JPH06334994A - Adaptive motion interpolation signal generator using motion vector - Google Patents

Abstract

PURPOSE:To suppress the picture distortion generated due to the quick change of the magnitude of a motion vector. CONSTITUTION:When the magnitude ¦V¦ of a motion vector V detected by a motion vector detecting circuit 13 exceeds a threshold THV outputted from a threshold generating circuit 42, an upper threshold THH of an adaptive motion interpolation switching control circuit 32 is controlled so as to be gradually increased in accordance with the increase of difference DELTAV between them. Then, the inclination of the control characteristic of an adaptive motion interpolation coefficient beta is reduced. As the result, a linear field interpolation signal S2 is selected more easily in comparison with the case that ¦V¦ does not exceed the threshold THV.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates a true interpolation signal by adaptively switching between an interpolation method using a motion vector and an interpolation method not using a motion vector based on the image quality of both. The present invention relates to an adaptive motion interpolation signal generation device using moving vectors.

[0002]

2. Description of the Related Art In recent years, in the field of television broadcasting, research and development relating to conversion technology of a television standard system have been actively carried out in response to an increasing demand for program exchange between different systems.

One of the conversion items of this television standard system
One is conversion of the number of fields. In principle, this conversion is achieved by thinning out one field or repeating one field for each predetermined number of fields.

However, this method has a problem that the motion of the moving image becomes discontinuous at each thinning cycle or repetition cycle. For this reason, the field interpolation method is often used in devices that require high image quality.

As the field interpolation method, at present, a field interpolation method based on 2-field linear interpolation (hereinafter referred to as "linear interpolation method") and a field interpolation method using 4 fields (hereinafter referred to as "field interpolation method"). "4 field interpolation method") and a field interpolation method using motion vectors have been put to practical use.

The linear interpolation method is a linear interpolation based on a field interpolation ratio from a television signal of the previous field (hereinafter referred to as "previous field signal") and a television signal of the current field (hereinafter referred to as "current field signal"). By interpolation, a television signal of an interpolated field (hereinafter referred to as "field interpolated signal") is generated.

The 4-field interpolation method obtains a field interpolation signal by treating a television signal as a signal sampled at a field frequency and processing the conversion of the number of fields as a conversion of the sampling frequency. .

The field interpolation method using a motion vector detects the direction and magnitude of the motion of the moving image, that is, the motion vector, and uses this motion vector to perform motion correction (correcting the position of the moving image. )
The field interpolation signal is obtained.

The linear interpolation method has a simple circuit structure, but has a problem that a so-called jerkiness phenomenon occurs in which a discontinuous portion occurs in a moving image. The 4-field interpolation method can reduce jerkiness more than the linear interpolation method, but has a problem that the resolution of a moving image is reduced.

On the other hand, in the field interpolation method using the motion vector, the position of the moving image itself is corrected and its position is corrected, so that jerkiness and the decrease in resolution can be eliminated. Therefore, when the field interpolation method is used as the field number conversion method, the field interpolation method using the motion vector is effective.

However, in the case of the field interpolation method using this motion vector, there is a problem that the motion vector detection accuracy and motion correction accuracy directly affect the image quality. Therefore, when the field interpolation method using this motion vector is used, it is necessary to adopt a highly accurate motion vector detection technique or motion correction technique.

However, at present, a highly accurate motion vector detecting technique and motion correcting technique have not been established. For this reason, when the field interpolation method using the motion vector is used, this is combined with, for example, a linear interpolation method, and these are adaptively switched based on the image quality of both, so that the true interpolation signal is obtained. Is obtained. Hereinafter, such a method is referred to as an adaptive switching interpolation method.

FIG. 2 is a block diagram showing a conventional structure of such an image quality adaptive switching type field interpolation signal generating apparatus.

In the figure, the motion vector detection circuit 13
, The motion vector correction circuit 14, and the motion correction memory 1
5, 16 and the multiplication circuits 17 and 18, and the addition circuit 19,
A field interpolation signal generation circuit of a field interpolation method using motion vectors is configured.

This circuit performs field interpolation processing using a motion vector from the current field signal PS supplied to the input terminal 11 and the previous field signal FS supplied to the input terminal 12 (hereinafter, referred to as a field interpolation signal). S1), which is referred to as a "motion compensation field interpolation signal", is generated.

