JP3395197B2 - Video signal recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a so-called 8 mm
The present invention relates to a video signal recording device that records a still image as a digital video signal in a so-called PCM audio area of a magnetic tape used in a video tape recorder or the like. 2. Description of the Related Art As an apparatus for recording a video signal on a recording medium, for example, a magnetic recording medium, for example, a video signal of a still image,
That is, a so-called electronic still camera that records video signals for one field or one frame on a so-called still video floppy disk, or a so-called camera-integrated 8 mm video tape recorder (hereinafter, referred to as a camera-integrated 8 mm VTR) that records video signals of moving images on a magnetic tape, for example. ) Etc. are known. For example, in a camera-integrated 8 mm VTR, a magnetic tape is placed around a rotary head drum 211.
As shown in FIG. 3, a pair of heads (hereinafter referred to as rotating heads) wound at an angle of 180 degrees and helically scanning the magnetic tape form a diagonal track 81 on the magnetic tape 80 as shown in FIG. . In a video area 82 corresponding to 180 degrees of the rotating head drum of each track 81, a luminance signal is FM-modulated, a carrier chrominance signal is converted to a low frequency, and an audio signal is FM-modulated.
A tracking signal for tracking servo, for example, a pilot signal for so-called ATF (Automatic Track Finding) control is frequency-multiplexed and recorded. Also, the remaining rotating heads of each track 81
PCM audio area 83 corresponding to about 30 degrees of the drum
In this example, a non-linearly quantized digital audio signal (hereinafter referred to as a PCM audio signal) is subjected to so-called cross-interleave code processing for error correction, and is recorded with a synchronization signal, parity, ID, and the like added thereto. It has become so. A cue track 84 and an audio track 85 are formed on both sides of the magnetic tape 80 by scanning with a fixed head. The cue track 84 records a cue signal used for, for example, the address of the recorded content or the beginning of the recorded content, and the audio track 85 records, for example, after-recording (after recording).
Audio signal is recorded. Here, for example, in the above-mentioned 8 mm VTR, recording and reproducing not only audio signals but also digitized still image video signals in the PCM audio area 83 have been considered. That is, for example, a camera-integrated V
In the TR, by pressing a still image recording shutter button separately from a normal recording button, the still image video signal at that time is digitized and recorded in the PCM audio area 83. [0005] By the way, for example, the photographing conditions for photographing a video signal with a camera-integrated 8 mm VTR and the conditions for processing the video signal are suitable for capturing a moving image. Specifically, an auto focus (hereinafter referred to as AF) for automatically focusing on a subject
matic Focus), iris control that adjusts the aperture of the optical system according to the brightness or light amount of the subject, shooting conditions such as exposure and shutter speed, and CRT to make the input light intensity of the camera proportional to the emission intensity of the CRT Various signal processing conditions such as gamma correction, dynamic range correction, and AGC (Automatic Gain Control) processing for correcting the gamma characteristic (light-to-light conversion characteristic) of the camera on the camera side are suitable for shooting moving images. Therefore, still image shooting is performed as one frame of a moving image under the shooting conditions and signal processing of the moving image. In general, in capturing a moving image, the time constant of the capturing condition is increased in anticipation of panning of the scene, and the signal processing is also performed in anticipation of the direction of the time axis. As described above, when a still image is shot under the moving image shooting conditions and video signal processing, the still image is an image of one frame or one field, and the time constant of the shooting conditions such as AF, iris, and shutter speed needs to be as long as the moving image. In addition, signal processing conditions such as gamma correction, dynamic range correction, and AGC processing are not appropriate, so that a still image with sufficient image quality cannot be obtained. Accordingly, the present invention has been made in view of the above-described circumstances, and switches the photographing condition and the video signal processing condition according to a moving image photographing mode and a still image photographing mode.
