JP2010288052A - Television receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid excess and deficiency of correction strength to perform video display with high image quality when performing correction processing of motion blurring of moving images caused in photography with a camera is performed to various source video signals to be displayed in a television receiver. <P>SOLUTION: The television receiver X is provided with: a motion blurring correction section 22d which performs motion blurring correction processing for improving the motion blurring of the moving images to the source video signals; and a control section 21 which changes strength/weakness or presence/no presence of execution of the motion blurring correction processing according to reference information such as metadata of the broadcasting content and fineness of video images of the source video signals, image quality of video display based on the source video signals, and a noise amount to be detected from the source video signals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a television receiver that displays video based on a video signal obtained by subjecting a predetermined source video signal to signal processing by video display means.

A television receiver performs various types of signal processing on a source video signal such as a video signal extracted from a broadcast signal by a tuner or a video signal input through an external input interface, and the resulting video signal is processed. The image based on the image is displayed by the image display means.
In recent television receivers, various measures are taken to improve the image display characteristics of the image display means in order to improve the image quality. For example, in a liquid crystal television receiver, an interpolated video signal is added between the source video signals for each frame to drive the liquid crystal panel at double speed, and backlight dimming is performed according to the video luminance for each video frame. Image quality is improved by adopting an active backlight dimming function and the like. The television receiver also has a function of increasing the contrast by performing signal level adjustment processing on the source video signal.

By the way, there are cases where the video of the video signal obtained by photographing with the camera has so-called blur. For example, a video signal obtained by a moving camera often includes motion blur of a moving image in which an afterimage appears in the direction in which the camera moves. Even when the camera is fixed, when the subject moves, the obtained video signal often includes motion blur of a moving image in which an afterimage appears in a direction opposite to the direction in which the subject moves. As described above, the video signal obtained by the imaging by the camera may include motion blur that occurs during the imaging.
The motion blur has a small effect on the viewer when video is displayed in a relatively small size. However, in recent television receivers with a large screen size, the viewer will notice image quality deterioration due to the motion blur more prominently.
On the other hand, Patent Document 1 discloses a moving image display device provided with a camera shake correction function for improving the motion blur caused by the movement of a camera at the time of capturing a moving image obtained through an input device. Furthermore, Patent Document 1 discloses a function for detecting a motion vector from a moving image and correcting the moving image based on the motion vector as the camera shake correction function.

JP 2007-279800 A

However, television receivers can be obtained under conditions where camerawork and subject movement are relatively intense, so sports video images with noticeable motion blur, animation video with no motion blur, and computer output video. A variety of source video signals such as these signals are displayed. If motion blur correction processing that uniformly improves the motion blur of a movie is applied to such various source video signals, the correction is too weak and the motion blur is not sufficiently improved, or the correction is too strong and the image is too strong. There is a problem in that the image quality may be deteriorated such that the outline portion of the image is displayed as whitish.
Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide motion blurring of moving images generated during imaging by a camera with respect to various source video signals to be displayed in a television receiver. It is an object of the present invention to provide a television receiver capable of displaying high-quality video images while avoiding excessive and insufficient correction strength.

In order to achieve the above object, a television receiver according to the present invention is an apparatus for displaying a video based on a video signal obtained by subjecting a predetermined source video signal to signal processing by video display means. ) And (2).
(1) Motion blur correction means for performing motion blur correction processing for improving motion blur of a moving image with respect to the source video signal.
(2) Motion blur correction control means for changing the intensity of the motion blur correction process or the presence / absence of execution according to predetermined reference information.
Examples of the reference information include information corresponding to the source video signal in the metadata of the broadcast content, information on video definition determined from the source video signal, and information on image quality of video display based on the source video signal. And information including one or a plurality of pieces of noise amount information detected from the source video signal.
Further, one or more of information indicating that the information corresponding to the source video signal in the metadata of the broadcast content is video genre information, video definition information, and a video of a combination of a plurality of screens. It is considered that the information includes.
The metadata of the broadcast content is data including basic information, copyright information, viewing condition information, etc. regarding a broadcast program and individual scenes in the program, such as EPG (Electronic Program Guide) data. The metadata of the broadcast content is data included in a vacant channel in the broadcast signal, data registered in a predetermined server on the Internet, and the like, and the television receiver is connected via a tuner or a network communication interface. The data to be acquired.
The source video signal is a video signal extracted from a broadcast signal by a tuner, a video signal input through an external input interface, or the like, and is used for a multi-screen display, an OSD (On-Screen Display) display, or the like. The video signal synthesized by the John receiver is not included.