The multiplication circuits 20 and 21 and the addition circuit 22 are
A field interpolation signal generation circuit of a linear interpolation method is configured. This circuit uses a current field signal PS supplied to the input terminal 11 and a previous field signal FS supplied to the input terminal 12 to perform a field interpolation signal (hereinafter, referred to as “linear field S2) which is referred to as "interpolation signal".

In addition, the multiplication circuits 23 and 24 and the addition circuit 2
5, subtraction circuits 27 and 29, absolute value conversion / accumulation circuit 2
The adaptive motion interpolation switching control circuit 31 includes the adaptive switching circuits 8 and 30.

This circuit detects the image quality of an image by the motion compensation field interpolation signal S1 (hereinafter referred to as "motion compensation field interpolation image") and the image by the linear field interpolation signal S2 (hereinafter referred to as "linear field interpolation image"). The true field interpolation signal S3 is output to the output terminal 26 by adaptively switching the two on the basis of the image quality of (1).

As a parameter indicating the image quality of the motion compensation field interpolated image, a difference value (hereinafter referred to as "motion compensation field difference value") D1 indicating the level difference between the motion compensated field signals PS and FS. Is used.
Further, as the parameter indicating the image quality of the linear field interpolated image, the field signal PS that is not subjected to motion correction,
A difference value (hereinafter, "motion 0 inter-field difference value") D2 indicating a level difference between FSs is used.

With such a configuration, the two can be adaptively switched according to the image quality of the motion-corrected field interpolated image and the linear field interpolated image, so that a detection error of the motion vector V or the like occurs. Therefore, it is possible to suppress the deterioration of the image quality of the true field interpolated image.

[0021]

However, in the above-mentioned configuration, there is a problem that the distortion of the true field interpolated image occurs when the magnitude of the motion vector V changes abruptly. Hereinafter, this problem will be described with reference to FIG.

Now, let us consider a case where the camera catches a moving object (circle in this figure) and is panning as shown in FIG. 3 (a). In this case, in the television image, the image of the moving object becomes a still image and the background image becomes a moving image.

In such a television image, when the background is flat (when the level of the image signal does not change) or when the movement is small, the true field interpolated image is hardly distorted.

However, when the background is not flat or its movement is large, the magnitude of the motion vector V changes abruptly behind the moving object, and its detection accuracy also deteriorates. Therefore, distortion occurs in the motion-compensated field interpolated image, and when this is selected, distortion occurs in the true field interpolated image. Therefore, in this case, the image distortion is smaller when the linear field interpolated image is selected as the true field interpolated image.

However, in this case, since the background, which is the shadow of the stationary object, appears on the screen of the current field, the difference value D2 between motion 0 fields becomes large. This facilitates selection of the motion compensation field interpolated image, and as shown in FIG. 3B, image distortion occurs behind the stationary object.

The present invention has been made to cope with the above situation, and an adaptive motion interpolation signal generation apparatus using a motion vector capable of suppressing image distortion caused by a sudden change in the magnitude of the motion vector. The purpose is to provide.

[0027]

To achieve the above object, the present invention provides a first interpolation signal obtained by an interpolation method using a motion vector and an interpolation method not using a motion vector. In the adaptive motion interpolation signal generation device that adaptively switches the obtained second interpolation signal according to the image quality of both, when the magnitude of the motion vector exceeds a predetermined threshold value, the second interpolation signal is The image quality adaptive switching operation is controlled in accordance with an increase in the difference between the two so that the selection becomes easier.

[0028]

According to the above configuration, when the magnitude of the motion vector exceeds the predetermined threshold value, the second interpolation signal is more easily selected than when the magnitude of the motion vector does not exceed the predetermined threshold value. Moreover, the tendency becomes larger as the difference between the magnitude of the motion vector and the threshold becomes larger. Therefore, even if the magnitude of the motion vector changes abruptly, it is possible to suppress the occurrence of image distortion.

[0029]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The apparatus of FIG. 1 has an inter-field difference value D1,
2 that the true field interpolation signal S3 is obtained by adaptively switching between the motion compensation field interpolation signal S1 and the linear field interpolation signal S2 based on D2.
It is the same as the device.