It is an object of the present invention to provide a video signal recording device capable of obtaining a high-quality still image. A video signal recording apparatus according to the present invention comprises a lens, an iris, a CCD image sensor and a camera signal processing circuit, a focus drive for adjusting the focus of the lens, An image signal recording device for recording moving images and still images on a recording medium, comprising an iris drive unit for adjusting the aperture of the iris and a CCD read control unit for controlling the read speed of the CCD. A feature extraction circuit for performing feature extraction from the output luminance signal, and data supplied from the feature extraction circuit for controlling the focus drive unit, the iris drive unit, and the CCD readout control unit, and performing automatic gain control processing and gamma correction A microprocessor that causes the camera signal processing circuit to perform signal processing such as A motion vector detection circuit capable of controlling an area to be extracted; automatic focus control of a lens used when photographing a subject; iris drive control;
D. Photographing conditions such as conditions relating to shutter control by readout control of D, and various correction processes such as gamma correction, dynamic range correction, and conditions relating to automatic gain control to be applied to an image signal obtained under the above photographing conditions, and video signal processing relating to gain control. The microprocessor switches conditions based on a still image shooting mode or a moving image shooting mode, controls the microprocessor based on the subject information extracted by the feature extraction circuit, and generates a still image signal or a moving image signal. Means and recording means for recording a still image video signal and a moving image video signal generated by the imaging means on the recording medium are provided, and the object is achieved. Here, the photographing conditions include, for example, an automatic focus (hereinafter, referred to as AF) for automatically focusing on a subject, and an iris control for adjusting an aperture of an optical system according to the brightness or light amount of the subject. AE (Automatic Exposure) for automatic exposure
Video signal processing conditions include, for example, gamma correction for correcting gamma characteristics (lightning conversion characteristics) of a cathode ray tube on the camera side in order to make the intensity of input light of the camera and the emission intensity of the cathode ray tube proportional. Dynamic range correction, AGC (Automatic Gain Control: Automatic Gain C
ontrol) treatment. The video signal recording apparatus according to the present invention has shooting conditions such as conditions relating to automatic focus control of a lens used for shooting a subject, drive control of an iris, shutter control by CCD read control, and the like. The microprocessor sets video signal processing conditions related to various kinds of correction processing and gain control, such as conditions related to gamma correction, dynamic range correction, and automatic gain control to be applied to the image pickup signal obtained under the shooting conditions, based on the still image shooting or moving image shooting mode. Switching is performed and control is performed based on the subject information extracted by the feature extraction circuit. An embodiment of a video signal recording apparatus according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention relates to a so-called camera-integrated 8 mm VTR (hereinafter simply referred to as V
TR), and FIG. 1 shows this VTR
FIG. 2 is a block circuit diagram showing the circuit configuration of FIG. As shown in FIG. 1, a VTR, which is an embodiment of a video signal recording apparatus according to the present invention, converts an image pickup signal obtained by photographing a subject into a digital signal, and performs, for example, gamma correction and AGC processing. A camera unit 10 for performing signal processing of
A camera control unit 20 for controlling the camera unit 10 for each of a moving image and a still image shooting mode, and one of digital video signals obtained by controlling the camera unit 10 according to the still image shooting mode by the camera control unit 20; A still image signal processor 30 that performs signal processing such as data compression processing on a frame or one field and outputs a still image signal, and converts the image signal from the camera unit 10 into an analog signal. A video signal processing unit 40 for performing signal processing such as contour compensation on a video signal of a reproduced moving image and the like, and an analog video signal from the video signal processing unit 40 and the still image video signal processing. The digital video signal from the unit 30 is time-division multiplexed and recorded in a so-called video area and a PCM audio area of the magnetic tape 1 respectively. And a head portion 50 for reproducing these video signals, and from the camera control unit 20, the still picture image signal processing unit 30, which controls the video image signal processing unit 40 such as a system control unit 60.. The VTR is controlled by the system control unit 6
