Algorithms take the target 3d intensity as input and compute the hologram that generates it. Osa calculation for computer generated hologram using. A line hologram with resolution of 4096x2730 occupies about 10 megabytes of hard drive spaces. Rs plane is set at near the object and the lightrays emitted by the object are sampled at the plane. With luminit threedimensional computer generated holography, a predetermined image e. A fast method that allows holograms to be efficiently generated by computer is described. The rainbow hologram is very practical to display 3d images because it can be reconstructed with white light. However, since the amount of calculation is very large, the fps becomes very low as the number of points of the object increases. Holograms, holographic, 3d holography, computer generated. The software also varies in the methods it uses to create holograms. We made software that simulates wave optics using previously known physical model to generate a hologram with the possibility of connection with commercial 3d. Computergenerated hologram how is computergenerated. Computergenerated holographic gratings in soft matter.
Fourier transform from a computer generated hologram phase mask. In this paper, we propose a novel fast computergenerated hologram calculation method using sparse fast fourier transform. This is especially the case when characterizing large convex telescope mirrors. In computergenerated hologram cgh calculations, a diffraction pattern needs to be calculated from all points of a 3d object, which requires a heavy computational cost. Digital holography optically generates a hologram, which is then recorded on a ccd camera, and an image is reconstructed using digital techniques. In fact, the running time is proportional to the image width and height. When sending the hologram to your printer, you want to reproduce it as faithfully as possible. The phase of the aspheric wavefront is calculated at the center of each cell.
Hologram software ranges from free, downloadable programs to expensive programs. A system includes a computer generated hologram cgh design plane and a processor capable of representing a three dimensional object. Hologram is a buzz word on internet world these days. You printed out your synthetic hologram as 300dpi laserprinter pages. Computer generated holography and diffractive optical. Computergenerated holograms for optical testing usually consist of patterns of curved lines drawn onto or etched into glass substrates. These computer generated holograms are then optically reconstructed. Us7649532b2 computer generated hologram display system. A computer generated hologram or a cgh is a computed interference pattern of such 3d scene. A computer generated hologram that could display a company logo in the lobby instead of a onedimensional sign is one example. Optimization the running time of each computer generated hologram is different depending on the resolution of the image. Computergenerated hologram how is computergenerated hologram abbreviated.
The new method is about 42 times faster than the conventional raytracing algorithm with approximately the same resolution. Full parallax threedimensional computer generated hologram with occlusion effect using. We describe an electrooptic apparatus capable of displaying a computergenerated hologram in real time. Holographic studios can transfer your 3d computer generated images into actual three dimensional holography displays. Hologram computers, mobiaq, illuminair, holographic. Computer generated holography using parallel commodity graphics. Computergenerated holograms for 3d imaging acm digital library. Computergenerated holograms cghs are diffractiveoptical elements that offer the possibility of creating waveoptical display systems that are under complete computer control. Testing large optical elements can require the use of largesize cghs. Improvement of direct fringe printer for computergenerated holograms. Clear, crisp, bright image with computer generated. Multiplane 4d cgh taking this concept another step forward, luminit is developing 4d multiplanar holography where different images could appear based on the position of the viewers eye. Synthetic holograms are specified by a computer and written with an electronic plotter. The computergenerated hologram is calculated by a supercomputer, read from a.
Check out this simple tutorial of making hologram video with powerdirector. Vividqs software brings real time computer generated holography cgh to everyday applications. The wavefront on the cgh plane is calculated by wavefront propagation. Fourier optics and computer generated hologram 3 computer generated holography is an optical numerical technique, which avoid the traditional light interference recording process by computer numerical calculation and record the hologram directly. Computergenerated hologram cgh 1 includes a unique capability for recording and reconstructing the desirable amplitude and phase of object light, leading to a wide use of this technique in optical applications such as threedimensional 3d displays 2, projections 3. A portion of it encoding into fourier computer generated hologramcgh, while the. In this case, it is a simple sinusoidal pattern along the xaxis and constant along y. Computergenerated hologram dainippon printing co ltd. Then the lightrays are transformed into the wavefront with using the fourier transforms. Luminit computer generated holograms allow viewers to see clear, crisp, and bright holographic images without the need of glasses or other special eyewear. To drive these, computer generated holograms cghs, rendered from point. Introduction computergenerated holograms, synthetic holograms and computer holograms are terms used to refer to a class of holograms which are produced as graphical output from a digital computer.
We propose a simplified model to calculate the computer generated rainbow hologram quickly. Here is the line hologram produced by the above phase function. Computer generated hologram construction kit freecode. An analysis of the errors produced by emulsion movement, incorrect hologram size and position, and distortion in hologram plotter and photoreduction lens is given, and it is shown that all the errors are proportional to the slope of the aspheric wavefront.