However, in the apparatus of FIG. 2, the adaptive switching operation is fixed, whereas in the apparatus of FIG. 1, the adaptive switching operation is controlled based on the magnitude of the motion vector V. They are different in that they are present.

The configuration of the apparatus shown in FIG. 1 having such characteristics will be described in detail below. First, the configuration of the field interpolation signal generation circuit of the field interpolation method using the motion vector will be described.

As described above, this circuit is composed of the motion vector detection circuit 13, the motion vector correction circuit 14, the motion correction memories 15 and 16, the multiplication circuits 17 and 18, and the addition circuit 19.

Here, the motion vector detection circuit 13 has a function of detecting the motion vector V of the moving image based on the current field signal PS supplied to the input terminal 11 and the previous field signal FS supplied to the input terminal 12. Have.

Various methods can be considered as the method of detecting the motion vector V. For example, a television image is subdivided into blocks of m pixels × n lines (m and n are integers). There is a method of detecting each block.

As this method, for example, JP-A-55-55
No. 162683, Japanese Patent Laid-Open No. 55-162684 and Japanese Patent Laid-Open No. 60-158786.
The iterative gradient method and the like described in No. 1 are well known.

The motion vector correction circuit 14 receives the motion vector V detected by the motion vector detection circuit 13,
It has a function of correcting the motion vector V based on the field interpolation ratio α, (1−α) by multiplying the field interpolation ratio α, (1−α) (0 ≦ α ≦ 1).

The motion correction memory 15 converts the coordinates of the current field signal PS supplied to the input terminal 11 into the motion vector (1-α) V output from the motion vector correction circuit 14.
It has the function of shifting only. Similarly, the motion correction memory 16 receives the previous field signal F supplied to the input terminal 12.
It has a function of shifting the coordinates of S by the motion vector αV output from the motion vector correction circuit 14.

The multiplication circuits 17 and 18 and the addition circuit 19 are
Current field signals PS and α deviated by (1-α) V
It has a function of generating the motion correction field interpolation signal S1 by adding the weight of the previous field signal FS deviated by V according to the field interpolation ratio α, (1−α).

The above is the configuration of the field interpolation signal generation circuit of the field interpolation method using the motion vector.

In this circuit, the motion compensation field interpolation is performed by adding the weight of the signal obtained by shifting the current field signal PS by (1-α) V and the signal obtained by shifting the previous field signal FS by αV. The signal S1 is generated in order to reduce image fluctuations that occur because the motion vector V cannot be corrected below a pixel and image fluctuations that occur when the motion vector cannot be accurately detected.

Next, the configuration of the field interpolation signal generation circuit of the linear interpolation method will be described.

As described above, this circuit has the multiplication circuit 20,
21 and an adder circuit 22 for converting the current field signal PS supplied to the input terminal 11 and the previous field signal FS supplied to the input terminal 12 into a field interpolation ratio α,
The linear field interpolation signal S2 is generated by adding the weights based on (1-α).

Next, the configuration of the adaptive switching circuit will be described.

As described above, this circuit has the multiplication circuit 23,
24, an addition circuit 25, subtraction circuits 27 and 29, absolute value conversion / accumulation circuits 28 and 30, and an adaptive motion interpolation switching control circuit 31.

Here, the multiplication circuits 23 and 24 and the addition circuit 2
Reference numeral 5 denotes an adaptive interpolation switching coefficient β, (1−β) (0 ≦ β, which is output from the adaptive motion interpolation switching control circuit 31 for the motion correction field signal S1 and the linear field interpolation signal S2.
It has a function of outputting a true field interpolation signal S3 by adding weights based on ≦ 1).

Subtraction circuit 27 and absolute value conversion / accumulation circuit 28
Has a function of detecting a difference value D1 between motion correction fields. Similarly, the subtraction circuit 29 and the absolute value conversion / accumulation circuit 30 have a function of detecting the motion 0 inter-field difference value D2.

