KR100601256B1 - Method and device for reading of the holographic digital data system - Google Patents

Abstract

The present invention relates to a reproducing method and a reproducing apparatus of a holographic digital data system. In particular, the reproducing method of the present invention captures the storage data of a storage medium as image data of a CCD pixel and sets the data of the CCD pixel to n × n ( n> 2) oversampling to a size, compensating adjacent data values between oversampling pixels in one pixel data among the oversampled pixels, and storing the compensated pixel data values. Therefore, the present invention oversamples a reproduced image of a storage medium photographed by a CCD into pixels of size n × n (n> 2) and deteriorates image data of the CCD pixel by using one pixel data and pixel data information adjacent thereto. By compensating for, the quality of the reproduced image data can be improved.

Holographic digital data, oversampling, CCD, signal processing

Description

Playback method and playback device of holographic digital data system {METHOD AND DEVICE FOR READING OF THE HOLOGRAPHIC DIGITAL DATA SYSTEM}

1 is a block diagram of a typical holographic digital data system,

2 is a block diagram showing a reproduction device of a holographic digital data system to which the present invention is applied;

3 is a block diagram of a signal processor for reproducing adjacent pixel information in a holographic digital data system according to the present invention;

4 is a diagram showing a matching relationship between a data pixel and a CCD pixel during reproduction of a holographic digital data system according to the present invention;

5 is a view for explaining data reproduction using adjacent data pixel information during reproduction of a holographic digital data system according to the present invention;

6A and 6B show an SLM image of a holographic digital data system and a degraded image of a CCD due to oversampling.

<Description of the code | symbol about the principal part of drawing>

42: detection array (CCD) 70: signal processing unit

72: Scan Control Unit 74: CPU

76: detection image buffer 78: adjacent pixel compensation unit

79: compensated image buffer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holographic digital data system (HDDS), and more particularly, to a method and apparatus for reproducing a holographic digital data system capable of improving the quality of reproduced image data.

Recently, technologies for storing holographic digital data have been actively researched in various fields, for example, thanks to remarkable developments such as semiconductor lasers, charge coupled devices (CCDs), and liquid crystal displays (LCDs). As a result, fingerprint recognition systems for storing and reproducing fingerprints have been put to practical use, and are being expanded to various fields that can apply the advantages of large storage capacity and ultra-high data transfer speed.

Among them, a holographic digital data system storing a large amount of data is a storage medium, for example, optical refraction, in which an interference fringe generated when the signal light from the target object and the reference light are interfered with each other is sensitive to the amplitude of the interference fringe. By recording to a storage medium such as a photorefractive crystal, it is possible to display a three-dimensional image of an object, and also to display hundreds to thousands of hologram data composed of pages of binary data. Can be stored in place.

1 is a block diagram of a general holographic digital data system. Referring to FIG. 1, a general holographic digital data system is installed at a position corresponding to a light source 12 and a light source 12 for generating a laser light, so that the light of the light source 12 is referred to as a reference beam and a signal beam. a beam splitter 18 separating the beam into a beam, a mirror 32 reflecting the reference light separated from the light splitter 20, and light reflected from the mirror 32 is incident on the storage medium 10. Spatial Light Modulator (SLM) that carries input data, that is, binary data of a plurality of pixels configured in units of pages, on the signal light separated by the rotating mirror 36 and the optical separator 20 for converting the angles to be converted. (26), a storage medium which diffracts and outputs an interference fringe generated by the interference of the signal light output from the spatial light modulator 26 and the reference light reflected by the rotation mirror 36, and recorded by the irradiation of the reference light. 10), based on storage medium 10 It consists of an interference pattern generated by irradiating only the original such as a CCD (42) for converting the output to electrical data. Unexplained reference numeral 14 denotes an optical magnification lens, 34 denotes a retardation lens, and 30 and 40 denote Fourier lenses.

The holographic digital data system thus constructed operates as follows.

The laser light irradiated from the light source 12 is divided into reference light and signal light in the light separator 18. At this time, the signal light is input to the spatial light modulator 26 and modulated. That is, the signal light is incident on the storage medium 10 after the data input from the spatial light modulator 26 is modulated in units of one page of the binary data of the intensity of real pixels. In addition, the reference light is incident on the storage medium 10 at an angle changed by the rotation mirror 32. That is, the reference light which slightly changes the angle of the rotation mirror 32 corresponding to each page is incident on the storage crystal 10 which is the storage medium 10. The signal light and the reference light cause interference inside the storage medium 10 for recording the hologram, and light-induced generation of mobile charge of the internal kinetic charge of the storage medium 10 according to the intensity of the interference fringe generated at this time. Is generated and an interference fringe is recorded through this process.

