JP4639555B2 - Motion vector detection apparatus and method, camera shake correction apparatus and method, and imaging apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motion vector detection apparatus and method, a camera shake correction apparatus and method, and an imaging apparatus that detect a motion vector due to camera shake, for example.
[0002]
[Prior art]
When a subject is imaged by a camera-integrated imaging apparatus, there is a problem that a captured image is shaken by camera shake. To correct this, camera shake correction is performed to detect a motion vector and correct the shake of the captured image. The motion vector is obtained by detecting the correlation between the previous field (or frame) and the current field (or frame). The motion due to camera shake correction is the motion of the entire screen, and the motion vector of the entire screen is detected.
[0003]
A conventional motion vector detection device detects a motion vector by calculating the correlation between the representative point set in the previous field and the luminance level of the pixel in the current field. For example, the absolute value of the field difference between the representative point and the value of a plurality of pixels within the search range of the current field is calculated, the absolute value of the difference is integrated for one field or one detection area, and the movement starts from the position of the minimum value of the integral value The vector was detected. Further, the reliability of whether or not the detected motion vector reflects camera shake is determined. If the reliability is low, that is, the motion vector is determined not to reflect camera shake, the detected motion vector is detected. The motion vector was treated as invalid. Conventionally, the reliability of a motion vector has been determined based on the minimum value, average value, gradient, etc. of the integral value.
[0004]
[Problems to be solved by the invention]
However, when a camera shake is detected when the captured image is a striped pattern, a motion vector that is not an original camera shake may be detected. The motion vector different from the original camera shake must be invalidated in the reliability determination, but the conventional reliability determination method is difficult to eliminate the motion vector detected in the case of a striped signal. .
[0005]
Therefore, an object of the present invention is to solve such problems and to eliminate a motion vector that is different from the original camera shake when a striped pattern is imaged, a motion vector detection apparatus and method, a camera shake correction apparatus and method, An object is to provide an imaging apparatus.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, the invention according to claim 1 is a motion vector detection device that detects a motion vector caused by camera shake of an imaging device from an input video signal.
Representative point storage means for extracting and storing a plurality of representative points from a temporally previous field or frame;
Correlation value calculating means for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating a correlation value between the plurality of pixels in each search range and the representative points;
A plurality of detection areas are set by dividing the screen of the input video signal, and integration means for integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
A motion vector detection means for detecting a motion vector for each detection region based on the integration value of the correlation value from the integration means ;
Reliability determination means for determining the reliability of the motion vector detected using the integral value of the correlation value from the integration means;
Motion vector determination means for determining the motion vector of the entire screen, which is supplied with the motion vector from the motion vector detection means and the reliability information from the reliability determination means ,
The reliability determination means detects that there are a plurality of integrated extreme values in the detection region, and detects that the first extreme value and at least the second extreme value are close to each other. , Determining that the motion vector in the detection area detected by the motion vector detection means is not reliable ,
A motion vector detecting device in which a motion vector determining means for determining a motion vector of the entire screen by excluding motion vectors determined to be low reliability. The invention of claim 2 is a motion vector detection method for performing such reliability determination.
[0007]
The invention of claim 3 is a camera shake correction device that detects a motion vector caused by a camera shake of an imaging device from an input video signal and corrects the camera shake based on the detected motion vector.
Representative point storage means for extracting and storing a plurality of representative points from a temporally previous field or frame;
Correlation value calculating means for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating a correlation value between the plurality of pixels in each search range and the representative points;
A plurality of detection areas are set by dividing the screen of the input video signal, and integration means for integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
A motion vector detection means for detecting a motion vector for each detection region based on the integration value of the correlation value from the integration means ;
Reliability determination means for determining the reliability of the motion vector detected using the integral value of the correlation value from the integration means;
Motion vector determination means for determining the motion vector of the entire screen, which is supplied with the motion vector from the motion vector detection means and the reliability information from the reliability determination means ,
The reliability determination means detects that there are a plurality of integrated extreme values in the detection region, and detects that the first extreme value and at least the second extreme value are close to each other. , Determining that the motion vector in the detection area detected by the motion vector detection means is not reliable ,
By excluding motion vectors by the motion vector determining means it is determined to be low reliability determining the motion vector of the entire screen, a camera-shake correction device for correcting the motion vector thus a shake determined. The invention of claim 4 is a camera shake correction method for correcting camera shake based on a highly reliable motion vector obtained by the motion vector determining means.