In this case, the inter-field difference values D1, D2
Are detected in units of a predetermined interpolation block. The size of this interpolation block is set to, for example, 4 pixels × 2 lines. The inter-field difference values D1 and D2 are obtained in a predetermined block unit, not in a pixel unit. In the case of a method of obtaining in a pixel unit, an insect-feeding phenomenon is likely to occur unless an air filter is used due to noise or the like. Because it will be.

Incidentally, by obtaining the inter-field difference values D1 and D2 in a predetermined block unit, even when a signal is read from the motion correction memories 15 and 16, one pixel is read out in this block unit. .

The adaptive motion interpolation switching control circuit 31 is based on the inter-field difference values D1 and D2 output from the absolute value conversion / cumulative addition circuits 28 and 30, and the adaptive motion interpolation coefficient β, (1- It has the function of generating β).

In this case, the adaptive motion interpolation switching control circuit 3
1 is the difference ΔD (= D2 between the inter-field difference values D1 and D2).
-D1) is obtained, and the adaptive motion interpolation coefficient β is controlled based on this difference ΔD. FIG. 4 shows the control characteristic. In the figure, the characteristic curve shown by the solid line C1 is the adaptive motion interpolation coefficient β.
Shows the control characteristics of.

As shown, the adaptive motion interpolation coefficient β is equal to the difference Δ
It is controlled so as to increase as D increases. As a result, when the difference ΔD increases, the selection amount of the motion correction field interpolation signal S1 increases and the selection amount of the linear field interpolation signal S2 decreases. On the contrary, when the difference ΔD becomes smaller, the selection amount of the motion correction field interpolation signal S1 decreases and the selection amount of the linear field interpolation signal S2 decreases.

The adaptive motion interpolation coefficient β is set to 1 when the difference ΔD exceeds the upper threshold value THH. As a result, in this case, as shown in FIG. 5, only the motion compensation field interpolation signal S1 is selected. Conversely, the lower threshold T
When it becomes smaller than HL, it is set to 0. This allows
In this case, as shown in FIG. 5, only the linear field interpolation signal S1 is selected.

Next, the configuration of the switching operation control circuit for controlling the switching operation of the adaptive switching circuit will be described.

The switching operation control circuit comprises a threshold value generation circuit 41, a determination circuit 42, a difference detection circuit 43, and a threshold value control circuit 44.

Here, the threshold generation circuit 41 has a function of generating a predetermined threshold THV. This threshold value THV may be fixed or variable, but if it is variable, versatility can be provided.

The determination circuit 42 is the motion vector detection circuit 1
The magnitude | V | of the motion vector V detected in 3 is compared with the threshold THV output from the threshold generation circuit 41, and | V
It has a function of determining whether or not | has exceeded THV. As a comparison method in this case, the two may be directly compared, or the magnitude | V | of the motion vector V is decomposed into a horizontal component | V | x and a vertical component | V | y, and these are divided into The thresholds THVx and THVy in the directions may be compared.

The difference detection circuit 43 has a difference ΔV (= Vth) between the threshold value THV output from the threshold value generation circuit 41 and the magnitude | V | of the motion vector V detected by the motion vector detection circuit 13.
| V | -THV).

When the determination circuit 42 determines that the magnitude | V | of the motion vector V exceeds the threshold value THX, the threshold control circuit 43 switches the adaptive motion interpolation according to the difference ΔV output from the difference detection circuit 43. It has a function of controlling the upper threshold THH of the control circuit 31.

FIG. 6 is a characteristic diagram showing this control characteristic. As shown in the figure, the threshold value THH is controlled to gradually increase as the difference ΔV increases. As a result, the increase rate of the adaptive motion interpolation coefficient β gradually decreases as the difference ΔV increases, as indicated by the broken line in FIG.

As a result, the magnitude of the motion vector V | V
When | exceeds the threshold THV, the selection amount of the linear field interpolation signal S2 at a certain difference ΔV becomes larger than when | V | does not exceed THV. In other words, | V | is TH
When V is exceeded, the linear field interpolation signal S2 is more easily selected than when V is not exceeded. This tendency increases as the difference ΔV increases.

The threshold value THV is set to be smaller when the magnitude | V | of the motion vector V at the upper limit of the motion vector detectable area is | V | max. That is, THV <| V | max is set. Here, the motion vector detectable area is an area where the motion vector V can be detected with a certain accuracy.

