JP3679803B2 - Image recording / playback device - Google Patents

Description

  The present invention relates to an image recording / reproducing apparatus that can be applied to, for example, a multi-mode camera-integrated VTR that can collectively perform camera shooting, compression signal processing, and VTR recording in a plurality of television standards.

  Conventionally, a camera-integrated VTR (hereinafter referred to as a camcorder) is dedicated to each television broadcasting system (NTSC, PAL, etc.), and it is known that a tape speed can be switched as a mode selection. FIG. 20 shows a configuration example of the camcorder described in Patent Document 1.

  In FIG. 20, a video signal output from a known circuit including an optical system 161, an image sensor 162, a camera signal processing circuit 163, and the like is based on a time code generated by a time code generator 166 in an adder 164. The character signal generated by the character generator 165 is multiplexed. This video signal is converted into a recording signal in a signal form suitable for recording in a recorder signal processing circuit 167 together with an audio signal (Audio) and four types of pilot signals (4f) used for four-frequency tracking control. Recording is performed alternately on the magnetic tape 171 by the rotary heads 170a and 170b via an amplifier 168 and a head switch 169 that is switched by a PG pulse of 30 Hz. A technique for discriminating between the standard mode and the long-time recording mode using the four-frequency pilot signals is described in, for example, Patent Documents 2 and 3.

JP-A-2-40165 JP-A-60-89854 JP 59-142864 A

  However, since a conventional camcorder does not support a plurality of television standards, it is necessary to prepare a plurality of camcorders according to applications and use them properly.

  In addition, as broadcasting systems become diversified, demands such as exchange of program software tapes between other countries and production of multi-system common software have increased, and multiple current VTRs dedicated to television broadcasting systems are required. Inconvenience and inconvenience on the surface will surface. Therefore, a single VTR corresponding to the multi-broadcast method has been desired.

  An object of the present invention is to solve the above-described problems and to provide an image recording / reproducing apparatus that can handle image signals having a plurality of resolutions.

An image recording / reproducing apparatus according to the present invention includes an imaging unit that photoelectrically converts a subject image and outputs a first image signal, and a first image signal that reduces the resolution of the first image signal and converts it into a second image signal. The first or second image signal is a combination of a conversion means, a digital conversion means for A / D converting and digitizing the first or second image signal, and a discrete cosine transform, quantization and encoding processing. A compression means for compressing the image, a display means for displaying the first image signal, a switching means for switching between the recording mode and the reproduction mode of the image signal, and a resolution selected in advance from a plurality of resolutions for the recorded image Together with the first or second image signal compressed by the compression unit and having the selected resolution, the operation unit for instructing the user to operate the resolution selection unit. Recording means for digitally recording identification information indicating the resolution selected and designated by the means on a recording medium; detection means for detecting identification information recorded on the recording medium; and a first image signal recorded on the recording medium And a second conversion means for increasing the resolution of the second image signal according to the identification information and converting it to the first image signal when reproducing the image in the reproduction mode. The first image signal outputted from the imaging means and the first image signal reproduced by the reproducing means and outputted via the second converting means are selectively displayed on the display means. It is characterized in that it has a control means for controlling.
According to another feature of the image recording / reproducing apparatus of the present invention, the control means converts the first image signal into a second image signal when the image is recorded in the recording mode. The point is to display on the means.

  ADVANTAGE OF THE INVENTION According to this invention, the image recording / reproducing apparatus which can respond to several resolution and can output a desired image signal as a display output can be provided.

  Figure 1 shows a multi-mode compatible camera that can handle camera shooting, compression signal processing, and VTR recording in multiple TV standards for the current broadcasting system and future high-definition television (HDTV). A configuration of a digital VTR (hereinafter referred to as a camcorder) is shown. As the multi-mode, 1. imaging mode; 2. compression mode and There are three main modes of the recording mode. Hereinafter, each mode will be described in detail with reference to FIG.

1. Selection of Imaging Mode In FIG. 1, a subject image is photoelectrically converted by a CCD as a solid-state imaging device built in an HDTV camera (hereinafter referred to as HD camera) 1 and output as a high-definition HD signal with a large amount of information. . For example, in the studio standard, the HD signal has an effective imaging pixel number of 1920 H × 1035 V pixels and a sampling frequency of 75.3 MHz. The HD signal is divided into two, one of which is input as it is to the imaging mode selection circuit 2 and the other is input to a system converter 3 such as a down converter.

  For example, as described in “Showa 60.9 NHK Giken Monthly Report pp. 359-364”, this system converter 3 is a standard broadcast system (hereinafter referred to as SD) NTSC, PAL, SECAM. The amount of information is reduced in order to convert the information into the same.

  Here, taking the HD-NTSC converter 3 as an example, the configuration is as shown in FIG. 2, and is configured by an aspect ratio converter 31, a scanning line number converter 32, a field frequency converter 33, and an NTSC encoder 34. ing. Hereinafter, each part will be described.

