JP2000036918A - Video signal processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a fogged image that a contour of an image is gradually suppressed with the lapse of time and to execute smoothly fader image processing that expresses depth perception by a video camera or the like. SOLUTION: The processing unit is provided with a luminance signal processing circuit 13 that adjusts a frequency component of a luminance signal Yin of an optional image, an operation switch 16 that instructs a fader image processing mode where a signal level of an image luminance signal Yin is gradually changed or a processing mode of a usual image, and a control microcomputer 15 that controls the luminance signal control circuit 13 based on an instruction of the processing mode by the operation switch 16, and the control microcomputer 15 controls the luminance signal processing circuit 13 so as to bias a frequency component of the luminance signal Yin toward a lower frequency in the case that the operation switch 16 instructs the processing mode of the fader image and controls the luminance signal processing circuit 13 so as to extend a frequency component of the luminance signal Yin toward a higher frequency in the case that the operation switch 16 instructs the processing mode of the conventional image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing apparatus suitable for use in a processing system or the like which uses a video camera or the like to handle a fader image expressing perspective. Specifically, an adjusting means for adjusting a frequency component of a luminance signal of an arbitrary image is provided, and when a processing mode of a fader image is instructed, the adjusting means is controlled so as to bias the frequency component of the luminance signal to a low frequency region. In addition, it is possible to display a blurred image in which the outline of the image gradually weakens as time passes, and to smoothly perform fader image processing for expressing perspective with a video camera or the like.

[0002]

2. Description of the Related Art In recent years, a video camera or the like often uses a fader processing system in order to more accurately represent the perspective between a background image of a subject and a main body image. As a method of blurring the background image, a luminance signal (original signal) obtained from a video signal of the image is subjected to a filtering process, and then the contour-enhanced signal and the original signal whose gain is controlled by the original signal are superimposed. Further, the luminance signal subjected to the contour emphasis correction is subjected to a process called a fader process for bringing the signal level of the luminance signal closer to a black level or a white level according to an external request. As a result, a luminance signal obtained by blurring the background image is obtained, so that the fader image can be reproduced based on the luminance signal.

A luminance signal processing circuit having such a fader processing function is disclosed in Japanese Patent Application Laid-Open No. 9-24750.
No. 5, published patent publication. FIG. 8 is a block diagram showing a configuration example of this type of luminance signal processing circuit 10. The luminance signal processing circuit 10 shown in FIG. The input terminal 1 receives a luminance signal Yin separated from R, G, and B color video signals, which is an original signal (a delay circuit is omitted). A digital low-pass filter (LPF) 2 having a fixed filter coefficient is connected to the input terminal 1, and a luminance signal Y1 in a low frequency band required for image display is extracted.

The output stage of the digital low-pass filter 2 has a horizontal contour correction circuit (hereinafter simply referred to as H aperture control).
3 is connected, and after inputting the luminance signal Y1 in the low frequency band and extracting the horizontal contour of the image, the contour component signal Yh
Is output. The input terminal 1 is further connected to a vertical contour correction circuit (hereinafter simply referred to as a V-aperture compensator) 4 for inputting a luminance signal Yin to extract a vertical contour of an image, and then outputting a contour component signal Yv. You. An output stage of the H aperture control 3 and the V aperture control 4 is connected to a contour effect imparting circuit (hereinafter referred to as an aperture control effect circuit) 5 for luminance correction after synthesizing horizontal and vertical contour component signals Yh and Yv. The signal Yap is output.

A gamma correction circuit 6 is connected to the output stages of the digital low-pass filter 2 and the aperture effect circuit 5, and converts the luminance signal Y1 in the low frequency band to the luminance correction signal Yap.
, And outputs a luminance signal Y (γ) after the γ correction. The output stage of the aperture control effect circuit 5 and the output stage of the γ correction circuit 6 are connected to a second outline correction circuit (aperture computer) 7, which outputs the outline component on the white level side of the luminance signal Y (γ) compressed by the γ correction. The correction is performed based on the luminance correction signal Yap '. By this contour correction, the contour emphasis characteristic becomes uniform over the entire range from the white signal level to the black signal level of the luminance signal Y (γ) ′.

[0006] A fader processing circuit 8 is connected to an output stage of the aperture control 7, and a luminance signal Y having undergone contour emphasis correction.
(Γ) ′ fader processing is performed. This process is to express the perspective of the subject's background image and body image,
Based on external requests to blur the background image,
This is performed by bringing the signal level of the luminance signal Y (γ) ′ closer to the black level or the white level. The luminance signal Yout after the fader processing is output from the output terminal 9 to an electronic viewfinder (ELV) circuit (not shown) at the next stage or the like. As a result, a fader image of the subject can be reproduced based on the corrected luminance signal Yout characterizing the blurring of the background image and a color signal (not shown).

