JP2001160909A - Noise reduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optimum noise reduction device, in response to a motion of an input video signal by controlling respective noise reduction devices in a way that a motion detection frame cyclic type noise reduction device is mainly used for a still image, to reduce noises and an area selection type noise reduction device is mainly used for a moving image to reduce noises. SOLUTION: The motion detection frame cyclic type noise reduction device 1010 outputs a motion detection circuit output (K) 1011, denoting motion information of an input video signal 1000 to a motion detection means 1009 in order to reduce a noise component, in response to the motion of the input video signal 1000. The motion detection means 1009 compares a preset motion threshold, denoting the motion of the input video signal with the motion detection circuit output (K) 1011 and allows the motion detection frame cyclic type noise reduction device 1010 to reduce the noise components, when the detection means discriminates a still image or allows the area type noise reduction device 1020 to reduce the noise component, when the detection means discriminates a moving image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction device for reducing noise of a video signal and improving S / N in a video signal processing device.

[0002]

2. Description of the Related Art Generally, a video signal is a signal in which image information is repeated at a frame period, and the autocorrelation between frames is very strong. On the other hand, since noise components included in a video signal generally have no autocorrelation, it is known that when the video signal is averaged temporally for each frame period, only the energy of the signal component is reduced, and noise can be reduced. Have been. For this reason, conventionally, a frame recursive noise reduction device that performs noise reduction based on motion detection information as a frame recursive noise reduction device (Japanese Patent Laid-Open No. 6-225178)
Is known.

FIG. 9 shows a frame cyclic noise reduction apparatus based on motion detection information. This is a two-dimensional LPF (low-pass filter) for accurately detecting motion.
04, adder 1006, adder 1007, and motion determination circuit 1003
And a multiplier 1001 for multiplying by (1-K) and a multiplier 10 for multiplying by K
02 and a frame memory 1005.

A motion determination circuit 1003 performs a motion detection with high accuracy on the input video signal 1000 and removes a noise component by removing a video signal delayed by one frame from a frame memory 1005 and a two-dimensional LPF (low-pass filter). ) 1004
To remove a noise component having no correlation in the frame and leave a small motion component, generate a difference from the video signal of the previous frame from which the noise has been removed, and if the difference is larger than the threshold value, determine the motion. When it is detected that the motion is large, the output (K) of the motion judgment circuit 10
Control is performed so as to reduce the value of 11 (close to 0), and conversely, if the motion is small, increase the value of the motion determination circuit output (K) 1011 (close to 1).

A multiplier 1001 and a multiplier 1002 are controlled by a motion determination circuit output (K) 1011 indicating the motion of the input video signal 1000 to control the amount of frame cycling of the video signal, and to be applied to the input video signal on which noise is superimposed. On the other hand, since motion detection can be performed with high accuracy, discomfort due to afterimages is reduced, and video signals 1000
Noise reduction.

Further, a noise reduction device (Japanese Patent Laid-Open No. 6-86104) is known as an area selection type noise reduction device which can reduce a noise component without using a frame memory without blunting an image edge portion.

In this method, a central pixel and its peripheral pixels are fetched, a difference between the central pixel and its peripheral pixels is calculated, and the difference is compared with a threshold value as a reference as to whether or not there is a correlation. Since only pixels with high correlation are extracted and averaged using only the number of pixels having high correlation with the center pixel, noise can be effectively reduced without dulling even the edges of the image, The noise component to be superimposed is also replaced by the average of pixels having high correlation, so that the noise component can be reduced.

FIG. 10 shows a configuration of a conventional area type noise reduction device. In FIG. 10, an input video signal 10000 is directly input to a peripheral pixel capturing circuit 10001. The peripheral pixel capturing circuit 10001 captures a central pixel and its peripheral pixels, and is input to absolute value circuits 10002 to 10005.

The absolute value circuits 10002 to 10005 calculate the absolute value of the difference between the center pixel and its peripheral pixels, and output the output together with a preset threshold value 100010 and a correlation judgment circuit 1000
The absolute value is compared with the threshold value 100010. The correlation determination circuits 10006 to 10009 compare, for example, the absolute value and the threshold value as follows, and determine whether or not there is a correlation (whether or not the edge is an image).

That is, if absolute value ≦ threshold 100010, there is a correlation, and thus it is not an edge of the image. If absolute value> threshold 100010, there is no correlation, and it is an edge of the image. I do.

As described above, the presence or absence of the correlation (whether or not it is an edge of the image) is determined, and the determination result is input to the pixel number counting circuit 100011 and the correlation pixel adding circuit 100012. Further, the pixel number counting circuit 100011 calculates the number of correlated pixels, and outputs the calculation result to the divider 100013. On the other hand, the correlation pixel addition circuit 100012 receives the outputs of the correlation determination circuits 10006 to 10009, adds only the pixels determined to have correlation, and outputs the sum of the correlation pixels to the divider 100013. Divider 100013
Then, the sum of correlated pixels at the output of the correlated pixel addition circuit 100012 is divided by the number of correlated pixels at the output of the correlated pixel count circuit 100012 to calculate an average value of only correlated pixels.

By using the output of the divider 100013 to replace the center pixel of the fetched pixel, a video signal with reduced noise components can be generated. In addition, the noise component can be reduced.

[0013]

However, such a noise reduction device described in Japanese Patent Application Laid-Open No. 6-225178 (hereinafter, referred to as a "motion detection frame cyclic noise reduction device") and Japanese Patent Application Laid-Open No. In the case where the noise reduction device described in Japanese Patent Application Laid-Open No. 6-86104 (hereinafter, referred to as an “area-selection-type noise reduction device”) is separately provided in the video signal processing circuit, the noise reduction device for holding peripheral pixels is provided. There is a problem in that two systems of storage means such as a register or a memory are required, and the circuit scale becomes large.

Further, in the noise reduction device (area-selection type noise reduction device) described in JP-A-6-86104, an edge component equal to or less than a threshold value is regarded as a correlated pixel. Ingredients may be lost.

In the case of a moving subject, even if the edge component of the image is slightly lost, the user is not bothered by the fact that the edge is originally rounded (unclear). However, when the edge component of the stationary portion is lost, a sense of incongruity may be given, and there is a problem that image quality is deteriorated.

The present invention has been made in order to solve such a problem, and a motion detection frame cyclic noise reduction device and an area selection type noise reduction device are optimally configured without increasing the circuit scale. In addition, the noise reduction is mainly performed by a motion detection frame cyclic noise reduction device for a still image, and the noise is mainly reduced by an area selection type noise reduction device for a moving image. An object of the present invention is to provide an optimum noise reduction device according to the movement of an input video signal by controlling the noise reduction device.

[0017]

According to a first aspect of the present invention, there is provided a noise reduction apparatus for reducing a noise in accordance with a motion component of a video signal.
An area-type noise reduction device that reduces a noise component of a video signal while minimizing deterioration of an image edge component, and a selector unit that switches between the output of the motion detection frame cyclic noise reduction device and the output of the area-type noise reduction device. Have.

With this configuration, when the video signal is a still image, the noise is reduced by the motion detection frame cyclic noise reduction device, and when the input video signal is a moving image, the noise is reduced by the area selection type noise reduction device. Thus, noise reduction according to the movement of the input video signal can be performed.

According to a second aspect of the present invention, there is provided a noise reduction apparatus for cyclically detecting motion in a frame which reduces noise in accordance with a motion component of a video signal. An area-type noise reduction device that reduces a noise component of a video signal and a weighting unit that weights motion detection information are provided.

With this configuration, by performing weighting according to the amount of motion of the video signal, noise reduction is performed by the motion detection frame cyclic noise reduction device when the amount of motion of the video signal is small, and when the amount of motion is large, By performing weighted averaging so that noise is reduced by the area-type noise reduction device, noise reduction according to the motion of the video signal can be performed.