[0008]
According to a fifth aspect of the present invention, there is provided an imaging apparatus including a camera shake correction apparatus that detects a motion vector caused by camera shake of the imaging apparatus from an input video signal and corrects the camera shake using the detected motion vector.
The image stabilizer is
Representative point storage means for extracting and storing a plurality of representative points from a temporally previous field or frame;
Correlation value calculating means for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating a correlation value between the plurality of pixels in each search range and the representative points;
A plurality of detection areas are set by dividing the screen of the input video signal, and integration means for integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
A motion vector detection means for detecting a motion vector for each detection region based on the integration value of the correlation value from the integration means ;
Reliability determination means for determining the reliability of the motion vector detected using the integral value of the correlation value from the integration means;
Motion vector determination means for determining the motion vector of the entire screen , which is supplied with the motion vector from the motion vector detection means and the reliability information from the reliability determination means,
The reliability determination means detects that there are a plurality of integrated extreme values in the detection region, and detects that the first extreme value and at least the second extreme value are close to each other. , Determining that the motion vector in the detection area detected by the motion vector detection means is not reliable ,
Motion vector determination means determines the motion vector of the entire screen by excluding motion vectors determined to be low reliability, it is constructed imaging apparatus to correct a shake Accordingly hand to the determined motion vector.
[0009]
In the present invention, when it is detected that there are a plurality of extreme values of the integral value and it is detected that the first extreme value and at least the second smallest extreme value are close to each other, It is presumed that an integral value has been generated by the image, and in this case, the detected motion vector is determined to have low reliability. Therefore, it is possible to avoid camera shake correction using a motion vector with low reliability.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In order to facilitate understanding of the present invention, an example of a camera shake correction apparatus will be described. FIG. 1 shows such a camera shake correction apparatus, and reference numeral 1 is an input terminal for a digital video signal to be subjected to camera shake correction. The input video signal is picked up by the image pickup apparatus. An input video signal is supplied to the motion vector detection device 2 and the field memory 4. The motion vector detection device 2 detects the motion vector, determines the reliability of the detected motion vector, and detects the motion vector of the entire screen from the highly reliable motion vector. The motion vector detected by the motion vector detection device 2 is supplied to the correction control unit 3.
[0011]
The correction control unit 3 performs camera shake correction based on the detected motion vector. A motion vector from the correction control unit 3 is supplied to the field memory 4. The field memory 4 stores input video signals (digital) from the imaging unit. For example, the imaging unit is configured to be an area larger than the output image area, and to perform camera shake correction using the surplus area generated thereby. In the field memory 4, an image including the surplus area is accumulated, and camera shake is corrected by changing a position to be cut out as an output image area based on the motion vector. The field memory 4 performs correction in units of integer pixels in camera shake correction. That is, a process for shifting the image in the direction opposite to the camera shake is performed. When this shift process is performed, the excess area is used so that no image is lost. The readout of the imaging unit may be controlled, or the captured image may be enlarged and stored in the field memory 4.
[0012]
The video signal read from the field memory 4 is supplied to the interpolation unit 5. In the interpolation unit 5, among the correction amounts based on the motion vector obtained by the correction control unit 3, correction amounts equal to or smaller than integer pixels are corrected by interpolation. Interpolation is realized by weighted addition according to a correction amount equal to or less than an integer pixel. If the horizontal motion vector component is 0.5 pixels, for example, an image shifted by 0.5 pixels in the horizontal direction is generated by the average value of two adjacent pixels. Similar interpolation is performed in the vertical direction.
