JP2947037B2 - Video camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera-integrated VTR (so-called video camera) capable of variably controlling the magnification of a zoom lens so that an image of a subject always has the same size.
It is about.

[0002]

2. Description of the Related Art It has been difficult to perform zoom control of an image pickup lens so that a video camera always obtains a subject image of the same size regardless of the movement of the subject.

That is, for example, when a child's subject is taken as an image of the athletic meet from start to finish, the size of the running child changes gradually from the start to the finish and gradually becomes larger. At this time, it is possible to keep the child in focus at all times, but it has been difficult to perform zoom control to keep shooting the child's image at the same size on the monitor screen.

For this reason, there has been a demand for a video camera capable of controlling the zoom of the imaging lens so as to always obtain a subject image of the same size regardless of the movement of the subject.

That is, the video signal relating to the photographed subject is 1
A memory for storing the subject image before and after the frame, a unit for detecting the size of the subject image in the monitor screen, and a unit for detecting the motion of the subject image between successive frames; A video camera having control signal generating means for detecting a change in the size of a subject from the amount of change in the motion of the subject and its direction (motion vector) and variably controlling the magnification of the zoom lens in accordance with the change in the size is proposed. (For example, JP-A-5-75908).

As a result, it is possible to obtain a video camera capable of controlling the zoom of the imaging lens so as to always obtain a subject image of the same size irrespective of the movement of the subject.

[0007]

However, the above-mentioned video camera can perform variable control of the magnification of the zoom lens so as to always obtain a subject image of the same size regardless of the movement of the subject. In the case of, there is a problem that a subject image of the same size cannot always be obtained.

That is, the above-mentioned video camera moves the cursor to a specific portion on the monitor screen and registers (stores) the coordinates (X, Y) and luminance information of the portion, thereby obtaining the coordinates (X, Y). And brightness information as a subject image. For this purpose, the coordinates (X,
Y) The area has substantially the same luminance information as the above-described luminance information and has a different color (for example, the color of the original subject image is “white”).
However, even if another image that is “cream” close to “white” is instantaneously replaced, the newly replaced image may be erroneously recognized as the original subject image. In some cases, zoom control of the imaging lens cannot be performed so as to always obtain a subject image of the same size regardless of the movement of the subject.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a video camera having the following configuration to solve the above-mentioned problems.

[0010] Binarization processing means for binarizing an image of a captured subject into a subject area and other areas, fill processing means for performing a fill process on a binary image signal relating to the subject area, and the fill processing means A data calculating unit that outputs an area information signal and a center-of-gravity position information signal of the subject region in the fill-processed image signal output from the processing unit; and the area information signal and the center-of-gravity position information signal, and a color information signal related to the subject region. The color information signal and the center-of-gravity position information signal are output to the binarization processing means and the fill processing means, respectively. Control signal generating means for outputting a control signal based on a difference from the information signal, and a zoom for variably controlling the magnification of the zoom lens based on the control signal Video camera comprising the lens drive control means.

[0011]

FIG. 1 is a block diagram for explaining an embodiment of a video camera according to the present invention, FIG. 2 is a diagram for explaining the operation of a binarization processing means, and FIG. 3 is an operation of a logical filter. FIGS. 4 and 5 are diagrams for explaining the operation of the fill processing unit, respectively, and FIG. 6 is a diagram for explaining the operation of the fill processing unit after the initial setting state.
Hereinafter, an embodiment of an automatic tracking device according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the video signal processing system of the video camera according to the present invention comprises a CCD 1, a signal processing unit 2, an A / D conversion unit 3, a pre-processing unit 4, a binarization processing unit 5, a logical filter 6 , Fill processing section 7, data calculation section 8, control signal generation section 9, zoom lens drive control system A
(Composed of a zoom lens drive control unit 10 and a motor 11), a zoom lens 12, and a video signal recording system (not shown)
Consists of Although not described in detail here, it goes without saying that there is an audio signal processing system in parallel with the video signal processing system.

The above-described zoom lens 12 is an imaging lens that can arbitrarily change the focal magnification for enlarging or reducing an optical image of a subject (not shown) to a desired size, and moves the lens barrel forward and backward. Variably control of the focal magnification. A lens barrel driving section (not shown) for driving the lens barrel forward and backward is supported by a rotation shaft of the motor 11 and drives the lens barrel forward and backward in accordance with the rotation of the rotation shaft.

The above-mentioned CCD 1 is a zoom lens 1
A line-sequential video signal obtained by photoelectrically converting the optical image incident through the signal processor 2 is output to the signal processor 2 at the next stage.

The above-mentioned signal processing section 2 converts the composite video signal obtained by subjecting the line-sequential video signal output from the CCD 1 to predetermined signal processing to an A / D conversion section 3 at the next stage and a well-known V
The signals are output to substantially the same video signal recording system as the recording system of the TR.