A hologram is an interference recording of a 3d surface. Part of the reason is a simple tip of making hologram viewer with a cd case, and turning your smartphone into a hologram viewer. This hologram will behave like one created using a laser and can be projected or viewed with a point source. It does not require the actual light and the actual. Imagine seeing your 3d images in true holographic 3d. The use of computer generated holograms for the testing of aspheric wavefronts is described. Instead, as figure 1 shows, a computer calculates a holographic fringe pattern that it then uses to set the optical prop. A computergenerated hologram with a complex amplitude of object light recorded therein so that a stereoscopic object is reconstructible, wherein. Basically the function of a computergenerated hologram is to create an optical wavefront from a set of computed. One of the first gray scale computergenerated hologram left and an image reconstructed from a gray scale computergenerated hologram right, adopted from 4 2 in sect. A photographically produced hologram is used to store and play back an existing wavefront. Software to make computergenerated hologram thread starter toan. Given a mathematical description o a wavefront or an object represented by an array of f points, the computer can calculate the amplitude transmittance of the hologram and display the result on a crt or plot it on paper.
Download hologram effect software for windows for free. Index terms computer generated hologram cgh, fourier transformation, gerchbergsaxton algorithm. The making of a computergenerated hologram features. Computer generated fresnel hologram fabrication for true life scene 3d display duration. The image position changes as the alignment of the viewing system changes. Threedimensional or 3d software products generally allow users to construct holograms on a personal computer. Digital recording and numerical reconstruction of holograms. Fourier transform from a computer generated hologram.
I also included in this document a short description of the. For binary holograms, the length of the four rectangles is. Scaling of threedimensional computergenerated holograms with. Burch suggested, then, that, in making computergenerated holograms, the amplitude transmittance o the hologram should be f because of the absence of the a2x, y term in tx, y in eq. Note also how simple this pattern was to calculate this is the basis for the idea of computergenerated holography. Miloth on 30 jun 2017 i am trying to perform a fourier transform of a phase mask to reconstruct my. Benefits of computer generated holography for nextgeneration. Computer generated hologram player cghplayer calculates and displays a hologram of an object consisting of point clouds in real time. Computer generated hologram cgh eric logean august 2003 abstract this document is an introduction to the design and fabrication of computer generated hologram cgh as i understood them back in 1997. Computergenerated holography cgh is the method of digitally generating holographic. As an alternative to the photochemistry and vibrationfree settings involved with regular holography, this program allows you to create a transmission hologram using just a computer, a laser printer, and an overhead transparency. In old circuit cellar magazine they had a hobbyist cgi hologram project. Software to make computergenerated hologram physics forums.
Computergenerated holographic techniques offer an efficient way for reconstructing holograms without complicated interference recording systems. We used a laser which shined through a beam expandercollimator a photographed cameras lens into the computer generated hologram. Improvement of direct fringe printer for computergenerated holograms duration. His company was designing the chrysler corporations information center at the mall of america. In my thesis, i implemented a computer program that is able to generate holograms.
Ive never seen a straightforward explanation of how computer holograms are actually transferred to the physical recording medium. Each cell contains four equally spaced rectangular apertures. Upon the proper recording, reconstruction, and viewing conditions, unlike the traditional 2d photography, the image appears to be 3d again. However, arbitrary patterns are generally infeasible, so solutions are approximate and often suboptimal. Because cghs can control all aspects of the optical wave, threedimensional imagery can be presented to. In the proposed method, we can simply generate the final hologram from intermediate data, whose total number of samples can be less than one tenth. By implementing cgh calculations in a gpuprogram that is executed once per.
We introduce a new algorithm for calculating computer generated hologram cgh using raysampling rs plane. It represents influence of all technological steps into quality of the final product. At that time, i was visiting professor toyohiko yatagai1 in japan. The final photoreduction step could, of course, be eliminated by using special output devices to write the hologram directly in the desired size. Generation and replication of computer generated hologram. In this work, holographic barcodes using computer generated holograms are. Some enable users to layer any photograph, creating a 3d effect. Numerical hologram reconstruction was initiated by yarosl avskii et al 11 at the early 1970s. Computergenerated holography is an emerging technology, made possible by increasingly powerful computers, that avoids the interferometric recording step in conventional hologram formation. The course is geared towards scientists, engineers, managers, and researchers interested in exploring fundamentals of computer generated holography, diffractive optical elements, lcos arrays and maskless grayscale lithography who want to.
This hologram will behave like one created using a laser, and can be. The null testing setup using a customized computer generated hologram cgh in a mach zehnder interferometer is demonstrated in this video clip. Computergenerated holography cgh is the method of digitally generating holographic interference patterns. Computer generated holograms have bean made practical. This requires ensuring software and memory compatibility with the gpu structure, which is. The qr code generated is then converted into a hologram, thus providing a high profile security to the product. Realization of fourier and fresnel computergenerated holograpm. It is possible for a computer software to calculate the phase of light of an object. It started when jeff at ross roy communications found us through the internet. Trial software fourier transform from a computer generated hologram phase mask. The processor is configured to represent a surface of the three dimensional object by a facet, impose a grid defining a set of nodes upon the facet, and associate object points with each node of the grid. Pdf computer generated fourier holograms for ug laboratory. The image is also cropped from the actual image due to its high resolution. Printing the hologram getting the output from the computer program to a transparency which will diffract light is a particularly crucial step in making computer generated holograms.