* Aspect ratio converter 31
FIG. 3 shows three types of typical aspect ratio conversion modes.
Mode A: This is called a side panel method, in which both sides of a 16: 9 high-definition image are deleted and the aspect ratio is 4: 3. This mode may be selected when a conventional NTSC signal is desired.
Mode B: Called squeeze mode or full mode, which compresses a high-definition image in the horizontal direction and sets the aspect ratio to 4: 3, and the converted image is vertically long. This mode may be selected when converting to an NTSC signal compatible with a wide screen.
Mode C: Letterbox method, which is converted to display a 16: 9 image on a 4: 3 aspect ratio screen. In an NTSC image, there is no image at the upper and lower ends, and the image is black. If you want to make a picture that takes advantage of the angle of view captured by the HD camera, you can select this mode.

* Scanning line number conversion unit 32
The conversion processing of the number of scanning lines is performed in the vertical interpolation filter, and constitutes a weighted average circuit that switches according to the line order with 7 cycles as one period.

* Field frequency converter 33
Field frequency conversion processing is performed using a buffer memory after conversion of the number of scanning lines, and real-time processing is possible with a time axis corrector having the same function as the frame synchronizer. A frame synchronizer generally used causes a frame skip once every approximately 33 seconds with the capacity of one frame memory. In contrast, in motion adaptive field number conversion, motion detection and scene change detection are performed using a frame difference signal, and frame skip is performed when any of the following four conditions is satisfied.
(1) When it is a still image (2) When a scene change occurs (3) When the moving image area is relatively small (4) When there is no remaining frame buffer memory The field frequency is 60 Hz for high vision and the NTSC system There is a difference of 1000/1001 at 59.94 Hz.

  Next, the overall operation of the HD-NTSC converter 3 will be described.

  In FIG. 2, the HD signal is converted from 16: 9 to 4: 3 by the aspect ratio converter 31, and then 1125 to 525 and 60 Hz to 59.94 Hz by the scanning line number converter 32 and the field frequency converter 33. And is output as an NTSC composite signal via the NTSC encoder 34.

  Next, in FIG. 1, the operation panel 4 selects HD, SD-Hi (business-use high-quality with about 450 horizontal resolutions), and SD-Low (standard image quality for general home use with about 230 horizontal resolutions). If the HD mode is selected, it is input to the imaging mode selection circuit 2 via the system controller 5, and the input HD signal is selected and output through. When SD-Hi or SD-Low is selected, the NTSC signal down-converted by the system converter 3 is selected and output.

2. Selection of Compression Mode The video signal output from the imaging mode selection circuit 2 is input to the compression circuit 6 as video information. The compression circuit 6 has a plurality of compression modes 1 and 2, and the compression rate and the compression method can be changed according to the compression modes 1 and 2. Examples of the compression ratio include 1/4, 1/8, 1/16, 1/32. Examples of the compression method include DCT, DPCM, Hadamard transform, ADRC, and the like. For example, the compression mode 1 can be DCT and the compression mode 2 can be DPCM. Alternatively, only the compression rate may be selected using the same compression method.

  The compressed signal is input to the compression mode selection circuit 7 to select a desired compression mode and output a compression processing signal. These mode selections are closely related to the recording time and image quality selection on the VTR side or the imaging image quality and mode setting of the camera, and are automatically selected and set according to the mode setting of the VTR or camera. The data rate after image compression is preferably an integer ratio such as 50 Mbps for HD, 25 Mbps for SD-Hi, and 12.5 Mbps for SD-Low, for example, in relation to a recording system described later.

3. Selection of recording mode The compressed signal output from the compression mode selection circuit 7 is input to the recording processing circuit 8, and is divided into two signals for each channel corresponding to the two pairs of heads Ha, Hb and Hc, Hd. Each of the signals is amplified by the recording amplifier 9 and digitally recorded on a track on the tape 11 by the magnetic heads Ha to Hd of two pairs of heads provided on the drum 10. The track width is the same for each recording mode, and the recording mode is appropriately selected according to the selection result of the compression mode selection circuit 7, and a data recording track corresponding to the data rate is formed on the recording tape 11.

  On the other hand, the drum 10 and the capstan 13 are driven and controlled by the drum motor 14 and the capstan motor 15 by the servo control circuit 12, respectively, and the rotational speed of the drum 10 and the tape running speed are maintained at predetermined target values. Further, the tape 11 travels while being clamped by the capstan 13 and the pinch roller 16.

  The predetermined target value of the servo control circuit 12 is set according to various modes via the system controller 5 in response to an operation instruction from the operation panel 4. The various modes are selected as shown in Table 1 according to the state of the mode selection switch provided on the operation panel 4.

  Next, an embodiment of the HD camera 1 according to the present invention will be described with reference to FIG.