The camera unit 1 according to the moving image shooting mode set at 0
The camera control unit 20 controls shooting conditions and video signal processing conditions of 0, converts the obtained video signals into digital signals,
The video signal subjected to the signal processing is converted into an analog signal, and is recorded in the video area of the magnetic tape 1 as a video signal of a moving image, and the video signal of the moving image recorded in the video area is reproduced. It is designed to be output as a video signal compliant with. In addition, this VTR controls the shooting conditions and the video signal processing conditions of the camera unit 10 according to the still image shooting mode set by the system control unit 60, and the VTR controls one frame or one frame of the obtained video signal. One field is recorded as a still image video signal in the PCM audio area of the magnetic tape 1, and the still image video signal recorded in the PCM audio area is reproduced, and the reproduced one frame or one field video signal is reproduced. Is repeatedly output as a video signal conforming to the NTSC system. That is,
When a video signal is obtained by the camera unit 10, the VTR includes, for example, shooting conditions such as AF, iris, and shutter speed and dynamics according to a moving image shooting mode and a still image shooting mode set by the system control unit 60. By switching the video signal processing conditions such as range correction, gamma correction, and AGC processing by the camera control unit 20, for example, when a still image is shot, a high-quality still image can be obtained. More specifically, as shown in FIG. 1, the camera section 10 includes a lens 11, an iris 12 for adjusting an aperture amount in accordance with the brightness or light amount of a subject, and a light passing through the iris 12. Is radiated through the lens 13,
A CCD image sensor (hereinafter referred to as CCD) 14 for outputting a video signal as an electric signal according to the intensity of light, and an analog / digital (hereinafter A / D) conversion for converting a video signal from the CCD 14 into a digital signal. Vessel 1
5 and a camera signal processing circuit 16 for performing various signal processing such as gamma correction and AGC on the digital video signal from the A / D converter 15. Further, as shown in FIG. 1, the camera control unit 20 controls the lens 11 of the camera unit 10 according to the moving image shooting mode and the still image shooting mode set by the system control unit 60. AF that automatically adjusts the focus
A driving unit 21, an iris driving unit 22 for adjusting the aperture of the iris 12, a CCD reading control unit 23 for controlling a reading speed of the CCD 14, and an AF from a luminance signal output from the camera signal processing circuit 16. And AE
A feature extraction circuit 24 for extracting feature data for use in the camera and data from the feature extraction circuit 24 are supplied, and the AF drive unit 21, the iris drive unit 22, the CCD reading control unit 23, and the like are controlled based on the data. Microprocessor (hereinafter M
PU) 25, and a motion vector detecting circuit 26 capable of controlling an area for feature extraction by the feature extracting circuit 24.
It is composed of Also, as shown in FIG. 1, the moving picture video signal processing section 40 includes the still picture video signal processing section 30.
Alternatively, a video RAM 42 for storing a video signal from the head unit 50 and signal processing suitable for recording are performed on the video signal from the camera unit 10 to form moving image data, and this moving image data is supplied to the head unit 50. In addition, a video signal processing circuit 41 that performs various signal processing such as contour compensation on the video signal read from the video RAM 42 and then converts the video signal into a video signal compliant with the NTSC system, for example, and the video signal processing circuit 41 A digital / analog (hereinafter, referred to as D / A) converter 43 for converting a video signal (digital signal) compliant with the NTSC system supplied from the digital camera into an analog signal and sending the converted signal to a monitor receiver or the like via a terminal 46; The moving image data from the video signal processing circuit 41 is converted into an analog signal and supplied to the head unit 50.
The A / A converter 44 converts the video signal (analog signal) reproduced by the head unit 50 into a digital signal, and supplies the digital signal to the video signal processing circuit 41 as moving image data.