In order to read the data recorded in the storage medium 10, only the reference light needs to be irradiated to the storage medium 10. That is, when the reproduction reference light having the same deflection angle as the deflection angle of the recording reference light enters the storage medium 10 on which the interference data is recorded, the reproduction reference light is diffracted to make a single page of binary data (consisting of the original pixel contrast ( That is, the checkerboard pattern) is restored. The binary data (one page unit) reproduced from the storage medium 10 is restored to the original data through the CCD 42 or the like. The holographic data reconstructed by the CCD 42 must undergo a series of signal processing before being decoded by a decoder.

That is, the pixel matching method between the spatial light modulator 26 and the CCD 42 pixels is used to process pixel data, that is, binary data, in units of pages. However, in the case of a system for storing holographic data in a storage medium by shift multiplexing, mismatching occurs when the pixel matching between the spatial light modulator 26 and the CCD 42 is 1: 1. To prevent this, one pixel of the reproduced image of the storage medium 10 is matched to nine CCD pixels (3 × 3) by oversampling, and only data of the center pixel is extracted as original data.

However, the pixel matching method according to the related art oversamples one pixel of the reproduced image in nine CCD pixels and uses only one pixel data in the center as original data information, thereby reducing the efficiency of the reproduced data. There was this.

SUMMARY OF THE INVENTION An object of the present invention is to oversample a playback image of a storage medium photographed by a CCD into 2 × 2 pixels and to use one pixel data and adjacent pixel data information to solve the problems of the prior art. The present invention provides a reproducing method and a reproducing apparatus of a holographic digital data system capable of improving the quality of reproduced image data by compensating deteriorated image data of a CCD pixel.

In order to achieve the above object, the present invention provides a method of reproducing holographic digital data stored in a storage medium, comprising the steps of: photographing the storage data of the storage medium as image data of a CCD pixel; oversampling to a size (n> 2), compensating adjacent data values between the oversampled pixels to one pixel data among the oversampled pixels, and storing the compensated pixel data values.

In order to achieve the above object, the apparatus of the present invention is a signal processing unit for oversampling CCD pixel data obtained by capturing an image stored in a storage medium in a holographic digital data system, wherein n × n (n> 2) An adjacent pixel compensator for oversampling to size and compensating for deterioration data of the CCD pixel by using one of the pixel data and adjacent horizontal and vertical pixel data information; And an image buffer, and a CPU to control the adjacent pixel compensator to compensate the data of the CCD pixel and to store the compensated data in the compensated image buffer.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a block diagram showing a playback apparatus of a holographic digital data system to which the present invention is applied.

Referring to FIG. 2, a reproducing apparatus of a holographic digital data system to which the present invention is applied includes a spatial light modulator 26 and a spatial light modulator for carrying input data, that is, binary data of a plurality of pixels configured in units of pages, in a signal light. 26, the storage medium 10 and the storage medium 10, which record the interference fringe generated by the interference of the signal light output from the reference mirror and the reference light reflected by the rotation mirror, and diffractize and output the interference fringe recorded by the irradiation of the reference light. The CCD 42 converts and outputs the interference fringe generated by the irradiation into the electrical data 62 of the original page unit, and oversamples one pixel of the image reproduced by the CCD 42 to a size of 2 × 2 pixels. A signal processor 70 for compensating for deterioration image data of the CCD pixel by using one of the pixel data and pixel data information adjacent thereto, and an image compensated by the signal processor 70 It includes a decoder 80 for decoding such data into binary data (i.e., a checkerboard shaped pattern) of a single page. Here, the reproducing apparatus of the present invention conventionally includes a signal processing section 70 and a decoder 80 in addition to the system configuration as shown in FIG.

3 is a block diagram of a signal processor for reproducing adjacent pixel information in a holographic digital data system according to the present invention.

Referring to FIG. 3, the signal processor 70 of the holographic digital data system according to the present invention includes an input unit 71 to which a user command is input, a detection array 42 which is a CCD to detect data photographed from a set pixel, And a scanning control unit 72 for photographing the reproduction data of the storage medium from the CCD pixel, a CPU 74 controlling the internal signal processing component, and a detection image buffer for storing the data of the CCD detection array 42 ( 76 and an adjacent pixel that oversamples the data pixel stored in the detection image buffer 76 to a size of 2 × 2 pixels and compensates for the degraded image data of the CCD pixel by using one pixel data and pixel data information adjacent thereto. Compensator 78 and a compensated image buffer 79 for storing data compensated in adjacent pixel compensator 78.

4 is a diagram showing a matching relationship between a data pixel and a CCD pixel during reproduction of a holographic digital data system according to the present invention. Reference numeral 100 denotes a pixel of a detection array that is a CCD and 110 denotes a data pixel for oversampling to a size of 2x2.