  Incident light from the subject 101 includes a focus lens 102 that changes a focal position (hereinafter referred to as focus), a magnification (focal length) (hereinafter referred to as zoom), a zoom lens 103, and an iris 104 that adjusts the amount of light. The light passes through the imaging optical system, enters a photoelectric conversion unit including a color filter 105 and a CCD (solid-state imaging device) 106, and is converted into a color video signal.

  The focus lens 102, the zoom lens 103, and the iris 104 are provided with driving units 109a, 109b, and 109c using, for example, a stepping motor, and the like, and the signals from the AF circuit 111, the AE circuit 110, or the key input unit 116 are received. Accordingly, by controlling the system via the system controller 113, an appropriate screen can be captured.

  In the CCD 106, the photoelectric charge generated in the light receiving unit is transferred to the transfer unit and taken out as an output signal. The noise of this signal is reduced by the CDS circuit 107 and the gain is controlled by the AGC circuit 108. At this time, referring to the information from the AE circuit 110, the gain is adjusted through the system controller 113, and then the signal is supplied to the color processing circuit 114 and the process circuit 115.

  The system controller 113 appropriately controls the drive units 109a to 109c of the imaging optical system according to values set by the key input unit 116 such as focus, zoom, and exposure. The clock generation circuit 117 is controlled so that the drive pulse of the CCD 106 is synchronized with various operations.

  After the gain adjustment, the AWB circuit 112 generates a control signal for white balance adjustment, and the color processing circuit 114 adjusts the gain of the color difference signal. Next, the color video signal separated into the three primary colors of RGB by the process circuit 115 is input to the encoder 118.

  The encoder 118 modulates and outputs the color video signal to a composite signal. This composite output signal is added by the adder 121 with the output signal of the display information generation circuit 119 so that information from the system controller 113 can be obtained, and is input to the viewfinder 120, so that various kinds of information are displayed together with the state of the subject 101. You can see the information.

The composite output signal may be extracted from the RGB primary color signal in the previous stage or may be extracted from the Y, RY, and BY signals in the previous stage. Further, two Y / C separation type (for example, S terminal type) color signals I, Q or RY, BY of the encoder 118 may be taken out in a form of orthogonal modulation.
Although not illustrated, when each signal processing is performed in the state of digital data, it may be output in the state of digital data before passing through a DAC (digital-analog converter).

  Next, the moving image compression technique will be described.

The purpose of digital data compression is to reduce the amount of data by removing the redundancy of the image. For a still image, processing focusing on the spatial redundancy of the image is performed. In the case of a moving image, processing focusing on temporal redundancy of an image is performed, but the basic principle is based on a still image compression technique. The technical elements of moving image compression are the following four points.
(1) DCT processing (2) Quantization processing (3) Encoding processing (4) Motion adaptation processing

The decompression process may be considered as the reverse operation of the compression process. The above items (1) to (4) are items common to still images and moving images. Details are described in, for example, “Electronics May 1992, Pursuing Multimedia and Information Compression (2)”.
Hereinafter, the outline of (1) to (4) will be described in order.

(1) DCT (Discrete Cosine Transform) processing Definition: Transforms the value of spatial coordinates into frequency.
As preprocessing for compression, the input screen is blocked into a group of pixels of about 8 × 8 pixels. Next, spatial data is converted to frequency data by performing multiplication processing of DCT coefficients. This DCT alone does not reduce the amount of data at all, but when the data widely distributed in the screen is viewed in another coordinate system, the coordinate conversion can be performed so that the data is centrally arranged. In other words, as a general characteristic of the image, this processing step plays a role of effectively executing the compression processing after DCT by utilizing the tendency that more information energy is concentrated on the low spatial frequency side. is there.

(2) Quantization processing Definition: The amount of data is reduced by rounding the word length of the coefficient converted to the frequency component.
A set of data coefficients for each frequency component generated by DCT is divided by an appropriate numerical value, and the decimal points are rounded down. As a result, the number of bits required to express each coefficient data can be reduced, and the entire amount of quantized data is compressed. By finely setting the divisor for each frequency component, the compression rate can be improved while maintaining the required image quality.

(3) Encoding process Definition: An encoding process characterized by assigning a code having a length corresponding to the data generation frequency, and includes the following three processes.

a. Zigzag scan In order to convert the two-dimensionally arranged frequency coefficient data into a one-dimensional data string, a data rearrangement operation is performed while moving from a DC component to a horizontal and vertical high-frequency component in a zigzag manner.

b. Run-length coding Replace with a code that expresses consecutive occurrences of the same numerical value (mainly zero). For example, “eight zeros are consecutive”. By assigning one code to a plurality of data in this way, the number of encoded bits is reduced. Also, if all data after a certain position is zero, an end code is assigned. This is defined as “the data transmission in this block is completed with this data”, and has a large data reduction effect.

c. VLC (Variable Length Coding)
By assigning a code with a small number of bits to a numerical value having a high appearance frequency, the total number of encoded bits is substantially reduced.