  The television receiver according to the present invention can discriminate the contents of various source video signals based on predetermined reference information, and can set the intensity or execution of the motion blur correction process suitable for the contents. For example, when the source video signal is a video signal of a sports live broadcast program or sports movie in which the motion blur is noticeable, the correction parameter of the motion blur correction process is set so as to increase the correction of the motion blur It is possible to do. In addition, when the source video signal is a video image of an animation in which the motion blur does not occur or a video signal of an output video of a personal computer, it may be controlled not to perform the motion blur correction process. As a result, when performing the motion blur correction process (motion blur correction process) that occurred during imaging by the camera, it is possible to display a high-quality image while avoiding excessive or insufficient strength of the motion blur correction process. .

By the way, when the motion blur correction process is performed on a video signal representing a combination of a plurality of screens such as a so-called picture-in-picture video signal, the boundary portion of the plurality of screens is emphasized whitish. An output video is obtained.
Therefore, when the blur correction control means determines that the video of the source video signal is a video of a combination of multiple screens based on information corresponding to the source video signal in the metadata of the broadcast content, It is also conceivable to perform control so that the motion blur correction process is weaker than other video areas or the motion blur correction process is not executed for a part of video areas including boundary lines of a plurality of screens. Thereby, it is possible to avoid image quality deterioration due to excessive motion blur correction processing.

  According to the present invention, when performing correction processing of motion blur of a moving image generated during imaging by a camera on various source video signals to be displayed in a television receiver, excessive or insufficient correction strength is avoided. Thus, high-quality video display can be performed.

The block diagram of the principal part of the television receiver X which concerns on embodiment of this invention. The schematic diagram of the brightness | luminance histogram for every flame | frame of the source video signal compared in the television receiver X. FIG. The schematic diagram which shows the relationship between the motion of the image in a source video signal, and a motion vector. The figure showing an example of the rule of the motion blur correction control based on the reference information in the television receiver. The schematic diagram of the image before and after motion blur correction.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

The television receiver X according to the embodiment of the present invention is provided with a function of performing a correction process of motion blur of a moving image generated at the time of image pickup by a camera without any deficiency with respect to various source video signals to be displayed. And
First, the configuration of the television receiver X will be described with reference to the block diagram shown in FIG.
As shown in FIG. 1, the television receiver X includes a tuner 1, a multi-core CPU 2, a liquid crystal drive circuit 3, a liquid crystal panel 4, a dimming circuit 5, a backlight 6, an external signal input interface 7, and the like. .
The tuner 1 is an electronic component that extracts a video signal and an audio signal of a broadcast program of a designated channel from a television broadcast signal. Furthermore, the tuner 1 also extracts metadata about broadcast contents other than video signals and audio signals and individual scenes in the contents from the digital television broadcast signal. The metadata includes, for example, EPG (Electronic Program Guide) data, other information provided for each broadcast content or each scene being broadcast, and the like.
The external signal input interface 7 is an interface for inputting a video signal and an audio signal from the external device by being connected to the external device.
The multi-core CPU 2 is a CPU (Central Processing Unit) in which a plurality of core processors are integrated, and executes signal processing and control related to video signals and audio signals in the television receiver X.
For example, the multi-core CPU 2 determines the levels of the three primary colors (R, G, B) of each pixel constituting one frame image in the moving image based on the video signal obtained through the tuner 1 and the external signal input interface 7. A frame signal representing a tone level is sequentially generated, and video signal processing for transmitting the frame signal to the liquid crystal driving circuit 3 is performed. The frame signal is a drawing signal that represents the level of gradation of each pixel.
Further, the multi-core CPU 2 executes acoustic signal processing such as equalization processing on the acoustic signal obtained through the tuner 1 and the external signal input interface 7. The processed acoustic signal is output through an acoustic amplifier and a speaker (not shown).
The multi-core CPU 2 receives a video signal and an audio signal output from the tuner 1 and a video signal and an audio signal input from an external device through the external signal input interface 7. Hereinafter, the video signal output from the tuner 1 and the video signal input from the external device through the external signal input interface 7 are referred to as a source video signal.
In the multi-core CPU 2, each of the plurality of core processors executes image processing, control, and other arithmetic processing by executing a predetermined program. For example, the plurality of multi-core CPUs 2 function as a control unit 21, a source video screen generation unit 22, a data broadcast screen generation unit 23, an OSD screen generation unit 24, a screen synthesis unit 26, and a gamma correction unit 27, which will be described later. Although not shown in FIG. 1, the multi-core CPU 2 includes the core processor that performs processing related to an acoustic signal.