[0013]
In this description, one field is handled as one screen, but one frame may be handled as one screen. The video signal may be either an interlace signal or a non-interlace signal. Furthermore, the present invention can be applied to camera shake correction of a color video signal. However, the motion vector is detected using the luminance signal, and camera shake correction is performed on both the luminance signal and the color component signal.
[0014]
The motion vector detection device 2 detects a motion vector by a representative point matching method. In the representative point matching method, a representative point is set in the previous field, the luminance level of the pixel in the search field of the current field is compared with the luminance level of the representative point in the previous field, and the pixel of the representative point in the pixels in the search range is compared. In this method, a motion vector is detected from the nearest pixel.
[0015]
FIG. 2 shows a motion vector detection method based on the representative point matching method.
A search range SRn composed of a plurality of pixels is set in the current field. For example, the value of the pixel at the center position of the region SRn-1 of the previous field having the same size and the same position as the search range SRn is set as the representative point St-1 (Xk, Yk). The absolute value of the difference in luminance level between the representative point St-1 (Xk, Yk) and a plurality of pixels in the search range SRn is calculated. The absolute value of the difference generated in the search range is the correlation value. A plurality of search ranges are set in one field, and correlation values obtained in each search range are integrated over one field, thereby forming an integrated value of correlation values. A motion vector is detected from this integrated value.
[0016]
As described above, the correlation value representing the correlation between the luminance levels is the absolute value of the difference between the luminance level of the representative point and the luminance level of each pixel in the search range SRn. When the correlation is high, the correlation value becomes small. is there. As the correlation value, the square of the difference may be used. A motion vector is detected from the integrated value obtained by integrating the correlation values. When the search range SRn is the integral value of the correlation value, the position a having the minimum integral value is detected. A motion vector Mv is detected from the deviation between the position of the representative point and the detected position a.
[0017]
Image shake caused by camera shake at the time of shooting is shake of the entire screen, and camera shake correction is a process of using the field memory 4 to shift the entire screen in the direction opposite to the motion vector generated by camera shake. An example of a method for obtaining the motion vector of the entire screen will be described more specifically.
[0018]
FIG. 3 is an example of a detection area set in one captured image. Detection areas D0, D1, D2, and D3 are set in each divided area obtained by dividing each field (each screen) into four. A motion vector of each detection area is obtained, and a motion vector of the entire screen is obtained using a highly reliable motion vector of each detection area.
[0019]
FIG. 4 shows an example of the detection area Di (i = 0, 1, 2, 3) in detail. The detection area of the previous field includes a total of 48 representative points, for example, 8 in the horizontal direction and 6 in the vertical direction. At the spatial position corresponding to each representative point, the same number of search ranges SRn (n = 0 to 47) as the representative points are set in the current field. The search range has a horizontal position of (0, 1, 2,..., X) and a vertical position of (0, 1, 2,..., Y). Both positions define the position of each pixel. The position of the representative point is, for example, the center position of the area at the same position as the search range. Then, deviation x and deviation y with respect to the position of the representative point are defined. At the same position as the representative point, the deviations x and y are both zero.
[0020]
In each of the detection areas Di, a correlation value, for example, an absolute value of a difference between the representative point and each pixel is obtained for each pixel in each search range. The correlation value is integrated for each detection region, and the motion vector of the detection region is obtained from the integration value of the correlation value (hereinafter referred to as the integration value of the detection region as appropriate). FIG. 5 shows a method for obtaining the integral value of the correlation value. FIG. 5 is an example in which Z + 1 search ranges SR0 to SRz are included in one detection region.
[0021]
In the uppermost part of FIG. 5, the correlation value obtained in the search range SR0 is shown. Since a correlation value is generated corresponding to the position of each pixel, the position of each correlation value is shown. Correlation values of other search ranges are similarly generated at the positions of the respective pixels. Then, among the correlation values of all the search ranges in the detection area, those at the same position are added to obtain the integral value SRd of the correlation values. For example the correlation value at position (0,0,0), the correlation value at position (0,0,1), · · ·, (0,0, Z) is the value of the correlation value is the sum of the position of the correlation This is the component at the position (0, 0) of the integrated value SRd of the value.
