JP3107161B2 - Image signal recording device and image signal reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal recording / reproducing system that records an image signal corresponding to a subject on a recording medium and reproduces the image signal recorded on the recording medium. is there.

2. Description of the Related Art As a system for recording and reproducing an image signal on a recording medium, there is a still video system (hereinafter, referred to as an SV system). In this SV system, of the image signals formed by the image sensor, the luminance signal is FM-modulated, the color signal is color-difference-line-sequentialized, and then FM-modulated to a low frequency band. The line-sequential signal is frequency-multiplexed, recorded on a disk-shaped magnetic recording medium, and an image signal recorded on the magnetic recording medium is reproduced.

In the system as described above, since an image signal is formed using an image sensor, it is necessary to adjust white balance.

For this reason, the white balance is adjusted by a simplified method of electrically adjusting the R, G, and B component signals of the image signal obtained from the image sensor.

[Problems to be Solved by the Invention] In recent years, however, there has been an increasing trend toward higher image quality even in consumer devices, and there has been a need for more accurate white balance adjustment.

The present invention has been made in order to solve such a problem, and has as its object to provide an image signal recording / reproducing system capable of adjusting the color reproducibility of an image signal with high accuracy by a simple and low-cost configuration. .

[Means for Solving the Problems] In order to achieve the above object, an image signal recording apparatus of the present invention performs conversion means for converting a subject image into a color image signal, and performs color balance adjustment of the color image signal. An adjusting unit; and a recording unit for recording on a medium a color image signal whose color balance has been adjusted by the adjusting unit and information indicating a state in which the color balance has been adjusted by the adjusting unit. An image signal recording device, and the image signal reproducing device of the present invention is a reproducing unit that reproduces a color image signal recorded on a medium and information indicating a state in which color balance has been adjusted for the color image signal,
Signal processing means for performing cyclic noise reduction and color balance adjustment on the color image signal reproduced by the reproduction means based on information indicating a state where the color balance has been adjusted recorded on the medium. An image signal reproducing apparatus characterized by the following.

[Operation] According to the above configuration, the image signal recorded on the recording medium is corrected at the time of reproduction according to the shooting conditions of the subject at the time of recording,
The output can be output, and the configuration of the recording unit can be simplified.

Embodiment FIG. 1 is a block diagram showing a schematic configuration of a recording apparatus in an SV system according to an embodiment of the present invention.

In FIG. 1, a CCD (Charge Cou
A subject image is formed on the imaging surface of the pled device 102.
On the imaging surface of the CCD 102, for example, R, G, B stripe filters of three colors are arranged, and R, G, B signals output from the CCD 102 according to the arrangement of the R, G, B stripe filters. Are subjected to gamma correction processing and the like by the camera process circuits 103 to 105, respectively, and then a broadband low-pass filter (LPF) 1
After the band is limited in 06 to 108, the sum is added in the adder 109 and supplied to a high-pass filter (HPF) 110.
The R, G, and B signals band-limited by the LPFs 106 to 108 are supplied to narrow-band LPFs 111 to 113, band-limited by the LPFs 111 to 113, and then subjected to a white balance adjustment circuit (hereinafter referred to as WB).
The R, G, and B signals, which have been supplied to the WB adjustment circuit 114 and supplied to the matrix circuit 115, respectively, are supplied to the matrix circuit 115, where the signals Y _L , R _L −Y _L , B _It is converted to _{L -} YL and output. On the other hand, the signal output from the adder 109 is output to the adder 1 via the HPF 110.
16 and is added to the _YL signal output from the matrix circuit 115 to form a broadband luminance signal Y.
It is supplied to the recording process circuit 117.

Was formed as described above, Y, R _L -Y _L, the respective signals B _{L-Y L} are supplied to the recording processing circuit 117, the luminance signal Y after being emphasized processed, FM modulation to a high frequency band And
The color difference signals R _L -Y _L , B _L- Y _L are line-sequentialized, then FM-modulated to a low frequency band, and the formed FM-modulated luminance signal and FM-modulated color-difference line-sequential signal are frequency-multiplexed. It is supplied to a head changeover switch (SW) 127.

The connection of the SW 127 is switched between the first field period and the second field period by the system controller 124,
The recording image signal output from the recording process circuit 117 is amplified by the recording amplifiers 128 and 129, and is amplified by the two magnetic heads 131 and 132.
Is recorded on the disk-shaped magnetic recording medium 130 rotated at a predetermined rotation speed by a motor (not shown).

On the other hand, the color temperature of the light source is measured from an AWB (Auto White Balance) sensor 119 and supplied to the AWB controller 120. Then, the AWB controller 120 adjusts the white balance by controlling the levels of the R, G, and B signals by the WB adjustment circuit 114 in accordance with the measurement result of the color temperature of the light source by the AWB sensor 119. The level range of each of the R, G, and B signals controlled by the WB adjustment circuit 114 is limited to a range that does not degrade the S / N. On the other hand, information on the color temperature of the light source measured by the AWB sensor 119 is supplied to a color temperature data generator 121, and the color temperature data generator 121 outputs a color corresponding to the color temperature information of the light source supplied from the AWB sensor 119. The temperature data is supplied to the recording process circuit 117, where the temperature data is multiplexed with a part of the recording image signal. The control signal of the WB adjustment circuit 114 output from the AWB controller 120 is transmitted to the control data generator 1
The control data generator 122 generates control data corresponding to the adjustment levels of the R, G, and B signals in the WB adjustment circuit 114, and supplies the control data to the recording process circuit 117. At 117, it is multiplexed with a part of the recording image signal. Note that the multiplexing method of the color temperature data and the control data with respect to the recording image signal is, for example, to add error correction data to the color temperature data and the control data, and then add the NRZ (Non Return
(Zero to Zero) modulation and addition during the vertical blanking period of the recording image signal.

1 are controlled by the system controller 124 in synchronization with the clock signal generated by the master clock generator 123. For example, the system controller 124 gives an instruction to the driving circuit 118 at the time of starting the driving operation of the CCD 102, and the driving circuit 118 drives the CCD 102 in synchronization with the clock signal supplied from the master clock generator 123 to correspond to the subject image. The image signal thus formed is formed.

The clock signal output from the master clock generator 123 is a synchronous signal generator 125, an ID signal generator
6 and a synchronizing signal generator 125 generates a composite synchronizing signal in synchronization with the supplied clock signal.
The ID signal generator 126 generates an ID signal indicating a track number, year, month, day, hour, minute, second, etc. in synchronization with the supplied clock signal. Both signals are supplied to the recording process circuit 117, and the recording image signal And recorded on a magnetic recording medium.

FIG. 2 is a block diagram showing a schematic configuration of a reproducing apparatus in an SV system according to one embodiment of the present invention.

In FIG. 2, a signal recorded on the magnetic recording medium 201 is reproduced by a magnetic head 202 from a magnetic recording medium 201 on which an image signal is recorded by the recording apparatus described above, and is amplified by a preamplifier 203. Supplied to 204.

The reproduction process circuit 204 separates the FM-modulated luminance signal and the FM-modulated color-difference line-sequential signal that are frequency-multiplexed into the reproduced signal, performs FM demodulation, de-emphasis processing, etc. on each of them, and then performs the color-difference line-sequential signal. two kinds of color difference signals by performing the synchronization processing for the R _L -Y _L, are converted to B _{L-Y L,} as a result, the luminance signal Y from the reproduction processing circuit 204,
The color difference signals _{R L -Y L, B L- Y} L is output.

The luminance signal Y output from the reproduction process circuit 204 is supplied to the HPF 205 and the LPF 206 as described above, and the high frequency component Y _H of the luminance signal Y separated by the HPF 205 is used as a delay circuit (DL) for time alignment. A / D converter after delay by 209
After being converted into a digital signal at 215, it is stored in the memory 219. Further, the low-frequency component Y _L of the luminance signal Y separated from the LPF206 is supplied to a matrix circuit 210. On the other hand, R _L -Y _L outputted from the reproduction process circuit 204, after passing through the respective signal is also LPF207,208 of B _L -Y _L, is supplied to a matrix circuit 210.

And Y _L are supplied as described above, R _L -Y _L, with B _L -Y _L signal, the matrix circuit 210, to form a respective signals _{R L, G L, B L} , formed The R _L , G _L , and B _L signals are output to the WB adjustment circuit 211.
Supplied to

In the reproduction process circuit 204, error correction data multiplexed at the time of recording is added, NRZ-modulated color temperature data and control data are separated from the reproduction signal,
The color temperature data and control data, which are supplied to the decoder 6 and are demodulated by the decoder 226 and subjected to error correction, are restored. The restored color temperature data and control data are supplied to the color signal control circuit 22.
Supplied to 7.

By the way, as described above, the recording side
In order to suppress the deterioration of S / N to some extent, the color signal is not sufficiently corrected for color temperature, and the color signal control circuit 227 controls the WB adjustment circuit 211 based on the supplied color temperature data and control data. By controlling, the level balance of each signal of R _L , G _L , and B _L supplied to the WB adjustment circuit 211 is corrected, and the corrected R ′ _L , G ′ _L , B ' _L
Are output.

