JP3109078B2 - Video signal recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal recording device, and more particularly to a video signal recording device capable of magnetically recording a still image.

[Conventional technology]

 2. Description of the Related Art Conventionally, still image recording apparatuses have been known.

The output of a still image recording device is often viewed on a monitor or printed out with a video printer and viewed as a photo, instead of being viewed as a moving image as in normal playback on a VTR. Is tough.

[Problems to be solved by the invention]

The output from the still image recording apparatus as described above may not reach the desired image quality as it is.

Therefore, there is a case where the output of the still image recording apparatus is corrected by a color corrector or the like in order to obtain a desired image quality. The color corrector decomposes the video signal into color difference signals and then mixes them again. The color corrector corrects hue, saturation, and the like.

However, such a correction can be performed only slightly within the range of recorded image information, although a slight correction can be made for the color, and the degree of correction is limited.
Moreover, it was troublesome.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a video signal recording apparatus capable of obtaining a still image of a desired image quality without post-processing by a color corrector or the like.

[Means for solving the problem]

According to the present invention, a plurality of sets of parameters that define shooting conditions related to image quality at the time of reproduction are stored by changing each of the parameters in a stepwise manner, and a plurality of sets are stored. An imaging condition setting means for setting a plurality of imaging conditions by a plurality of parameter sets selected from a set of parameter sets; and a plurality of imaging outputs for each of the plurality of imaging conditions set by the imaging condition setting means. Recording means for recording as still images; selecting and outputting a plurality of still images recorded by the recording means; and selecting a desired one from among the plurality of still images.

[Action]

A plurality of parameters that define shooting conditions, for example, iris opening amount, electronic shutter speed, AGC amplifier gain, γ characteristic and knee characteristic correction amount, white balance,
A numerical value or a level is set stepwise for each of the linear matrix and the like.

Then, a plurality of photographing conditions are set by combining the values or levels of the respective parameters.

Images are recorded under a plurality of shooting conditions desired by the user. Thereafter, the recorded still image is reproduced and confirmed on a monitor, or is printed out by a video printer, thereby obtaining a still image of a desired image quality. As a result, a still image having a desired image quality can be obtained without performing post-processing by a color corrector as in the related art.

〔Example〕

One embodiment of the present invention will be described with reference to FIGS. In this embodiment, an area for recording a video signal in a track formed on a magnetic tape and a PC
A video camera capable of setting an area for recording an M-encoded signal is described as an example.

1 and 2 show the overall configuration of the video camera.

In FIG. 1, a fixed lens, a zoom lens, a focus lens, and the like are provided in the lens unit 1, and an iris ring is provided between the zoom lens and the fixed lens. The focus lens can be moved by the focus drive motor 3, thereby obtaining a focus position. The zoom lens can be moved by a zoom drive motor (not shown). The position of the zoom lens is detected by the zoom position detector 6, and the output of the zoom position detector 6 is supplied to the system controller 12.

The opening and closing of the iris ring in the lens unit 1 is controlled by the iris drive motor 4. The open / closed state of the aisle ring is detected by an iris position detector 5 composed of, for example, a Hall element, and the output of the iris position detector 5 is supplied to a system controller 12.

In the CCD 2, a subject image passing through the lens unit 1 is formed and photoelectrically converted. Thereby, an imaging signal is obtained from the CCD2. The CCD 2 is driven by the driver 10, and the output of the CCD 2 is supplied to the sample and hold circuit 7.

In the sample and hold circuit 7, the imaging signal from the CCD 2 is sampled and held. The output of the sample hold circuit 7 is supplied to an A / D converter 9 via an AGC circuit 8, and an image signal digitized by the A / D converter 9 is obtained. The output of the A / D converter 9 is supplied to a luminance signal processing circuit 13 and a chroma signal processing circuit 14, and also to a system controller 12.

The luminance signal processing circuit 13 is provided with a Y / C separation circuit (not shown), and the Y / C separation circuit extracts a luminance signal from the supplied image signal. Further, the luminance signal processing circuit 13 includes a γ correction circuit 75, a knee correction circuit 76 for giving a non-linear characteristic to a digitized luminance signal, and the like. Under the control of the system controller 12,
Signal processing such as γ correction and knee correction is performed on the luminance signal. The processed luminance signal is converted to an analog luminance signal by the D / A converter 15 and the NTSC encoder 16
Supplied to Also, if necessary, the luminance signal processing circuit 13
A luminance signal may be fed back to the system controller 12 from the CPU.