According to a third aspect of the present invention, there is provided a noise reduction apparatus for reducing the noise in accordance with a motion component of a video signal. An area-type noise reduction device for reducing a noise component of a video signal; and a motion threshold value control means for controlling a threshold value for determining a correlation between a central pixel and a peripheral pixel in the area-type noise reduction device. are doing.

With this configuration, the threshold value for determining the correlation between the central pixel and the peripheral pixels in the area-type noise reduction device can be controlled in accordance with the amount of motion of the video signal. Appropriate noise reduction according to the above.

According to a fourth aspect of the present invention, there is provided a noise reduction apparatus for cyclically detecting a motion, which reduces noise in accordance with a motion component of a video signal. An area-type noise reduction device that reduces a noise component of a video signal, and a gain adjustment device that adjusts a gain of the video signal so that the video signal can be easily viewed.
It has a GC device, a gain amount calculating means for calculating an AGC gain amount, and a gain threshold value controlling means.

With this configuration, the amount of motion of the video signal and A
Since the threshold value for determining the correlation between the central pixel and the peripheral pixel in the area type noise reduction device can be controlled according to the gain amount of the GC device, even if the gain amount is increased in the AGC device, S / S Appropriate noise reduction according to the movement of the input video signal can be performed while suppressing deterioration of N.

A noise reduction device according to a fifth aspect of the present invention is an area-type noise reduction device for reducing the noise component of a video signal while minimizing the deterioration of the edge component of an image, and for making the video signal easier to see. An AGC device for adjusting the gain of a video signal, a gain amount calculating means for calculating an AGC gain amount, and a gain threshold value controlling means.

With this configuration, the threshold value for determining the correlation between the central pixel and the peripheral pixels in the area type noise reduction device can be controlled according to the gain amount of the AGC device. Even when the amount is increased, appropriate noise reduction can be performed while suppressing the deterioration of the S / N of the video signal.

According to a sixth aspect of the present invention, there is provided a noise reduction apparatus for cyclically detecting a motion which reduces noise in accordance with a motion component of a video signal. An area-type noise reduction device for reducing a noise component of a video signal and a luminance level detection unit for the video signal are provided.

With this configuration, a threshold for judging the amount of recirculation of the motion detection frame recursive noise reduction device and the correlation between the central pixel and the peripheral pixel in the area type noise reduction device in accordance with the luminance level of the video signal. Can be controlled, so that S is affected by gamma correction or the like at low brightness.
/ N can be improved, and appropriate noise reduction according to the motion of the video signal can be performed.

According to a seventh aspect of the present invention, there is provided a noise reduction apparatus for repetition of a motion detection frame which reduces noise in accordance with a motion component of a video signal, or a video signal while minimizing deterioration of an edge component of an image. An area type noise reduction device for reducing a noise component of a signal and a luminance level detecting means for detecting a luminance level of a video signal are provided.

According to this configuration, the threshold for judging the amount of circulation of the motion detection frame cyclic noise reduction apparatus or the correlation between the center pixel and the peripheral pixels in the area type noise reduction apparatus according to the luminance level of the video signal. Since the value can be controlled, it is possible to improve the deterioration of the S / N of the video signal due to the influence of gamma correction or the like at the time of low luminance, and to perform appropriate noise reduction according to the motion of the video signal.

The noise reduction apparatus according to the eighth aspect of the present invention includes a motion detection frame cyclic noise reduction apparatus that reduces noise according to a motion component of a video signal, and a noise reduction apparatus that minimizes deterioration of edge components of an image. An area-type noise reduction device that reduces a noise component of a video signal, and a gain adjustment device that adjusts a gain of the video signal so that the video signal can be easily viewed.
It has a GC device, a gain amount calculating means for calculating an AGC gain amount, and a luminance level detecting means for detecting a luminance level of a video signal.

With this configuration, the amount of repetition of the motion detection frame recursive noise reduction device is controlled in accordance with the luminance level of the video signal and the amount of gain of the AGC device. Can be controlled, so that the S / N deterioration when the gain amount of the AGC device is large and the S / N deterioration in a low luminance portion due to gamma correction or the like can be improved. Further, appropriate noise reduction according to the movement of the video signal can be performed.

A noise reduction apparatus according to a ninth aspect of the present invention includes a motion detection frame cyclic noise reduction apparatus for reducing noise in accordance with a motion component of a video signal, and a video signal while minimizing deterioration of an edge component of an image. Area type noise reduction device for reducing noise component of signal and AG for adjusting gain of video signal to make video signal easier to see
It has a C device, a gain amount calculating means for calculating an AGC gain amount, and a luminance level detecting means for detecting a luminance level of a video signal.

With this configuration, the amount of recirculation of the motion detection frame cyclic noise reduction device is controlled according to the luminance level of the video signal, and the area type noise reduction device is controlled according to the luminance level of the video signal and the gain amount of the AGC device. It is possible to control the threshold value for determining the correlation between the central pixel and the peripheral pixels in. For this reason,
It is possible to improve the S / N deterioration when the gain amount of the AGC device is large and the S / N deterioration in a low luminance portion due to gamma correction and the like, and further reduce the noise according to the motion of the video signal.

According to a tenth aspect of the present invention, there is provided a noise reduction apparatus for cyclically detecting a frame which reduces noise in accordance with a motion component of a video signal, and a video image while minimizing deterioration of an edge component of an image. Area type noise reduction device for reducing noise component of signal and AG for adjusting gain of video signal to make video signal easier to see
It has a C device, a gain amount calculating means for calculating an AGC gain amount, and a luminance level detecting means for detecting a luminance level of a video signal.

With this configuration, the amount of repetition of the motion detection frame cyclic noise reduction device is controlled according to the gain amount of the AGC device, and the area type noise reduction device is controlled according to the gain amount of the AGC device and the luminance level of the video signal. It is possible to control the threshold value for determining the correlation between the central pixel and the peripheral pixels in. For this reason,
It is possible to improve the S / N deterioration when the gain amount of the AGC device is large and the S / N deterioration in a low luminance portion due to gamma correction and the like, and further reduce the noise according to the motion of the video signal.

A noise reduction apparatus according to an eleventh aspect of the present invention includes a motion detection frame cyclic noise reduction apparatus for reducing noise according to a motion component of a video signal of a video signal, and a noise reduction apparatus for reducing a noise component of a video signal. A two-dimensional filter device, an AGC device that adjusts the gain of the video signal so that the video signal can be easily viewed, a gain amount calculation unit that calculates an AGC gain amount, and a brightness level detection unit that detects a brightness level of the video signal. Have.

According to this configuration, the amount of repetition of the motion detection frame recursive noise reduction device can be controlled in accordance with the gain amount of the AGC device or the luminance level of the video signal.
The characteristics of the dimensional filter device can be controlled according to the gain amount of the AGC device or the luminance level of the video signal. Therefore, it is possible to improve the S / N deterioration when the gain amount of the AGC device is large and the S / N deterioration in the low luminance portion due to the gamma correction and the like, and to further reduce the noise according to the motion of the video signal.

An image processing apparatus according to a twelfth aspect of the present invention is an image processing apparatus including the noise reduction apparatus according to any one of the first to eleventh aspects, wherein the accuracy of the image processing apparatus is reduced with the influence of a noise component of a video signal. Image processing device with high image quality.

An imaging apparatus according to a thirteenth aspect of the present invention is an imaging apparatus including the noise reduction apparatus according to any one of the first to eleventh aspects, wherein the S / N ratio of the image signal reduced by the noise component is reduced. A good and good imaging device can be configured.

An image processing apparatus according to a fourteenth aspect of the present invention is an image processing apparatus including the imaging apparatus according to the thirteenth aspect, and includes a highly accurate image processing apparatus capable of reducing the influence of a noise component of a video signal. Can be configured.

A noise reduction method according to a fifteenth aspect of the present invention is characterized in that a different noise reduction method is switched and used according to the movement of an image, and the noise reduction method is switched according to the movement of an image. Can be used.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. Note that the configuration of the motion detection frame cyclic noise reduction apparatus 1010 follows the noise reduction apparatus of FIG. 9 which is a conventional technique, and the configuration of the area selection type noise reduction apparatus 1020 is that of FIG. It follows the noise reduction device.