The A / D conversion section 3 converts the analog composite video signal output from the signal processing section 2 into a digital composite video signal (hereinafter referred to as a digital video signal) obtained by A / D conversion at the next stage. Is output to the pre-processing unit 4.

The pre-processing unit 4 converts the pre-processed digital video signal to the next stage of the digital video signal output from the A / D conversion unit 3 in order to perform a binary image processing described later. Output to the value processing unit 5. That is, the pre-processing unit 4 has a low-pass filter and a sub-sampling circuit (both not shown), and the low-pass filter causes the digital video signal output from the A / D conversion unit 3 to have an unnecessary high level. The sub-sampling circuit performs a pre-process of removing the frequency components and compressing the digital video signal output from the low-pass filter at the preceding stage into a predetermined amount of information.

The above-mentioned binarization processing unit 5 is adapted to provide an image area to be set as a subject (hereinafter referred to as a subject area. The subject area does not indicate the entirety of the object to be imaged, For example, in the case where the subject is a person wearing a red shirt and wearing jeans as a subject, if a user specifies a red shirt area, binarization corresponding to the red shirt is performed. The image area of the signal is a subject area, and points (pixels) specified by the user in the area 5C shown in FIG.
The digital video signal output from the pre-processing unit 4 is converted into a digital image signal based on color information (information on a color including information on hue, saturation, lightness, and the like) constituting point 5A in FIG. A binary signal obtained by subjecting an image area including color information and an image area not including the color information to two-division (binarization) processing is output to the logical filter 6 at the next stage.

The above logical filter 6 is composed of the above 2
A large number of small regions (a large number of regions 5E such as isolated points and fine lines in FIG. 2) existing near the subject region 5C in the binarized signal output from the binarization processing unit 5 are removed.
Image processing for shaping (filtering) C is performed to clarify an image area (subject candidate area) having specified color information including the object area 5C (filtering the image shown in FIG. 2). By doing so, two regions 6A shown in FIG. 3 are obtained. The shaped binary signal thus filtered is supplied to the next-stage fill processing unit 7.

The above-mentioned fill processing section 7 is provided in an area corresponding to the object area 5C in the shaped binary signal output from the logical filter 6 (the area 6 on the left side in FIG. 3).
As a result of performing image processing (hereinafter, referred to as fill processing) for filling the entire area A) using the color information designated by the user, an area 7D (shown in FIG. 5) that has been filled with the designated color information is obtained. The supplied binary signal is supplied to the data calculator 8 in the next stage.

The data calculating section 8 calculates the total number of pixels of the partial area having the above-mentioned color information in the area 7C in the binary signal output from the fill processing section 7 which has been subjected to the fill processing. , The area information is obtained by integrating (counting), and the coordinates (X, Y) encompassing the entire area 7C are virtually set, and the X value and the Y value at which the number of pixels becomes the maximum are respectively set. The center of gravity of the total number of pixels (that is, the center of gravity of the area information) is obtained, and the area information signal of the obtained area information, the center of gravity information signal of the center information, and the color information of the color information are obtained. The color information signals are supplied to the control signal generator 9 at the next stage. In the “initial setting state” described later, the area information value of the area information signal supplied to the control signal generator 9 is stored as a reference value, and the area supplied sequentially for each frame period after this initial setting. The area information value of the information signal is compared with the reference value, and a signal corresponding to the obtained difference value is supplied to the next-stage zoom lens drive control unit 10 as a control signal for controlling the focal magnification of the zoom lens 12. As a result, when the difference value becomes zero, the control signal is not output. In addition, a center-of-gravity information signal and a color information signal, which are sequentially supplied for each frame period, in a “shooting state (after initial setting)” described later, are respectively stored (updated). Then, the center-of-gravity information signal and the color information signal of the immediately preceding one frame period (previous frame screen) are sequentially supplied to the above-described fill processing unit 7 and binarization processing unit 5, respectively. As a result, the fill processing unit 7 and the binarization processing unit 5
Compares the center-of-gravity information signal and color information signal in the previous frame screen with the center-of-gravity information signal and color information signal of the current one frame period (current frame screen), and the comparison result has a correlation with that of the previous frame screen. If it is within the range, the current frame screen is determined to be substantially the same as the previous frame screen, and the subject image is continuously recognized.

The above-described zoom lens drive control unit 10 includes:
A motor rotation drive control signal based on the control signal output from the control signal generator 9 and an instruction signal output from a zoom lens magnification variable operation unit (not shown) is supplied to the motor 11 at the next stage.

