KR100301958B1 - Apparatus and method for recording and reproducing still picture in universal video tape - Google Patents

Abstract

PURPOSE: A recording/reproducing device of a still picture to a general video tape and a method thereof are provided to prevent the loss of a previously recorded still picture by adding a dummy picture at the front and back side of a still picture. CONSTITUTION: A recording/reproducing device of a still picture to a general video tape includes a digital recording/reproducing control unit for converting analog image signals to digital signals in real time, sampling the digital image signals by a predetermined picture number per second, recording the sampled still picture data to a digital storing unit, reading a predetermined amount of the still picture if more than a predetermined amount of the sampled still picture data is stored in the digital storing unit, and converting the read still picture data to analog image signals by adding a predetermined dummy screen data, and a general video tape recorder unit for repeating the recording-stopping-recording operations for analog image signals provided periodically from the digital recording/reproducing control unit.

Description

APAPATUS AND METHOD FOR RECORDING AND REPRODUCING STILL PICTURE IN UNIVERSAL VIDEO TAPE}

The present invention relates to a still image recording and reproducing apparatus and method using a general video tape recorder, and more particularly, to record a still image using a hard disk driver and a general video tape recorder in a video surveillance system, and to record a recorded image with high quality and high speed. A still picture recording and reproducing apparatus and method which can be retrieved.

The video surveillance system (VSS) was initially recorded by connecting one VCR to one camera. However, in normal VCRs, it is not possible to record still images and to record movies, so recording time per tape is very short, making it difficult to record for long periods of time. It is improved by showing the screen sequentially through the equipment. However, this method also shows only the screens in order, and thus has a disadvantage of not being able to monitor overall.

Therefore, in order to compensate for this, as shown in FIG. 1, the four-division equipment 12 has been introduced to improve the system for simultaneously monitoring four cameras 10 by dividing the screen of one monitor 16 into four equal parts. In addition, a TIME LAPSE VCR 14 has been developed to reduce the number of tapes. Time Lapse VCR 14 is a method of extending the recording time of the tape by recording the screen as if taking a picture as a still picture instead of a normal video.

The analog video surveillance system has a slow screen switching time, and the image quality is degraded due to the deterioration of the magnetic material of the tape and the tape sagging due to the repeated use of the tape. In addition, time-lapse VCRs cause a high system cost because of the high cost of the mechanism and control configuration for low-speed recording for long-term storage on videotape compared to conventional videotape recorders.

In recent years, a digital video surveillance system using a personal computer has been introduced to improve the problems of the analog system.

As shown in FIG. 2, the digital video surveillance system converts a video signal provided from the plurality of cameras 20 through the switching means 22 into a digital video signal to perform screen processing and screen switching on the personal computer 24. It has the advantage of providing various modes of surveillance environment and providing clear picture quality with excellent screen capture function. In addition, by storing the surveillance video on the hard disk of the personal computer 24, not tape, there is no fear of deterioration of image quality even after repeated playback, so that a clean screen can be always displayed and random search is possible to quickly find a desired scene at high speed. have.

However, hard disk drivers have to build a backup system because the system itself is often unstable or down. In addition, considering the price of the recording medium to the storage capacity, the value of the HDD is still higher than that of the video tape.

Therefore, research and development for storing still images in a low cost general video tape recorder is required.

In a general video tape recorder, when recording-stopping-recording an image on one tape, if a video is recorded immediately after a stop, a non-recording section exists between the recording section and the recording section due to the inertia force due to the mechanical characteristics of the video head. In such a non-recorded section, a noise screen appears on the monitor during playback. Therefore, in general, in the general video tape recorder, as shown in FIG. 3, when a recording command is input after stopping after recording, a predetermined section is rewound and a new image is placed on a part of the end of the previously recorded section. You will be recording. Therefore, part A of the drawing of the previously recorded section is lost. However, when recording a moving picture, 60 pictures per second are recorded continuously, so even if some recording sections are lost, it does not matter much. Rather, it is recognized as a more important problem to prevent a non-normal screen from being displayed between the sections and the sections, so that a part of the existing recorded video is lost during the recording.

However, when every still picture is important information such as a video surveillance system, the loss of information due to the operation of such a general video tape recorder is not a very big problem. Therefore, when a surveillance video is formed into a still picture in a video surveillance system and recorded on a general video tape recorder, such a problem is required.