The liquid crystal driving circuit 3 sequentially transfers one frame of video (one frame image) corresponding to the frame signal to the liquid crystal panel 4 based on the frame signal sequentially transmitted from the multi-core CPU 2 in a predetermined cycle. This is a circuit to be displayed.
More specifically, the liquid crystal driving circuit 3 has the gradation levels of R, G, and B3 primary colors (also referred to as image luminance levels) for the liquid crystal elements of the respective pixels provided in the liquid crystal display panel. A gradation signal having a voltage corresponding to the voltage is supplied. Thereby, the liquid crystal panel 4 displays an image corresponding to the frame signal.
That is, the liquid crystal driving circuit 3 and the liquid crystal panel 4 are examples of video display means for displaying video.
The dimming circuit 5 is a circuit that adjusts the power supplied to the light source of the backlight 6, that is, the luminance of the backlight 6 by, for example, PWM control in accordance with a control command from the control unit 21 in the multi-core CPU 2. .
The dimming circuit 5 is embodied by, for example, an FPGA or an ASIC.
The backlight 6 is an illuminating unit that is disposed on the back side of the liquid crystal panel 4 that displays an image, and illuminates the liquid crystal panel 4 using a plurality of LEDs or a plurality of fluorescent tubes as light sources.

The external signal input interface 7 includes a PC terminal 71 and an HDMI circuit 72 (High Definition Multimedia Interface).
The PC terminal 71 is an input terminal for RGB signals that are video signals output from a computer such as a personal computer.
The HDMI circuit 72 is a signal transmission interface for simultaneously transmitting a digital video signal and an audio signal from an external device to the own device by a baseband method. Transmission of video signals and audio signals is performed through a TMDS (Transition Minimized Differential Signaling) line.
The HDMI circuit 72 also has a function of transmitting control information other than the video signal and the audio signal through a CEC (Consumer Electronics Control) line different from the TMDS line. Information transmission through the CEC line is possible in both directions.
Hereinafter, for convenience, a device connected to the PC terminal 71 or the HDMI circuit 72 is referred to as an external connection device.

Next, processing of each component in the multi-core CPU 2 will be described.
The control unit 21 executes control processing of each component included in the television receiver X.
For example, the control unit 21 detects an operation input through an operation key of a remote controller (not shown), and executes various processes according to the content of the operation input.
More specifically, the control unit 21 controls the tuner 1 so that a broadcast program signal of a designated channel is extracted from a television broadcast signal in response to an operation input for channel designation in the remote controller. Control. In addition, the control unit 21 adjusts the volume of the output sound of the broadcast program by controlling a sound amplifier (not shown) according to an operation input for volume adjustment in the remote controller.