By the way, as described above, in the WB adjustment circuit 211, R _L , G _L , B
_When the signal level balance of _L is adjusted, if the level of the color signal is raised too much, S / N deteriorates and the image quality deteriorates. Therefore, in the present embodiment, a control signal supplied from the color signal control circuit 227 to the WB adjustment circuit 211 is also supplied to the memory controller 228, and a signal of a portion whose level is raised by a predetermined amount or more in the WB adjustment circuit 211 is The memory controller 228 controls a coefficient of a coefficient multiplier, which will be described later, so as to apply the cyclic noise reduction, thereby preventing deterioration of image quality due to deterioration of S / N of a color signal. That is, the signals R ′ _L , G ′ _L , and B ′ _L output from the WB adjustment circuit 211 are output to the A / D converters 212 and 2.
It is digitized in 13,214, multiplied by (1-k) in coefficient multipliers 232,233,234, and supplied to memories 216,217,218 after passing through adders 223,224,225. The outputs of the memories 216, 217, and 218 are supplied to adders 229, 230, and 231 and multiplied by k in coefficient multipliers 220, 221, and 222, respectively.
Will be returned to

As described above, the coefficient multipliers 220, 221, 222, 232, 233, 234,
A cyclic noise reduction is configured by the adders 223, 224, 225 and the memories 216, 217, 218, and the memory controller 228 generates coefficient multipliers 220, 22 according to the supplied control signal.
By setting the value of the coefficient k in 1,222,232,233,234, and by instructing the number of times of writing and reading data to and from the memories 216,217,218, by setting the number of times of the round of noise reduction, the level correction amount of the color signal in the WB adjustment circuit 211 The corresponding noise reduction is performed.

Signal that has been subjected to noise reduction as described above
R _L, G _L, B _L is summed with the signal Y _H outputted from the memory 219 in adder 229,230,231, output color signals R, G, as a B.

In the present embodiment, the signal Y _H output from the A / D converter 215 has a residual jitter component, so that the cyclic noise reduction is performed to prevent the resolution from being reduced by applying the cyclic noise reduction. Was not applied,
Since the resolution of the signals R _L , G _L , and B _L is originally low, there is no risk that image quality will deteriorate due to a reduction in resolution even when a cyclic noise reducer is applied. Further, the noise reducer may be of another type such as a core type, or may be used in combination.

Further, in the present embodiment, the S / N deterioration of the color signal is prevented by the cyclic noise reduction. However, another noise reduction such as a core type noise reduction may be used.

Further, in this embodiment, the color temperature data and the control data are added to the vertical blanking period of the recording image signal.
Add color temperature data and control data by ID signal,
Alternatively, the pilot signal having a frequency between the valleys of the frequencies of the FM luminance signal and the FM color difference line-sequential signal may be used as a carrier wave, and the pilot signal may be modulated by the color temperature data and the control data, and may be added by frequency multiplexing.

As described above, in the present embodiment, information indicating the color temperature of the illumination at the time of recording, and information indicating how the R, G, and B level balances in the camera unit have been adjusted together with the recorded image signal. Based on this information, the color balance of the color signal is adjusted based on the information, and as a result, for the color signal whose S / N is reduced by the adjustment of the color balance, noise reduction according to the level correction amount is performed. Is performed, it is possible to obtain a sufficient color signal at the time of reproduction without strictly adjusting the white balance in the camera unit, which is particularly effective for a commercial SV system.

[Effects of the Invention] As described above, according to the present invention, when a color image signal after color balance adjustment is recorded on a medium, information indicating the color balance adjustment state is also recorded. At the time of reproduction from a medium, appropriate signal processing according to the adjustment state, that is, noise reduction and color balance adjustment can be performed.

Further, when recording, since a color image signal having a certain degree of color balance adjusted is recorded, it is possible to prevent a color image having an unbalanced color from being obtained even when reproduced by another general reproducing apparatus. It is possible to obtain an image of a certain quality.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a recording device in an SV system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of a reproducing device in the SV system according to an embodiment of the present invention. is there. In the figure. 102: CCD 103, 104, 105: Process circuit 114, 211: WB adjustment circuit 115, 210: Matrix circuit 117: Recording process circuit 119: AWB sensor 120: AWB controller 121: Color temperature data generator 122: Control data generator 123: Master clock generator 124: System controller 131, 132, 202: Magnetic head 130, 201: Magnetic recording medium 204: Reproduction process circuit 216, 217, 218, 219: Memory 220, 221, 222, 232, 233, 234: Coefficient multiplier 226: Decoder 227: Color signal control circuit 228: Memory controller

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/222-5/257 H04N 5/76-5/956 H04N 9/79-9/898

Claims (2)

(57) [Claims] A converting means for converting a subject image into a color image signal; an adjusting means for adjusting a color balance of the color image signal; a color image signal having a color balance adjusted by the adjusting means; An image signal recording apparatus, comprising: recording means for recording on a medium together with the information indicating the state in which the color balance has been adjusted. 2. A reproducing means for reproducing a color image signal recorded on a medium and information indicating a state in which color balance has been adjusted for the color image signal, and a state in which the color balance recorded on the medium has been adjusted. An image signal reproducing apparatus comprising: a signal processing unit that performs cyclic noise reduction and color balance adjustment on a color image signal reproduced by the reproducing unit based on information indicating the following.