(First Embodiment) FIG. 1 is a block diagram showing the configuration of a noise reduction apparatus according to a first embodiment of the present invention. The conventional noise detection frame cyclic noise shown in FIG. For the reduction device 1010, the motion determination circuit output (K) 1011 is input to the motion detection means 1009, and the output is output as a control signal of the selector means 1030. The configuration is such that the output of the noise reduction device is input and the output of the conventional area selection type noise reduction device 1020 shown in FIG. 10 is input to the B input.

With this configuration, the selector unit 1030 can control the output based on the motion detection information of the motion detection frame cyclic noise reduction apparatus 1010.

In this case, the motion detection means 1040 provides a threshold value for presuming motion to the motion determination output (K) 1011.
If the motion determination circuit output (K) 1011 is larger than the threshold value 10111, the input video signal 100
0 is determined as a still image, and conversely, motion determination output (K) 1011
Is smaller than the threshold 10111, the input video signal 1000
Is determined to be a moving image.

If the motion detecting means 1009 determines that the moving picture is a moving picture, the video signal (A input of the selector means 1030) whose noise has been reduced by the area selection type noise reduction apparatus 1020 is selected by the selector means.
In the case of a 1030 output, in the case of a still image, a motion is performed based on a threshold value 10111 so that the video signal (B input of the selector means 1030) whose noise has been reduced by the motion detection frame cyclic noise reduction apparatus 1010 is output to the selector means 1030. By controlling the output of the detecting means 1009, the output of the selector means 1030 is controlled.

As a result, in the case of a moving image, when the amount of repetition is increased by using only the motion detection frame recursive noise reduction device 1010, a residual image is more likely to appear, so that the noise component in the moving image is difficult to reduce. However, the noise component can be improved by using the area selection type noise reduction device 1020. In the case of a still image, the noise component can be sufficiently reduced by increasing the amount of repetition in the motion detection frame recursive noise reduction device 1010 without noise reduction by the area selection type noise reduction device 1020. It is not necessary to perform signal processing of the mold noise reduction device 1020, and the edge component of the stationary portion can be held. Therefore, it is possible to obtain an output video signal 1031 in which noise is appropriately reduced according to the movement of the input video signal 1000.

Also, for the motion information of the input video signal 1000, the use of the motion detection information in the motion detection frame recursive noise reduction apparatus 1010 eliminates the need for providing a new motion determination circuit, so that the circuit scale is greatly increased. Can be prevented.

Further, peripheral pixel storage means for the two-dimensional LPF (low-pass filter) 1004 in FIG. 9 in the motion detection frame cyclic noise reduction apparatus 1010 and peripheral pixel capture circuit in FIG. 10 in the area selection type noise reduction apparatus 1020 By sharing the storage means of the peripheral pixels for 10001, the circuit scale can be reduced.

Therefore, it is possible to appropriately reduce noise included in a video signal regardless of a moving image or a still image without an extreme increase in circuit scale.

If an imaging device is configured using the output video signal 1031, an imaging device with reduced noise components can be configured. Also, for example, even if an image processing apparatus such as an image recognition apparatus is configured, image processing such as image recognition can be performed with a video signal in which a noise component is reduced. A processing device can be configured.

(Second Embodiment) FIG. 2 is a block diagram showing a configuration of a noise reduction device according to a second embodiment of the present invention. The noise reduction device shown in FIG. On the other hand, multipliers 1040 and 1041, an adder 1042, and weighting means 10121 are provided, and selector means 1030 and motion detection means 1009 are omitted. In the apparatus 1010, a motion determination circuit output (K) 1011 is configured to be output to a multiplier (α) 1041 and a multiplier (1-α) 1040. Means shall have equivalent functions.

The weighting means 10121 weights the motion determination circuit output (K) 1011 in accordance with the output (K) 1011 to generate a weighted output (α) 10122. For example, weighting such as weighting output (α) 10122 = {motion detection determination circuit output (K) 1011} ² is performed. When the input video signal 1000 is a moving image, the output (K) 1011 of the motion detection determination circuit is smaller than that of a still image. Therefore, the noise of the moving image is reduced by the area-type noise reduction device 1020.

Thus, when the input video signal 1000 is a moving image, the after-image appears remarkably if the amount of repetition is increased only by the motion detection frame recursive noise reduction device 1010, so that noise in a moving image for which it is difficult to reduce noise is difficult. Ingredients
By increasing the weight of the noise reduction processing in the area selection type noise reduction device 1020, the noise component can be appropriately reduced.

When the input video signal 1000 is a still image, the weight of the noise reduction processing in the area selection type noise reduction device 1020 is reduced, and the weight of the motion detection frame cyclic noise reduction device 1010 is increased. The components can be appropriately reduced. Therefore, the input video signal
An output video signal 1043 in which noise components included in 1000 are appropriately reduced in accordance with the motion of the video signal can be generated.

As for the motion information of the input video signal 1000, the use of the motion detection information in the motion detection frame recursive noise reduction apparatus 1010 eliminates the need for providing a new motion determination circuit, so that the circuit size is greatly increased. Can be prevented.

Further, peripheral pixel storage means for the two-dimensional LPF (low-pass filter) 1004 shown in FIG. 9 in the motion detection frame cyclic noise reduction apparatus 1010 and peripheral pixel capture circuit shown in FIG. 10 in the area selection type noise reduction apparatus 1020. By sharing the storage means of the peripheral pixels for 10001, the circuit scale can be reduced.

Therefore, it is possible to appropriately reduce noise included in a video signal regardless of a moving image or a still image without an extreme increase in circuit scale.

It should be noted that if an imaging device is configured using the output video signal 1043, an imaging device with reduced noise components can be configured, and even if an image processing device is configured, the accuracy with reduced noise components can be improved. A good image processing device can be configured.

(Third Embodiment) FIG. 3 is a block diagram showing a configuration of a noise reduction device according to a third embodiment of the present invention. In the noise reduction device shown in the first embodiment, FIG. On the other hand, a motion threshold value control means 1012 is provided, and a motion detection means 1009 and a selector means 1030 are eliminated, and the motion threshold value control means 1012 is different from the conventional motion detection frame cyclic noise reduction apparatus 1010 shown in FIG. The determination circuit output (K) 1011 is configured to be output to the movement threshold value control means 1012, and other components having the same names and the same numbers have the same functions.

Thus, the motion threshold value control means of FIG.
At 1012, based on the motion determination circuit output (K) 1011 including the motion detection information of the input video signal 1000, it is determined whether or not there is a correlation between the peripheral pixel and the central pixel of the area selection type noise reduction device 1020. The threshold 100010 of the area selection type noise reduction device 1020 shown in FIG.

For example, if the input video signal 1000 is a moving image, the motion detection frame recursive noise reduction apparatus 1010 produces an afterimage, so that effective noise reduction cannot be performed. Therefore, in order to reduce the afterimage and reduce noise even if the input video signal 1000 is a moving image, and to increase the noise reduction effect of the area selection type noise reduction device 1020 when the input video signal 1000 is a moving image, FIG. The threshold value 100010 of the area selection type noise reduction device 1020 shown in the figure is increased, and control is performed so that the ratio of pixels having a correlation between the center pixel and the peripheral pixels is increased.

Thus, the area selection type noise reduction device
Since the ratio of the center pixel 1020 replaced with the average value of only the correlated pixels increases, the noise component can be reduced. Also, since the input video signal 1000 is a moving image, the sharpness of the edges of the image is somewhat small, and even if the image is deteriorated, there is little discomfort. The motion detection frame cyclic noise reduction apparatus 1010 can reduce the noise with less discomfort than the conventional noise reduction apparatus in which an afterimage occurs by increasing the amount of recursion.

If the input video signal 1000 is a still image, the threshold 100010 of the area selection type noise reduction apparatus 1020 shown in FIG. Is controlled to be small. That is, the motion threshold control unit 1012 is controlled so as to reduce the proportion of pixels having a correlation between the center pixel and the peripheral pixels.