[0022]
FIG. 6 shows the integral value of the correlation value of one detection area thus obtained in three dimensions (shifts x and y and the magnitude of the correlation value). In FIG. 6, a motion vector is detected from a position a where the integral value is minimum. That is, the values of the deviations x and y corresponding to the position a are set as the minimum value of the correlation value integral value in the detection region. Note that, as described above, by having a plurality of search ranges in one detection region, it is possible to prevent a decrease in detection accuracy. Furthermore, a plurality of search ranges set in one detection area may have overlapping portions.
[0023]
FIG. 7 illustrates an exemplary configuration of the motion vector detection unit 20 in the motion vector detection device 2. A video signal is input from the input terminal 21 and supplied to the filter processing circuit 22. The filter processing circuit 22 removes frequency components unnecessary for motion detection. The output signal of the filter processing circuit 22 is supplied to one input terminal of the representative point storage circuit 23 and the subtractor 24. The value of the representative point from the representative point storage circuit 23 is supplied to the other input terminal of the subtracter 24.
[0024]
The representative point storage circuit 23 stores the value of the pixel at the center position of the two-dimensional region corresponding to the search range as a representative point. For example, the representative point storage circuit 23 includes a memory that selectively stores a representative point of the current field and a memory that holds a representative point of the previous field. The value of the representative point of the previous field is supplied from the representative point storage circuit 23 to the other input terminal of the subtractor 24.
[0025]
In the subtracter 24, each pixel value in the search range is subtracted from the representative point. The difference data from the subtractor 24 is supplied to the absolute value conversion circuit 25 and converted into the absolute value of the difference. The absolute value of the difference is the correlation value. The correlation value is supplied to the cumulative addition circuit 26, and all the correlation values included in the detection region are integrated as described with reference to FIG. The cumulative addition circuit 26 obtains an integral value of the correlation values of one detection area.
[0026]
The integral value of the correlation value from the cumulative addition circuit 26 is supplied to the motion vector generation circuit 27. The motion vector generation circuit 27 detects the minimum integral value, detects a motion vector from the deviations x and y, and outputs it. The output motion vector is detected in one detection area.
[0027]
FIG. 8 shows an example of the configuration of the motion vector detection device 2. Regarding the motion vector detection unit 20 in the motion vector detection device 2, the same reference numerals are given to portions corresponding to those in FIG. 7, and the description thereof is omitted to avoid duplication. In addition to the motion vector detection unit 20, the motion vector detection device 2 includes a vector feature detection circuit 31, a reliability determination circuit 32, and a vector determination circuit 33. The integral value of the correlation value output from the cumulative addition circuit 26 of the motion vector detection unit 20 is supplied to the vector feature detection circuit 31 together with the motion vector generation circuit 27.
[0028]
The vector feature detection circuit 31 is a circuit that detects a feature around the minimum value point a shown in FIG. 6 and a feature of the correlation value integral value. Features detected by the vector feature detection circuit 31 are supplied to the reliability determination circuit 32. The reliability determination circuit 32 generates reliability information indicating the degree of reliability based on the detected feature, and supplies the reliability information to the vector determination circuit 33. The vector determination circuit 33 determines a highly reliable motion vector using the reliability information. The motion vector determination circuit 33 determines the motion vector of the entire screen using the reliability information and the motion vector of each detection area, and outputs the determined motion vector.
[0029]
As described with reference to FIG. 3, four detection areas D1 to D4 are set on one screen. The motion vector detection unit 20 detects the motion vector of each detection region in order from D1, and the vector determination circuit 33 detects the detected motion vector and each detection region in the order of detection regions D1, D2, D3, and D4. Reliability information is provided. In addition, you may obtain | require the motion vector of each detection area | region in parallel. Moreover, you may implement | achieve the whole or one part function of the motion vector detection apparatus 2 by software processing.
[0030]
The vector determination circuit 33 detects the motion vector of the entire screen from the motion vector and reliability information obtained in each of the four detection areas. Various algorithms are possible. As a simple example, the motion vector determined to have the highest reliability is selected as the motion vector for the entire screen. As another example, when there are a plurality of highly reliable motion vectors, the average value thereof is adopted as the motion vector of the entire screen. Other methods are possible.