The chroma signal processing circuit 14 is provided with a Y / C separation circuit (not shown), and the chroma signal is extracted from the supplied image signal by the Y / C separation circuit. Also,
The chroma signal processing circuit 14 includes an auto white balance circuit 77, a linear matrix circuit 78, and the like. Under the control of the system controller 12, signal processing such as auto white balance and linear matrix is performed on the chroma signal. . The processed chroma signal is converted to an analog chroma signal by the D / A converter 17, and the NTSC
It is supplied to the encoder 16. Further, a chroma signal may be fed back from the chroma signal processing circuit 14 to the system controller 12 as needed.

The NTSC encoder 16 converts the above-described analogized luminance signal and chroma signal into an NTSC composite signal, and supplies the composite signal to the recording / reproducing unit 18.

The system controller 12 controls the video camera system.
A key switch 19 for inputting a mode signal and various data for defining various modes such as recording or reproduction is connected to the memory 12, and a memory 20 for holding values of various parameters for defining shooting conditions. Is connected.

The memory 20 connected to the system controller 12 has parameters for defining various photographing conditions, such as an iris opening amount, an electronic shutter speed, an AG amplifier gain,
By changing the values of the γ characteristic correction amount, knee characteristic correction amount, white balance, linear matrix, etc. stepwise little by little and combining the values of each parameter, multiple shooting conditions are set and summarized as a table Have been.

Therefore, in a certain shooting condition, a numerical value is set for each of the above-described plurality of parameters, and the numerical values of the plurality of parameters are combined for each shooting condition and are summarized in a table.

From the system controller 12, a control signal for controlling the circuit operation in the recording / reproducing unit 18 is used for recording / reproducing.
The data is supplied to the reproducing unit 18.

The lens drive signal output from the system controller 12 is supplied to the focus drive motor 3 via the driver 21. Thereby, the position of the focus lens is controlled so as to be the in-focus position.

An iris control signal is output from the system controller 12, and an AGC control signal is output. The iris control signal is supplied to the driver 22, and the AGC control signal is supplied to the AGC circuit 8 via the D / A converter 23.
Thus, the iris ring is opened and closed according to the level of the output signal from the CCD 2 and the gain of the AGC circuit 8 is set.

A CCD control signal is output from the system controller 12. When the CCD control signal is supplied to the driver 10, the drive of the CCD 2 is controlled, for example, the shutter speed is controlled.

Next, selection of shooting conditions by the user and recording / reproduction of a shot moving image and still image will be described.

The user selects a shooting condition that seems appropriate in consideration of the shooting location, brightness, characteristics of the subject, etc., and operates the key switch 19 by operating the key switch 19 with the selected shooting condition.
When supplied from 19 to the system controller 12, the system controller 12 reads out the values of the parameters defining the designated photographing conditions from the memory 20 and takes them into a memory (not shown) in the system controller 12.

Then, the values of the respective parameters read from the above-described memory 20 are stored in the driver circuits 21, 22, 10, the D / A converter 23,
The gamma correction circuit 75, the knee correction circuit 76, the auto white balance circuit 77, the linear matrix 78, and the recording / reproducing unit 18 are supplied.

The driver circuit 22 controls the drive of the iris drive motor 4 based on the values of the respective parameters read from the memory 20 to set the opening amount of the iris to a predetermined value. The drive of the focus drive motor 3 is controlled to set the position of the zoom lens to a predetermined position.

Then, the driver circuit 10 controls the electronic shutter speed of the CCD 2 based on the above-mentioned value, and sets the predetermined speed, and the AGC
The circuit 8 sets the gain to a predetermined level based on the above value.

The gamma correction circuit 75 performs gamma correction based on the above value, and the knee correction circuit 76 adjusts the gain of the high luminance portion based on the above value to perform knee correction.

The auto white balance circuit 77 sets the gains of the three primary color signals R, G, and B based on the above-mentioned values so that the integrated values of the levels of the three primary color signals R, G, and B have a predetermined ratio, and adjusts the white balance. adjust.

The linear matrix circuit 78 adjusts the hue and saturation by adjusting the gain and axis angle of the color difference signal based on the above values.

In the above description, the combination of the values of each parameter is described as being stored in the memory 20, but in addition to this, the user resets the value of each parameter to a desired value. It is also possible to set new photographing conditions.

In this state, a moving image of the subject is photographed. When the user operates a predetermined key in the key switch 19 to set a still image recording mode during shooting of this moving image, a signal corresponding to this is transmitted from the key switch 19 to the system controller 12.
Supplied to Under the control of the system controller 12,
In the recording / reproducing unit 18, one frame of image data when the user operates the key switch 19 is recorded as still image data in the track format PCM recording part 50 shown in FIG. You. Alternatively, while the key switch 19 is operated, image data for one frame may be recorded as still image data at regular intervals.