(4) Motion adaptation processing Definition: The basic principle is that a technology for “detecting and predicting motion” is added to still image compression.
Below, three points of the moving picture information compression technique of the television broadcast standard will be described.

a. Motion detection Image data corresponding to an integral multiple of a field or frame is accumulated in a buffer of image data such as a frame memory to generate a time delay. The movement is determined according to how much the corresponding pixel data has changed in the time difference between the input and output ends of the memory.
In the simplest example, a difference in luminance data between fields is calculated, and an absolute amount of the difference value is used as a motion amount.
In addition, a method for detecting a motion vector by calculating the movement of a two-dimensional coordinate at a position where the degree of correlation of pixel data is high, such as a correlation matching method, has been established.

b. Motion prediction compensation A motion of an image is predicted from a motion vector, and a new image is generated by calculation. The amount of data can be reduced by transmitting only the difference between this screen and the actual screen as compensation data. In other words, the compression effect is higher for a screen with a small amount of motion and a moving image surface with a small amount of prediction errors and a motion image that is gentle or linear.

c. Interlace coding Television signals such as NTSC have a structure called interlace in which scanning lines (hereinafter referred to as lines) are interlaced as shown in FIG. An odd field composed of 262.5 odd lines and an even field composed of 262.5 even lines are paired to form one frame screen (525 lines).

  However, when the movement of the subject in the screen is large, simply combining the odd and even fields results in a blurred image that is difficult to see. In this blurred portion, the spatial correlation in the screen is reduced in the vertical direction, and the spatial redundancy is reduced in the compression encoding process.

  Therefore, when the amount of motion is small, a compression-processed pixel block is formed using a frame image having a high vertical correlation. However, if it is determined that motion of a predetermined amount or more has occurred as a result of motion detection, A compression-processed pixel block is formed by using only odd and even field images having moderate intra-screen correlation while avoiding frame images in which the correlation is extremely lowered.

If the above frame / frame switching process is not performed and frame processing is always performed, a satisfactory compression result is obtained for most images, but the background and the person are comb-like in a large moving part. As a result, different data are generated alternately for one line, and a large amount of vertical maximum frequency components, which were originally assumed to be the lowest in frequency, are generated. In this way, means for avoiding the worst case is provided to prevent the compression system from failing due to the so-called poor subject.
As described above, by appropriately switching the encoding process according to the motion, it is possible to realize a compression process that achieves better efficiency and image quality for the entire moving image.

  Next, an embodiment of the compression circuit 6 partially utilizing the above-described moving image compression basic technique will be described below with reference to FIG.

After selecting the imaging mode, an SD or HD signal as a video signal is supplied to the input buffer memory 660. Then, the video signal output from the input buffer memory 660 is divided into blocks each having 8 × 8 pixels by the blocking processing circuit 661.
Then, orthogonal transformation is performed by a DCT (Discrete Cosine Transform) processing circuit 662 to convert the frequency component into a transformed coordinate plane. As a result, as a general tendency of images, only the DC coefficient and the AC coefficient of the low frequency component have large values, and the AC coefficient of the high frequency component has a small value close to zero.

  On the other hand, among the signals output from the input buffer memory 660, when the correlation between the screens is high, the odd-numbered field and the even-numbered field are frame-processed together, and conversely, when the correlation is low, Each even field is processed independently. This is determined by the motion detection circuit 663, and information for determining the amount and direction of motion of the image is input to the system controller 664 depending on how much the corresponding pixel data has changed in the time difference between the input and output ends of the input buffer memory 660. Is done.

  Depending on the result of the motion detection circuit 663, the system controller 664 issues a frame or field processing command to the block processing circuit 661. The blocking processing circuit 661 performs blocking processing according to the instruction. The frequency coefficient data output from the DCT processing circuit 662 is input to the quantization processing circuit 665. Then, the set of data coefficients for each frequency component is divided by an appropriate numerical value, and the numbers after the decimal point are rounded off to reduce the number of bits and compress the entire quantized data amount. Furthermore, by arbitrarily setting the divisor for each frequency component, the compression rate can be improved while maintaining the required image quality.

  Next, the quantized data compressed in this way is input to the encoding circuit 666. Here, in order to convert the data into a one-dimensional data string, the data is rearranged from the DC component to the horizontal and vertical high frequency components by zigzag scanning. This data is replaced with, for example, a code that collectively represents the continuous occurrence of zeros having the same numerical value, and run-length encoding is performed. In addition, when the data after a certain position in the block is all zero, by assigning the above end code, it is possible to significantly reduce the data. Then, by VLC, a code having a small number of bits is assigned to a numerical value having a high appearance frequency, and the total number of encoded bits is substantially reduced.

  The variable length encoded data is input to the data amount calculation circuit 667 and the data amount is input to the system controller 664. The system controller 664 and the coefficient setting circuit 668 are connected so that the coefficient for each horizontal and vertical frequency component is set according to the data amount. The coefficient is set to a predetermined value by the coefficient setting circuit 668, and the output result is input to the quantization processing circuit 665. Next, the quantized data is compressed in the above order.