[0007]

However, according to the conventional luminance signal processing circuit 10, the filter coefficients of the digital low-pass filter 2 are fixedly set.
Therefore, since the half-value width and the center frequency of the digital low-pass filter are fixed, the bandwidth is fixed, and the frequency band that emphasizes the outline of the image or, conversely, blurs it is always a constant value. turn into. As a result, there is a problem that a truly optimum luminance correction signal corresponding to the original signal cannot be created.

Accordingly, the present invention has been made in view of the above problems, and enables display of a blurred image in which the outline of an image gradually weakens over time, and expresses perspective with a video camera or the like. It is an object of the present invention to provide a video signal processing device capable of smoothly executing fader image processing.

[0009]

An object of the present invention is to provide an adjusting means for adjusting a frequency component of a luminance signal of an arbitrary image and a fader image for gradually bringing a signal level of the luminance signal of the image closer to a white side or a black side. Processing mode, or operating means for instructing one of the normal image processing mode other than the fader image processing mode, and control means for controlling the adjusting means based on the processing mode instruction by the operating means, When the processing mode of the fader image is instructed by the operation unit, the control unit controls the adjusting unit so as to bias the frequency component of the luminance signal to the low frequency region, and when the processing mode of the normal image is instructed. Is solved by a video signal processing device characterized by controlling an adjusting means so as to spread a frequency component of a luminance signal to a high frequency region.

According to the present invention, when the fader image processing mode is instructed from the operation means to the control means, the control means controls the adjustment means so as to bias the frequency component of the luminance signal to a low frequency region. Is done.

Therefore, the adjusting means adjusts the frequency component of the luminance signal so that the signal level of the luminance signal of the image gradually changes. This makes it possible to display a blurred image in which the outline of the image is gradually weakened (suppressed) over time.

Further, for example, when the mode is switched from the fader image processing mode to the normal image processing mode, the control means controls the adjusting means so as to spread the frequency component of the luminance signal to a high frequency region. The adjusting means adjusts the frequency component of the luminance signal so that the signal level of the luminance signal of the image gradually changes. This makes it possible to display a clear image in which the outline of the image is gradually enhanced with the passage of time.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(1) First Embodiment FIG. 1 is a block diagram showing a configuration example of a video camera 100 to which a video signal processing device as each embodiment of the present invention is applied.

In this embodiment, an adjusting means for adjusting a frequency component of a luminance signal of an arbitrary image is provided, and when a processing mode of a fader image is instructed, the frequency component of the luminance signal is biased toward a low frequency region. Control the adjusting means, without increasing the configuration of the fader processing circuit, etc.
The present invention is capable of displaying a blurred image in which the outline of the image is gradually weakened with the passage of time and fading image processing for expressing a perspective with a video camera or the like.

In this example, a case is described in which the video signal processing apparatus according to the embodiment is applied to a color video camera 100 having a fader image processing mode. The video camera 100 has a CCD as an image pickup means.
An apparatus 11 is provided, and an image of the subject 30 is obtained.
The CCD device 11 is provided with an imaging lens similar to that of a conventional system (not shown), and forms an image of incident light from the subject 30. Three prisms are provided downstream of the imaging lens, and these prisms separate red light, green light, and blue light, respectively.

In addition, for each prism, a stage for red is provided.
An image sensor for green and blue is provided, and a red acquisition signal (hereinafter simply referred to as an R signal), a green acquisition signal (hereinafter simply referred to as a G signal), and a blue color, which receive and photoelectrically convert red light, green light and blue light. An acquisition signal (hereinafter, simply referred to as a B signal) is output.

The CCD device 11 has signal processing means 12
Is connected, and a color signal (video signal) obtained by performing signal processing on the R, G, and B signals by the CCD device 11 to be composited
Cin and a luminance signal Yin are output. Signal processing means 12
Is a sample and hold circuit (hereinafter referred to as an S / H circuit) 2
1, an analog / digital conversion circuit 22 (hereinafter referred to as an A / D conversion circuit) 21 and a luminance-color separation circuit (hereinafter referred to as a YC separation circuit) 23.

In the S / H circuit 21, R, G, and B signals as analog image signals by the CCD device 11 are held in a capacity (not shown) or the like. The voltage held in this capacitance is converted into a digital signal by the A / D conversion circuit 22. The R, G, B signals that have become digital signals are YC
The signal is output to the separation circuit 23. In the YC separation circuit 23, R,
The luminance signal Yin is separated from the G and B signals.

