interaction. In the current paper we present a totally new algorithm also based on the two hologram technique.
Recording and reconstruction process in holography. Digital holography became feasible since charged coupled devices ccds with suitable numbers and sizes of pixels and computers with suf. When the developed hologram is illuminated by the same reference wave, the reconstructed object wave as was previously emitted from the actual object. Reconstruction of image in the reconstruction process, the hologram is illuminated by laser beam and this beam is called reconstruction beam. 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. Holography holography mathematics proposed by dennis gabor 1948.
Realtime construction and reconstruction of fresnel holograms is demonstrated using an opticallyaddressable ferroelectric liquidcrystal spatial light modulator. Digital recording and numerical reconstruction of holograms. Dec 05, 2017 this is small topic of engineering physics. Signal processing 5 1983 531540 531 northholland image reconstruction from acoustical holograms using microprocessors b. This paper discusses the reconstruction of sectional images from a hologram generated by optical scanning holography.
Pdf 3d volume reconstruction using hologram researchgate. Image is seen after light passedtransmitted through the holographic plate reflection hologram recording. Resolution enhancement in digital holography by self. For a fair comparison, the reconstruction parameters for both spatial. Here we describe a new method for numerically reconstructing an object with variable viewing angles. 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. Construction and reconstruction of image on 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. Pdf holography is the science of making holograms which are usually intended for displaying three dimensional images. This beam is identical to reference beam used in construction of hologram. Osa direct recording of holograms by a ccd target and. First, we create the hologram of the point object using a reference beam and an object beam. 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. Whenever required the object can be viewed by illuminating the hologram as shown in the figure below 2. The principle of recording holograms directly on a ccd target is described. T1 reconstruction depth adaptive coding of digital holograms. Optics for reflection holographic stereogram systems core. In this process,a wave identical to reference beam is used. Dynamic digital holography for recording and reconstruction of 3d. Osa reconstruction of sectional images in holography using. 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.
This framework is much more flexible than existing work, in the sense that it can handle objects with multiple sections. Such a reconstruction algorithm simulates the coherent reconstruction. 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. The object is stored in the hologram in the form of interference pattern. Computergenerated holograms of images reconstructed on. The phases of the stored light waves can be calculateddirectly from the digital holograms, without.
We present a mathematical model for the holographic image capture, which facilitates the use of inverse imaging techniques to recover individual sections. We developed an experimental setup that allowed the optical recording construction of dynamic digital holograms dhs from real threedimensional objects in. One more thing to note, the type of holograms made here are referred to as transmission. Recording and reconstruction process in holography winner. Explain the construction and reconstruction of hologram. Introduction first experiments in numerical reconstruction of optical holograms date back to 196070th. 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. Jan 18, 2018 in this paper, a digital hologram reconstruction process is investigated. Nov 15, 2011 the superposition of the two beams creates an interference pattern on the ccd sensor. Jeong lake forest college lake forest, illinois holography is a much broader field than most people have perceived. The reconstruction of the object field encoded within the hologram is based on the principle of light diffraction. Posso department of electrical and electronic engineering, the merz laboratories, university of newcastleupontyne, newcastle upon tyne. The details of a software implementation of a digital hologram reconstruction methods are presented.
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