Referring to FIG. 4, the signal processor of the holographic digital data system according to the present invention causes the CCD pixel 100 and the 2 × 2 oversampling pixel 110 to be mismatched. One size of the pixel 110 for oversampling determines the size of one pixel of the CCD and the pixels adjacent thereto.

5 is a view for explaining data reproduction using adjacent data pixel information during reproduction of a holographic digital data system according to the present invention.

3 to 5, the signal processor 70 of the holographic digital data system according to the present invention performs signal processing on pixel data of a CCD as follows.

When a user command is input through the input unit 71, the CPU 74 controls the scan control unit 72 to capture a reproduced image of the storage medium through the CCD 42, and then stores the reproduced image in the detection image buffer 76. .

The CPU 74 oversamples the CCD pixel stored in the detection image buffer 76 by 2 × 2 pixel size through the adjacent pixel compensator 78 and uses one of the pixel data and pixel data information adjacent thereto. Compensate for deteriorated image data of the CCD pixel due to oversampling. That is, when only the data of the upper left first pixel 110a is used as the original pixel data among the 2 × 2 oversampling pixels as shown in FIG. 5, the pixel 110a and other 1 'and 1' 'pixels adjacent thereto are adjacent to the pixel 110a. The second or third pixel data between 110b and 110c affects the pixels 110a, 110b and 110c adjacent to each other to create an image degradation phenomenon (pixel having gray intensity). Therefore, the present invention compensates the pixel data value of pixel 2 or 3 to the data value of pixel 110a.

A = intensity of pixel 3 (data)-w1 × (intensity of pixel 1 '-intensity of pixel 1)

B = Intensity of pixel 2 (data)-w2 × (intensity of pixel 1 ''-intensity of pixel 1)

Here, w1 and w2 have weight values (constants) indicating the influence of adjacent pixels.

The A and B values thus obtained are combined with the intensity of the first pixel 110a to compensate for the first pixel data value. As a result, the compensated data value of pixel 1 has the intensity + A + B of pixel 1.

The CPU 74 then stores the data having pixel values compensated by the adjacent pixel compensator 78 in the compensated image buffer 79.

6A and 6B illustrate an SLM image of a holographic digital data system and a degraded image of a CCD due to oversampling. FIG. 6A shows an image of a data pixel modulated in a spatial light modulator (SLM), and FIG. 6B shows a degraded image of a CCD due to oversampling between an image reproduced in a storage medium and a CCD pixel.

As described above, in the holographic digital data system, when there are many pixels having intermediate values (grays) other than the ON / OFF values of the CCD pixels, the degradation of the reproduced image data processed by the signal processor and the decoder is greatly increased. Degrades. However, in the system of the present invention, the signal processor compensates for the deterioration component (adjacent pixel data) of the CCD pixel.

As described above, the present invention oversamples a playback image of a storage medium photographed by a CCD into pixels of size n × n (n> 2), and uses one pixel data and pixel data information adjacent thereto to make a CCD pixel. By compensating for deteriorated image data, the quality of reproduced image data can be improved.                     

Meanwhile, although the present invention has been described with respect to 2x2 oversampling, various modifications may be made by those skilled in the art within the spirit and scope of the present invention described in the following claims rather than being limited to the above-described embodiment.

Claims (4)

A method for reproducing holographic digital data stored in a storage medium, Photographing the storage data of the storage medium as image data of a CCD pixel; Oversampling the data of the CCD pixel to a set n × n (n> 2) size; Compensating adjacent data values between the oversampled pixels on one pixel data among the oversampled pixels; Storing the compensated pixel data value Reproduction method of a holographic digital data system comprising a. The method of claim 1, The oversampling may include oversampling one oversampling pixel of size n × n (n> 2) such that a CCD pixel is matched with horizontal and vertical pixels adjacent thereto. Way. In the signal processing unit for oversampling the CCD pixel data photographed the image stored in the storage medium in the holographic digital data system, An adjacent pixel compensator for oversampling the pixel data of the CCD to a size of n × n (n> 2) and compensating for deterioration data of the CCD pixel by using one pixel data and horizontal and vertical pixel data information adjacent thereto; Wow, A compensated image buffer for storing data compensated by the adjacent pixel compensator; A CPU which controls the adjacent pixel compensator to compensate data of a CCD pixel and stores the compensated data in the compensated image buffer Playback device of the holographic digital data system comprising a. The method of claim 3, wherein The adjacent pixel compensator and the n × n (n> 2) oversampling pixel are oversampled so that the CCD pixel and the horizontal and vertical pixels adjacent thereto are matched with each other. .

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