[0031]
The reliability determination circuit 32 is provided because the motion vector output from the motion vector detection unit 20 may be different from the original motion vector due to camera shake.
Conventionally, the reliability is determined based on the average value of the minimum value and the integral value.
[0032]
In FIG. 9, reference numeral 41 indicates a change in the integrated value with respect to a normal subject shift, and 41 av indicates an average value thereof. The integrated value distribution is a three-dimensional distribution as shown in FIG. 6, but in FIG. 9, the level change along one shift (for example, X or Y) is shown for simplicity. Reference numeral 42 indicates a change in the integral value when a moving object enters the screen. In this case, the extreme value level is larger than that in the normal case. Reference numeral 43 indicates a change in the integral value at the time of low contrast. At low contrast, the average value is small. Since the motion vector detected in these cases often does not accurately reflect camera shake, it is determined that the reliability is low.
[0033]
In the case of a subject that is not a striped pattern, as shown in FIGS. 6 and 10, the level distribution of the integral value of the correlation value with respect to the deviation exists even if there is only one extreme value, or even if there are multiple extreme values. As shown in FIG. 11, these levels are significantly different from the minimum extreme values. In these cases, a conventional reliability determination method can be applied to the detected motion vector.
[0034]
However, in the case where the luminance level of the subject in the detection area is a binary striped pattern, as shown in FIG. 12, there are a plurality of extreme values (positions a and b in FIG. 12) as an integrated value distribution. In many cases, there are extreme values whose levels are relatively close. In addition, as shown in FIG. 13, there may be a plurality of extreme values having relatively close levels. Therefore, although the original motion vector should be detected from the position of the point b, the motion vector is detected from the position a having the minimum level. This motion vector is different from the original camera shake vector.
[0035]
When the subject has a striped pattern, the conventional reliability determination configuration based on the minimum value of the integral value or the average value treats a motion vector different from the original motion vector as an effective motion vector. As a result, there is a problem that unnatural camera shake correction is performed during camera shake correction.
[0036]
The present invention makes it possible to determine the reliability even when a striped pattern exists in the detection region. That is, by detecting a plurality of extreme values in the distribution of integrated values, the extreme value with the smallest integrated value is set as the minimum (first) extreme value, and compared with the other extreme values, When it is detected that at least the second smallest extreme value is at a close level, it is determined that the reliability of the detected motion vector is low. This is to prevent malfunction due to the existence of an extreme value whose level is close to the minimum extreme value detected as a motion vector. However, the reliability determination circuit may be used together with the reliability determination method according to the present invention in combination with the conventional reliability determination using features such as the minimum value level and the average value.
[0037]
One method is to compare the minimum extreme value with all extreme values. The other method is a method of comparing only the second smallest integrated value (second extreme value) with the minimum extreme value. Even if there is no information regarding the integral value of the extreme value other than the second extreme value, the determination can be made sufficiently. Thus, if only two extreme values are handled instead of all extreme values, the circuit scale can be reduced.
[0038]
Therefore, as shown in FIG. 12, in the deviation-correlation value graph, when there are a plurality of extreme values, the minimum extreme value and the second extreme value (second smallest value) are used to obtain the following equation: If the discriminant shown is satisfied, it is determined that there is no reliability. ABS () means an absolute value.
[0039]
Second extreme value / minimum extreme value ≦ threshold
Or ABS (second extreme value−minimum extreme value) ≦ threshold
In the case of using all existing extreme values, the reliability is determined by the following equation. Σ means the sum of the number of all extremums that exist other than the minimum extremum.
[0042]
ΣABS (extreme value−minimum extreme value) / number of all extreme values other than minimum extreme value ≦ threshold
In one embodiment, the vector feature detection circuit 31 detects the positions of a plurality of extreme values existing in the integral value distribution and the levels of the extreme values. Information on the position and level of the detected extreme value is supplied to the reliability determination circuit 32, and the reliability determination circuit 32 determines the reliability of the motion vector based on the above-described discriminant. Information on the presence / absence of reliability is supplied to the vector determination circuit 33. The vector determination circuit 33 uses only motion vectors detected in each of, for example, four detection areas and determined to have high reliability. Determine the overall motion vector.