The luminance signal processing circuit 13 as an adjusting means is connected to the output stage of the YC separation circuit 23. The luminance signal processing circuit 13 adjusts the frequency component of the luminance signal Yin. An example of the internal configuration of the luminance signal processing circuit 13 will be described with reference to FIGS. Also, the YC separation circuit 23
A color signal processing circuit 14 is connected to the output stage, and a shading correction circuit for a black portion (not shown), a gain increase circuit for +3 dB, +6 dB,...
It comprises a white balance circuit, a gain control circuit for white shading correction, a flare correction circuit, and the like.

A control microcomputer (hereinafter simply referred to as a control microcomputer) 15 as control means is connected to the above-mentioned luminance signal processing circuit 13.
5 is connected to an operation switch 16 as operation means and a ROM 17 as storage means.

The operation switch 16 allows the user to specify one of a fader image processing mode and a normal image processing mode. Here, the processing mode of the fader image refers to an operation of gradually bringing the signal level of the luminance signal Yin of the image closer to the white side or the black side. The normal image processing mode refers to an operation other than the fader image processing mode. In this example, regarding the processing mode of the normal image / fader image, for example, by selecting the operation switch 16, the mode setting data D2 is output to the control microcomputer 15.

In this example, the control microcomputer 15 controls the luminance signal processing circuit 13 based on a processing mode instruction from the operation switch 16. For example, when the processing mode of the fader image is instructed by the operation switch 16, the control microcomputer 15 controls the luminance signal processing circuit 13 so as to bias the frequency component of the luminance signal to a low frequency region. Also, when the normal image processing mode is instructed,
The luminance signal processing circuit 13 is controlled so as to extend the frequency component of the luminance signal to a high frequency region.

For this purpose, the ROM 17 stores reference table information D1 shown in FIG. This reference table information D1 previously expresses the relationship between the frequency characteristic pattern N of the luminance signal Yin and the adjustment time t as a function n = f (t). In FIG. 2, the horizontal axis represents time t, and Tma
x is the maximum elapsed time. The vertical axis is the frequency characteristic pattern N
This is information for changing a filter coefficient of, for example, a digital low-pass filter in the luminance signal processing circuit 13.

In this example, with respect to the frequency characteristics of the suppression filter 31, N patterns having many resolutions shown in FIGS. 3A to 3C are prepared. In this example, N = 3. 3A to 3C, the horizontal axis represents the frequency f, and the vertical axis represents the gain G. Here, the half width means the suppression filter 31.
And the bandwidth connecting the frequencies at which the gain G becomes 1/2.

FIG. 3A shows a frequency characteristic pattern (N = 3) in which the half-width at which the suppression filter 31 passes the frequency component of the normal image is w3. In this case, the frequency characteristic pattern includes the highest frequency component in the luminance signal, and the clearest image can be obtained. FIG. 3B
Indicates a frequency characteristic pattern (N = 2) in which the half value width w2 at which the frequency component of the intermediate image between the normal image and the fader image passes through the suppression filter 31 is w2.

FIG. 3C shows a frequency characteristic pattern (N = 1) in which the half-width at which the low-frequency component of the fader image is passed by the suppression filter 31 is w1. In this case, the high-frequency component in the luminance signal becomes a frequency characteristic pattern with the most cut, and the most blurred image can be obtained. The half-value width is w3>w2> w1, and as the high-frequency component is cut, the half-value width gradually decreases to w3, w2, and w1, as shown in FIGS. 3B and 3C.

Therefore, when the processing mode of the fader image is instructed, the control microcomputer 15 controls the ROM 17.
, And the luminance signal processing circuit 13 can be controlled based on the reference table information D1.

Returning to FIG. 1, the luminance signal processing circuit 1
3 and an addition circuit 1 at the output stage of the color signal processing circuit 14.
8 is connected, and the composite signal Si after adding the color signal Cout and the luminance signal Yout subjected to the fader processing is added.
n is output. A digital / analog conversion circuit (hereinafter referred to as a D / A conversion circuit) 19 is provided at an output stage of the addition circuit 18.
Is connected, and the analog video signal Sout after digital-to-analog conversion of the composite signal Sin is output to the output terminal 20.
Output from In this example, a video recording / reproducing device 24 as recording / reproducing means is provided at the output stage of the D / A conversion circuit 19
Is connected so that fader images can be recorded and reproduced.

Next, a configuration example of the luminance signal processing circuit 13 will be described. FIG. 4 is a block diagram showing a configuration example of the luminance signal processing circuit 13, and FIG. 5 is a block diagram showing a configuration example of the suppression filter 31. In this example, it is assumed that when the luminance signal Yin is input to the luminance signal processing circuit 13, the outline of the image is extracted and the fader processing is performed based on an external request.