Thus, the area selection type noise reduction device
Since the ratio of the center pixel 1020 to be replaced by the average value of only the correlated pixels decreases, the ratio of maintaining the edge increases. Also, since the noise component has been sufficiently reduced by the motion detection frame cyclic noise reduction device 1010,
An output video signal 1021 with appropriately reduced noise components can be obtained.

Therefore, optimal noise reduction according to the movement of the input video signal 1000 can be performed without an extreme increase in circuit scale.

If an imaging device is configured using the output video signal 1021, an imaging device with reduced noise components can be configured. Further, even if an image processing device is configured, the accuracy with reduced noise components can be improved. A good image processing device can be configured.

(Fourth Embodiment) FIG. 4A is a diagram showing a configuration of a noise reduction device according to a fourth embodiment of the present invention. On the other hand, an AGC device 1050 and a gain amount calculating means 1051 are provided, and a gain threshold control means 1052 is provided instead of the motion threshold control means 1012.
The threshold value 100010 of the conventional area selection type noise reduction device 1020 shown in FIG. 10 is linked to the gain amount 10511 calculated by the gain amount calculation means 1051 and the motion detection circuit output (K) 1011 Is configured to be controlled in accordance with It is assumed that other components having the same name and the same number have the same functions.

The AGC device 1050 is generally used to apply a gain to the video signal 1000 when the luminance is low to make it easy to see a video in a dark part. However, when the gain amount of the AGC device 1050 is large, the gain is applied even to the noise component included in the input video signal 1000, so that the S / N
Easily deteriorates.

Therefore, the threshold value 100010 of the area selection type noise reduction device 1020 for judging whether or not there is a correlation between the peripheral pixel and the center pixel shown in FIG. 10 according to the gain amount 10511 of the output of the AGC device 1050. If controlled, appropriate noise reduction can be achieved. That is, first, the AGC device
The gain amount 10511 of 1050 is calculated by the gain amount calculation means 1051, and this gain amount 10511 is calculated by the gain threshold value control means 1051.
Output to 2.

Next, the gain threshold value control means 1052
Based on the motion detection circuit output (K) 1011 and the gain amount 10511 of the AGC device 1050, it is determined whether or not there is a correlation between the peripheral pixel and the center pixel of the area selection type noise reduction device 1020 shown in FIG. Control the threshold 100010.

The gain threshold value control means 1052 calculates the peripheral pixel of the area selection type noise reduction device 1020 shown in FIG. 10 according to the gain amount 10511 of the AGC device 1050 and the motion detection circuit output (K) 1011 as follows. The threshold 100010 for determining whether or not there is a correlation between the threshold value and the center pixel is weighted and controlled. For example, if the gain amount 10511 is large and the video is
010 = 10 Threshold 1 if gain amount 10511 is large and still image
00010 = 6 If the gain amount 10511 is small and a moving image, the threshold value 100
010 = 4 Threshold 1 if gain amount 10511 is small and still image
Control is performed with a weight such as 00010 = 2.

As described above, by controlling the threshold value 100010 of the area selection type noise reduction apparatus 1020 by using the two elements of the gain amount 10511 and the motion detection circuit output (K) 1011, the effect of noise reduction can be improved. Can control. Therefore, it is possible to perform appropriate noise reduction in accordance with the gain amount of the AGC device 1050 and the amount of motion with respect to the input video signal 1000, and thus it is possible to obtain an output video signal 1021 with little afterimage and a good S / N.

Here, the gain amount of the AGC device 1050
In accordance with 10511 and the motion detection circuit output (K) 1011 for the input video signal 1000, it is determined whether or not there is a correlation between the peripheral pixel and the central pixel of the area selection type noise reduction apparatus 1020 shown in FIG. Although the threshold value 100010 was controlled,
By controlling the threshold value 100010 of the area-selective noise reduction device 1020 shown in FIG. 10 with only the gain amount 10511 of the AGC device 1050 as shown in FIG. You can also get a signal. In that case, the gain threshold control means 1052
1, a threshold 100010 for determining whether or not there is a correlation between a peripheral pixel and a central pixel of the area selection type noise reduction apparatus 1020 shown in FIG.
The threshold may be controlled by weighting according to 511.
For example, if the gain amount 10511 is large, the threshold value 100010 = 10. If the gain amount 10511 is small, the threshold value 100010 = 2.

As described above, using only the gain amount 10511, the threshold value 100010 of the area selection type noise reduction apparatus 1020 is used.
Can also reduce the noise of the video signal.

Therefore, the AGC device for the video signal 1000
Since appropriate noise reduction according to the gain amount of 1050 can be performed, an output video signal 1021 with a low S / N and a low S / N can be obtained not only for a normal video signal but also for a video signal at low luminance. be able to.

Therefore, it is possible to perform optimal noise reduction according to the movement of the input video signal 1000 without extremely increasing the circuit scale.

If an image pickup apparatus is constructed using this output video signal 1021, an image pickup apparatus with reduced noise components can be constructed, and even if an image processing apparatus is constructed, the accuracy of noise components reduced is reduced. A good image processing device can be configured.

(Fifth Embodiment) FIG. 5A is a diagram showing a configuration of a noise reduction device according to a fifth embodiment of the present invention, which is shown in FIG. 3 of the third embodiment. The noise level reducing means is provided with a luminance level detecting means 1060, as shown in FIG.
A brightness circulation amount control means 1070 is provided inside 1010, and a brightness threshold value control means 1080 is provided instead of the movement threshold value control means 1012. It is assumed that other components having the same name and the same number have the same functions.

In general, the S / N of a low-luminance video signal tends to deteriorate due to the effects of gamma correction, AGC processing, and the like. Therefore, first, the brightness level of the input video signal 1000 is detected by the brightness level detection means 1060, and the detected brightness level 1061 is used as the brightness threshold value control means 1080 and the brightness circulation amount control means 10 shown in FIG.
Output to 70.

The luminance recursive amount control means 1070 of FIG. 6 controls the recursive amount (K ') 10701 according to the motion judging circuit output (K) 1011 output from the motion judging circuit 1003 and the luminance level 1061.

For example, weighting is performed as follows to control the amount of circulation (K ') 10701. That is, when the image is a still image and the luminance level 1061 is low, the amount of circulation (K ') 10701 = 0.8. When the image is a still image and the luminance level 1061 is high, the amount of circulation (K') 10701 = 0.6. If the value is low, the amount of recursion (K ') 10701 = 0.4. If the luminance level 1061 is high, the revolving amount (K') 10701 = 0.3 (0 <= recurring amount (K ') 10701 <1). The amount of circulation (K ') 10701 is controlled by giving a weight.

As a result, the noise reduction apparatus 1010 for the motion detection frame cyclic type can perform noise reduction in accordance with the output (K) 1011 of the motion determination circuit and the luminance level 1061.

The brightness threshold value control means 1080 controls the area selection type noise reduction device 1020 according to the brightness level 1061.
The threshold value 100010 for determining whether or not there is a correlation between the peripheral pixel and the central pixel shown in FIG. 10 is controlled.

For example, when the luminance level 1061 is low,
Noise is reduced by increasing the proportion of pixels regarded as having a correlation, and when the luminance level 1061 is high, the proportion of pixels regarded as having a correlation is reduced, giving priority to image edges over the noise reduction effect. The threshold 100010 for determining whether or not there is a correlation between the peripheral pixel and the central pixel of the area selection type noise reduction device 1020 shown in FIG. 10 is weighted according to the luminance level 1061 so as to keep sharpness. Control. For example, the threshold 100010 is controlled as follows. That is, when the luminance level 1061 is low, the threshold value 100010 = 8. When the luminance level 1061 is high, the threshold value 100010 = 3.