The reason for setting THV <| V | max is as follows. That is, the magnitude of the motion vector V |
If V | does not exceed | V | max, the image distortion as described above does not occur. Therefore, THV <| V | ma
The setting of x means that the control of the threshold THH will be performed even in a portion that does not need to be controlled.

On the other hand, the motion vector detection circuit 13 has | V
A motion vector V having a magnitude | V | larger than | max can also be detected. Therefore, it is preferable that THV = | V | max be set and the threshold THH is controlled only in a portion that requires the control.

However, in the vicinity of | V | max, the detection accuracy of the motion vector V decreases. Therefore, for example, as shown in FIG. 7, the magnitude | V that requires the control of the threshold THH
Although the motion vector V having | 1 has occurred, the magnitude | V | of the detected motion vector V is | V |
It may become | V | 2 smaller than max.

In such a case, although the threshold THH needs to be controlled, that control is not performed. This causes image distortion.

Therefore, in this embodiment, THV <| V |
It is set to max. That is, the control of the threshold value THH is started in a region where the detection accuracy of the motion vector V is stable.

According to such a configuration, the motion vector V
Even if the original magnitude | V | 1 of is erroneously detected as | V | 2, the threshold THH can be controlled as long as | V | 2 does not become smaller than the threshold THV.

The operation of the above configuration will be described. First, the operation of generating the true field interpolation signal S3 will be described.

The field signals PS and FS supplied to the input terminals 11 and 12 are supplied to the motion vector detection circuit 13. As a result, the motion vector V of the moving image is detected. This motion vector V is the motion vector correction circuit 1
4 is supplied. As a result, the motion vectors αV, (1-α) V corrected based on the field interpolation ratio α are obtained.

The motion vectors (1-α) V, αV are supplied to the motion correction memories 15, 16. As a result, the field signals PS and F supplied to the input terminals 11 and 12
The coordinates of S are shifted by (1-α) V and αV, respectively.

The field signal P subjected to this motion correction
S and FS are multiplied by field interpolation ratios (1-α) and α in multiplication circuits 17 and 18, respectively, and then added to an addition circuit 19
Is added in. As a result, the motion-compensated field interpolation signal S1 is obtained by weight-adding the motion-compensated field signals FS and PS with the field interpolation ratio α.

Similarly, the field signals PS and FS supplied to the input terminals 11 and 12 are supplied to the multiplication circuits 20 and 21,
After being multiplied by the field interpolation ratio (1−α) and α, they are added by the adder circuit 19. As a result, a linear field interpolation signal S2 is obtained by weight-adding the field signals FS and PS that have not been subjected to motion correction with the field interpolation ratio α.

The field interpolation signals S1 and S2 thus obtained are multiplied by the adaptive motion interpolation coefficients β and (1−β) in the multiplication circuits 23 and 24, respectively, and then added in the addition circuit 25. To be done. As a result, the true field interpolation signal S3 is obtained.

Next, the threshold control operation, which is a feature of the present invention, will be described.

If the magnitude | V | of the motion vector V detected by the motion vector detection circuit 13 is smaller than the threshold value THV, the threshold value control circuit 44 does not control the threshold value THH. Therefore, in this case, as shown in FIG.
The threshold THH is set to THH0. As a result, the adaptive motion interpolation coefficient β is controlled according to the characteristic curve C1 shown by the solid line in FIG.

In this case, the inter-field difference values D1, D2
If the difference ΔD of is ΔD1, for example, the adaptive motion interpolation coefficient β is β1. As a result, in this case, the field interpolation signals S1 and S2 are weight-added based on the adaptive motion interpolation coefficient β1.

On the other hand, the magnitude of the motion vector V | V
When | exceeds the threshold value THV, the control of the threshold value THH by the threshold value control circuit 44 is started. As a result, the threshold T
As shown in FIG. 6, HH gradually increases as the difference ΔV detected by the difference detection circuit 42 increases. as a result,
The slope of the control characteristic of the adaptive motion interpolation coefficient β gradually decreases, and the linear field interpolation signal S2 is easily selected. As a result, image distortion due to a sudden change in the magnitude | V | of the motion vector V is less likely to occur.