[0044]
The present invention is not limited to the above-described embodiment of the present invention, and various modifications and applications can be made without departing from the gist of the present invention. For example, the level of the extreme value is not limited to the level from 0 but may be defined by the difference from the maximum value of the integrated value (for example, 255 in the case of 8-bit data).
[0045]
【The invention's effect】
In the present invention, when a subject having a binary luminance level, such as a striped subject, is photographed, a plurality of extreme values are generated in the distribution of integral values, and the first one and at least the second one are obtained. In such a case, it is determined that the reliability of the detected motion vector is low. With this reliability determination process, when determining the motion vector of the entire screen, motion vectors with low reliability can be eliminated, and malfunctions such as unnatural correction during camera shake correction can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an example of a camera shake correction apparatus.
FIG. 2 is a schematic diagram used for explaining a motion vector detection method;
FIG. 3 is a schematic diagram illustrating a detection region for motion vector detection.
FIG. 4 is a schematic diagram showing a relationship between a representative point for motion vector detection and a search range.
FIG. 5 is a schematic diagram for explaining an integral value of correlation values;
FIG. 6 is a schematic diagram illustrating an integral value of a correlation value in a three-dimensional manner.
FIG. 7 is a block diagram illustrating an example of a motion vector detection unit.
FIG. 8 is a block diagram of an example of a motion vector detection device.
FIG. 9 is a schematic diagram illustrating an example of a deviation-integral value.
FIG. 10 is a schematic diagram illustrating an example of a deviation-integral value obtained from a normal subject.
FIG. 11 is a schematic diagram illustrating an example of a deviation-integral value obtained from a normal subject.
FIG. 12 is a schematic diagram illustrating an example of a deviation-integral value obtained from a binary subject such as a striped pattern.
FIG. 13 is a schematic diagram illustrating an example of a deviation-integral value obtained from a binary subject such as a striped pattern.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Motion vector detection apparatus, 3 ... Correction control part, 4 ... Field memory, 31 ... Vector feature detection circuit, 32 ... Reliability discrimination circuit, 33 ... Motion vector determination circuit

Claims (5)

In a motion vector detection device that detects a motion vector generated by camera shake of an imaging device from an input video signal,
Representative point storage means for extracting and storing a plurality of representative points from a temporally previous field or frame;
Correlation value calculation means for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating a correlation value between the plurality of pixels in each search range and the representative points When,
A plurality of detection areas are set by dividing the screen of the input video signal, and integration means for integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
Motion vector detection means for detecting a motion vector for each detection region based on an integration value of the correlation value from the integration means ;
Reliability determination means for determining the reliability of the motion vector detected using the integral value of the correlation value from the integration means;
Motion vector determination means for determining the motion vector of the entire screen, supplied with the motion vector from the motion vector detection means and reliability information from the reliability determination means ;
The reliability determination means detects that there are a plurality of extreme values of the integral value in the detection region, and determines that at least the second extreme value is close to the first extreme value. If detected, it is determined that the motion vector in the detection area detected by the motion vector detection means has low reliability ,
A motion vector detection apparatus for determining a motion vector of the entire screen by excluding a motion vector determined by the motion vector determination means as having low reliability . In a motion vector detection method for detecting a motion vector caused by camera shake of an imaging device from an input video signal,
A representative point storing step of extracting and storing a plurality of representative points from the previous field or frame in time;
Correlation value calculating step for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating correlation values between the plurality of pixels in each search range and the representative points When,
A plurality of detection areas are set by dividing the screen of the input video signal, and an integration step of integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
A motion vector detection step for detecting a motion vector for each detection region based on an integral value of the obtained correlation values ;
A reliability determination step of determining the reliability of the motion vector detected using the integral value of the correlation value;
A motion vector determination step for determining a motion vector of the entire screen from the motion vector detected by the motion vector detection step and the reliability information;
The reliability determination step detects that there are a plurality of extreme values of the integral value in the detection region, and determines that at least a second extreme value is close to the first extreme value. If detected, it is determined that the motion vector in the detection area detected by the motion vector detection step has low reliability ,
A motion vector detection method for determining a motion vector of the entire screen by excluding motion vectors determined to have low reliability in the motion vector determination step . In a camera shake correction apparatus that detects a motion vector caused by a camera shake of an imaging device from an input video signal and corrects the camera shake based on the detected motion vector.