An object of the present invention is to digitally sample a surveillance image in a video surveillance system, store the sampled still image data in a digital storage means, and add a dummy image to the stored still image data in order to solve the problems of the related art. The present invention provides a still image recording and reproducing apparatus and method capable of recording still images on a video tape and retrieving recorded images at high quality and high speed by recording an analog image signal using a video tape recorder. Preferably, the dummy screens are added to front and rear ends of a predetermined amount of still images, respectively.

Another object of the present invention is to prevent the end of the recorded portion from being overlapped and lost by the leading end of the signal to be recorded in the case of recording a still image intermittently using a general video tape recorder. The present invention provides a still image recording and reproducing apparatus and method.

1 is a view showing the configuration of a conventional analog video surveillance system.

2 is a diagram showing the configuration of a conventional digital video surveillance system.

3 is a view for explaining a recording state on a tape during recording-stopping-recording of a general video tape recorder.

4 is a diagram showing the configuration of a video surveillance system capable of reproducing still image recording using a general video cassette tape recorder according to the present invention.

Fig. 5 is a block diagram showing the construction of one preferred embodiment of the digital recording and reproducing control apparatus of Fig. 4;

6 is a view for explaining a recording state on a tape during recording-stopping-recording of a general video tape recorder according to the present invention;

<Explanation of symbols for the main parts of the drawings>

30: surveillance camera 32: switching means

34, 44: analog-to-digital converting means 36: digital recording / reproducing means

38, 42; Digital analog conversion means 40: monitor

46: regular VCR 48, 49: hard disk driver

50: system control means 52: alarm means

216; Image compression means 222: Video extension means

218, 220: interface means 226: index encoder

230: dummy screen additional means

In order to achieve the above object of the present invention, digital storage means for recording and reproducing data on a digital recording medium of the present invention, converts an analog video signal into a digital video signal in real time, and converts the converted digital video signal. Sampling at a predetermined number of screens per second, recording the sampled still picture data to the digital storage means, and when a predetermined amount or more of still picture data is recorded in the digital storage means, a predetermined amount of still picture data is read out, and the read still picture data is read. Digital recording / playback control means for adding predetermined dummy screen data and converting it into an analog video signal, and recording analog video signals intermittently provided from the digital recording / playback control means on a magnetic tape by repeating the recording-stopping-recording operation. Characterized by having a general video tape recorder The.

The digital storage means may be configured as a large capacity hard disk driver, an optical disk driver or a semiconductor memory module.

Preferably, the digital recording / reproducing control means is composed of one chip composed of an ASIC. The digital recording / playback control means includes analog conversion means for converting an analog video signal into a digital video signal in real time, a memory means for storing the converted digital video signal on a screen basis, and a digital video signal stored in the memory means per second. Image compression means for sampling a predetermined number of screens, compressing the sampled still picture data, and providing the compressed data through the image compression means to the hard disk driver, and storing the compressed data if the data stored in the hard disk driver is equal to or larger than a predetermined amount. Interface means for reading out, image expansion means for expanding the compressed data read out through the interface means into still picture data, an index encoder for adding index information to the decompressed still picture data, and a still picture data with an index. Analog video scene by adding dummy screen And digital to analog converting means for converting to a call.

The recording method of the present invention comprises the steps of: converting an analog video signal provided from a surveillance camera into a digital video signal in real time; sampling the digital video signal with a predetermined number of screens per second; and digitally storing the sampled still picture data. Storing a predetermined amount of still image data in the digital storage means, converting the image into an analog image signal by adding a dummy image to the read still image data; And recording the converted analog video signal on a video tape by a general video tape recorder.

Here, it is preferable to compress the screen data before storing the still picture data in the digital storage means, read out from the digital storage means, and then expand the compressed data. In addition, adding index information to the read screen data before conversion into an analog video signal facilitates retrieval during reproduction.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the present invention through an embodiment of the present invention.

4 is a block diagram of a video surveillance system capable of recording and reproducing still images using a general video cassette tape recorder according to the present invention. The video surveillance system includes a plurality of surveillance cameras 30, a switching means 32, a first analog-digital converting means 34, a digital recording / reproducing means 36, a first digital analog converting means 38, a monitor ( 40, second analog to digital conversion means 42, second digital to analog conversion means 44, general video tape recorder 46, a plurality of hard disk drivers 48 and 49, system control means 50, alarm And means 52.

FIG. 5 shows the configuration of a preferred embodiment of the digital recording and reproducing control apparatus of FIG. In FIG. 4, the first analog-to-digital converting means 34 includes four video decoders 34a for digitally converting four-channel video signals for four-division display and a video decoder 34b for digitally converting video signals for recording. ). Each video decoder converts an analog video signal into a digital video signal, and the converted video signal is separated into a luminance signal (Y) and a color difference signal (U, V).