For example, if the difference ΔV is ΔV1 (> 0), the threshold value THH becomes THH1 larger than THH0 as shown in FIG. As a result, the adaptive motion interpolation coefficient β
Is controlled by a characteristic curve C2 having a smaller inclination than the characteristic curve C1, as shown in FIG. As a result, when the difference ΔD is ΔD1, the adaptive motion interpolation coefficient β is β2 smaller than β1. As a result, the magnitude of the motion vector V | V
Compared with the case where | does not exceed the threshold value THV, (1-β) becomes large, and the selection amount of the linear field interpolation signal S2 becomes large.

If the difference ΔV is ΔV2 which is larger than ΔV1, the threshold value THH becomes THH2 which is larger than THH1 as shown in FIG. As a result, the adaptive motion interpolation coefficient β is controlled by the characteristic curve C3 having a smaller inclination than the characteristic curve C2, as shown in FIG. As a result, when the difference ΔD is ΔD1, the adaptive motion interpolation coefficient β is β
Β3 is smaller than 2. As a result, the selection amount of the linear field interpolation signal S2 is further increased as compared with the case where the difference ΔV is ΔV1.

According to this embodiment described in detail above, the following effects can be obtained.

(1) First, the magnitude of the motion vector V | V
When | exceeds the threshold value THV, the upper threshold value THH for controlling the adaptive motion interpolation coefficient β is increased.
The linear field interpolation signal S2 can be selected more easily than when | V | does not exceed THV. As a result, it is possible to suppress the occurrence of image distortion due to a sudden change in | V |.

(2) Also, the magnitude of the motion vector V | V
Since the selection amount of the linear field interpolation signal S2 is increased with an increase in the difference ΔV between | and the threshold value THV, the selection amount of the signal S2 can be controlled according to the degree of image distortion. . As a result, it is possible to prevent the linear field interpolation signal S2 from being selected more than necessary for suppressing image distortion.

(3) Further, since the threshold value THV is set to a value smaller than the magnitude | V | max of the motion vector V at the upper limit of the motion vector detectable area, the threshold value is set in the portion where the detection accuracy of the motion vector V is high. The THH control can be initiated. As a result, even if the detection error of the motion vector V occurs, the threshold THH can be controlled appropriately.

(4) Since the threshold THH is controlled to control the ease with which the linear field interpolation signal S2 is selected, the adaptive motion interpolation switching circuit 31 is used.
Can be used as it is by simply changing the threshold THH.

FIG. 8 is a block diagram showing the configuration of the second embodiment of the present invention. In FIG. 8, the same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the previous embodiment, the field interpolation signal S
The case where the present invention is applied to an apparatus that generates the true field interpolation signal S3 by adding the weights of these signals according to the image quality of S1 and S2 has been described.

On the other hand, in this embodiment, an apparatus for selectively selecting one of the field interpolating signals S1 and S2 according to the image quality of the field interpolating signals S1 and S2,
It shows a case where the present invention is applied.

That is, in FIG. 8, 51 is the field interpolation signals S1 and S based on the adaptive motion interpolation coefficient β.
It is a selection circuit that selectively selects one of the two.
Reference numeral 52 is an adaptive motion interpolation coefficient control circuit that obtains a difference ΔD between the inter-field difference values D1 and D2 and generates an adaptive motion interpolation coefficient β based on the difference ΔD.

As shown in FIG. 9, the adaptive motion interpolation control circuit 52 sets the adaptive motion interpolation coefficient β to 0 when the difference ΔD is smaller than a predetermined threshold value TH, and when it becomes larger than the threshold value TH, Set to 1. As a result, as shown in FIG. 10, when the difference ΔD is smaller than the threshold value TH, the linear field interpolation signal S2 is selected as the true interpolation signal S3, and when it exceeds the threshold value TH, the motion correction field interpolation signal is detected. S1 is selected.

In such a configuration, the threshold control circuit 4
4 is the magnitude of the motion vector V, as shown in FIG.
When V | exceeds the threshold value TH, the threshold value TH is controlled so that the threshold value THV increases as the difference ΔV between them increases.