As described above, in accordance with the luminance level 1061 of the input video signal 1000 and the motion determination circuit output (K) 1011 for the video signal 1000, the amount of recursion (K ') 10701 of the recursive noise reduction apparatus 1010 for motion detection frames. By increasing the number of pixels, it is possible to obtain a video signal with an improved S / N, and determine whether or not there is a correlation with the center pixel of the area selection type noise reduction device 1020 shown in FIG. By controlling the threshold value 100010, it is possible to improve the visibility of noise components due to the effects of gamma correction processing, AGC, and the like in the case of a dark subject, and to further reduce deterioration in sharpness of image edges. Can be.

As a result, since the noise component can be appropriately reduced based on the luminance level 1061 of the input video signal 1000 and the output (K) 1011 of the motion judgment circuit, the S / N ratio can be improved while keeping the edges of the image sharp. An output video signal 1021 with few afterimages can be obtained.

It is to be noted that here, a motion detection frame cyclic noise reduction apparatus 1010 and an area selection type noise reduction apparatus 1020
Although the example in which the control according to the luminance level 1061 is performed is shown for both of them, the output video signal 1021 in which the noise component is reduced can be obtained by performing the control according to the luminance level 1061 independently of each other.

For example, as shown in FIG.
The noise of the video signal 1000 can also be reduced by controlling only the cyclic amount (K ′) 10701 of the motion frame cyclic noise reduction unit 1010 according to the luminance level 1061 of 1000.

In this case, for example, in the case of a still image and the luminance level 1061 is low, the amount of circulation (K ') 10701 = 0.9. In the case of a still image and the luminance level 1061 is high, the amount of circulation (K') 10701. = 0.7 Moving amount (K ′) 10701 = 0.5 when moving image and low luminance level 1061 = 0.5 Moving amount (K ′) 10701 = 0.4 (0 ≦ circulating amount (K ′) when moving image and high luminance level 1061 ) 10701 ≦ 1) The weight is controlled as follows.

As a result, the noise reduction apparatus 1010 in the motion detection frame cyclic type can reduce noise according to the output (K) 1011 of the motion determination circuit and the luminance level 1061. Further, the noise can be further reduced by the area selection type noise reduction device 1020 with respect to the output 1010 of the noise detection device of the recursive motion detection frame whose noise has been reduced. Therefore, in the case of a dark subject, gamma correction processing, AGC, etc. Makes it possible to improve the noise component from being noticeable, and to obtain a good video signal.

Also, as shown in FIG. 5C, only the area selection type noise reduction device 1020 is set to the threshold value 100010 of the area selection type noise reduction device 1020 shown in FIG. 10 according to the luminance level 1061 of the input video signal 1000. Output video signal 1021 with reduced noise components at low brightness
Can be obtained.

In this case, the luminance threshold control means 1080
Then, the threshold 100010 for determining whether or not there is a correlation between the peripheral pixel and the central pixel shown in FIG. 10 of the area selection type noise reduction apparatus 1020 is controlled in accordance with the luminance level 1061.

For example, when the luminance level 1061 is low,
When the luminance level 1061 is high, the proportion of pixels regarded as having a correlation is increased to reduce noise, and when the luminance level 1061 is high, the proportion of pixels regarded as having a correlation is decreased, and the edge of the image is prioritized over the noise reduction effect. The threshold 100010 for determining whether or not there is a correlation between the peripheral pixel and the central pixel of the area selection type noise reduction device 1020 shown in FIG. 10 is weighted according to the luminance level 1061 so as to keep sharpness. Control. For example, the threshold 100010 is controlled as follows. That is, when the luminance level 1061 is low, the threshold value 100010 = 9. When the luminance level 1061 is high, the threshold value 100010 = 3.

Therefore, in the case of a dark subject, it is possible to improve that the noise component becomes conspicuous due to the influence of the gamma correction processing, the AGC, and the like, and it is possible to reduce the deterioration of the sharpness of the image edge.

Further, as shown in FIG. 5D, a threshold 100010 for determining whether or not there is a correlation between a peripheral pixel and a central pixel in the area selection type noise reduction apparatus 1020 of FIG. Detection frame cyclic noise reduction device 10
By controlling the motion of the video signal 1000 and the luminance level 1061 using the motion judgment circuit output (K) 1011 generated in the S 10, the S / N ratio is maintained while keeping the edge components of the image sharp.
And an output video signal 1021 with less afterimage can be obtained.

In this case, according to the luminance level 1061 and the motion judgment circuit output (K) 1011, for example, when a moving image and the luminance level 1061 are low, the threshold 1000
10 = 7 If the video and brightness level 1061 are low, the threshold is 1000
10 = 6 When the still image and the luminance level 1061 are high, the threshold 10
0010 = 3 When the still image and the luminance level 1061 are high, the threshold 10
Control is performed by performing weighting such as 0010 = 2.

As described above, by controlling the threshold value 100010 for judging whether or not there is a correlation between a peripheral pixel and a central pixel in the area selection type noise reduction apparatus 1020 of FIG.
According to the amount of motion of the video signal 1000 and the luminance level 1061, in the case of a dark subject, it can be improved that the noise component becomes more conspicuous due to the effects of gamma correction processing, AGC, etc., and in a still image, the edge component of the image is sharpened. , It is possible to obtain an output video signal 1021 with a good S / N ratio and little afterimage even in a moving image.

Further, if an imaging device is configured using the output video signal 1021, an imaging device with reduced noise components can be configured, and even if an image processing device is configured, the accuracy with reduced noise components can be improved. A good image processing device can be configured.

(Sixth Embodiment) FIG. 7A is a diagram showing a configuration of a noise reduction device according to a sixth embodiment of the present invention, and FIG. 5A of the fifth embodiment. 8), an AGC device 1050 and a gain amount calculating means 1051 are provided, and as shown in FIG.
71 is provided, and a threshold control means 1090 is provided in place of the luminance threshold control means 1080, and other constituent elements having the same names and the same numbers have the same functions.

In general, the S / N of a low-luminance video signal tends to deteriorate due to the effects of AGC processing and gamma correction processing. Therefore, first, the input video signal 1000
Of the luminance level 1061, and furthermore, a gain amount calculating means.
In 1051, a gain amount 10511 in the AGC device 1050 is calculated.

The detected luminance level 1061 and gain 10
511 is output to the cyclic amount control means 1071 shown in FIG. 8 provided inside the motion detection frame cyclic noise reduction apparatus 1010 shown in FIG.

The recursive amount control means 1071 of FIG. 8 controls the recursive amount (K ″) 10711 in accordance with the output (K) 1011 of the motion judging circuit 1003, the luminance level 1061 and the gain amount 10511.

For example, the amount of recursion (K ″) 10711 is controlled by weighting as follows: That is, when the image is a still image and the luminance level is low and the amount of gain is large, the amount of recursion (K ″) 10711 = 0.9 In the case of a still image and the luminance level is low and the gain amount is small, the cyclic amount (K ″) 10711 = 0.8. In the case of a still image and the luminance level is high and the gain amount is large, the cyclic amount (K ″) 10711 = 0.7 When the image is a still image and the luminance level is high and the gain amount is small, the amount of circulation (K ″) 10711 = 0.6. When the moving image is a moving image and the luminance level is low and the amount of gain is large, the amount of circulation (K ″) 10711 = 0.5. In the case of a moving image, when the luminance level is low and the gain amount is small, the amount of circulation (K ″) 10711 = 0.4. In the case of a moving image, when the luminance level is high and the amount of gain is large, the amount of circulation (K ″) 10711 = 0.3. And when the brightness level is high and the gain amount is small Cyclic amount (K ") 10711 = 0.2 (0 ≦ cyclic amount (K") 10711 ≦ 1) to have a weight as that controlled.

Thus, in the motion detection frame cyclic noise reduction apparatus 1010, the output (K) 1011 of the motion judgment circuit, the luminance level 1061, and the AGC apparatus 1050 for the input video signal 1000 are obtained.
The noise can be reduced by using three elements according to the gain amount 10511 of the first embodiment.

Next, in the threshold control means 1090, A
According to the gain amount 10511 of the GC device 1050 and the luminance level 1061, the threshold 100010 for judging whether or not there is a correlation between the peripheral pixel and the central pixel shown in the area selection type noise reduction device 1020 of FIG. Control.

