JPH08251606A - Image pickup device - Google Patents

Abstract

PURPOSE: To obtain wide-band R, G and B signals. CONSTITUTION: Respective R, G and B signals from an image pickup element 101 are applied to a white balance circuit WB, a white-balanced G signal is narrowed in its band through an LPF 150 and then the processed R, G and B signals are applied to subtractors 151, 152 to obtain R-G and B-G signals. The G signal is added to an aperture-compensated signal DTL obtained from the G signal by an adder 153 to obtain a wide-band G signal. The wide-band G signal is added to the R-G and B-G signals by adders 154, 155 to offset the G component. Since the narrow-band G signal is offset by the wide-band G signal, the band of the R-B signal is extended. Consequently the bands of R, G and B signals can be extended without excessively compensating the aperture of a picture reducing R and B signal components or reducing the aperture compensation of a picture reducing a G signal component as compared with a conventional case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device such as a color video camera.

[0002]

2. Description of the Related Art A conventional image pickup system is shown in FIG. In the solid-state imaging device 101, color filters are separately arranged for even fields and odd fields of interlaced scanning as shown in FIG. 4, and R and B are every other pixel from VOUT1 and every pixel is from VOUT2 in the figure. G is read. The signals of these two systems are sampled and held by the sample hold circuits 102 and 103,
AGC circuits 104 and 105 perform automatic gain adjustment, and analog-to-digital (AD) converters 106 and 107 perform AD adjustment.
It is converted into a digital signal. The G component appears in the output of the AD converter 107, but these are 1 of the television signal.
It is delayed by the memory 133 having a capacity for a horizontal period (hereinafter referred to as 1H). The output of the memory 133 is further delayed by the memory 134 having a capacity of 1H. AD
The output of the converter 107 and the outputs of the memories 133 and 134 form a continuous 3H G signal.

In the aperture correction circuit 100, these continuous 3H G signals are extracted as high-pass components by the high-pass filter 135 and then removed by the base clip circuit 137 to remove noise components, thereby forming vertical aperture signals. Become. Further, the output of the memory 133 is extracted with a high-pass component by a high-pass filter 136, and the base clip circuit 13
By removing the noise component at 8, the horizontal aperture signal is obtained. The vertical and horizontal aperture components are added by the adder 139, and then the signal level is adjusted by the gain control circuit 140 to become a detail signal (DTL).

On the other hand, an R component and a B component appear at every other pixel in the output of the AD converter 106, but this is delayed by the memory 108 having a capacity of 1H. afterwards,
The synchronization circuit 109 synchronizes the R component and the B component. For these R component and B component, folding components are removed by low-pass filters 110 and 111, respectively. Output of low pass filter 110 (R component), memory 133
The output (G component) and the output (B component) of the low-pass filter 111 are subjected to gain adjustment by the multipliers 112 and 113 in the white balance circuit (WB) with the G component as a reference to obtain white balance. These three signals are
All of them are delayed by the 1H memory, so that the phases are aligned.

The white-balanced RGB components are
The detail signal (DTL) output from the gain control circuit 140 is added to the adders 114, 115, and 1, respectively.
Aperture correction is realized by adding 16 together. At this time, the outputs of the multipliers 112 and 113, the output of the memory 133, and the detail signal (DTL) are aligned in phase by a delay device (not shown). These signals are
The knee circuits 117 to 119 suppress the gain of the high level component, and the gamma correction circuits 120 to 122 perform gamma correction. Next, in the matrix operation circuit 123

[0006]

[Equation 1]

Thus, the color signals RY, BY and the luminance signal Y are generated. The hue correction circuit 124 corrects the hue of the color difference signal, and the low-pass filters 125 and 126 cut the high-pass signal so as to be suitable for the subsequent modulation. Next, the modulation circuit 12
7, the modulation and the burst signal are added, the analog signal is returned by the digital-analog (D / A) converter 128, the low-pass filter 129 is passed, and the video color signal CO
UT. On the other hand, the luminance signal is a blanking addition circuit 1
After the blanking signal is added at 30, it is DA converted by a digital-analog (D / A) converter 131 into an analog signal, which then becomes a video luminance signal YOUT via a low pass filter 132.

The selectors 14 output the outputs of the knee circuits 117 to 119 and the gamma correction circuits 120 to 122, respectively.
1 to 143 and the blanking addition circuits 144 to 1
By adding a blanking signal at 46, a digital red signal ROUT, a digital green signal GOUT and a digital blue signal BOUT are obtained. These digital outputs are input to multimedia equipment such as a computer and a printer (not shown). The inputs of the selectors 141 to 143 are switched according to the necessity of gamma correction of these multimedia devices.

[0009]

However, in the above-mentioned conventional example, the detail signal DTL obtained from the G component is set to RB.
Since it is also added to the component, the aperture correction is applied too much to an image that does not contain much RB component, and the aperture correction is sufficient for an image that contains many RB component and does not contain much G component. Not done For this reason, there has been a drawback that the wide band of the digital RGB output is not properly performed in consideration of multimedia support, and the edge emphasis becomes unnatural when displayed on the screen of a multimedia device such as a computer or a printer.