And a D converter 45. The still image / video signal processing unit 30
Similarly, as shown in FIG. 1, a video RAM 32 for storing a digital video signal from the camera section 10 and a digital video signal from the video RAM 32 are supplied, and a predetermined number of frames are provided for one frame or one field of the digital video signal. A still image video signal processing circuit 31 for performing data compression processing to form compressed data, and conversely, performing data expansion processing for the compressed data to reproduce a video signal;
A synchronous signal, an error correction code, and the like are added to the compressed data from the still image video signal processing circuit 31 to form still image data and supply the still image data to the head unit 50. A PCM processing circuit 33 that performs error correction processing to reproduce compressed data and the like and supplies the compressed data and the like to the RAM 34. The head section 50 also time-division multiplexes the analog video signal from the moving picture video signal processing section 40 and the still picture data from the still picture video signal processing section 30, as shown in FIG. At the same time, an MUX 51 that reproduces an analog video signal and still image data of a moving image from the reproduced RF signal and supplies them to the moving image video signal processing unit 40 and the still image video signal processing unit 30, respectively, and performs time division multiplexing from the MUX 51. An amplifier 53 for amplifying the recording signal, an amplifier 54 for amplifying the reproduced RF signal, a changeover switch 52 for switching the amplifier 53 and the amplifier 54 between recording and reproduction, and an excitation current from the amplifier 53. A rotary head 55 that records a signal on the magnetic tape 1 and reproduces a reproduced RF signal and supplies the reproduced RF signal to the amplifier 54.
It is composed of Also, as shown in FIG. 1, the system control section 60 operates the VTR, for example, a moving image pickup mode for recording a moving image signal, a still image pickup mode for recording a still image signal. Function control circuit 61 for setting various operation modes such as
The camera control unit 20 according to the mode set from
And a memory controller 63 for controlling the addresses of the video RAMs 32 and 42 under the control of the system controller 62. The magnetic tape 1 has the same tape format as, for example, the magnetic tape 80 shown in FIG. That is, a track formed obliquely on the magnetic tape 1 by the helical scanning of the rotary head 55 is divided into a video area and a PCM audio area, a moving image is recorded in the video area as an analog video signal, and a static image is recorded in the PCM audio area. Images are recorded as digital video signals. Next, the operation of each unit constituting the VTR will be described. First, the camera unit 10 responds to a shooting mode (moving image shooting mode or still image shooting mode) set by the system control unit 60.
The subject is photographed under the photographing condition and the video signal processing condition which are switched, the video signal obtained by the photographing is subjected to signal processing, and the digital video signal obtained by the signal processing is converted into the moving picture video signal processing section 40 or the still picture video signal processing section To supply. The camera control unit 20 controls the AF, AE, iris, video signal read speed, etc. of the camera unit 10 according to the moving image shooting mode and the still image shooting mode set by the system control unit 60. It controls shooting conditions and video signal processing conditions such as gamma correction, dynamic range correction, and AGC processing. The moving picture image signal processing section 40 FM-modulates the luminance signal of the picture signal from the camera signal processing circuit 16 by a predetermined carrier, converts the carrier chrominance signal to a low frequency, and frequency multiplexes the moving picture. After forming the moving image data and supplying the moving image data to the head unit 50 and performing various kinds of signal processing on the video signal from the head unit 50 or the still image video signal processing unit 30, for example, an analog signal conforming to the NTSC system Convert to video signal and output. The still image signal processing section 30 performs predetermined data compression, for example, so-called adaptive dynamic range coding (ADRC: Adaptive Dynam) for one frame or one field of the image signal from the camera section 10.