For example, when the luminance level 1061 is low,
Reduce the noise by increasing the percentage of pixels considered to be correlated and, if the luminance level 1061 is high, reduce the percentage of pixels considered to be correlated to keep the edges of the image sharper than noise reduction Weighting is performed as follows, and the threshold 100010 of the area selection type noise reduction device 1020
Control. That is, when the luminance level 1061 is low and the gain amount 10511 is large, the threshold value 100010 = 8. When the luminance level 1061 is low and the gain amount 10511 is small, the threshold value 100010 = 6. Is large, the threshold value 100010 = 3. When the luminance level 1061 is high and the gain amount 10511 is small, weighting is performed such that the threshold value 100010 = 2.

As described above, in accordance with the luminance level 1061 and the gain amount 10511 of the input video signal 1000, the amount of recursion (K ″) 10711 of the recursive noise reduction apparatus 1010 for motion detection frames is increased, and the area shown in FIG. Selective noise reduction device
Since the threshold value 100010 of 1020 can be controlled, it is possible to obtain a video signal with a good S / N and few afterimages in accordance with the movement of the video signal 1000 while keeping the edges of the image sharp.

Here, a motion detection frame cyclic noise reduction apparatus 1010 and an area selection type noise reduction apparatus 1020
Brightness level 1061 and the gain of the AGC device 1050
Although the example in which the control according to 10511 is performed is shown, the brightness level 1061 or the gain amount 10
Even if control according to 511 is performed, a video signal with reduced noise components can be obtained.

For example, as shown in FIG. 7B, the recursive amount control means 1071 of the motion detection frame recursive noise reduction apparatus 1010 is controlled only by the luminance level.

In this case, as shown in FIG. 6, the cyclic amount control means 1071 determines the cyclic amount (K ″) 10711 according to the motion determining circuit output (K) 1011 output from the motion determining circuit 1003 and the luminance level 1061 of the video signal. For example, the amount of circulation (K ″) 10711 is controlled by assigning weights as follows. That is, if the image is a still image and the luminance level is low, the amount of circulation (K ″) 10711 = 0.9. If the image is a still image, and if the luminance level is high, the amount of circulation (K ″) 10711 = 0.7. Is low (K ″)
10711 = 0.5 The amount of circulation (K ") when the video is moving and the brightness level is high
The weighting is controlled as follows: 10711 = 0.3 (0 ≦ tour amount (K ″) 10711 ≦ 1).

Thus, the motion detection frame cyclic noise reduction apparatus 1010 can perform noise reduction using three elements according to the motion determination circuit output (K) 1011 and the luminance level for the video signal 1000.

Next, in the threshold control means 1090 of FIG. 7B, depending on the gain amount 10511 of the AGC device 1050 and the luminance level 1061, the peripheral pixels shown in the area selection type noise reduction device 1020 of FIG. And a threshold value 100010 for determining whether or not there is a correlation with the center pixel.

For example, when the luminance level 1061 is low,
Reduce the noise by increasing the proportion of pixels considered to be correlated and, if the luminance level 1061 is high, reduce the proportion of pixels considered to be correlated to keep the edges of the image sharper than noise reduction The threshold 100010 of the area selection type noise reduction apparatus 1020 is controlled by giving a weight to the threshold 100010 as described below. That is, when the luminance level 1061 is low and the gain amount 10511 is large, the threshold value 100010 = 8. When the luminance level 1061 is low and the gain amount 10511 is small, the threshold value 100010 = 6. Is large, the threshold value 100010 = 3. When the luminance level 1061 is high and the gain amount 10511 is small, weighting is applied such as the threshold value 100010 = 2.

As described above, the luminance level of the video signal 1000
According to 1061, motion detection frame cyclic noise reduction device
The amount of recirculation (K ″) 10711 of 1010 is controlled, and the threshold 100010 of the area selection type noise reduction device 1020 shown in FIG.
, A good video signal according to the movement of the video signal 1000 can be obtained.

As shown in FIG. 7C, the AGC device
The recursive amount control means 1071 of the motion detection frame recursive noise reduction device 1010 may be controlled only by the gain amount 10511 of 1050.

In this case, the traveling amount control means 1071 compares the output (K) 1011 of the motion judgment circuit 1003 output with the AGC
The amount of circulation (K ″) 10711 according to the amount of gain 10511 of the device 1050
Control.

Further, a motion detection circuit output 1011 generated inside the motion detection frame cyclic noise reduction apparatus 1010 is output to the threshold control means 1090. The output of the threshold control means 1090 controls the threshold 100010 for determining whether or not there is a correlation with the center pixel of the area selection type noise reduction device 1020. A video signal with a good S / N and few afterimages can be obtained while maintaining sharp edges.

The threshold control means 1090 includes a motion judgment circuit output (K) 1011, a video signal luminance level 1061, and a gain
The threshold 100010 of the area selection noise reduction device of FIG. For example, weighting is performed as follows, and the threshold 10
0010 is controlled. That is, in the case of a moving image, when the luminance level 1061 is low and the gain amount 10511 is large, the threshold value 100010 = 9. In the case of a moving image and when the luminance level 1061 is low and the gain amount 10511 is small, the threshold value 100010 = 9. 8 Threshold value 100010 = 7 when the video is a moving image, the luminance level 1061 is high, and the gain amount 10511 is large, and the threshold value 100010 = 6 when the moving image is a moving image, the luminance level 1061 is high, and the gain amount 10511 is small. Image, the luminance level 1061 is low, and the gain amount 10511
Is large, the threshold value 100010 = 5 is a still image, the luminance level 1061 is low, and the gain amount 10511
Is small, the threshold value is 100010 = 4, the luminance level 1061 is high, and the gain amount 10511 is high.
Is large, the threshold value is 100010 = 3, the luminance level 1061 is high, and the gain amount 10511
Is small, the threshold value is controlled such as 100010 = 2.

Thus, the area type noise reduction means 1020
Then, the motion judgment circuit output (K) 1011 for the video signal 1000
, Brightness level 1061, and gain amount 10511 of the AGC device.
Noise can be reduced according to the two factors.

Further, the amount of recursion (K ″) 10711 of the motion detection frame recursive noise reduction device 1010 can be controlled in accordance with the amount of gain 10511 of the AGC device 1050.
/ N can be obtained.

Further, an area selection type noise reduction device
Instead of 1020, a plurality of low-pass filters having different characteristics as shown in FIG. 7D are provided, and two elements or one element of the luminance level 1061 of the video signal 1000 and the gain amount 10511 of the AGC device 1050 are used. The noise component of the video signal 1000 can be reduced by controlling the characteristics of the two-dimensional low-pass filter using the filter.

In this case, as shown in FIG. 7D, a motion detection frame cyclic noise reduction apparatus 1010, a two-dimensional LPFA 1022 for noise reduction in a low luminance region, and a two-dimensional LPFB 1023 for noise reduction in a high luminance region are provided. Provided, video signal 1000
Brightness level 1061 and the gain amount 10511 of the AGC device
The threshold control means 1090 is controlled according to the two factors.

First, the luminance level detecting means 1060 detects the luminance level 1061 of the input video signal 1000, and the gain amount calculating means 1051 calculates the gain amount 10511 in the AGC device 1050. The detected luminance level 1061 and gain amount 10511 are converted to the motion detection frame cyclic noise reduction apparatus 1010 shown in FIG.
It outputs to the traveling amount control means 1071 provided inside.

The cyclic amount control means 1071 shown in FIG. 8 controls the cyclic amount (K ″) 10711 according to the motion determining circuit output (K) 1011, the luminance level 1061 and the gain amount 10511 of the motion determining circuit 1003.