The data broadcast screen generation unit 23 generates a data broadcast screen signal that is a drawing signal for displaying information included in the metadata extracted by the tuner 1 as an image on the liquid crystal panel 4. The data broadcast screen signal is, for example, a signal for drawing a screen of a program guide based on the information of the EPG.
The OSD screen generation unit 24 is an OSD screen which is a drawing signal for displaying the internal parameters on the liquid crystal panel 4 in order to set the internal parameters of the television receiver X in accordance with a user operation. Generate a signal. The internal parameters include, for example, a video display image quality mode, a parameter for adjusting the reference luminance of the backlight 6, a parameter for adjusting the color and contrast of the display color, and a parameter for setting a broadcast channel. .
For example, the display image quality mode is selected from three operation modes: a dynamic mode, a standard mode, and a cinema mode. The dynamic mode is an operation mode in which video display is performed after processing for increasing the contrast is performed on the source video signal. The standard mode is an operation mode in which automatic contrast adjustment is slightly weaker than the dynamic mode for the source video signal. The cinema mode is an operation mode in which automatic contrast adjustment is adjusted for a movie with respect to the source video signal.
The data broadcast screen generation unit 23 generates the data broadcast screen signal only when necessary in accordance with a control command from the control unit 21. Similarly, the OSD screen generation unit 24 also generates the OSD screen signal only when necessary in accordance with a control command from the control unit 21.

Further, the source video screen generation unit 22, the screen synthesis unit 26, and the gamma correction unit 27 execute a process of converting the source video signal into the drawing frame signal.
That is, the source video screen generation unit 22 converts one or a plurality of the source video signals designated by the control unit 21 into source video frame signals that are drawing signals corresponding to the source video signals. . At that time, the source video screen generation unit 22 performs motion blur correction processing for improving motion blur of a moving image generated at the time of shooting on the source video signal (an example of motion blur correction means).
FIG. 5 is a schematic diagram of an image before and after motion blur correction.
As shown in FIG. 5 (a), the video signal obtained while moving the camera is a moving image in which an afterimage Ge with respect to the original image Gt appears in the direction in which the camera moves (leftward toward FIG. 5 (a)). Often includes motion blur.
The source video screen generation unit 22 removes the afterimage Ge (motion blur) by performing motion blur correction processing for improving motion blur of a moving image generated at the time of shooting on the source video signal. Generate a frame signal to display the sharpened video as shown in b). Details thereof will be described later.

Further, the screen synthesis unit 26 synthesizes other drawing signals generated by the data broadcast screen generation unit 23 and the OSD screen generation unit 24 with the source video frame signal as necessary. Execute. The other drawing signals include the data broadcast screen signal and the OSD screen signal.
That is, the screen composition unit 26, when there is no other drawing signal generated by each of the data broadcast screen generation unit 23 and the OSD screen generation unit 24, outputs the source video frame signal as it is. The data is transmitted to the gamma correction unit 27. On the other hand, when there are other drawing signals generated by the data broadcast screen generation unit 23 and the OSD screen generation unit 24, a part of the source video frame signal is used as the other drawing signal. A synthesized frame signal, which is the replaced signal, is generated and transmitted to the gamma correction unit 27.
Hereinafter, the source video frame signal or the synthesized frame signal input to the gamma correction unit 27 is referred to as a primary frame signal. The frame signal transmitted from the gamma correction unit 27 to the liquid crystal driving circuit 3 is referred to as a secondary frame signal.

The gamma correction unit 27 performs gamma correction on the primary frame signal input through the screen synthesis unit 26 and outputs the corrected secondary frame signal. The gamma correction is performed so that the display color of the liquid crystal panel 4 based on the secondary frame signal approaches the original display color of the broadcast program video signal or the source video signal that is the basis of the secondary frame signal. This is a process for correcting the primary frame signal.
The gamma correction unit 27 generates the secondary frame signal having a contrast corresponding to the set display image quality mode by switching a gamma correction coefficient, that is, a gamma correction curve, according to the display image quality mode. .

