Method for acquiring colorful digital holographic image

Abstract

The invention relates to a method for acquiring a colorful digital holographic image. The method is technically characterized in that a black and white type area array CCD and multiple recording wavelength lens-free fourier transform hologram recording optical path are used for respectively shooting a single-color digital hologram of an object to be recorded under the irradiation of red, green and blue laser; after the zeroing treatment of the acquired single-color digital holograms is carried out to acquire the corresponding zeroed digital holograms, the median filtering pretreatment is respectively carried out to acquire the corresponding median filtering pretreatment holograms, then the inverse fast fourier transform operation is carried out, and the acquired red, green and blue single-color digital holograms are respectively inputted into a three-layer zero matrix to acquire a colorful digital holographic image of the object to be recorded. According to the method, the position ofa reproduced image on a value reconstruction image plane is fixed by the distance between the recorded object on an object plane and a reference point light source during the recording and is not changed with the recording distance. In addition, the method has less constraint on the horizontal size of the object to be recorded and has a larger space-bandwidth product.

Description

technical field [0001] The invention relates to a method for acquiring a color digital hologram, belonging to the technical field of digital holography. It is a color digital holographic image acquisition method based on digital holography and lensless Fourier transform holography. Background technique [0002] The holographic recording and display of colored objects is an important aspect of the application of holographic technology. At present, the commonly used methods are traditional optical holography, such as rainbow holography, transmission true color holography, reflective true color holography, true color holography Synthetic holography, etc. ("Optical Holography and Its Applications", written by Yu Meiwen). Their implementation methods are relatively complicated. The main reasons are: firstly, the recording optical path of holograms is complex and difficult to build and adjust; secondly, chemical recording media such as dry plates cannot be reused, and the cost of...

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Problems solved by technology

B.Javidi and D.Alfieri et al. in their paper "Method for superposing reconstructed images from digital holograms of the same object recorded at different distance and wavelength" (Optics Communications 260 (2006), 113-116) and "Three-dimensional image fusion by useof multiwavelength digital holography"(Optics Letters 30(2005), 144-146) adjusts different hologram recording conditions (recording wavelength and recording The display size of the digital hologram under the distance) is based on this. On this basis, the obtained red and green monochrome holograms with the same display size are synthesized to obtain a color digital hologram, but the digital hologram recorded by the off-axis Fresnel holographic recording optical path Figure, the position of the numerical reconstruction image on the reconstructed image plane changes with the change of the included angle of the object parameters and the recording distance when the hologram is recorded, so the accurate superposition of the numerical reconstruction image at different recording distances cannot be guaranteed, which will lead to the synthesis The boundaries and details of the color digital hologram become unclear, which affects the quality of the color hologram reproduction

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