The luminance signal processing circuit 13 shown in FIG. To this input terminal 25, a luminance signal Yin separated from the R, G, and B color video signals, which are original signals, is input. A suppression filter 31 is connected to the input terminal 25, and executes a filtering process based on, for example, operation coefficient information output from the control microcomputer 15. In this example, the operation coefficient information is, for example, five filter coefficients K1 to K5.

The suppression filter 31 includes a delay circuit 41, a bandpass filter 42, an amplifier 43, and an addition circuit 4 shown in FIG.
Four. A delay circuit 41 is connected to the input terminal 25, and delays the luminance signal Yin of the image to make the output timing uniform. The output stage of the delay circuit 41 is connected to an adder circuit 44 having an output terminal 26. On the other hand, a band-pass filter 42 is connected to the input terminal 25 so as to extract and pass a luminance signal Yin in a specific low-frequency band according to the five filter coefficients K1 to K5 output from the control microcomputer 15. I have.

In this example, the bandpass filter 42 forms a transversal filter (finite-length impulse response circuit),
It has four delay elements 52, 54, 56, 58, five multiplication circuits 51, 53, 55, 57, 59, and one filter addition circuit 60. In this example, when the processing mode of the fader image is instructed, the filter coefficient K
1 is automatically variably set in the multiplication circuit 51, similarly, the filter coefficient K2 is automatically variably set in the multiplication circuit 53, the filter coefficient K3 is automatically variably set in the multiplication circuit 55, and the filter coefficient K4 is automatically variably set in the multiplication circuit 57. The filter coefficient K5 is variably set, and is automatically variably set in the multiplication circuit 59.

That is, the control microcomputer 1 is connected to the input terminal 25.
5 is connected to a multiplication circuit 51 to which a filter coefficient K1 is supplied, and multiplies the filter coefficient K1 by the luminance signal Yin. The multiplication result of the multiplication circuit 51 is output to the addition circuit 60. A delay element 52 is connected to the input terminal 25, and the luminance signal Yin is delayed by a predetermined timing, for example, one horizontal period (H). Similarly, a multiplying circuit 53 to which a filter coefficient K2 is supplied is connected to the output stage of the delay element 52, and the filter coefficient K2 and the delay element
2 is multiplied by the luminance signal Yin. The multiplication result of the multiplication circuit 53 is output to the addition circuit 60.

Similarly, a delay element 54 is connected to the output stage of the delay element 52, and the luminance signal Yin is delayed by a predetermined timing, for example, one horizontal period (H). A multiplying circuit 55 to which a filter coefficient K3 is supplied is connected to the output stage of the delay element 54.
3 and the luminance signal Yin output from the delay element 54 are multiplied. The multiplication result of the multiplication circuit 55 is output to the addition circuit 60.

A delay element 56 is connected to the output stage of the delay element 54, and the luminance signal Yin is further delayed at a predetermined timing, for example, one horizontal period (H). A multiplying circuit 57 to which a filter coefficient K4 is supplied is connected to the output stage of the delay element 56, and the filter coefficient K4 is multiplied by the luminance signal Yin output from the delay element 56. The multiplication result of the multiplication circuit 57 is output to the addition circuit 60.

Further, a delay element 58 is connected to the output stage of the delay element 56, and the luminance signal Yin is delayed by a predetermined timing, for example, one horizontal period (H). A multiplying circuit 59 to which a filter coefficient K5 is supplied is connected to the output stage of the delay element 58, and the filter coefficient K5 is multiplied by the luminance signal Yin output from the delay element 58. The multiplication result of the multiplication circuit 59 is output to the addition circuit 60. For each of the delay elements 52, 54, 56, 58, a tapped delay line or the like is used.

In this addition circuit 60, five multiplication circuits 5
The outputs of 1, 53, 55, 57, and 59 are added, and the addition result is output to the amplifier 43 as the output of the bandpass filter 42, that is, the luminance correction signal AP. The gain of the luminance correction signal AP is controlled by an amplifier 43 as an arithmetic circuit based on a gain control signal Gc as a correction coefficient from the control microcomputer 15.

In this example, a desired correction coefficient is calculated for the low frequency component of the luminance correction signal AP by variably setting the gain of the amplifier 43 based on the processing mode of the fader image or the processing mode of the normal image. be able to. An addition circuit 44 is connected to the output stage of the amplifier 43, and the output of the amplifier 43 (the luminance correction signal AP ') and the output of the delay circuit 41 (the luminance signal Yin') are added. The luminance signal Y0 after the addition becomes a luminance signal optimal for the fader processing.