ics Range Coding) and so-called sub sampling (Sub S
ampling), discrete cosine transform (DCT)
In addition to performing data compression processing such as nsform), a synchronization signal, an error correction code and the like are added to the data, and the resulting data is supplied to the head unit 50 and recorded in the PCM audio area on the magnetic tape 1. Conversely, still image data reproduced by the head unit 50 is subjected to signal processing such as data decompression processing, and the obtained video signal of a still image is supplied to the video RAM 42. The head section 50 time-division multiplexes the analog video signal from the D / A converter 44 and the digital video signal (still picture data) from the PCM processing circuit 33 to form a video area on the magnetic tape 1 and a PCM audio signal. A / D converter 45, PCM processing circuit 3
3 respectively. For example, the system control unit 60 controls the camera according to a moving image capturing mode for capturing a video signal of a moving image set by the photographer in the function control circuit 61 and a still image capturing mode for capturing a video signal of a still image. The control unit 20 is controlled to switch between a shooting condition and a video signal processing condition. Then, for example, when the still image capturing mode is set, every time the shutter is operated, a shutter signal sent via the terminal 64 is detected, and the camera unit 10 captures the image signal of the subject. One frame or one field is recorded as a still image video signal in the PCM audio area of the magnetic tape 1. Here, the operation of the VTR will be described in detail focusing on the control operation of the camera control unit 20. First, the amount of light collected through the lens 11 of the camera unit 10 is controlled by the iris 12 and converted into an electric signal by the CCD 14. This electric signal (hereinafter referred to as a video signal)
After being converted into a digital video signal by the A / D converter 15, it is supplied to the camera signal processing circuit 16. The camera signal processing circuit 16 converts the digital video signal into a luminance component and a color difference component, supplies one to the video signal processing circuit 41 of the moving image video signal processing unit 40, and supplies the other to the camera control unit 20.
To the feature extraction circuit 24. This feature extraction circuit 24
Is a filter for controlling AF and AE. The filtering of the feature extraction circuit 24 extracts the edge of the screen or a specific component for AF, for example,
In the case of E, the average of the level of the luminance signal in the screen is calculated, and the degree of the signal above or below an arbitrary level is measured with respect to the whole. Based on the signal filtered by the feature extraction circuit 24, the MPU2
5, based on a specific algorithm, for example, in the case of AE, the aperture amount of the iris 12,
Controls AGC signal processing, filter windows, and weights. Also, in the case of AF,
Control of lens position and weighting of filters. At this time, the extraction area in the feature extraction circuit 24 can be appropriately controlled at high speed based on the amount of motion from the motion vector detection circuit 26. Next, in this VTR, the operation from switching the mode for recording a still image to recording a still image in the PCM area of the magnetic tape will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 2 is a diagram illustrating an operation example when the still image shooting mode is set by the control unit. [0028] For example, when the user presses the mode button 91 to perform the setting of the still image capturing mode at the timing of time t _a, the system controller 62, the camera control by detecting a control signal corresponding to the set the section 20 is controlled to operate from the time t _b in the still image shooting mode. Then, switches at a timing of time t _b of the field F _n from moving picture mode to the still image shooting mode, the image feature extraction, metering, detection of a motion vector is started. Then, from the timing of the time t _c field F _{n + 1} starts, before photometry was performed in the field F _n, receives the result of detection of a motion vector, iris control, A
GC control and electronic shutter control are started. In the field _{Fn + 1} , exposure is also performed, and a gamma curve (characteristic) for performing gamma correction is also selected.
Here, _assuming that the shutter button 92 is pressed at the timing of the time t _d , the time t t when the next field F _{n + 2} starts
_{From e} , the camera control performed in field F _{n + 1} above,
The still image video signal obtained from the camera signal processing is
Recorded in M32. When the field F _{n + 2} ends, a still image is recorded in the PCM area on the magnetic tape 1 from time t _f . More specifically, at the time of still image shooting, the system controller 62 notifies the MPU 25 of the camera control unit 20 that the camera is in the still image shooting mode. This MPU
25 controls the AF drive unit 21 and the iris drive unit 22 based on the subject information extracted by the AF / AE feature extraction circuit 24 so that the video of the field or frame has an optimal dynamic range. AGC processing,
Signal processing such as gamma correction is performed by the camera signal processing unit 16 so as to be suitable for the video. In addition, the MPU 25
The shutter speed can be selected from the motion vector amount detected by the motion vector detection circuit 26, and the reading speed of the CCD reading control unit 23 can be controlled. The still image video signal thus obtained is recorded in the video RAM 32 under the control of the memory controller 63. Depending on the operation mode set by the function control unit 61, the still image is band-compressed by the still image video signal processing unit 30, the ID information is added by the PCM processing circuit 34, and the still image data and Then, it is supplied to the rotary head 45 via the MUX 51 to the amplifier 53. At this time, the system controller 62
A running system (not shown) is controlled so that the magnetic tape 1 starts running in synchronization with the supply of the still image data to the rotary head 55. Then, the system controller 62 controls the magnetic tape 1 to stop running, for example, a few seconds after the recording is started. As a result, a still image is recorded as a digital video signal on several tens to several hundred tracks (depending on the data compression ratio) in the PCM audio area of the magnetic tape 1. As described above, in the VTR to which the embodiment of the video signal recording apparatus according to the present invention is applied, the shooting conditions and the signal processing can be divided between the time of shooting a still image and the time of shooting a moving image. High-quality still images can be shot under shooting conditions and signal processing conditions corresponding to the mode. The present invention is not limited to the above-described embodiment. For example, a so-called deep recording method in which a recording area is divided in a thickness direction of a magnetic tape is adopted, and an analog video signal and a digital signal are It is needless to say that the present invention can be applied to a video tape recorder or the like that can record on each of the areas. According to the video signal recording apparatus of the present invention, photographing conditions such as conditions relating to automatic focus control of a lens used for photographing a subject, iris drive control, shutter control by CCD readout control, and the like, And various kinds of correction processing such as conditions relating to gamma correction, dynamic range correction, and automatic gain control to be applied to an image pickup signal obtained under the shooting conditions, and video signal processing conditions related to gain control, based on a still image shooting mode or a moving image shooting mode. Since the processor switches and performs control based on the subject information extracted by the feature extraction circuit, camera control and camera signal processing suitable for each shooting mode can be performed. You can get a picture.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block circuit diagram showing a circuit configuration of a camera-integrated 8 mm VTR to which a video signal recording device according to the present invention is applied. FIG. 2 is a diagram for explaining an operation in a still image shooting mode of a camera-integrated 8 mm VTR to which the video signal recording device according to the present invention is applied. FIG. 3 is a diagram showing a tape format of a magnetic tape used in an 8 mm video tape recorder. [Description of Signs] 1 ... Magnetic tape 10 ... Camera unit 16 ... Camera signal processing circuit 20 ... Camera control unit 24 ... Feature extraction circuit 25 ... Microprocessor (MPU) 26 Motion detection circuit 30 Still image video signal processing unit 40 Moving image video signal processing unit 50 Head unit 60 System control unit

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-256584 (JP, A) JP-A-3-261287 (JP, A) JP-A-59-148471 (JP, A) JP-A-2- 130080 (JP, A) JP-A-1-280440 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/222-5/257

Claims (1)

(57) [Claims] [Claim 1] A lens, an iris, and a CCD image
Sensor and camera signal processing circuit, and focus of the lens
Adjust the focus drive and adjust the aperture of the iris.
Iris drive unit to adjust the read speed of the CCD
In a video signal recording device having a CCD readout control unit for controlling a moving image and a still image on a recording medium, a video signal recording device is provided based on a luminance signal output from the camera signal processing circuit.
A feature extraction circuit for extracting features and data from the feature extraction circuit.
Data is supplied to the focus drive unit and the iris drive.
Unit and CCD readout control unit, and
Signal processing such as gain control processing and gamma correction
A microprocessor executed by a processing circuit;
An operation that can control the area for feature extraction in the output circuit
Can and a vector detection circuit, an automatic focus control of the lens used when shooting a subject, an iris driving system
Control, shutter control by CCD readout control
Photographing conditions such as conditions, and gamma correction performed on the imaging signal obtained by the image capturing conditions, the dynamic range correction and automatic
The microprocessor switches various correction processes such as gain control conditions and video signal processing conditions related to gain control based on a still image shooting mode or a moving image shooting mode.
Control based on the subject information extracted by the feature extraction circuit.
A video signal for a still image or a video signal for a moving image, and a recording device for recording the video signal for a still image and the video signal for a video generated by the imaging device on the recording medium. Video signal recording device.