For example, the amount of circulation (K ″) 10711 is controlled by assigning weights as follows: That is, in the case of a still image and a low luminance level and a large amount of gain, the amount of circulation (K ″) 10711 is controlled. = 0.9 If the image is a still image and the luminance level is low and the gain is small, the amount of circulation (K ") 10711 = 0.8 If the image is a still image and the luminance level is high and the amount of gain is large, the amount of circulation (K") 10711 = 0.7 When the image is a still image and the luminance level is high and the gain amount is small, the amount of circulation (K ") 10711 = 0.6 When the image is a moving image and the luminance level is low and the amount of gain is large, the amount of circulation (K") 10711 = 0.5 In the case of a moving image and the luminance level is low and the gain amount is small, the amount of circulation (K ″) 10711 = 0.4. In the case of a moving image, and when the luminance level is high and the gain amount is large, the amount of circulation (K ″) 10711 = 0.3. And the brightness level is high and the gain amount is small Cyclic amount (K ") 10711 = 0.2 (0 ≦ cyclic amount (K") 10711 ≦ 1) to have a weight and so controlled.

Thus, the motion detection frame cyclic noise reduction apparatus 1010 uses three elements according to the motion determination circuit output (K) 1011 for the input video signal 1000, the luminance level, and the gain amount 10511 of the AGC apparatus 1050. Noise can be reduced.

Next, in this case, the threshold control means 1090 determines the gain amount 10511 of the AGC device 1050 and the luminance level 106
According to 1, two-dimensional LPFA102 with a large noise reduction effect
The selector means 10 for switching the characteristics of the two-dimensional LPFD 1025 with priority given to holding the edge from 2 and having little effect of noise reduction.
Control 26.

For example, the output of selector means 1026 may be controlled as follows. That is, when the luminance level 1061 is low and the gain amount 10511 is large, the two-dimensional LPFA 1022 is low when the luminance level 1061 is low and the gain amount 10511 is small. When the two-dimensional LPFB 1023 luminance level 1061 is high and the gain amount 10511 is large, Two-dimensional LPFC 1024 When the luminance level 1061 is high and the gain amount 10511 is small, control is performed as a two-dimensional LPFD 1025.

It is to be noted that the filter coefficient may be adaptively varied by using one low-pass filter capable of varying the filter coefficient.

As described above, the luminance level of the video signal 1000
The amount of recursion (K ″) 10711 of the motion detection frame recursive noise reduction device 1010 can be controlled in accordance with 1061 and the amount of gain 10511, and low-pass filters with different characteristics can be controlled. Therefore, the noise component of the video signal 1000 has been reduced. A video signal having a good S / N can be obtained.

Note that the threshold value control means 1090
Motion judgment circuit output (K) 1011 and luminance level for 1000
By reducing the noise according to the three elements 1061 and the gain amount 10511 of the AGC device, the video signal 1000 is further reduced.
Therefore, it is possible to select the characteristics of the low-pass filter more suitable for noise reduction in consideration of the motion information, and thus it is possible to obtain the output video signal 1021 with further reduced noise.

Further, if an image pickup apparatus is constructed by using the output video signal 1021, an image pickup apparatus with reduced noise components can be constituted. A good image processing device can be configured.

[0135]

As described above, according to the present invention, by controlling the outputs of the motion detection frame cyclic noise reduction device and the area selection type noise reduction device based on the motion detection information of the video signal, Noise is reduced by a cyclic reduction device in a portion, and noise is reduced by an area selection noise reduction device in a moving portion. This makes it possible to reduce noise without discomfort while retaining the edge of the stationary portion.

Also, since the edges are blurred in the moving image portion, the effect of area-type noise reduction is increased, and even if the edges are slightly lost, there is almost no visual problem. In other words, by controlling the threshold for judging whether or not there is a correlation between the peripheral pixel and the center pixel based on the result of the motion detection, it is possible to maintain the sharpness of the image edge of the video signal, It is possible to sufficiently reduce noise in a moving portion that cannot be reduced only by the noise reduction device.

Furthermore, the luminance level of the video signal or the AGC is controlled by controlling the amount of repetition of the motion detection frame recursive noise reduction device or the threshold value of the area selection type noise reduction device.
When the gain amount of the device is used, a video signal whose S / N is degraded due to a large gain amount applied to the AGC device at the time of low illuminance and a signal whose S / N is degraded by a gamma correction for a signal of low luminance are also used. Noise can be sufficiently reduced, and a video signal with good S / N and few afterimages can be obtained.

Since the output of the area selection type noise reduction device can be controlled by the detection result of the motion detection circuit provided in the motion detection frame cyclic noise reduction device, an increase in the circuit scale can be prevented.

Further, the noise can be reduced in accordance with the movement of the input video signal by using a two-dimensional low-pass filter, not limited to the area selection type noise reduction device.

Further, if the present invention is applied to an image pickup apparatus, not only can an image having a good S / N be picked up, but the image signal can be darker than the conventional image pickup apparatus by controlling the luminance level of the video signal or the gain of the AGC apparatus. It is possible to shoot at a place.

If the present invention is applied to an image processing apparatus such as an image recognition apparatus, image processing can be performed with an image having a high S / N ratio, so that an effect that a highly accurate processing result can be obtained can be expected.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a noise reduction device according to a first embodiment;

FIG. 2 is a diagram illustrating a configuration of a noise reduction device according to a second embodiment;

FIG. 3 is a diagram illustrating a configuration of a noise reduction device according to a third embodiment;

FIG. 4A is a diagram illustrating a first configuration of a noise reduction device according to a fourth embodiment; FIG. 4B is a diagram illustrating a second configuration of the noise reduction device according to a fourth embodiment;

FIG. 5A is a diagram illustrating a first configuration of a noise reduction device according to a fifth embodiment; FIG. 5B is a diagram illustrating a second configuration of the noise reduction device according to a fifth embodiment; FIG. 14 is a diagram illustrating a third configuration of the noise reduction device according to the fifth embodiment, and FIG. 14D is a diagram illustrating a fourth configuration of the noise reduction device according to the fifth embodiment.

FIG. 6 is a diagram illustrating a configuration of a cyclic noise reduction device for motion detection frames according to a fifth embodiment;

7A is a diagram illustrating a first configuration of a noise reduction device according to a sixth embodiment; FIG. 7B is a diagram illustrating a second configuration of the noise reduction device according to a sixth embodiment; FIG. 14 is a diagram illustrating a third configuration of the noise reduction device according to the sixth embodiment, and FIG. 14D is a diagram illustrating a fourth configuration of the noise reduction device according to the sixth embodiment.

FIG. 8 is a diagram illustrating a configuration of a motion detection frame cyclic noise reduction apparatus according to a sixth embodiment;

FIG. 9 is a diagram showing a configuration of a conventional motion detection frame cyclic noise reduction apparatus.

FIG. 10 is a diagram showing a configuration of a conventional area selection type noise reduction device.

[Explanation of symbols]

 1000, 10000 Input video signal 1001, 10011, 100111 Multiplier 1002, 10021, 100211 Multiplier 1003 Motion decision circuit 1004 Two-dimensional LPF (Low-pass filter) 1005 Frame memory 1006, 1007, 1042 Adder 1008, 1021, 1031, 1043 Output Video signal 1009 Motion detection means 1010 Motion detection frame cyclic noise reduction apparatus 1011 Motion judgment circuit output (K) 1012 Motion threshold control means 1020 Area type noise reduction apparatus 1022 Two-dimensional LPF (low-pass filter) A 1023 Two-dimensional LPF ( Low-pass filter) B 1024 two-dimensional LPF (low-pass filter) C 1025 two-dimensional LPF (low-pass filter) D 1026, 1030 selector means 1040, 1041 multiplier 1050 AGC device 1051 gain amount calculation means 1052 gain threshold value control means 1060 brightness level Detecting means 1061 Luminance level 1070 Luminance recursive amount control means 1071 Recursive amount control means 1080 Luminance threshold control means 1090 Threshold control means 10001 Peripheral pixel capture circuit 10002 Absolute value circuit 10003 Absolute value circuit 10004 Absolute value circuit 10005 Absolute value circuit 10006 Correlation judgment circuit 10007 Correlation judgment circuit 10008 Correlation judgment circuit 10009 Correlation judgment circuit 10111, 100010 Threshold 10121 Weighting means 10122 Weighting control means output (α) 10511 Gain amount 10701 Recursive amount K '10711 Recursive amount K "100011 Pixel number coefficient circuit 100012 Correlated pixel addition circuit 100013 Divider 100014 Output video signal