The circuit configuration at the subsequent stage of the suppression filter 31 is almost the same as that of the conventional system. Returning to FIG. 4, a digital low-pass filter (LPF) 32 having a fixed filter coefficient is connected to the output stage of the suppression filter 31,
Based on the luminance signal Y0, a luminance signal Y1 in a low frequency band required for image display is extracted.

The output stage of the digital low-pass filter 32 is connected to a horizontal contour correction circuit (hereinafter simply referred to as H aperture control) 33, which receives the luminance signal Y1 in the low frequency band to extract the horizontal contour of the image. Later, the contour component signal Yh is output. The input terminal 1 is further connected to a vertical direction contour correction circuit (hereinafter simply referred to as V aperture control) 34, which outputs a contour component signal Yv after inputting a luminance signal Yin to extract a vertical direction contour of an image. You. An output stage of the H aperture control 33 and the V aperture control 34 is connected to a contour effect imparting circuit (hereinafter referred to as an aperture control effect circuit) 35, and a contour component signal Yh in the horizontal and vertical directions of the image.
And a luminance correction signal Yap after combining Yv.

The output stage of the digital low-pass filter 32 and the aperture effect circuit 35 has a γ correction circuit 3
6 is connected, and the luminance signal Y (γ) after the γ correction of the low frequency band luminance signal Y1 based on the luminance correction signal Yap is output. At the output stage of the aperture control effect circuit 35 and the γ correction circuit 36, a second contour correction circuit (a
Is connected, and the luminance signal Y compressed by the γ correction
The contour component on the white level side of (γ) is corrected based on the luminance correction signal Yap ′. By this contour correction, the contour emphasis characteristic becomes uniform over the entire range from the white signal level to the black signal level of the luminance signal Y (γ) ′.

A fader processing circuit 38 is connected to the output stage of the aperture control 37, and performs a fader process on the luminance signal Y (γ) ′ whose outline enhancement has been corrected. In this processing, the signal level of the luminance signal Y (γ) ′ is changed to a black level or a white level based on an external request to blur the background image in order to emphasize the perspective between the background image of the subject and the main body image. It is done by approaching. The luminance signal Yout after the fader processing is output from an output terminal 39 to an electronic viewfinder (ELV) circuit (not shown) at the next stage or the like. As a result, a fader image of the subject can be reproduced based on the corrected luminance signal Yout characterizing the blurring of the background image and a color signal (not shown).

Next, the operation of the video camera 100 to which the video signal processing device according to the present embodiment is applied will be described. FIG. 6 is a flowchart showing a control example of the control microcomputer 15 in the normal image / fader image processing mode.

In this example, four H delay elements 52, 54, 5 are used to characterize the blur of the background image of the luminance signal Yin input to the luminance signal processing circuit 13.
It is assumed that a band-pass filter 42 using 6, 58 is used. Further, when the user selects the operation switch 16, the control microcomputer 15 is instructed on the normal image / fader image processing mode. Further, the control time (hereinafter referred to as fader control time) t relating to the processing mode of the fader image is performed until a preset maximum elapsed time Tmax is reached.

Assuming these control conditions, first, in step P1, the control microcomputer 15 waits for an instruction of a processing mode of a normal image or a processing mode of a fader image with respect to the acquired image of the subject 30. At this time, when the user selects the operation switch 16 for instructing the normal image processing mode, the mode setting data D2 for setting the normal image processing mode is output to the control microcomputer 15.

Thereafter, in step P2, it is determined whether the designated processing mode is a normal image processing mode or a fader image processing mode. At this time, the control microcomputer 15 determines whether the mode setting data D2 output from the operation switch 16 is the normal image processing mode or the fader image processing mode by, for example, activating or deactivating the mode setting data D2.

Here, when the normal image processing mode is instructed, the control microcomputer 15 controls the suppression filter 3.
For example, the multiplication circuits 51, 5 shown in FIG.
Filter coefficients K1 to K5 for 3, 55, 57 and 59 are set. As a result, the frequency component of the luminance signal Yin is broadened to a high frequency band (up to the maximum) by the suppression filter 31, so that the frequency characteristic is as shown in FIG. 3A. Of course, the luminance signal Yin relates to the acquired image of the subject 30 captured by the CCD device 11 and is signal-processed by the signal processing unit 12 thereafter.

Each of the multiplication circuits 51, 53, 55, 57,
At 59, the luminance signal Yin delayed by a predetermined timing is multiplied by the respective filter coefficients K1, K2, K3, K4, and K5. Thereafter, the multiplying circuits 51, 5
The outputs of 3, 55, 57 and 59 are all added. After the addition, the brightness correction signal AP is amplified by the amplifier 43 with the optimum gain G. The amplification of the amplifier 43 is controlled by a gain control signal Gc from the control microcomputer 15.