The user selects a certain shooting condition and shoots the subject, and then specifies another shooting condition and shoots the subject under the shooting condition. Then, as will be described later, a still image of a desired image quality can be obtained by reproducing the still image on a monitor or by a video printer or the like.

 The configuration of the recording / reproducing unit 18 is shown in FIG.

The video signal supplied from the NTSC encoder 16 via the terminal 25 is a video recording circuit 26, an input / output switching circuit.
Supplied to 27.

The same video signal as the video signal supplied from the NTSC encoder 16 via the terminal 25 is supplied to the A / D converter 29 via the terminal 28 and converted into a digitized image signal at a sampling frequency of 4 fsc. After the video RAM30
Supplied to

One frame of still image data designated by the user's operation of the key switch 19 as described above is written into the video RAM 30 under the control of the system controller 12.

Then, under the control of the system controller 12, the still image data is read from the video RAM 30, and the still image data is subjected to high-efficiency encoding by the encoder 31, for example,
After data compression for about 5 seconds, channel switching circuit
Supplied to 42.

An ID signal is generated by the ID generation circuit 36 based on a control signal supplied from the system controller 12 via the terminal 37. This ID signal identifies whether the content of the signal recorded in the PCM recording section 50 is audio data or still image data, controls the data capture at the time of reproduction, and reproduces audio and video. It is a code signal for designating an aspect. The ID signal is supplied to the PCM recording circuit 38.

Right and left channels L + supplied via terminals 39 and 40
R, LR audio signal, or L, R audio signal,
The signals are supplied to the A / D converter 41 and the channel switching circuit 42.

In the channel switching circuit 42, the audio data supplied from the A / D converter 41 and the still image data supplied from the encoder 31 are switched under the control of the system controller 12, output, and supplied to the PCM recording circuit 38. I do.

The PCM recording circuit 38 performs additional processing such as an error correction code, a data sync, and a PLL synchronization clock, and performs processing such as time axis compression, conversion to an NRZ code system, and FM modulation. The signal PCM-encoded by the PCM recording circuit 38 is supplied to the input / output switching circuit 27.

The input / output switching circuit 27 includes a PCM recording portion 50 in the track TR where the magnetic heads 34 and 35 are formed on the magnetic tape 43.
At the timing when the recording of the PCM encoded signal is started, either the supplied still image data or audio data is supplied to one of the magnetic heads 34 and 35. Then, it is recorded in the PCM recording portion 50 of the track TR shown in FIG. When the recording on the PCM recording portion 50 is completed, the analogized image signal supplied from the video recording circuit 26 is supplied to the magnetic heads 34 and 35 and recorded on the video signal section 56.

FIG. 3 shows a track format of a track TR formed on the magnetic tape 43 by the video camera having the above configuration.

In the standard of the so-called 8 mm video tape recorder, a pair of magnetic heads 34, 3 provided at an angle of 180 degrees from each other
Recording and playback are performed using the
Is wound around the rotating surface of the magnetic heads 34 and 35 within a range of 221 degrees. Then, the recording and reproduction of the analog image signal are performed in the 180-degree section of the above-mentioned 221 degrees, and the recording and reproduction of the PCM coded signal are performed in the remaining 36-degree section. ing.

FIG. 3 shows a track format formed on the magnetic tape 43 according to the above-mentioned standard. From the right side, where the magnetic heads 34 and 35 start to contact the magnetic tape 43, first, the rotation angles of the magnetic heads 34 and 35 In the second half of this rush portion 51, a clock run-in portion 52 synchronized with the subsequent PCM data portion 53 is provided for a period of 2.06 degrees (corresponding to 3H of the video signal). ing.

Subsequent to the clock run-in unit 52, a PCM data unit 53 for recording a PCM coded signal that has been time-axis-compressed is provided over 26.32 degrees. A period of 2.06 degrees (for 3H) following the PCM data section 53 is a back margin section 54 for a recording position shift or the like at the time of after-recording, and after that, 2.
62 degree guard part 5 between video signal part 56 and PCM data part 50
5 are provided.

Subsequent to the guard unit 55, a video signal unit 56 capable of recording an analog image signal for one field or a PCM coded signal by multitracking is provided over 180 degrees. Further, a separating portion 57 for 5 degrees is provided after this.