The motor 11 rotates so as to obtain a rotation angle and a rotation number based on a motor rotation drive control signal output from the zoom lens drive control unit 10. As a result, the power based on the motor rotation drive control signal can be transmitted to the lens barrel drive section of the zoom lens 12, so that the focus magnification of the zoom lens 12 can be automatically adjusted according to the power.

Now, regarding the operation of the video camera having the above-described configuration, the "initial setting state" in which the subject image is first initialized to a desired size, and then the subject image moves, The operation of the “shooting state” for performing automatic zoom control (auto zoom) for returning the size of the image to the size of the initially set image when the size of the image changes compared with the size of the initially set subject image will be described in detail below.

1. "Initial setting state" In this initial setting state, the subject image is identified as a subject area and other areas based on the color information of the subject image captured at the center on the imaging screen, and the area information and the center of gravity of the subject area are identified. The information is calculated, each initial value is set, and the color information is held.

First, the subject is set and photographed at the center on the monitor screen by a viewfinder or the like (not shown), or the subject image is specified by using a cursor or the like on the monitor screen, and is output from the zoom lens variable operation section. The zoom lens drive control unit 10
To set the zoom position (focal magnification) of the zoom lens 12 (so-called zoom control), and image the subject so that the subject image has a desired size on the monitor screen. The above-described zoom control is performed on the assumption that the focus setting of the subject has been completed by a well-known automatic focus setting (so-called auto focus) mechanism which will not be described in detail here. Needless to say, it has a configuration for performing auto focus. In addition, the above-described zoom control is performed on the assumption that the video camera according to the present invention always captures the subject on the monitor screen for convenience of explanation.

Now, in this initial setting state, video signal processing is performed according to the following procedures (1) to (3). That is, (1) extraction of color information and binarization based on color information (2) shaping of binarized information (3) collection of subject information (1) extraction of color information and binarization based on color information The digital video signal output from the pre-processing unit 4 is supplied to the above-mentioned binarization processing unit 5, and the extraction of the color information of the point designated by the user as described above in the image area based on the digital video signal is performed. Will be This color information is the phase (hue) of the color signal contained in the digital video signal,
It is a set of data relating to each information of the amplitude (chroma) of the color signal, the amplitude (brightness) of the luminance signal, and the like, and is necessary for performing binarization and fill processing described later.

When the color information is extracted, all the image areas based on the digital video signal are converted into an area where the color information exists and an area having other color information based on the color information. Are divided into two (binarization). That is, as shown in FIG. 2, an arbitrary point 5A (or a plurality of points) in the area 5B where the subject designated by the user exists.
And specify the color (hue, saturation,
Brightness, etc.) as color information of the subject. Then, a binarized signal (for example, the area 5C specified as a subject is set to “1” and the other area 5C having the color information and the area 5D having the other color information are divided into two). The area 5D is set to "0"). After the binarization, the color information is used as information for identifying a subject in a “photographing state” described later.

In the above description, the user specifies the subject image by using a cursor or the like. However, the present invention is not limited to this.
For example, a point at which the diagonal of the area 5B intersects may be used as a point for extracting color information, and an image at this point may be automatically set as a subject image. (2) Shaping of binarized information As shown in FIG. 2, the image of the binarized signal has a plurality of isolated points near the region 5C due to signal noise or the like.
Many regions 5E such as thin lines are generated. Since this area 5E must be subjected to complicated signal processing in fill processing and data processing described later, this area 5E is removed.
The area 5C needs to be shaped (filtered), and this shaping is performed by the logical filter 6. The logical filter 6 searches for the above-mentioned "1" area, and removes only the detected "1" isolated point. An isolated point is detected because the area around the area of “1” is all “0”. Also, since the thin line is connected to the area of “1” in one direction of the area (up, down, left and right) around the area of “1”, the direction in which the connected area of “1” is continuously detected , And the detected area of “1” is sequentially removed to remove the thin line of “1”. Thus, as shown in FIG. 3, the logical filter 6 removes a number of small areas existing near the area 5C having the color information of the subject, and shapes a relatively large “1” area.
Shaping 2 having large and small subject candidate areas 6A shown in FIG.
Outputs a digitized signal. The plurality of subject candidate regions 6A obtained at this time are large regions having subject color information (information of “1”). Therefore, as described above, this shaping is performed to identify an area corresponding to the object area 5C existing within the area 5B designated by the user by using the cursor or the like, among the plurality of object candidate areas 6A obtained here. The binarized signal is supplied to the fill processing unit 7, and a fill process described later is performed based on the color information of an arbitrary point 5A in the area 5B previously specified by the user. (3) Collection of subject information Here, the user first specifies a region corresponding to the subject region 5C from the plurality of subject candidate regions 6A based on the shaped binary signal supplied from the logical filter unit 6 described above. Performs fill processing only on the subject candidate area 6A corresponding to the subject area 5C based on the color information of an arbitrary point 5A in the designated area 5C, and the binary signal output from the fill processing unit 7 is subjected to data calculation. The unit 8 calculates the area information and the center-of-gravity position information of the filled subject candidate area corresponding to the subject area 5C. Thereafter, by supplying the color information, the area information, and the center-of-gravity position information of the region to the control signal generating unit 9 as subject information, it is possible to perform the above-mentioned variable control of the zoom magnification in the “photographing state” described later. Become.