As a result, the control characteristic of the adaptive motion interpolation coefficient β is shifted as the difference ΔV increases, as shown by the broken line in FIG. As a result, the linear field interpolation signal S2
Is easier to be selected than when the magnitude | V | of the motion vector V does not exceed the threshold value THV. Therefore,
Also in this embodiment, the same effect as the previous embodiment can be obtained.

Although two embodiments of the present invention have been described in detail above, the present invention is not limited to such embodiments.

(1) For example, in the above-described embodiment, the case where the present invention is applied to an apparatus for performing an interpolation process in a predetermined block unit has been described. However, the present invention can also be applied to a device that performs interpolation processing in pixel units. However, in this case, as described above, it is necessary to consider an interpolation error due to noise.

(2) Further, in the above embodiment, the case where the present invention is applied to the apparatus using the inter-field difference values D1 and D2 as the parameters indicating the image quality of the field interpolation signals S1 and S2 has been described. However, the present invention can also be applied to devices using other parameters.

(3) Further, in the above embodiment, the case where the present invention is applied to an apparatus using a linear interpolation method as a field interpolation method that does not use a motion vector has been described.
However, the present invention can also be applied to an apparatus using a 4-field interpolation method, for example. It can also be applied to an apparatus that uses an interpolation method other than the interpolation method in the time axis direction, such as a linear interpolation method or a 4-field interpolation method.

(4) Further, in the above embodiment, the case where the present invention is applied to the inter-field interpolation processing has been described.
However, the present invention can also be applied to other time-axis direction interpolation processing, for example, interframe interpolation processing.

(5) Further, in the above embodiment, the case where the present invention is applied to the conversion of the number of fields has been described. However, the present invention is also applicable to other interpolation processing, for example, in the high-efficiency coding method, the interpolation processing for reproducing the fields thinned by the transmission side on the reception side and the interpolation processing in the high-definition system. can do.

(5) In addition to the above, it goes without saying that the present invention can be variously modified and implemented without departing from the scope of the invention.

[0100]

As described above in detail, according to the present invention, an adaptive motion interpolation signal generation apparatus using a motion vector capable of suppressing image distortion caused by a sudden change in the magnitude of the motion vector. Can be provided.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration of a conventional device.

FIG. 3 is a diagram for explaining a conventional problem.

FIG. 4 is a characteristic diagram showing a control characteristic of an adaptive motion interpolation coefficient β according to the first embodiment.

FIG. 5 is a characteristic diagram showing a switching characteristic of a field interpolation signal of the first embodiment.

FIG. 6 is a characteristic diagram showing a control characteristic of a threshold THH according to the first embodiment.

FIG. 7 is a diagram for explaining the reason why the threshold value THV is set to a value smaller than | V | max.

FIG. 8 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 9 is a characteristic diagram showing a control characteristic of an adaptive motion interpolation coefficient β according to the second embodiment.

FIG. 10 is a characteristic diagram showing a switching characteristic of a field interpolation signal of the second embodiment.

FIG. 11 is a characteristic diagram showing control characteristics of a threshold value THH according to the second embodiment.

[Explanation of symbols]

11, 12 ... Input terminals, 13 ... Motion vector detection circuit,
14 ... Motion vector correction circuit, 15, 16 ... Motion correction memory, 17, 18, 20, 21, 23, 24 ... Multiplication circuit, 19, 22, 25 ... Addition circuit, 26 ... Output terminal, 2
7, 29 ... Subtraction circuit, 28, 30 ... Absolute value conversion / accumulation circuit, 31, 52 ... Adaptive motion interpolation switching control circuit, 51 ...
Selection circuit.

Claims (1)

[Claims] 1. An interpolation process using a motion vector,
A first interpolated signal generation means for generating a first interpolated signal; a second interpolated signal generation means for generating a second interpolated signal by interpolation processing that does not use a motion vector; An adaptive switching unit that outputs a true interpolation signal by adaptively switching the two based on the image quality of the first interpolation signal and the second interpolation signal, and the magnitude of the motion vector is predetermined. When the threshold value is exceeded, the second interpolation signal is easily selected, and the adaptive switching control means controls the switching operation of the adaptive switching means in accordance with an increase in the difference between the two. An adaptive motion interpolation signal generation device using motion vectors.