Therefore, according to this standard, an image signal of one field is recorded / reproduced by the video signal unit 56, and a signal for (1/60) seconds is PCM-encoded during this time, and processing such as error correction is performed. After being applied, the time axis is compressed to about (1 / 6.8) and P
Recorded / reproduced in the CM data section 53. This track TR
As shown in FIG. 4, the magnetic tapes 43 are sequentially and obliquely provided in the longitudinal direction of the magnetic tape 43.

Note that the video signal section 56 described above can also form a multi-track by dividing it into five at every 36 degrees, and record a PCM encoded signal on each track. In the figure, X is a magnetic tape
Reference numeral 43 denotes a moving direction, and Y denotes a tracing direction of the magnetic heads 34 and 35.

In this embodiment, one frame of a still image is recorded, for example, over 300 tracks in 5 seconds.

Since the above-described PCM recording portion 50 can be after-recorded, for example, at a desired insertion position, the video RA
Still image data can be read from M30 and recorded via the encoder 31 and the PCM recording circuit 38. A still image requires at least 284 dots vertically and 512 dots horizontally, and has 8 bits per pixel.

 Next, reproduction will be described.

Reproduction signals reproduced by the magnetic heads 34 and 35 are supplied to a video reproduction circuit 46 and a PCM reproduction circuit 47 via an input / output switching circuit 27, respectively.

In the video reproduction circuit 46, the analog image signal is separated and supplied to the switching circuit 48.

In the PCM reproducing circuit 47, the PCM coded signal is separated and the ID signal is extracted, and is supplied to the ID detecting circuit 66. PCM
In the reproducing circuit 47, the reverse processing to the signal processing in the PCM recording circuit 38 described above is performed to decode the original data. The decoded data is either audio data or still image data, and each reproduced data is supplied to the distribution switch circuit 65.

In the ID detection circuit 66, various control signals for controlling a reproduction mode of an image and a sound based on the detected ID signal are formed.

When audio data is recorded in the PCM recording section 50 described above, the distribution switch circuit 65 is controlled based on a control signal from the ID detection circuit 66, and the output from the PCM reproduction circuit 47 passes through the distribution switch circuit 65. Are supplied to a D / A converter 67 as audio signals of two channels (L, R),
Extracted from 9 as an analog audio signal.

When still image data is recorded, the distribution switch circuit 65 is controlled based on the control signal from the ID detection circuit 66, and the still image data from the PCM reproduction circuit 47 is transmitted from the distribution switch circuit 65 to the decoder 61. Supplied.

The decoder 61 decodes the still image data that has been compressed by the high-efficiency encoding, and supplies the still image data to the video RAM 30 for writing.

The still image data written in the video RAM 30 is read out under the control of the ID detection circuit 66, is converted into an analog still image signal by the D / A converter 71, and is supplied to the switching circuit 48.

The switching circuit 48 is controlled by the control signal from the ID detection circuit 66.
Is controlled. For example, control is performed such that a still image signal and an image signal output from the video reproduction circuit 46 are switched and transmitted in accordance with the ID signal.

An image display means such as a monitor or a video printer (not shown) is connected to the terminal 72, and the above-described still image or image signal can be projected on the monitor or printed out as a hard copy from the video printer. .

The user can obtain a still image with a desired image quality by reproducing the still image on a monitor or by using a video printer or the like and selecting a still image with the best image quality.

According to this embodiment, a still image of a desired image quality can be obtained without the post-processing conventionally performed by a color collector or the like.

〔The invention's effect〕

According to the video signal recording apparatus of the present invention, a plurality of shooting conditions are set by combining the values or levels of a plurality of parameters defining the shooting conditions. The still image recorded below can be played back on a monitor and checked, or printed out with a video printer, so that a still image of the desired image quality can be obtained without post processing by a conventional color corrector or the like. There is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an example of a video camera to which the present invention can be applied, FIG. 2 is a block diagram showing a configuration of an example of a video camera to which the present invention can be applied, and FIG. 3 is a video to which the present invention can be applied. FIG. 4 is a schematic diagram for explaining a format of a recording track in the camera. Description of main reference numerals in the drawings 12: system controller, 18: recording / playback unit, 19: key switch, 20: memory.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/232 H04N 5/765 H04N 9/79

Claims (1)

(57) [Claims] 1. A storage means for storing a plurality of sets of parameters defining shooting conditions relating to image quality at the time of reproduction by gradually changing each of the parameters in a stepwise manner. Imaging condition setting means for setting a plurality of imaging conditions by a plurality of parameter sets selected from the plurality of parameter sets; and a plurality of imaging conditions set by the imaging condition setting means. Recording means for recording the imaging output as a plurality of still images, selecting and outputting the plurality of still images recorded by the recording means, and selecting a desired one from among the plurality of still images. A video signal recording device, characterized in that: