JP2744614B2 - How to make holographic stereogram - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a holographic stereo capable of obtaining a high-quality image from a low-quality video image signal recorded on a video tape and obtaining a high-quality reproduced image. It relates to a method for producing gram. (Technical Background and Problems to be Solved) Currently, with the development of laser devices for obtaining coherent light, the technology of holograms has been dramatically advanced. Among these holograms, a method called a holographic stereogram has been devised for hologram formation of a moving object and hologram formation for enlarging or reducing an object.
This method of producing a holographic stereogram includes a first step of photographing a series of images having different viewpoints on a three-dimensional object to produce a plurality of original films, and a method of combining light from the original films with reference light. And a second step of exposing and forming a hologram diffraction image utilizing interference. For this reason, it can be seen that the quality of the original film in the first step affects the quality of the holographic stereogram. Here, FIG. 5 shows a conventional method for producing an original film in the first step. First, as shown in FIG. 5, a three-dimensional subject 51 is placed on a film 53 built in a camera 52.
To shoot. At this time, an image is shot on a plurality of films while the camera 52 is translated in a plane separated by l3 from the subject 51 by a distance d3. That is, a plurality of holographic original films are produced from video information obtained by photographing the subject 51 from a plurality of directions. In such shooting, a movie camera is usually used as a camera. Therefore, a developing process is required to confirm the photographed subject image. On the other hand, video technology in recent years has been remarkably developed and spread, and if a predetermined screen can be used as a photograph from continuous video information recorded on a video tape, many advantages can be obtained. I have. In other words, since a video camera is used for shooting, a desired subject image can be confirmed in real time, as compared with a method for shooting a film using a movie camera.
In addition, with the spread of video cameras, it is possible to very easily obtain an original image for a holographic stereogram. However, in order to use a predetermined screen as the original film from the continuous video information currently recorded on the video tape, the video tape is set once in the playback device and the continuous video is displayed on the CRT by slow or stop playback. In reality, a desired image is photographed by a still camera while observing the screen to obtain an original film. Therefore, the quality of the original film, that is, the quality of the holographic stereogram image depends on the resolution of the television image. By the way, at present, television broadcasting in Japan is called the NTSC system, and one screen is formed with 525 scanning lines regardless of the size of a television image. Therefore, the actual situation is that the image quality of one frame is extremely poor in resolution and the like as compared with a general color film. Further, the number of TV scanning lines does not only affect the quality of resolution. For example, when an image projected on a cathode ray tube is accurately focused and photographed by a camera, there is a disadvantage that scanning lines are markedly recorded as horizontal stripes on the film. For this reason, it has been attempted to take a camera image with a slightly shifted focus, but this method has a problem that it is difficult to accurately capture a desired screen and that the screen is blurred. . (Object of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-quality image suitable for producing a holographic stereogram from a conventional low-definition image quality television video signal. An object of the present invention is to provide a method for producing the obtained holographic stereogram. (Means for Solving the Problems) According to the present invention, a three-dimensional subject is photographed from a plurality of directions by a video camera, and a holographic original film is produced from continuous video information recorded on a video tape.
And dividing the photosensitive surface of the hologram photosensitive plate into a plurality of divided regions, and for each of the plurality of original films, the light from the original film and the reference light fall in the divided regions corresponding to the photographing direction in the first step. The present invention relates to a method for producing a holographic stereogram having a second step of exposing and forming a hologram diffraction image utilizing interference with a video image recorded on a video tape in the first step. In the case of creating from the information, the selected picture is extracted when a desired picture is selected using a video recording medium on which a different time code is recorded from the video tape on which the continuous video signal is recorded, and the extracted video is Performing image quality improvement processing that performs temporal shift correction of the video signal and noise removal and contour enhancement processing contained in the video video signal,
After storing the digital image information obtained by digitizing the video image signal in the frame memory, the scanning line information of the odd field and the scanning line information of the even field are sequentially read, and the information between the read scanning line information is read. An image signal conversion process for interpolating by two-dimensional interpolation is performed, and an image displayed on a high-resolution flying spot scanner tube having a white phosphor is exposed to a photosensitive film using the signal subjected to the image signal conversion process. Achieved by obtaining a film. (Operation of the Invention) In the method for producing a holographic stereogram according to the present invention, when an original image is produced from a continuous video signal recorded on a video tape, a video tape editing unit can easily select a desired screen from video video signals. After that, the signal conversion processing unit performs image quality improvement processing such as time lag correction, noise elimination, contour emphasis processing, and interpolation processing on scanning line information on the video image signal, and outputs the result to the output unit. By using the provided high-resolution flying spot scanner tube to expose the image to the photosensitive film to obtain a film, a high quality image is realized, and the S / N is achieved by using the original image thus obtained. A holographic stereogram reproduction image with a good ratio can be obtained. (Embodiment of the Invention) FIG. 1 is a block diagram showing an embodiment of a video tape editing unit for realizing the holographic stereogram producing method of the present invention. In the present invention, a 3/4 inch wide video cassette tape 1 provided by a customer is set on a 3/4 inch video tape recorder 2 as shown in FIG.
A 1-inch wide video tape 8 previously set on a 1-inch helical scan video tape recorder 5
Has been re-recorded. The 1-inch wide video tape 8 has a time code track for recording a time code in addition to a video track for recording video information and an audio track for recording audio information. Then, via the time record generator / reader 4, the 1-inch wide video tape 8
The time code generated from the time code generator / reader 4 is continuously recorded on a 1-inch video tape corresponding to one frame of video information. Since the customer can specify a screen to be used for the hologram using the time code, the screen can be extracted accurately and in a short time. At the time of re-recording, the automatic electronic editing unit 3 controls playback stop of the 3/4 inch and 1 inch helical scan type video tape recorder 5, and the re-recording status is displayed on the display monitor 7 via the video switcher 6. Can be observed. Therefore, if it is not necessary to re-record the entire 3 / 4-inch wide video tape 1 provided by the customer, it is possible to re-record only the necessary portions while viewing the image on the display monitor 7. 1-inch wide video tape 8 re-recorded as described above
Is once rewound on the 1-inch helical scan type video tape recorder 5 and reproduced. The playback is performed by operating the slow playback and stop playback knobs of the automatic electronic editing unit 3, and the video information can be observed on the display monitor 7 via the video switcher 6. The display monitor 7 has a built-in Y / C separation decoder and uses a high-resolution CRT, so that better image quality can be obtained as compared with a normal monitor. Therefore, while reproducing the re-recorded image on the display monitor 7, a desired screen is selected at any time based on the hologram use screen instruction from the customer or the presence of the customer, and at the same time, the screen selection instruction console 10 is used. By pressing the frame designation switch, the time code generator / reader 4
The time code of the selection screen read in step (1) is registered in the memory unit of the time code reading unit 9. In this way,
After the frame registration for all the necessary screens of the re-recorded 1-inch wide video tape 8 is completed, the frame registration completion switch of the screen selection instruction console 10 is pressed. As a result, the registered time code information is sequentially read from the time code reading unit 9, coded, and output from the paper tape puncher 11 to the paper tape 12. The system control of this part is managed by a microcomputer (not shown). Here, a 1-inch video tape was used at the time of re-recording, but this can be changed to a video disk, and a paper tape on which a time code is recorded can be changed to a magnetic tape, a disk, a floppy disk, or the like. FIG. 2 is a block diagram showing a signal conversion processing unit and an output unit according to the present invention. The signal conversion processor automatically searches and extracts a desired screen from the re-recorded 1-inch wide video tape 8 and the paper tape 12 on which time code information corresponding to the desired screen is recorded. Performs image quality improvement processing such as correction, noise removal, contour emphasis, gradation correction, and scanning line interpolation. In the present invention, the video tape editing section and the signal conversion processing section for performing the image quality improvement processing have an online configuration. With this off-line configuration, the video tape editing work and the signal conversion processing work can be performed independently, so that the workability can be improved and the efficient use of the system can be expected. In FIG. 2, a re-recorded 1-inch wide video tape 8 and a paper tape 12 on which time code information corresponding to a desired screen is recorded are set on a 1-inch helical scan video tape recorder 21 and a paper tape reader 24, respectively. I do. Next, by pressing the frame extraction switch located on the console 25, the information of the paper tape 12 is read into the frame search unit 23 for one frame and the re-recorded information set on the 1-inch helical scan video tape recorder 21 is recorded. The reproduction of the 1-inch wide video tape 8 is started. At the same time as the reproduction is started, time code information recorded in advance for each frame is sequentially read by the time code reader 22, input to the frame search unit 23, and
Is compared with the frame code read through the paper tape reader 24. When the information from the time code reader 22 and the information of the frame search unit 23 read from the paper tape 12 match, a freeze instruction of the corresponding image signal is output from the frame search unit 23 to the noise reducer 27, and The screen information is stored in the frame memory incorporated in the noise reducer 27. At the same time, a reproduction stop signal is output from the frame search unit 23 to the 1-inch helical scan video tape recorder 21 to stop the tape recorder 21. Until the information from the time code reader 22 and the information of the frame search unit 23 read from the paper tape 12 match, the reproduced image signal of the video tape is transmitted through the time base collector 26 and the noise reducer 27. The contents of the built-in frame memories are sequentially compared to remove noise components. This content can be observed on the display monitor 29. Time base collector 26
The noise reducer 27 is a part of the image quality improvement processing in the signal conversion processing unit. The time base corrector 26 is for correcting a temporal shift of a video image signal usually called a jitter. When recording in a frame memory in a state where a temporal jitter occurs, a sampling start point of each scanning line and This prevents a difference in the number of sample pixels from occurring. The noise reducer 27 suppresses various noises and enhances the outline to improve the image quality. The image quality recorded on the original 3 / 4-inch wide video tape 1 provided by the customer is determined by noise or the like. To prevent the image quality from deteriorating due to noise in the video editing unit or the signal conversion system in the middle of the reproduction of the re-recorded video tape 8. An outline emphasis process is performed so as to emphasize points and sharpen an image. The image signal after this processing is sent to the RGB decoder 30 in FIG. 2 and is converted from an NTSC signal to an RGB signal. This decoder uses a comb filter, similar to the one built into the display monitor 29.
Since the Y / C separation is performed, an image signal excellent in resolution and color tone can be obtained as described above. The signals separated into RGB signals can be observed on the RGB display monitor 35 via the gradation correcting unit 31. A correction unit and a display 32 are connected to the gradation correction unit 31. The contrast correction, the parallel movement of the gradation, and the gradation of the light part or the jadow part can be adjusted manually for each of the RGB signals. The correction result is displayed on the RGB display monitor 35 at any time. Since the still image signal frozen by the noise reducer 27 is also displayed on the display monitor 29 in a state before the gradation correction, the still image signal is frozen by the RGB display monitor 35 displaying the result of the gradation correction. The gradation is corrected as needed while comparing. Also, by inserting a cursor signal from the display unit 32 and the correction unit to the still image, the video level at any point of the still image displayed on the RGB display monitor 35 can be changed to the video white signal reference value ( A numerical value can be displayed on the display unit of the corrector and the display 32 with a comparison value with respect to 0.7 V). Further, the printer 33 can print out the situation in which tone correction has been applied to each of the RGB signals and the set position information of the tone correction knobs of the corrector and the display as needed. Also, when using each R, G, B output of RGB camera without using video tape,
This can be achieved by directly inputting each output to the tone correction unit 31. When the correction is completed, the R, G, B still image signal, if necessary, is pressed by pressing the correction completion instruction switch on the console 25 when the correction is completed. Is converted to a digital signal, and recorded in the frame memory 37 corresponding to each of the R, G, and B signals.
B recording ends. If the R, G, B video information has been digitized in advance, it is possible to directly input the digital data to the frame memory 37. Next, the corrected still image information of R, G, and B recorded in the frame memory 37 is a scanning line interpolation unit corresponding to each signal.
The data is transferred to 38 one line at a time. The frame memory
In FIG. 37, even field information and odd field information are stored at different addresses, respectively, and constitute one frame of a still image. Therefore, signals for one scanning line transferred to the scanning line interpolation unit 38 are odd field and even field fields. Are alternately read out in ascending order of the numbers. Here, the scanning method is sequentially switched from the jumping method to the scanning method. By this switching, pairing, which is a drawback of the jumping method, can be prevented, and deterioration in image quality can be prevented. The number of signals of the scanning lines to be transferred to the scanning line interpolation unit 38 is obtained by subtracting the number of scanning lines corresponding to the blanking period from the number of television scanning lines of 525.
This is the main signal. In the scanning line interpolation unit 38, interpolation is performed to increase the number of scanning lines from 484 lines to about 1924 lines, which is about four times as large as that of the scanning lines. To Further, the resolving power can be increased by the interpolation effect. In the interpolation calculation according to the present invention, a point at which a new pixel is to be set, that is, an interpolation point is determined in consideration of the contribution ratio of peripheral pixels, and the nearest neighbor method, the bilinear method, and the cubic convolution method are switched. Is configured to be selectable by switching. The nearest neighbor method is a method in which data of adjacent pixels are directly used as pixel data at interpolation points, and is suitable for a binarized image. The bilinear method is based on the assumption that data between scanning lines changes linearly. The cubic convolution method determines the pixel data of the interpolation point from the correlation of the data of the 16 pixels around the interpolation point, and determines the pixel data of any of the pixels. Are suitable. This interpolation calculation is
Since about 1.5 million pixels per screen need to be multiplied and added 16 times per interpolated pixel, the computer software processing is slow and takes too much time. Therefore, according to the present invention, the scanning line interpolating unit 38 is configured by a hard element, and outputs data in real time to the output unit at the next stage, thereby making it possible to produce an extremely high-speed film. The image information that has been subjected to the scanning line interpolation operation simultaneously by the scanning line interpolation unit 38 of the signal conversion processing unit is input to the color film creation device interface 39 via the color film creation device interface 39.
It is sent to 40 high-resolution CRTs (flying spot scanner tubes) and sequentially displays each color of R, G, B as a black-and-white image with a wide range of visible wavelength energy. As a holographic stereogram original image, a black-and-white positive image is required, and in general, the R, G,
B Obtained by three exposures of each monochrome image signal. Further, when an image subjected to three-color separation (R, G, B) is desired to be obtained, exposure of only the R signal, exposure of only the G signal, and exposure of only the B signal may be performed. When the exposure is completed, the color film or the black-and-white film is automatically advanced by one frame so that the next selected and extracted screen can be exposed. The color film is 6 × 7cm
Size roll film can be used and the image size is 51 as standard
× 68 mm, which is about 8 times larger in area ratio than the image size obtained by the conventional color cathode ray tube photographing method, and the image quality is extremely good. Although the NTSC television system has been described above as an example, the present invention can be similarly applied to other television systems. Next, a specific example of the production of a holographic stereogram by the above apparatus will be described. First, a doll with a height of 5 cm was used as the three-dimensional object 54, and as shown in FIG. 3, an image was taken from a distance of 1 = 600 mm with a video camera 55 filled with 3/4 inch videotape while moving in a range of d1 = 400 mm. . This 3/4 inch video tape was applied to the video tape editing system shown in FIG. 1 to obtain a 1 inch video tape 8 to which time code was added. The 1-inch video tape 8 was applied to a system having a signal conversion processing section and an output section shown in FIG. 2 to output 100 images at regular intervals of 4 mm within the range of 400 mm. This output film
The 56 has the advantage that there is no scanning line as compared with the conventional tube photographing film. Using this output film 56, a holographic stereogram was produced in an exposure system as shown in FIG. As the projection light and the reference light 52, argon laser light having a wavelength of 4880 ° and an output of 0.8W was used. An image of the output film 56 is projected onto the diffusion plate 58 by using a lens having a diameter of 50 mm and a focal length of 100 mm as the lens 57, and the scattered light from the hologram photosensitive plate 59 (for example, Ag Irradiated on a photographic dry plate 8E56HD, size 30 mm × 400 mm × 3 mm, manufactured by Fergewald. The reference beam 52 was applied to the hologram dry plate 59 at an angle of 30 °. The opening window 51 of the light-shielding plate 50 has a width d2 = 4 mm.