  Data whose total number of bits has been reduced by the encoding circuit 666 and subjected to predetermined compression is input to the output buffer memory 669. The encoded data is output from the output buffer memory 669 at a constant data rate, but the point rate of the data is controlled by the system controller 664 so that the output buffer memory 669 does not underflow or overflow. For example, when the state is close to overflow (when the occupation ratio is large), the coefficient setting is increased, and the amount of transmitted data is adjusted to be small. Further, when the state is close to underflow, the reverse operation is performed. Further, switching of the compression ratio and compression method of the moving image is performed under the control of the system controller 664 in accordance with the operation of the mode selection unit 670.

  As described above, the system controller 664 appropriately switches the contents of DCT, quantization, and encoding processing according to the image motion detection result and various mode settings input from the mode selection unit 670, thereby moving the moving image. It is possible to adaptively control the compression rate and compression method of the image compression circuit. Thereby, efficient compression processing of moving images can be realized. Of course, the compression rate can be arbitrarily changed by changing the setting of the divisor by the coefficient setting circuit 668.

  Next, the configuration of the digital VTR and the recording operation will be described with reference to the recording system configuration diagram of FIG.

* Each AD converter and the luminance signal Y and color signal C of the video input input video 81Y, digital data D _y at 81C, are incorporated in the system is converted to D _c.

* Video data processing circuit 82
The data D _y and D _c are multiplexed by the data multiplexer 821, and the data amount of the image information is compressed by the information amount compression circuit 822 using the compression circuit described above according to the mode information from the system controller 5. In some cases, a compression processing circuit may be provided independently of YC. Next, shuffling is performed by the shuffle circuit 823 in order to make the image data resistant to transmission path errors. In addition, if the purpose is to equalize the bias in the generation of the information amount due to the density in the plane of the image, a variable length code such as run length is used if a shuffling process is brought before the compression process. Even if it is convenient.

  In response to this, the ID adding circuit 824 adds data identification (ID) information for restoring data shuffling. In the ID, the mode information of the system is recorded at the same time, and is used as auxiliary information at the time of reverse compression processing (information amount expansion processing) at the time of reproduction. Next, an ECC correction circuit (825) adds an error correction signal (ECC) for reproducing these data without error. Up to the addition of such a redundant signal is processed for each information of video and audio.

* Audio input Stereo audio signals L and R are taken into AD converters 80L and 80R, and the compression method is different from that for images, but is processed by an audio data processing circuit 86 having the same circuit configuration. When the recording rate of the video data is high, for example, in the case of an HD signal, the audio information may be shifted to the recording process without being compressed.

* Data distribution The video data V and the audio data A generated in this way are data distributed so that the data rate matches the capacity of the transmission path (in this case, the individual magnetic head system for recording and reproduction). This is performed by the distributors 83 and 84.

* Additional information In addition to the A and V signals, pilot signal P output from the pilot signal generator 85 for tracking servo, and auxiliary data S generated from the subcode generator 87 based on information from the system controller 5 Are multiplexed for each recording / transmission path by the data multiplexers 88 and 89. For example, if this is a time-axis multiplexing process, it is appropriate that the pilot signal P takes a form such as a known area division ATF by a digital audio tape recorder (hereinafter referred to as DAT).

* Digital modulation Digital modulation circuits 90 and 91 perform digital modulation processing for recording corresponding to the binary signal of MPX output. For example, 8-10 conversion and conversion processing such as NRZI.
Since each transmission line is provided with a magnetic head system of two channels in this embodiment, the recording amplifiers 9a to 9d corresponding to the heads Ha to Hd are changed according to the rotation state of the drum 10 by the head switching circuits 92 and 93. Thus, the switching process is selectively executed as appropriate under the instruction of the servo control circuit 12.

As a result, a recording current corresponding to the information signal can be supplied to the plurality of heads Ha to Hd on the rotary drum 10 at a predetermined recording timing.
FIG. 8 shows a track pattern recorded on the tape 11 by switching the signals A, P, S, and V every predetermined period and sequentially supplying signals to the magnetic recording system.

* System control system A servo and system control part for controlling the running of the tape 11 will be described.
The system controller 5 manages the response to the instruction information input from the operation panel 4 in FIG. 1, the operation mode of the entire system of the digital VTR, and various state transitions. The servo control circuit 12 is mainly responsible for steady maintenance. These two circuits can be regarded as one microcomputer block 94.

  The servo control circuit 12 includes a capstan motor 15 for controlling the tape feed speed and a capstan FG 95 for grasping the rotation state thereof, a drum motor 14 for rotating the rotary drum 10, and a rotation speed and rotation. Each detector FG96 and PG97 for phase confirmation is connected and each is controlled.

  Next, the configuration and playback operation of the digital recording type VTR will be described with reference to the playback system configuration diagram of FIG.

  In response to an operation mode switching instruction input to the system controller 5 from the operation panel 4 of FIG. Rotation control is performed.

  Data obtained from the plurality of magnetic heads Ha to Hd on the rotation-controlled drum 10 are amplified by the reproduction head amplifiers 61, 62, 63, and 64, respectively, and two sets of azimuth angles facing each other at approximately 180 degrees are different. The heads are supplied to the head switching circuits 56 and 59, the appropriate signal output is selected based on the servo control circuit 12, and supplied to the digital demodulation circuits 55 and 58 in the next stage.

The digital demodulation circuits 55 and 58 reconvert the reproduced signal into a binary signal of “0, 1” using techniques such as differential detection, integral detection, redundant detection such as Viterbi decoding, and the like.
Output signals of the digital demodulation circuits 55 and 58 are supplied to signal distribution circuits 54 and 57, respectively, and separated and distributed into a video signal V, an audio signal A, a tracking servo pilot signal P, subcode information S, and the like.

V: Video signal The video signal V distributed to a plurality of heads is output from the signal distributors 54 and 57, integrated by the data integration circuit 65, and restored to the original video signal by the video data process circuit 52. The

  First, an error correction circuit 525 detects a data transmission error generated in the recording / reproducing system, corrects an error within a correctable range, and corrects an interpolation when it cannot be corrected. Next, the ID detection circuit 524 extracts various ID signals and V signal subcode data inserted in the video data, and supplies information to the system controller 5.

  The deshuffling circuit 523 restores the data arrangement based on the ID information and the like as a shuffling process performed at the time of recording in order to prevent image quality deterioration caused by an unrecoverable error due to continuous lack of data. Also, the information amount decompression circuit 522 restores information by a procedure reverse to the information amount compression processing for reducing the data amount at the time of recording. When the recording mode is set at the time of recording, there is a possibility that the information amount compression method and the compression rate are different for each recording mode, so recording is performed via the system controller 5 based on the reproduction ID information. The restoration process corresponding to the mode setting at the time is performed. Finally, the data separation circuit 521 outputs each YC information to the DA converters 51Y and 51C. As described above, an image substantially equivalent to the signal input at the time of recording is reconstructed.

A: Audio signal The audio signal A distributed to a plurality of heads is output from the signal distributors 54 and 57, integrated by the data integration circuit 66, and restored to the original audio signal by the audio data process circuit 60.

  First, an error correction circuit 605 detects a transmission error of data reproduced by the recording / reproducing system, corrects an error within a correctable range, and corrects an interpolation when it cannot be corrected. Next, the ID detection circuit 604 extracts various ID signals and subcode data dependent on the A signal inserted in the audio data, and supplies information to the system controller 5.

The deshuffling circuit 603 restores the data arrangement based on the ID information and the like after the shuffling process performed at the time of recording in order to prevent the sound quality deterioration caused by the unrecoverable error due to the continuous loss of data.
The information amount decompression circuit 602 restores information by a procedure reverse to the information amount compression processing for reducing the data amount at the time of recording. When the recording mode is set at the time of recording, there is a possibility that the information amount compression method and the compression rate are different for each recording mode, so recording is performed via the system controller 5 based on the reproduction ID information. The restoration process corresponding to the mode setting at the time is performed.
Next, the data separation circuit 601 outputs the L and R information to the DA converters 50L and 50R. As described above, sound substantially equivalent to the signal input during recording is reproduced.

P: Pilot signal The area division ATF tracking pilot signal is output from the signal distributors 54 and 57 and input to the pilot signal detector 53. Here, if processing similar to DAT is performed, a time difference from the timing reference signal corresponding to the off-track amount from the left and right tracks is detected as an error signal. This error signal is supplied to the servo control circuit 12 and used to control the tape feed speed or the like, or is used as auxiliary information for determining the recording mode.

S: Subcode information When V and A are the main information, a data group with a small capacity, which is auxiliary to this, is called a subcode and can be recorded and reproduced in another area. In particular, the difference from the ID data is that guard spaces are provided before and after the subcode area so that recording and reproduction can be performed independently of the A and V data. This makes it possible to post-record subcodes. As the difference in use, the ID data is information indispensable for normal reproduction such as a recording mode unique to the main data, and this subcode is suitable for address codes for tape position search, program index recording, and the like. These pieces of information are subjected to determination processing by the system controller 5, and each unit is controlled as necessary.

  As shown in FIG. 10, the subcode includes a search mark portion and a subdata portion for realizing a so-called cueing function. In this example, the sub data portion is composed of 4 blocks (Block 0 to Block 3). This block further comprises eight data words (word0 to word7), a sync word for synchronization, and a CRCC section for error correction. Further, each data word is composed of 8 bits, and in this portion, each broadcasting system, tape speed, audio channel mode, compression rate, etc. are recorded as mode discrimination information.