Therefore, an object of the present invention is to realize an appropriate wide band of digital RGB output of an image pickup device,
It is to realize high image quality when displaying on a multimedia device.

[0011]

According to the present invention, image pickup means for picking up an image of a subject and outputting first, second and third video signals, and signal processing for widening the bandwidth of the third video signal. Means and the first, second and third video signals which have been widened by performing a predetermined calculation based on the first, second and third video signals and the third video signal which has been widened by the signal processing means. And a calculation means for obtaining the video signal of.

[0012]

According to the present invention, of the first, second and third video signals obtained by the image pickup means, the third video signal is processed and converted into a wideband third video signal. , By processing the wideband third video signal and the first, second, and third video signals, respectively, the wideband first, second, and
It is possible to obtain the third video signal.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first and second embodiments of the present invention will be described with reference to FIG.
2 will be described. Incidentally, 101 in FIG. 1 and FIG.
The blocks denoted by ˜146 have substantially the same functions as the blocks having the same numbers in FIG.

FIG. 1 shows the first embodiment. Instead of the adders 114, 115 and 116 of FIG. 3, a low pass filter 150, subtractors 151 and 152 and an adder 153,
154 and 155 are provided.

Next, the operation of the above configuration will be described. Of the signals that have been white-balanced by the white balance circuit (WB), the G component is the low-pass filter 15
At 0, the band is narrowed to the same extent as the RB component, and the subtracters 151, 1
At 52, RG and BG are generated, respectively. The white-balanced G component is also sent to the adder 153 and is added to the detail signal (DTL) which is the output of the gain control circuit 140 to realize aperture correction and obtain a wideband G signal. This signal is added to the outputs of the subtracters 151 and 152 by adders 154 and 155, respectively, and the G components of the R-G and B-G components are canceled out. At this time, the narrow band G component is canceled by that of the wide band, so that the wide band of the RB component is realized.

The wide band RGB has knee circuits 117 to 119.
After the gain of the high level component is suppressed by, the gamma correction circuits 120 to 122 perform gamma correction. Next, the matrix calculation circuit 123 performs the calculation of the equation (1) to generate the color difference signals RY, BY and the luminance signal Y. The subsequent operation is the same as in FIG.

FIG. 2 shows a second embodiment. Subtractors 160, 161, 162, 163 are provided in place of the subtractors 151, 152 and the adders 154, 155 in FIG. The low pass filter 150 and the adder 153 are shown in FIG.
It is provided in the same way as.

Next, the operation of the above configuration will be described. Of the signals white-balanced by the white balance circuit WB, the band of the G component is narrowed to the same level as the RB component by the low-pass filter 150, and the subtractors 160 and 161 generate GR and GB, respectively. . The white-balanced G component is also sent to the adder 153 and is added to the detail signal (DTL) which is the output of the gain control circuit 140 to realize aperture correction and obtain a wideband G signal. From this signal, the subtracters 162 and 163 subtract the outputs of the subtracters 160 and 161, respectively, and the G components of the GR and GB components are canceled to cancel the R component.
Leave the B component. At this time, the narrow band G component is canceled by that of the wide band, so that the wide band of the RB component is realized. Operations other than the broadband RB component generation are the same as those in the first embodiment and FIG.
Is the same as

[0019]

As described above, according to the present invention, the third video signal is processed by processing the third video signal from the first, second and third video signals obtained by the imaging means, and the third broadband signal is processed. The video signal is converted into the wideband third video signal and the first, second and third video signals.
By performing the arithmetic processing on the video signal of 1), it is possible to obtain the first, second, and third video signals of widebands respectively, and it is possible to obtain a high-quality image by various display devices in various multimedia devices. There is an effect that can be done.

The first, second and third video signals are R,
In the case of B and G signals, first, the G signal is formed into a wide band G signal by aperture correction, and two signals of R-G and B-G signals or G-R and G-B signals are obtained, and these signals are obtained. By canceling the G components of the two signals with the wideband G signal, wideband R and B signals can be easily obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional imaging device.

FIG. 4 is a configuration diagram showing a color filter array on an image sensor.

[Explanation of symbols]

 100 Aperture correction circuit 101 Image sensor 150 Low-pass filter 151, 152, 160-163 Subtractor 153-155 Adder

Claims (5)

[Claims] 1. An image pickup means for picking up an image of a subject and outputting first, second, and third video signals, a signal processing means for widening the bandwidth of the third video signal, and the first and second , A calculating means for obtaining the widened first and second video signals by performing a predetermined calculation based on the third video signal and the third video signal widened by the signal processing means. Imager equipped. 2. The image pickup apparatus according to claim 1, wherein the signal processing means performs aperture correction processing. 3. The image pickup apparatus according to claim 1, wherein the first, second, and third video signals are color signals indicating different color components of the subject. 4. The calculating means calculates the third video signal component in two signals obtained by subtracting or adding the third video signal from the first and second video signals, respectively, to obtain the wide band. The image pickup apparatus according to claim 1, further comprising a calculation for canceling the converted third video signal. 5. The first, second and third video signals are an R signal, a B signal and a G signal, respectively, and the R signal and the B signal are dot sequential. Imaging device.