Hereinafter, the conversion process from the source video signal to the source video frame signal and the motion blur correction process by the source video screen generation unit 22 will be described in more detail.
As shown in FIG. 1, the source video screen generation unit 22 includes a frame signal generation unit 22a, a signal buffer 22b, a histogram calculation unit 22c, and a motion blur correction unit 22d.
The frame signal generation unit 22a sequentially generates frame signals for each screen from the source video signals that are sequentially input, and outputs each of the frame signals to the signal buffer 22b. Hereinafter, a frame signal based on the source video signal generated by the frame signal generation unit 22a is referred to as a source frame signal. The gradation level of each of the three primary colors in the source frame signal is a level corresponding to the luminance level of each of the three primary colors in the source video signal.
The signal buffer 22b is temporary storage means for always accumulating the latest two frames of the source frame signal.
The histogram calculator 22c calculates a histogram of luminance (gradation) for each of the source frame signals temporarily stored in the signal buffer 22b.
Further, the histogram calculation unit 22c sequentially compares the luminance (gradation) histograms of the source frame signals.
FIG. 2 is a schematic diagram of a luminance histogram for each source frame signal calculated and compared by the histogram calculation unit 22c.
For example, each time a new source frame signal is input, the histogram calculation unit 22c includes the luminance histogram in the new source frame signal and the luminance histogram in the previous source frame signal. The amount of change between is calculated. As the amount of change in the luminance histogram, for example, the total value or the average value of the frequency differences for each luminance level (gradation level) in the luminance histogram can be considered.

The motion blur correction unit 22d performs the motion blur correction process for improving motion blur of the moving image with respect to the source frame signal representing one frame of the moving image of a series of shooting scenes. At this time, the motion blur correction unit 22d switches a correction coefficient of the motion blur correction process or switches whether to perform the motion blur correction process according to a control command from the control unit 21. Hereinafter, a specific example of control of the motion blur correction process by the control unit 21 will be described.
The control unit 21 performs motion blur correction control for changing the intensity and execution presence / absence of the motion blur correction processing according to predetermined reference information. Here, the reference information is, for example, information corresponding to the source video signal in the metadata of the broadcast content and setting contents of the display image quality mode. The information corresponding to the source video signal in the metadata may be video genre information and video definition information. Further, as information on the genre of the video, for example, “action”, “sports”, “comedy”, “music / musical”, “romance”, etc. can be considered.

FIG. 4 is a diagram illustrating an example of a motion blur correction control rule based on the reference information in the television receiver X.
The controller 21 classifies the strength and absence and presence / absence of the motion blur correction process according to a rank of 5 levels from 0 to 4. Hereinafter, this rank is referred to as a motion blur correction rank d0.
The motion blur correction rank d0 indicates that “0” does not perform the motion blur correction processing, and “1” to “4” indicate that the motion blur correction processing is stronger as the number is larger.
In the example shown in FIG. 4, the control unit 21 includes the video genre information d1 corresponding to the source video signal, the video type information d2 of the source video signal, and the display image quality mode information d3. The motion blur correction rank d0 is determined according to the combination. Here, the video genre information d1 and the video type information d2 are information determined based on, for example, information included in the metadata or input source information of the source video signal. For example, when the source video signal is a video signal extracted from a television broadcast signal, the video type information d2 is a high-definition video according to the video definition information included in the metadata. Whether it is a standard definition image or not is determined. Here, the high-definition image is an image having 1080 effective scanning lines and an aspect ratio of 16: 9 in digital broadcasting. When the source video signal is a computer output video signal input through the PC terminal 71, it is determined that the video type information d2 is a computer output video. The determination is performed by the control unit 21.
Further, as described above, the display image quality mode information d3 is information set in accordance with a user operation on the remote controller.

When the video of the source video signal is a video of a “sport” or “action” genre in which camera work or subject movement is intense, motion blur in the video becomes noticeable. On the other hand, if the video of the source video signal is a video of the “news”, “variety”, or “documentary” genre with relatively little camera work or subject movement, motion blur may occur in the video. The degree of is relatively small. Further, when the video of the source video signal is a video of the “animation” genre, motion blur cannot occur in the video.
In addition, when the source video signal is a high-definition video, the sharpening effect of the video by the motion blur correction process appears more prominently. Similarly, when the video based on the source video signal is displayed in the dynamic mode, the sharpening effect of the video by the motion blur correction process appears more remarkably.
Further, when the video of the source video signal is the computer output video, motion blur cannot occur in the video.