Representative point storage means for extracting and storing a plurality of representative points from a temporally previous field or frame;
Correlation value calculation means for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating a correlation value between the plurality of pixels in each search range and the representative points When,
A plurality of detection areas are set by dividing the screen of the input video signal, and integration means for integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
Motion vector detection means for detecting a motion vector for each detection region based on an integration value of the correlation value from the integration means ;
Reliability determination means for determining the reliability of the motion vector detected using the integral value of the correlation value from the integration means;
Motion vector determination means for determining the motion vector of the entire screen, supplied with the motion vector from the motion vector detection means and reliability information from the reliability determination means ;
The reliability determination means detects that there are a plurality of extreme values of the integral value in the detection region, and determines that at least the second extreme value is close to the first extreme value. If detected, it is determined that the motion vector in the detection area detected by the motion vector detection means has low reliability ,
Shake correction apparatus the motion vector determining means excludes the determined motion vector is low the reliability determining the motion vector of the entire screen, shake to correct Accordingly hand to the determined motion vector. In a camera shake correction method for detecting a motion vector caused by a camera shake of an imaging device from an input video signal and correcting the camera shake by the detected motion vector,
A representative point storing step of extracting and storing a plurality of representative points from the previous field or frame in time;
Correlation value calculating step for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating correlation values between the plurality of pixels in each search range and the representative points When,
A plurality of detection areas are set by dividing the screen of the input video signal, and an integration step of integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
A motion vector detection step for detecting a motion vector for each detection region based on an integral value of the obtained correlation values ;
A reliability determination step of determining the reliability of the motion vector detected using the integral value of the correlation value ;
A motion vector determination step for determining a motion vector of the entire screen from the motion vector detected by the motion vector detection step and the reliability information ;
The reliability determination step detects that there are a plurality of extreme values of the integral value in the detection region, and determines that at least a second extreme value is close to the first extreme value. If detected, it is determined that the motion vector in the detection area detected by the motion vector detection step has low reliability ,
Shake correction method for correcting by excluding motion vectors determined to be low the reliability in the motion vector determining step determines the motion vector of the entire screen, vibration thus hand determined motion vector. In an imaging apparatus provided with a camera shake correction device that detects a motion vector caused by camera shake of the imaging device from an input video signal and corrects the camera shake based on the detected motion vector.
The camera shake correction device
Representative point storage means for extracting and storing a plurality of representative points from a temporally previous field or frame;
Correlation value calculation means for setting a plurality of search ranges including pixels at the same position as each of the representative points in the current field or frame, and calculating a correlation value between the plurality of pixels in each search range and the representative points When,
A plurality of detection areas are set by dividing the screen of the input video signal, and integration means for integrating the correlation values from the correlation value calculation means in respective ranges of the detection areas ;
Motion vector detection means for detecting a motion vector for each detection region based on an integration value of the correlation value from the integration means ;
Reliability determination means for determining the reliability of the motion vector detected using the integral value of the correlation value from the integration means;
Motion vector determination means for determining the motion vector of the entire screen , supplied with the motion vector from the motion vector detection means and reliability information from the reliability determination means;
The reliability determination means detects that there are a plurality of extreme values of the integral value in the detection region, and determines that at least the second extreme value is close to the first extreme value. If detected, it is determined that the motion vector in the detection area detected by the motion vector detection means has low reliability ,
The motion vector determining means excludes the determined motion vector is low the reliability determining the motion vector of the entire screen, constructed imaging apparatus to correct a shake Accordingly hand to the determined motion vector.

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