The VTR of this embodiment has three recording / reproducing modes as described above.
Since each recording track pattern differs according to the setting of the arbitrarily selected recording mode, the discrimination ID information is recorded in the subcode area so that reproduction can be performed accordingly. Hereinafter, three kinds of recording track patterns and a mode discrimination procedure during reproduction will be described.

1. SD-low
The long-time recording mode of SD will be described with reference to FIGS.
As shown in FIG. 11B, five tracks are formed per screen using Ha and Hb of the four magnetic heads mounted on the rotary drum 10 shown in FIG. In the case of 150 revolutions per second, the drum PG indicating the rotational phase is supplied with a recording current to the heads Ha and Hb according to the high and low timings of the rectangular pulse indicated by 150 rps in FIG.

2. SD-high
The SD high-quality recording mode will be described with reference to FIGS.
As shown in FIG. 13B, 10 tracks are formed per screen using Ha and Hc of the four magnetic heads mounted on the rotary drum 10 shown in FIG. In the case of 150 revolutions per second, the drum PG indicating the rotational phase is supplied with a recording current to the heads Ha and Hc in accordance with the high and low timings of the rectangular pulse indicated by 150 rps in FIG.

3. HD
The HD high-definition image quality recording mode will be described with reference to FIGS.
All four magnetic heads Ha to Hd mounted on the rotary drum 10 shown in FIG. 15A are used to form 20 tracks per screen as shown in FIG. 15B. In the case of 150 revolutions per second, the drum PG indicating the rotational phase is supplied with a recording current to the heads Ha to Hd in accordance with the high and low timings of the rectangular pulse indicated by 150 rps in FIG.

  Table 2 shows parameters such as tape speed, number of tracks per field, and compression rate for the above three modes.

  FIG. 17 shows the mode discrimination and control procedure during reproduction.

  In step S1, the current VTR regeneration running mode is confirmed. In step S2, the process branches to any of N = 5, N = 10, and N = 20 in steps S3, S4, and S5 according to the three modes. Next, in step S6, a subcode is detected from the reproduced digital signal, and a mode to be reproduced is determined by determining a recording mode from the subcode. Even in step S7, the number of required tracks per unit time M = 5, M = 10, and M = 20 in steps S8, S9, and S10 is branched according to one of the three modes of the reproduction ID. . In step S11, the target value of capstan speed control is reset according to the result of comparing the magnitudes of N and M. Again, the process branches to one of steps S12, S13, and S14 depending on the three cases. When N> M, the current speed is higher than that at the time of recording, so the speed is lowered. In the case of N <M, the current speed is lower than that at the time of recording, so the speed is increased. When N = M, the current speed is maintained as it is. Then, returning to the confirmation of the current mode again, the above routine is repeated.

  In the above-described embodiments, the combination of the main image pickup means and the TV standard conversion means has been described in order to obtain a plurality of TV standard video signals. However, a plurality of image pickup systems including photoelectric conversion means are provided for each TV standard. Alternatively, a plurality of video signals may be taken out independently. Further, separate image pickup means are provided for the HD-TV system and the SD-TV system, respectively, and the output of each image pickup means is scanned with different HD-TV standards and SD-TV standards (NTSC, PAL) (1050 lines / 1125). The above-mentioned combined configuration of providing a book / 1250 book) system conversion means may be used.

  Next, an embodiment of a video recording / reproducing apparatus using the above-described system converter as a down converter as shown in FIG. 2 and the system converter as an up converter as shown in FIG. 18 will be described with reference to FIG.

  FIG. 18 shows an example of an NTSC-HD converter as an up-converter. In FIG. 18, the NTSC signal is demodulated through the motion adaptive NTSC decoder 70, converted from 4: 3 to 16: 9 by the aspect ratio converter 71, and then converted to 525 by the scanning line number converter 72 and the field frequency converter 73. 1125 lines are converted from 59.94 Hz to 60 Hz, and output as HD signals.

  FIG. 19 shows a block diagram of a video recording / reproducing apparatus of the present invention. On the operation panel 200, recording / reproduction, HD / SD, and the like can be selected. The operation of the four recording / reproducing systems will be described below. In this embodiment, the input signal is an HD signal.

(1) When recording with SD (long-time recording mode)
“Record” and “SD” are selected on the operation panel 200, and the terminal of the switch 206 is connected to (1) or (2) via the system controller 201. The HD input signal is down-converted by the down converter 203 to be an SD (for example, NTSC) signal. Further, the system controller 201 controls the terminal of the switch 202 to connect to (1), and the SD signal is recorded on the tape 210 through the recording system 209. The monitor at this time uses the SD monitor 204.

(2) When recording in HD (high quality mode)
“Record” and “HD” are selected on the operation panel 200, the terminal of the switch 202 is connected to (2) via the system controller 201, and HD is recorded through. At this time, either the HD monitor 205 or the SD monitor 204 can be selected as the monitor.

When the HD monitor 205 is used, the terminal of the switch 206 is connected to (1) or (2) and the HD signal is output through.
When the SD monitor 204 is used, the terminal of the switch 206 is connected to (1) or (2) in the same manner as described above, converted to SD by the down converter 203, and the terminals (1) and (2) of the switch 207 are converted. If any one of (4) and (4) is selected and connected, SD monitoring becomes possible. The camera-integrated VTR can be downsized by adopting the above configuration.

(3) When playing back with SD: “Playback” and “SD” are selected on the operation panel 200, and the terminal of the switch 207 is connected to (3) via the system controller 201. The reproduction SD signal is reproduced and output by the SD monitor 204 through the tape 210 and the reproduction system 211. In addition, when output is made by the HD monitor 205, it is only necessary to convert it to an HD signal by the up converter 208 and connect the terminal of the switch 206 to (3).

(4) When playing in HD Select “Playback” and “HD” on the operation panel 200, and connect the terminal of the switch 206 to (4) via the system controller 201. The reproduced HD signal is reproduced and output on the HD monitor 205 through. On the other hand, in the case of reproducing and outputting to the SD monitor 204, it is connected to the terminal (4) of the switch 206 in the same manner as described above. Monitoring is possible. Table 3 shows connections of terminals (1) to (4) corresponding to SD and HD of the switches 202, 206, and 207.

  As described above, since the down converter 203 is shared for recording and playback of video signal input, the circuit scale can be reduced and recording or playback can be selectively performed according to the HD signal and SD signal. Is possible. Further, an SD monitor can be used as an output monitor even for an HD input signal. Furthermore, when used as a camera-integrated VTR, an SD monitor can be used as a monitor, and therefore, the size can be reduced as compared with the prior art.

  In this embodiment, the up-converter 208 is used. However, if a multi-scan monitor is used instead of the HD monitor 205, when an SD (for example, NTSC) signal is input, 525 scanning lines are scanned. The up-converter 208 is not necessary. Further, an SD signal having a standard picture quality for general households and about 230 horizontal resolutions may be added as the SD-Low mode.

It is a block diagram which shows the Example of this invention. It is a block diagram which shows the Example of the system converter as a down converter. It is a block diagram of a screen showing an aspect ratio conversion mode. It is a block diagram which shows the Example of HD camera. It is a block diagram of a television screen. It is a block diagram which shows the Example of a compression circuit. It is a block diagram which shows the Example of a recording system. It is a block diagram which shows the recording format of a magnetic tape. It is a block diagram which shows the Example of a reproduction | regeneration system. It is a block diagram which shows the data format of a subcode. It is a block diagram which shows an example of the structure of a head, and the recording format of a tape. It is a timing chart which shows operation | movement of each head. It is a block diagram which shows the other example of the structure of a head, and the recording format of a tape. It is a timing chart which shows operation of each head by the above-mentioned other example. It is a block diagram which shows the further another example of the structure of a head, and the recording format of a tape. It is a block diagram which shows operation | movement of each head by said further another example. It is a flowchart which shows the control action at the time of reproduction | regeneration. It is a block diagram which shows the Example of the system converter as an up converter. It is a block diagram which shows the other Example of this invention. It is a block diagram which shows the conventional camera integrated VTR.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera 2 Imaging mode selection circuit 3 System converter 5 System controller 6 Compression circuit 8 Recording processing circuit 11 Magnetic tape Ha-Hd Head 202, 206, 207 Switch 203 Down converter 209 Recording system 211 Playback system

Claims (2)

Imaging means for photoelectrically converting a subject image and outputting a first image signal;
First conversion means for reducing the resolution of the first image signal and converting it to a second image signal;
Digital conversion means for A / D converting and digitizing the first or second image signal;
Compression means for compressing the first or second image signal by combining discrete cosine transform, quantization and encoding processing;
Display means for displaying the first image signal;
Switching means for switching between image signal recording mode and playback mode;
Resolution selection means for selecting a resolution in advance from a plurality of resolutions for an image to be recorded;
An operation means for a user to instruct the resolution selection means to operate;
A recording means for digitally recording on the recording medium identification information indicating the resolution selected by the operation means together with the first or second image signal compressed by the compression means and having the selected resolution;
Detecting means for detecting identification information recorded on the recording medium;
Reproducing means for expanding and reproducing the first image signal recorded on the recording medium;
A second conversion means for increasing the resolution of the second image signal according to the identification information and converting the image to the first image signal when reproducing the image in the reproduction mode;
Control to selectively display the first image signal output from the imaging unit and the first image signal reproduced by the reproducing unit and output via the second converting unit on the display unit. And an image recording / reproducing apparatus.   2. The image recording / reproducing according to claim 1, wherein when recording an image in the recording mode, the control unit converts the first image signal into a second image signal and displays the second image signal on the display unit. apparatus.

Images