Therefore, the control unit 21 indicates that the genre information d1 of the video represents a genre of “sports” or “action”, the video type information d2 represents a high-definition video, and the display image quality mode d3 is a dynamic mode. In this case, the motion blur correction rank d0 is determined as the maximum “4”.
Further, the control unit 21 is a case where the genre information d1 of the video indicates a genre of “sports” or “action”, and the video type information d2 is other than a high definition video or the computer output video. If the display image quality mode d3 is other than the dynamic mode, the motion blur correction rank d0 is determined to be the second largest “3”.
Further, the video genre information d1 represents a "news", "variety", or "documentary" genre, the video type information d2 represents a high-definition video, and the display image quality mode d3 is a dynamic mode. In this case, the motion blur correction rank d0 is determined as a standard “2”.
In addition, the control unit 21 may be configured such that the video genre information d1 indicates a “news”, “variety”, or “documentary” genre, and the video type information d2 is a high-definition video or the computer. When the image other than the output video is represented, or when the display image quality mode d3 is other than the dynamic mode, the motion blur correction rank d0 is determined as “1”, which is weaker than the standard.
The control unit 21 determines that the motion blur correction rank d0 is “0” in cases other than those described above. The condition for determining that the motion blur correction rank d0 is “0” is, for example, when the information d1 of the video genre corresponding to the source video signal represents “animation” or the type information d2 of the source video is For example, it represents the computer output video.
Then, the control unit 21 outputs the determination result of the motion blur correction rank d0 as a control command to the motion blur correction unit 22d.

On the other hand, when the determination result of the motion blur correction rank d0 by the control unit 21 is any one of “1” to “4”, the motion blur correction unit 22d uses the correction coefficient corresponding to the rank. The motion blur correction process is performed on the source frame signal.
In addition, when the determination result of the motion blur correction rank d0 by the control unit 21 is “0”, the motion blur correction unit 22d does not perform the motion blur correction process and uses the latest source frame signal as it is. The source video frame signal is output to the screen synthesis unit 26.
When the motion blur correction control generated by the camera 21 is performed on the various source video signals to be displayed on the television receiver X by the motion blur correction control by the control unit 21, the correction is performed. Therefore, it is possible to display a high-quality video by avoiding excessive or insufficient strength.

Hereinafter, the outline of the motion blur correction process by the motion blur correction unit 22d will be described with reference to FIG. The motion blur correction process may be, for example, a known camera shake correction process.
First, the motion blur correction unit 22d calculates a motion vector Vm by calculating a correlation value between the latest video of the source frame signal and the video of the previous source frame signal.
In FIG. 3, A0 represents a reference video area that is a part of the video area set in advance in the entire video area in the source frame signal. G0 represents a reference video that is a video in the reference video area A0 in the latest source frame signal. Ax represents an extended video area which is a video area expanded by a predetermined range based on the reference video area A0. A1 represents a search video area A1, which is a video area having the same shape and size as the reference video area A0 set while being sequentially moved in the extended video area Ax. G1 represents a search video that is a video in the search video area A0 in the previous frame signal from the latest. Here, one or a plurality of reference video areas A0 may be set. For example, when there is one reference video area A0, the reference video area A0 may be the entire remaining area except for a very small part of the edge of the entire video area. When there are a plurality of reference video areas A0, it is conceivable to divide the entire video area into a number of small areas and set each of the small areas as the reference video area A0. The extended video area Ax is set for each reference area A0.
The motion blur correction unit 22d sequentially sets the search video area A1 in the extended video area Ax, and sets the reference video G0 in the reference video area A0 in the latest source frame signal, A correlation value with the search video G1 in the search video area A1 in the previous frame signal is sequentially calculated.
Then, the movement vector from the search video area A1 to the reference video area A0 when the highest correlation value is obtained is calculated as the motion vector Vm.