Claims (15)

[Claims] The present invention relates to a motion detection frame cyclic noise reduction device that reduces a noise component of a still part without causing an afterimage by changing a cyclic amount according to a motion component of a video signal, and a correlation between surrounding pixels. Area-type noise reduction device that reduces the noise component of the video signal while minimizing the deterioration of the edge component of the image by using the presence or absence of the image, and the output of the motion-detection frame cyclic noise reduction device and the area-type noise reduction device. Selector means for switching between
A noise reduction apparatus characterized by switching between the output of the cyclic noise reduction apparatus of the motion detection frame and the output of the area type noise reduction apparatus in accordance with the amount of motion of an input video signal. 2. A correlation between a motion detection frame cyclic noise reduction device that reduces a noise component of a stationary portion without causing an afterimage by changing a cyclic amount according to a motion component of a video signal, and a correlation between surrounding pixels. An area-type noise reduction device that reduces the noise component of the video signal while minimizing the degradation of the edge component of the image by using the presence or absence of the image signal; and a weighting unit that weights the motion detection information. Accordingly, when the motion amount of the input video signal is small, the weight of the motion detection frame cyclic noise reduction device is increased, and when the motion amount is large, the weight of the area type noise reduction device is increased. A noise reduction apparatus characterized by taking a weighted average of 3. A correlation between a motion detection frame cyclic noise reduction device that reduces a noise component of a still portion without causing an afterimage by changing a cyclic amount according to a motion component of a video signal, and a correlation between surrounding pixels. Area noise reduction device that reduces the noise component of the video signal while minimizing the degradation of the edge component of the image by utilizing the presence or absence of the central pixel in the area noise reduction device according to the amount of motion of the input video signal Motion threshold value control means for controlling a threshold value for determining a correlation with a peripheral pixel with respect to a peripheral pixel. A noise reduction device for controlling a threshold value for determining a correlation. 4. A correlation between a motion detection frame cyclic noise reduction device that reduces a noise component of a stationary portion without causing an afterimage by changing a cyclic amount according to a motion component of a video signal, and a correlation between surrounding pixels. An area-type noise reduction device that reduces the noise component of the video signal while minimizing the degradation of the edge component of the image by using the presence or absence of
An AGC device that adjusts the gain of the video signal so that the video signal can be easily viewed; a gain amount calculating unit that calculates an AGC gain amount; and a gain threshold control unit; A threshold value for determining a correlation between a central pixel and a peripheral pixel in the area-type noise reduction device in accordance with the amount of motion and the amount of AGC gain. 5. An area type noise reduction device for reducing a noise component of a video signal while minimizing deterioration of an edge component of an image by utilizing the presence / absence of a correlation with surrounding pixels, and for facilitating viewing of the video signal. An AGC device for adjusting the gain of the video signal, a gain amount calculating means for calculating an AGC gain amount, and a gain threshold value control means, wherein the gain threshold value control means controls the area according to the AGC gain amount. A noise reduction device for controlling a threshold value for determining a correlation between a center pixel and a peripheral pixel in the noise reduction device. 6. A correlation between a motion detection frame cyclic noise reduction device that reduces a noise component of a stationary portion without causing an afterimage by changing a cyclic amount according to a motion component of a video signal, and a correlation between surrounding pixels. An area-type noise reduction device that reduces the noise component of the video signal while minimizing the degradation of the edge component of the image by using the presence or absence of
A luminance level detection unit for the video signal, and a luminance threshold control unit, and the amount of movement of the motion detection frame cyclic noise reduction device and the center pixel in the area type noise reduction device are determined according to the luminance level of the video signal. A noise reduction device for controlling a threshold value for determining a correlation with peripheral pixels. 7. A motion detection frame cyclic noise reduction device that reduces a noise component of a stationary portion without causing an afterimage by varying a cyclic amount according to a motion component of a video signal, or a correlation with surrounding pixels. An area-type noise reduction device that reduces a noise component of a video signal while minimizing deterioration of an edge component of an image by utilizing the presence or absence of a video signal; and a luminance level detection unit that detects a luminance level of the video signal. One of the amount of repetition of the motion-detection frame recursive noise reduction device and the threshold value for determining the correlation of a peripheral pixel with the center pixel in the area-type noise reduction device in accordance with the luminance level of A noise reduction device characterized by the above-mentioned. 8. An AGC apparatus for performing gain adjustment on a video signal so that the video signal can be easily viewed, a gain amount calculation unit for calculating an AGC gain amount, a brightness level detection unit for detecting a brightness level of the video signal, and a video signal. A motion detection frame cyclic noise reduction device that reduces a noise component in a stationary portion without causing an afterimage by changing a cyclic amount according to a motion component of a signal, and an image utilizing correlation presence / absence with surrounding pixels. An area-type noise reduction device that reduces the noise component of the video signal while minimizing the deterioration of the edge component of the motion detection frame. The motion detection frame cyclic noise reduction device according to the brightness level of the video signal and the amount of AGC gain For controlling the amount of recirculation and for determining the correlation between a central pixel and peripheral pixels in the area-type noise reduction apparatus. A noise reduction device characterized by controlling a noise value. 9. An AGC apparatus for adjusting a gain of a video signal so that the video signal can be easily viewed, a gain amount calculating unit for calculating an AGC gain amount, a brightness level detecting unit for detecting a brightness level of the video signal, and a video signal. A motion detection frame recursive noise device that reduces the noise component of the still part without causing an afterimage by varying the amount of repetition according to the motion component of the signal, and utilizes the presence or absence of correlation with surrounding pixels to determine the image. While minimizing deterioration of edge components,
An area noise reduction device for reducing a noise component of a video signal is provided. The amount of movement of the motion detection frame cyclic noise reduction device is controlled according to the brightness level of the video signal. A noise reduction device, wherein a threshold value for determining a correlation between a central pixel and a peripheral pixel in the area-type noise reduction device is controlled in accordance with a gain amount. 10. An AGC device for adjusting a gain of a video signal so that the video signal can be easily viewed, a gain amount calculating unit for calculating an AGC gain amount, a brightness level detecting unit for detecting a brightness level of the video signal, and a video signal. A motion detection frame recursive noise device that reduces the noise component of the still part without causing an afterimage by varying the amount of repetition according to the motion component of the signal, and utilizes the presence or absence of correlation with surrounding pixels to determine the image. An area-type noise reduction device that reduces the noise component of the video signal while minimizing the degradation of the edge component is provided, and the amount of repetition of the motion detection frame recursive noise reduction device is controlled according to the AGC gain amount. , The correlation between a central pixel and peripheral pixels in the area type noise reduction device is determined in accordance with the AGC gain amount and the luminance level. A noise reduction device for controlling a threshold value for noise reduction. 11. An AGC apparatus for performing gain adjustment on a video signal so that the video signal can be easily viewed, a gain amount calculation unit for calculating an AGC gain amount, a brightness level detection unit for detecting a brightness level of the video signal, and a video signal. A motion detection frame cyclic noise reduction device that reduces a noise component of a still part without causing an afterimage by changing a cyclic amount according to a motion component of a signal, and a two-dimensional noise reduction device that reduces a noise component of a video signal. A noise reduction device for the motion detection frame cyclic noise reduction device according to either one of the luminance level of the video signal and the AGC gain amount or the two components of the luminance level of the video signal and the AGC gain amount. And a control for varying characteristics of the two-dimensional filter device. 12. An image processing apparatus comprising the noise reduction device according to claim 1. 13. An imaging device comprising the noise reduction device according to claim 1. 14. An image processing apparatus comprising the imaging device according to claim 13. 15. A noise reduction method characterized by switching between different noise reduction methods according to the motion of an image.