The digital record / playback control means 36 is composed of an ASIC one chip. The digital recording and reproducing control means 36 is largely divided into the display image processing unit 100, the recording and reproducing image processing unit 200, and the system interface unit 300.

The display image processing unit 100 is for generating and outputting a 4-split display screen, and inputting four digital image signals to decode the luminance signal and the color signal in a CCIR656 format that processes 4: 2: 2 in a ratio of 102. A scaler 104 for adjusting the horizontal and vertical sizes of the decoded image data to a quad screen size, an input buffer 106, an SDRAM controller 108 for writing and reading image data to and from the SDRAM 402, and an output buffer. 110, a zoom processor 112, an OSD processor 114, and an encoder 116. The scaler 104 is provided with image data read out from the hard disk driver 48.

The recording and reproducing image processor 200 stores a video signal provided from the surveillance camera in a hard disk drive and reads the stored data to provide it to the VCR, or processes the playback screen to display the image reproduced from the VCR on a monitor. The recording and playback image processing unit 200 is a decoder 202 for decoding the image data provided from the video decoder 34b into the CCIR656 format, an input buffer 204, and a decoder 206 for decoding the playback image data into the CCIR656 format. An index decoder 208 for extracting and decoding index information, an input buffer 210, an SDRAM controller 212 for outputting and reading image data into the SDRAM 404, an output buffer 214, and image compression means ( 216, an interface unit including a hard disk formatter 218 and a hard disk deformatter 220, an image expansion means 222, a multiplexer 224, an index decoder 226, a CCIR656 encoder 228, a dummy screen And additional means 230, and the like.

The system interface unit 300 includes a detector 302, a microcomputer interface unit 50, and a synchronization generator 306.

Effects of the embodiment of the present invention configured as described above are as follows.

The surveillance video signal captured from the sixteen surveillance cameras 30 is provided to the first analog-to-digital converter 34 via a switching means 32. The switching means 32 switches the desired surveillance cameras 30 by switching control of the system controller 50.

The digitally converted digital image signals of the plurality of CCIR656 formats are each scaled down to a 4-split size and stored in the SDRAM 402 through the input buffer 106. The 4-segmented surveillance video data stored in the SDRAM is read out through the output buffer 110, ZOOM and OSD processed, and then CCIR656 reverse-formatted and transferred to the first digital-to-analog converter 38. The analog-switched four-segment surveillance video signal is applied to the monitor 40 and displayed as a four-segment screen on the screen.

As such, when a recording event occurs in the monitored four-split screen, the system control means 50 issues a switching control command to the switching means 32 to control the video signal of the surveillance camera to be input to the video decoder 34b. do. The video signal input to the video decoder 34b is digitally converted and converted into CCIR656 format and stored in the SDRAM 404 through the input buffer 204 in real time.

The SDRAM controller 404 reads only five still picture data out of 60 pictures per second by the read timing provided from the system control means 50. Therefore, only five still picture data are sampled out of the 60 pieces of picture data per second, which is compressed to 1/12 on the time axis.

The still image data read out through the output buffer 214 is transmitted to the image compression means 216 and compressed to approximately 1/10. In other words, approximately 350k byte of image data is compressed to 35k byte of image data for each field. The compressed video data is formatted in HDD format and stored in the hard disk driver 48.

Image data stored in the hard disk driver 48 may be classified and stored by camera number, time zone, or event, or may be stored in chronological order. This storage classification facilitates retrieval during retrieval.

The image data stored in the hard disk driver 48 is read in a predetermined amount unit, for example, file size, time unit, and the like, deformatted by the HDD deformatter 220, decompressed by the image expansion means 222, and then decompressed. Restored to still picture data.

The restored data is provided to the scaler 104 for display on the monitor 38 or transmitted to the dummy picture adding means 230 through the multiplexer 224, the index encoder 226, and the CCIR656 encoder for recording.

The index encoder 226 inserts information for indexing the position of the video signal on the video tape in the vertical blanking section.

The dummy screen adding means 230 adds predetermined dummy screen data before and after a certain amount of still picture data. That is, the normal video tape recorder 46 adds a dummy screen to the extent that the video tape recorder 46 can sufficiently include a rewind section by a rewind operation by a recording command after stopping. Still picture data to which the dummy picture is added before and after is provided to the second digital-to-analog converter 42.