After that, the output of the amplifier 43 (luminance correction signal AP ′) and the output of the delay circuit 41 (luminance signal Yin ′) are added by the addition circuit 44. In this example, the luminance signal Yin is delayed by four horizontal periods (4H) by the delay circuit 41 so that the output of the bandpass filter 42 and the output of the delay circuit 41 are aligned. The luminance signal Y0 optimal for processing the normal image after the addition is output from the addition circuit 44 to the digital low-pass filter 32, the V-aperture controller 34, and the like, as in the conventional method.

For the processing after step P3 described above, the flow shifts to step P10 to execute other processing. For example, a normal image is recorded in the electronic viewfinder processing or the video recording / reproducing device 24 in the same manner as in the conventional method.

When it is determined in step P2 that the processing mode of the fader image is instructed, the process proceeds to step P4, where the reference table information D1 shown in FIG. With this,
The fader command D3 is output from the control microcomputer 15 to the fader processing circuit 38.

Thereafter, in Step P5, the control microcomputer 1
5, after the fader flag is cleared, the function n = n obtained from the reference table information D1 in step P6.
Regarding f (t), the filter coefficients K1 to K5 are automatically set in the bandpass filter 42 every time the unit time elapses.

That is, in step P7, the function n = f (t)
Is substituted for t = 0, and the filter coefficients K1 to K5 are set to the control microcomputer 1 as the frequency characteristic pattern N = 1 based on this.
5 is calculated. The filter coefficients K1 to K5 are supplied from the control microcomputer 15 to the multiplication circuit 5 of the suppression filter 31.
1, 53, 55, 57, 59.

Each of the multiplication circuits 51, 53, 55, 57,
At 59, the luminance signal Yin delayed by a predetermined timing is multiplied by the respective filter coefficients K1, K2, K3, K4, and K5. Thereafter, the multiplication circuits 51, 53, 55, 5
After all the outputs of 7 and 59 are added, the luminance correction signal AP is amplified with the optimum gain G as in the normal image processing mode. As a result, the frequency characteristic of the suppression filter 31 can be changed so that the frequency component of the luminance signal Yin shifts to the low frequency band as the unit time elapses.
After that, the luminance correction signal AP 'and the luminance signal Yin' are added to become the optimal luminance signal Y0 for the processing of the fader image.

The optimum luminance signal Y0 is supplied from the adding circuit 44 to the digital low-pass filter 32 or the V
4 and so on. In the digital low-pass filter 32, a luminance signal Y1 in a low frequency band necessary for image display is extracted from the luminance signal Y0. This low frequency band luminance signal Y
In the H aperture control 33 to which 1 has been input, a contour component signal Yh is output after the horizontal contour of the image is extracted.

In the V-aperture controller 34, the luminance signal Y0
To extract a vertical contour of the image, and then output a contour component signal Yv. The output of each of the H aperture control 3 and the V aperture control 4, that is, the horizontal and vertical contour component signals Yh and Yv of the image are synthesized by an aperture control effect circuit 35, and then become a luminance correction signal Yap to become a gamma correction circuit. 36.

In the γ correction circuit 36, the luminance signal Y (γ) after the γ correction of the luminance signal Y1 in the low frequency band based on the luminance correction signal Yap is converted into a second contour correction circuit (aperture computer).
37. In the aperture controller 37, the outline component on the white level side of the luminance signal Y (γ) compressed by the γ correction is corrected based on the luminance correction signal Yap ′. By this contour correction, the contour emphasis characteristic becomes uniform over the entire range from the white signal level to the black signal level of the luminance signal Y (γ) ′.

The luminance signal Y subjected to the contour enhancement correction
(Γ) ′ is output to the fader processing circuit 38, where the fader processing is performed. This process is based on a luminance signal Y (γ) ′ based on a fader command D3 from the control microcomputer 15 or R to “blur the background image” in order to emphasize the perspective between the background image of the subject and the main body image. Is made closer to the black level or the white level. The luminance signal Yout after the fader processing is output to the next buffer memory or the like.

Accordingly, in order to perform the fader processing within the maximum elapsed time, the process shifts to step P8 to determine whether the fader control time t has exceeded the maximum elapsed time Tmax. If the fader control time t has not exceeded the maximum elapsed time Tmax, the flow shifts to step P9, where the fader control time is set to t = t + 1, and returns to step P8 to continue the correction of the optimal luminance signal for the fader processing. .

For example, as the unit time elapses, the function n =
.. are substituted for f (t), and the filter coefficients K1 to K
5 are calculated, and filter coefficients K1 to K5 are calculated with the frequency characteristic pattern N = 3. The filter coefficients K1 to K5 based on the frequency characteristic patterns N = 1, 2,... Are automatically set in the multiplication circuits 51, 53, 55, 57, 59 shown in FIG. As a result, the suppression filter 31 causes the frequency component of the luminance signal Yin to be biased toward the low frequency band. As shown in FIG. 3B and FIG. 3C, the half-width of the frequency characteristic of the suppression filter 31 gradually narrows to w3, w2, and w1.

If the fader control time t has reached the maximum elapsed time Tmax in step P8, the program proceeds to step P8.
Then, the process proceeds to 10 to execute other processing. For example, after the corrected luminance signal Yout characterizing blurring of the background image read from the buffer memory and a digital color signal (not shown) are digital-to-analog converted by the D / A conversion circuit 19, the video recording / reproducing device 24 For example, a fader image is recorded.

As described above, according to the video camera 100 to which the video signal processing apparatus of the present embodiment is applied, when the operation mode of the fader image is instructed from the operation switch 16 to the control microcomputer 15, the control microcomputer 1
5, the luminance signal processing circuit 13 is controlled so as to bias the frequency component of the luminance signal Yin to the low frequency region.

Accordingly, the luminance signal processing circuit 13 adjusts the frequency component of the luminance signal Yin so that the signal level of the luminance signal Yin of the image gradually approaches, for example, the white side. This makes it possible to display a blurred image in which the outline of the image is gradually suppressed over time.

When the mode is switched from the fader image processing mode to the normal image processing mode, the control microcomputer 15 controls the luminance signal processing circuit 13 so as to extend the frequency component of the luminance signal Yin to a high frequency region. Therefore, in the luminance signal processing circuit 13, the image luminance signal Yin
The frequency component of the luminance signal Yin is adjusted so that the signal level gradually approaches, for example, the black side.

As a result, the luminance signal Yin containing many low-frequency components is converted from the luminance signal Yin containing many frequency components of a normal image.
The transition to the in state can be made, and conversely, the transition from the luminance signal Yin containing the frequency component of the normal image to the luminance signal Yin containing many low frequency components can be made. Therefore, it is possible to display a clear image in which the outline of the image is gradually enhanced with the passage of time, and the outline between the background image of the subject 30 and the main image can be expressed as a natural blur. A fader image with perspective can be obtained with good reproducibility.

(2) Second Embodiment FIG. 7 is a block diagram showing a configuration example of a luminance signal processing circuit 61 according to a second embodiment of the present invention. In this example,
A digital low-pass filter 61 having both the function of the suppression filter 31 and the function of the low-pass filter 32 of the first embodiment is provided. In addition, since the thing with the same code | symbol and name as 1st Embodiment has the same function,
The description is omitted.

The digital low-pass filter 61 of this example has substantially the same configuration as the suppression filter 31 shown in FIG. 5, and uses a digital low-pass filter as the bandpass filter. Therefore, while the filter coefficient is fixed by the conventional digital low-pass filter 2, in this example, for example, five filter coefficients K1 to K5 are controlled by the control microcomputer 15 according to the processing mode of the normal image / fader image. Since the setting is automatically variably set, the filter coefficients K1 to K5 are used to extract a luminance signal Yin in a low frequency band required for displaying a normal image and a luminance signal Yin in a specific low frequency band required for displaying a fader image. Can be passed.

As described above, the digital low-pass filter 62
By providing the function of the suppression filter 31 described above, the increase in the circuit scale of the luminance signal processing circuit 61 can be suppressed as compared with the first embodiment. In addition, as in the first embodiment, transition from the luminance signal Yin containing many low-frequency components to the state of the luminance signal Yin containing frequency components of the normal image, on the contrary, including the frequency component of the normal image Luminance signal Y containing many low frequency components from luminance signal Yin
The state can be changed to in. Therefore, it is possible to provide a video camera or the like having a fader function for changing a blurred image from a normal image to a normal image, and vice versa.

Although the present embodiment has been described with reference to the case where the frequency characteristic pattern changes stepwise with the passage of time, the present invention is not limited to this. Of course, if a smooth function n = f (t) with an increased resolution is prepared in advance, the suppression filter 31 and the digital low-pass filter 62
Since the frequency characteristics of can be changed smoothly,
It is possible to obtain a fader image without a sense of discomfort.

In each of the embodiments, the case where the fader processing circuit 38 is provided at the final stage of the luminance signal processing circuits 13 and 61 to perform the fader processing has been described. However, the frequency characteristic pattern is controlled by the suppression filter 31 and the digital low-pass filter 62. , The same fader processing can be performed, so that the fader processing circuit 38 can be omitted.