Next, the motion blur correction unit 22d performs the motion blur correction process on the latest source frame signal based on the calculated motion vector Vm. Specific examples will be described below.
A place where the motion vector Vm is large is estimated to have a large amount of motion blur caused by blurring during imaging by the camera, and a place where the motion vector Vm is small is estimated to be a small amount of motion blur caused by blurring during imaging by the camera. Is done. Note that the motion blur is large is a state in which the high-frequency component (a portion where the change is fine and intense) is lower than the low-frequency component (a portion where the change is small).
Therefore, the motion blur correction unit 22d applies, to the latest source frame signal, a high-pass filter having different strengths according to the magnitude of the motion vector Vm in the motion blur correction process. The relationship between the magnitude of the motion vector Vm and the strength of the high-pass filter is preset. The strength of the high-pass filter is synonymous with the level of the attenuation rate of the low-frequency component. The stronger the high-pass filter, the greater the attenuation amount of the low-frequency component, and the higher-frequency component is emphasized.
Specifically, the motion blur correction unit 22d applies a high-pass filter to the source frame signal corresponding to the region where the motion vector Vm is large and the motion between frames is large, thereby reducing the high-frequency component that has been reduced. to correct. As a result, the edge is emphasized, the sharpness is increased, and the motion blur appears to be reduced.
On the other hand, if a high-pass filter is applied to the part where the motion blur is small, the high-frequency component of the image is extremely increased compared to the low-frequency component, and the edge is unrealistically emphasized in appearance. It feels uncomfortable, and the image is emphasized with noise more than necessary.
Therefore, the motion blur correction unit 22d weakly applies a high-pass filter to the source frame signal corresponding to the region where the motion vector Vm is small and the motion between frames is small. As a result, it is possible to realize an image in which the high frequency component and the low frequency component of the image are balanced.
Thus, in the television receiver X, the motion blur correction process is executed by the motion blur correction unit 22d, so that the high-pass filter strength of each part of the screen depends on the magnitude of the motion vector Vm. Therefore, it is possible to realize a video display without any sense of incongruity while reducing blurring on the entire screen.

In addition, the motion blur correction unit 22d is a video that represents one frame of a moving image of a series of shooting scenes for each of the source frame signals based on the source video signal based on the change amount of the luminance histogram. It is determined whether or not.
For example, when the change amount of the luminance histogram is in a range from a preset lower limit value to an upper limit value, the motion blur correction unit 22d generates a series of images of the source frame signal corresponding to the change amount. It is determined that the image represents one frame of the moving image of the shooting scene. When the change amount of the luminance histogram is very small, the video of the source frame signal is a video of a series of shooting scenes, but is considered to be a video that can be regarded as a still image or almost a still image. In addition, when the change amount of the luminance histogram is very large, the video of the source frame signal is considered to be a video at the time of shooting scene switching.
If the source video signal is a video that can be regarded as a still image or almost a still image, or a video at the time of switching of the shooting scene, there is a high possibility that the problem of motion blur of the video has not occurred. Normally, the motion blur correction is not required. When the motion blur correction is performed on the frame signal in such a source video signal, excessive (unnecessary) edge enhancement is performed on the edge portion of a noise video or a still image, and the image quality deteriorates.
Therefore, the motion blur correction unit 22d performs the motion blur correction processing only when it is determined that each of the source frame signals is a video representing one frame of a moving image of a series of shooting scenes. In this case, the motion blur correction process is skipped.
When the motion blur correction unit 22d performs the motion blur correction process on the latest source frame signal, the motion blur correction unit 22d outputs the corrected source frame signal to the screen synthesis unit 26 as the source video frame signal. To do. On the other hand, when the motion blur correction unit 22d skips the motion blur correction process, the latest source frame signal stored in the signal buffer 22b is directly output to the screen synthesis unit 26 as the source video frame signal. To do.