The analog video signal converted through the second digital-to-analog converter 42 is provided to the general VCR 46 and recorded on a video tape. That is, the recorded video signal is recorded as a still picture in field units. Therefore, the recording of still images, which can be performed only in a time-lapse VCR, is also possible in a general VCR, so that it is possible to record video information of the same or longer time period compared to the time-lapse VCR.

As shown in Fig. 6, the existing recording signal RECI on the tape has a dummy screen I at the rear of the effective screen I. In this way, when the recording signal RECI is stopped and the recording command is input again, the general video tape recorder performs a rewind operation to reverse the tape for a predetermined period, and then newly supplies the recording signal RECII. ) To start recording. The dummy screen II exists at the beginning of the effective screen II of the recording signal RECII, and overlaps and records on the existing dummy screen I.

Therefore, the effective screens do not overlap with each other, so that they are safely recorded on the tape without loss.

When the recorded video tape is reproduced in the general VCR 46, the reproduced video signal is converted into a digital video signal by the second analog-to-digital converter 44, so that the CCIR656 decoder 206, the index decoder 208, and the input buffer ( It is written to the SDRAM 404 via 210. Only valid screen data among the written data is read out in a first-in first-out manner and stored in the hard disk driver 48 via the image compression means 216 and the HDD formatter 218 via the output buffer 214. Therefore, the reproduced dummy picture is not stored on the hard disk but only a valid still picture is stored.

The corresponding reproduced image data stored in the hard disk driver 48 is read with reference to the decoded index in response to the search command provided from the system control means 50. The read out reproduced image data is provided to the scaler 104 via the HDD deformatter 220 and the image expansion means 222. The reproduced image data provided to the scaler is synthesized with other image data and displayed on the monitor 40.

Therefore, instead of viewing the image reproduced from the videotape as it is, it is once re-saved as digital image data in the hard disk driver 48, and then the re-stored image data is retrieved and displayed on the monitor. Therefore, high-speed search and random access are possible on the hard disk, and the image quality is clear and clear because the digital image data is analog-converted and displayed on the monitor 40.

The system control means 50 checks whether or not the hard disk driver 48 is broken, and when the hard disk driver 48 is broken, the alarm means 52 informs the administrator of the failure of the hard disk driver 48. When the hard disk driver 48 fails, the system control means 50 blocks the connection path of the hard disk driver 48 and connects the hard disk driver 49 to control the storage of the surveillance image to continue without interruption. do.

In addition, the system control means 50 reads the screen data written to the SDRAM 404 in real time without time compression in case of failure of the hard disk drivers 48 and 49 so as to be recorded on the video tape recorder 46. . Therefore, in the event of a failure of the hard disk driver, it is possible to save the surveillance video as a video on videotape.

In the above-described embodiment, the dummy screen is added by the digital circuit unit 36, but it is also possible to add the dummy screen by the video encoder 42.

As described above, in the present invention, when the surveillance video is periodically stored in the general video tape recorder, a dummy picture is added before and after the still picture and recorded. Therefore, in the recording-stopping-recording operation of the general VCR, it is possible to prevent the previously recorded still picture from being lost in the next recording.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (5)

Digital storage means for recording and reproducing data on a digital recording medium; Converts an analog video signal into a digital video signal in real time, samples the converted digital video signal at a predetermined number of screens per second, records the sampled still picture data in the digital storage means, and stores a predetermined amount or more in the digital storage means. Digital recording / reproducing control means for reading a predetermined amount of still picture data when the still picture data is recorded, and adding predetermined dummy picture data to the read still picture data to convert it into an analog video signal; And And a general video tape recorder for recording an analog video signal periodically provided from the digital recording / reproduction control means on a magnetic tape by repeating a recording-stopping-recording operation. Device. 2. The still image recording and reproducing apparatus using a general video tape recorder according to claim 1, wherein the analog video signal inputted to said digital recording and reproducing control means is provided from a surveillance camera. 2. The still picture recording and reproducing apparatus using a general video tape recorder according to claim 1, wherein the dummy pictures are respectively added before and after a predetermined amount of still picture data. 2. The still picture recording using the general video tape recorder according to claim 1, wherein the dummy screen is a data amount sufficient to include a section rewinding by a recording command after the recording-stopping of the general video tape recorder. Playback device. Converting an analog video signal provided from a surveillance camera into a digital video signal in real time; Sampling the digital video signal at a predetermined number of screens per second; Storing the sampled still picture data in the digital storage means; Reading a certain amount of still picture data when a predetermined amount of still picture data is stored in the digital storage means; Adding a dummy picture before and after the read still picture data and converting the dummy picture into an analog video signal; And And recording the converted analog video signal on a video tape by a general video tape recorder.