[0072]

As described above, according to the present invention,
Adjustment means for adjusting the frequency component of the luminance signal of the arbitrary image is provided, and when the processing mode of the fader image is instructed, the adjustment means is controlled so as to bias the frequency component of the luminance signal to a low frequency region, Further, when the normal image processing mode is instructed, the adjusting means is controlled so that the frequency component of the luminance signal is extended to a high frequency region.

With this configuration, it is possible to display a blurred image in which the outline of the image is gradually suppressed with the passage of time, or to display a clear image in which the outline of the image is gradually emphasized with the passage of time. Can be. This makes it possible to smoothly perform fader image processing for expressing perspective with a video camera or the like without complicating the circuit configuration.

The present invention is very suitable when applied to a fader processing system necessary for smoothly performing a fader image expressing a perspective with a video camera or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a video camera 100 to which a video signal processing device according to each embodiment of the present invention is applied.

FIG. 2 is a conceptual diagram showing an example of the contents of reference table information D1 in a ROM 17.

FIGS. 3A to 3C are diagrams illustrating examples of frequency characteristics (low frequency band) of the suppression filter 31. FIGS.

FIG. 4 is a luminance signal processing circuit 13 according to the first embodiment;
FIG. 3 is a block diagram illustrating a configuration example of FIG.

FIG. 5 is a block diagram showing a configuration example of the suppression filter 31.

FIG. 6 is a flowchart showing a control example of the control microcomputer 15 in a normal image / fader image processing mode.

FIG. 7 shows a luminance signal processing circuit 61 according to a second embodiment.
FIG. 3 is a block diagram illustrating a configuration example of FIG.

FIG. 8 is a block diagram illustrating a configuration example of a luminance signal processing circuit 10 of a conventional system.

[Explanation of symbols]

11 ... CCD device (imaging means), 12 ... Signal processing means, 13, 61 ... Brightness signal processing circuit, 14 ...
・ Color signal processing circuit, 15 ・ ・ ・ Control microcomputer (control means), 16 ・ ・ ・ Operation switch (operation means), 17 ・
..ROM (storage means), 24, recording / reproducing apparatus, 31
... suppression filters, 32, 62 ... digital low-pass filters, 38 ... fader processing circuits, 41 ...
-Delay circuit, 42 ... bandpass filter, 43 ... amplifier, 44, 60 ... addition circuit, 51, 53, 55, 5
7, 59... Multiplication circuits, 52, 54, 56, 58,.
.Delay elements, 100 video cameras

Claims (6)

[Claims] An adjusting means for adjusting a frequency component of a luminance signal of an arbitrary image; a processing mode of a fader image for gradually bringing a signal level of the luminance signal of the image closer to a white side or a black side; Operating means for instructing any one of the normal image processing modes other than the processing mode described above, and control means for controlling the adjusting means based on an instruction of the processing mode by the operating means. When the processing mode of the fader image is instructed by the means, the adjusting means is controlled so as to bias the frequency component of the luminance signal to a low frequency region. A video signal processing apparatus, wherein the adjusting means is controlled so that a frequency component of a signal is extended to a high frequency region. 2. The method according to claim 1, wherein the operation unit and the control unit are provided, and a storage unit is provided which stores reference table information in which a frequency characteristic pattern of a luminance signal and an adjustment time are functioned in advance. 2. The video according to claim 1, wherein when a processing mode of a fader image is instructed by the operation unit, reference table information is read from the storage unit, and an adjustment unit is controlled based on the reference table information. Signal processing device. 3. An adjusting device for adjusting a frequency component of the luminance signal, the adjusting device comprising: a delay circuit for delaying the luminance signal and adjusting output timing; A band-pass filter for extracting a component, a calculation circuit for calculating a desired correction coefficient for a low-frequency component of the luminance signal extracted by the band-pass filter, and an addition for adding an output of the calculation circuit and a luminance signal from the delay circuit. And a circuit.
A video signal processing device according to claim 1. 4. The method according to claim 1, wherein the arithmetic circuit is provided, wherein a gain of the arithmetic circuit is variably set based on a processing mode of a fader image or a processing mode of a normal image, so that the low frequency of the luminance signal is reduced. 4. The video signal processing device according to claim 3, wherein a desired correction coefficient is calculated for the component. 5. An imaging device for obtaining an image of a subject, wherein the adjustment device is provided, and a signal processing device for performing signal processing on an output from the imaging device to output a video signal and a luminance signal of the subject. The video signal processing apparatus according to claim 1, wherein the adjustment unit adjusts a frequency component of a luminance signal of the subject image by the signal processing unit. 6. The video signal processing apparatus according to claim 1, further comprising recording / reproducing means for recording / reproducing the fader image.