In the embodiment described above, as shown in FIG. 4, the control unit 21 performs the video genre information d1 and the video type information d2 included in the metadata, and the display image quality mode information. An example in which the motion blur correction rank d0 is determined according to a combination of three pieces of information d1 to d3 including d3 is shown.
In addition, it is conceivable that the control unit 21 determines the motion blur correction rank d0 based on one or two of the three pieces of information d1 to d3.
Further, as to whether the definition of the video of the source video signal is the high-definition video or the standard definition video, for example, the frame signal generation unit 22a or the like, based on the source video signal, It is also conceivable to make a determination by counting the number of scanning lines.
Further, as another example of the reference information, the control unit 21 may use information on the amount of noise detected from the source video signal for the motion blur correction control. For example, it is conceivable that the controller 21 lowers the value of the motion blur correction rank d0 as the amount of noise detected from the source video signal increases. This is because when the amount of noise included in the source video signal is large, the motion blur correction process causes image degradation by performing a process in response to the noise. The change processing of the motion blur correction rank d0 based on the noise amount can be performed alone or in accordance with a combination with one or more of the three pieces of information d1 to d3.
The detection of the amount of noise is performed, for example, by the frame signal generation unit 22a detecting the amount of a signal component in a predetermined high frequency band from the source video signal.

In addition, the metadata may include information indicating that the video of the source video signal is a video of a combination of a plurality of screens such as a so-called picture-in-picture video. When the motion blur correction process is performed on such a source video signal, an unnatural output video in which boundary portions of a plurality of screens are emphasized in white is obtained.
Therefore, the control unit 21 determines whether or not the video of the source video signal is a video of a combination of a plurality of screens based on information corresponding to the source video signal in the metadata, and according to the determination result. It is also conceivable to perform the motion blur correction control.
For example, when the control unit 21 determines that the video of the source video signal is a video of a combination of a plurality of screens, the motion blur correction rank d0 is set to “0” and the motion blur correction process is executed. It is conceivable to control such that it does not.
Further, there may be a case where the metadata includes layout information of a plurality of screens in the video of the source video signal. In this case, the motion blur correction unit 22d performs a process of weakening the motion blur correction process over a part of the video areas including the boundary lines of the combined multiple screens based on the layout information as compared with the other video areas. It is also conceivable to perform the control or not to execute the motion blur correction process.
Further, for example, the frame signal generation unit 22a determines whether or not the video of the source video signal is a video of a combination of a plurality of screens, detects the layout information of the plurality of screens, and results of the determination and detection Based on the above, it is also conceivable that the motion blur correction unit 22d performs control of the strength of the motion blur correction process or the execution / non-execution thereof.

  The present invention can be used for a television receiver.

X: Television receiver 1: Tuner 2: Multi-core CPU
3: Liquid crystal drive circuit 4: Liquid crystal panel 5: Light control circuit 6: Backlight 7: External signal input interface 21: Control unit 22: Source video screen generation unit 22a: Frame signal generation unit 22b: Signal buffer 22c: Histogram calculation unit 22d: Motion blur correction unit 23: Data broadcast screen generation unit 24: OSD screen generation unit 26: Screen composition unit 27: Gamma correction unit 71: PC terminal 72: HDMI circuit

Claims (4)

A television receiver for displaying a video based on a video signal obtained by subjecting a predetermined source video signal to signal processing by a video display means,
Motion blur correction means for performing motion blur correction processing for improving motion blur of a moving image with respect to the source video signal;
Motion blur correction control means for changing the intensity or execution of the motion blur correction process according to predetermined reference information;
A television receiver, comprising:   The reference information includes information corresponding to the source video signal in the metadata of the broadcast content, video definition information determined from the source video signal, video display image quality information based on the source video signal, and the source The television receiver according to claim 1, comprising one or more pieces of information on a noise amount detected from a video signal.   The information corresponding to the source video signal in the metadata of the broadcast content includes one or more of video genre information, video definition information, and information indicating that the video is a combination of multiple screens. The television receiver according to claim 2, comprising:   When the blur correction control unit determines that the video of the source video signal is a video of a combination of multiple screens based on information corresponding to the source video signal in the metadata of the broadcast content, the combined multiple screens 4. The television receiver according to claim 3, wherein control is performed such that the motion blur correction process is weaker than other video areas or the motion blur correction process is not executed for a part of the video area including the boundary line.