The recording of the hologram diffraction image was performed 100 times for each decomposed region while being moved by mm. In addition, based on the holographic steogram obtained in this manner, a known method (for example, US PAT 36339)
A holographic stereogram reproducible with white light was prepared in 89), but the results were good. (Effect of the Invention) According to the holographic stereogram creating method of the present invention, a process of selecting a desired image from continuous video information shot by a video camera and recorded on a video tape, and time lag correction, After performing noise removal, contour emphasis processing, and interpolation processing on scanning line information, an image is exposed on a photosensitive film using a high-resolution flying spot scanner tube to obtain an original film. Therefore, there is an advantage that a high-quality image can be realized even with an original film obtained based on a low-definition image quality television video signal. Furthermore, since a holographic stereogram is produced using this original film, an advantage that a reproduced image having a high S / N ratio equivalent to that of a holographic stereogram produced by an original film produced by a conventional movie camera can be obtained. There is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a video tape editing unit as one embodiment for realizing a holographic stereogram producing method of the present invention, and FIG. 2 realizes the method of the present invention. 3 and 4 are diagrams showing a method for producing a holographic stereogram according to the present invention, and FIG. 5 is a diagram showing a conventional holographic stereogram. It is a figure showing a manufacturing method. 1 ... Video cassette tape, 2 ... Video tape recorder for 3/4 inch, 3 ... Automatic electronic editing unit, 4 ...
… Time code generator reader, 5,21… 1 inch helical scan type video tape recorder, 6… Video switcher, 7,29,35… Display monitor, 8…
... 1-inch wide video tape, 9 ... time code reading section, 10 ... screen selection instruction scanning desk, 11 ... paper tape puncher, 12 ... paper tape, 22 ... time code reader, 23 ...
... Frame search unit, 24 ... Paper tape reader, 25 ... Control console, 26 ... Time base collector, 27 ... Noise reducer, 28 ... Detail collector, 30 ... RGB decoder, 31 ... Tone correction unit, 32 …… Modifiers and indicators, 33…
… Printer, 34… Print, 36… A / D converter, 37…
... frame memory, 38 ... scanning line interpolation unit, 39 ... interface for color film production device, 40 ... color film production device.

Claims (1)

(57) [Claims] A first step of photographing a three-dimensional subject from a plurality of directions with a video camera and producing an original holographic film from continuous video information recorded on a video tape;
The photosensitive surface of the hologram photosensitive plate is divided into a plurality of divided areas, and for each of the plurality of original films, interference with light from the original film and reference light is applied to the divided regions corresponding to the photographing direction in the first step. In a method for producing a holographic stereogram having a second step of exposing and forming a hologram diffraction image used, when producing an original film from continuous video information recorded on a video tape in the first step, A selected screen is extracted when a desired screen is selected by using a video recording medium on which a different time code is recorded from a video tape on which video information is recorded, and a time shift correction of the extracted video video signal and the video video are performed. A digital image obtained by performing image quality improvement processing for removing noise contained in a signal and performing outline enhancement processing and digitizing the video image information After storing the image signal in the frame memory, image signal conversion for sequentially reading the scanning line information of the odd field and the scanning line information of the even field, and interpolating the information between the read scanning line information by two-dimensional interpolation. Processing, and an image displayed on a high-resolution flying spot scanner tube having a white phosphor is exposed to a photosensitive film according to the image signal-converted signal to obtain the original film. How to make a holographic stereogram.