Now, the operation of the above-mentioned fill processing unit 7 will be described in detail with reference to FIGS. Here, the fill processing refers to an area corresponding to the subject candidate area 5C of the two subject candidate areas 6A shown in FIG.
A) is a process of replacing all areas including a starting point 7A described later with a set area including only the above-described color information (it goes without saying that many color information different from the above-described color information exist in this area). Existing). This starting point 7A
May be at any place in the area 6A, and may be an arbitrary point (or a plurality of points) 5A in the area 5B specified by the user first.

That is, first, a fill process is performed from the start point (pixel) 7A to the left to the left boundary of the region 6A, and then a fill process is performed to the right to the right boundary of the region 6A. Next, the fill process is sequentially performed on the upper and lower pixel columns of the column on which the fill process has been performed up to the left and right boundary lines.
When all the pixels in A have been scanned, the filling process ends. Thus, as shown in FIG. 5, an area where the fill processing has been performed, that is, a subject area 7C is obtained.

The binarized signal that has been subjected to the fill processing in the above-described fill processing section 7 is supplied to the above-described data calculation section 8, where the total number of pixels that have been subjected to the above-described fill processing of the subject area 7C is integrated ( (Counting), the area information of the subject area 7C is obtained. Further, the coordinates (X, Y) in the image area including the entire subject area 7C are virtually set, and the X value and the Y value at which the number of pixels is maximized are set.
By obtaining the respective values, the value of the coordinates at the center of gravity 7D of the subject area 7C can be obtained as the center of gravity position information. The area information and the center-of-gravity position information thus obtained are supplied to the control signal generator 9 as an area information signal and a center-of-gravity position information signal, respectively. The area information signal is stored in the control signal generator 9 as initial area information (reference area information) of the object area 7C for successive comparison with the area information of the object information obtained in the “photographing state”. Also, this center-of-gravity position information is held as data for predicting a starting point for performing a fill process only on a true subject region in a “photographing state” described later. 2. "Shooting state" Now, the state in which the normal video camera is in the shooting state after the initial setting in the "initial setting state" is called "shooting state". The operation for performing the zoom control at this time will be described. In the “shooting state”, the image to be captured is changing every moment. Therefore, based on the subject information set in the above “initial setting state”, the subject always changes according to the change in color and size of the subject. Zoom control is performed so that the size is always kept the same. Here, after subjecting the video signal of the subject to signal processing in accordance with the above-described procedures (1) to (3) in the above-mentioned “initial setting state”, (4) resetting of subject information, which will be described later,
(5) Each procedure of the zoom control is sequentially repeated for each frame. (4) Resetting of subject information In this “shooting state”, when the color or shape of the subject changes every moment, the color information, area information, and center of gravity position information of the subject area (these three pieces of information are hereinafter referred to as subject information) are also obtained. Change. Therefore, the color information and the barycentric position information of the subject information are sequentially obtained, and the color information and the barycentric position information of the current one frame period (current frame screen) and the color information of the immediately preceding one frame period (previous frame screen) are obtained. If the comparison result is within a range having a correlation with that of the previous frame screen, it is determined that the current frame screen is substantially the same as the previous frame screen, and the subject image is continuously recognized. At the same time, the subject information on the current frame screen is reset as the latest subject information. The video signal imaged in the “shooting state” is subjected to the same processing as in “(1) Setting of color information and binarization based on color information” described above, and thereafter, a subject area 7E described later (FIG. 6). (Shown in FIG. 6).
For convenience, the subject area 7C in the “initial setting state”
This shows a state in which the subject area 7E in the “shooting state” is displayed on the same monitor screen). At this time, based on the color information (color information of the previous frame screen including the “initial setting state”) stored and held in the control signal generator 9, the hue and the saturation closest to the range having a correlation with the color information are displayed. , An area having color information (color information of the current frame screen) composed of lightness is determined. Then, the binarized signal from which the area determined at this time is obtained is supplied to the above-described logical filter 6, and the above-mentioned “(2) Shaping of binarized information” is performed.
After the isolated point and the thin line are filtered by performing the same processing as described above, the resulting data is supplied to the above-described fill processing unit 7, and the same processing as the above-described "(3) Collection of subject information" is performed.

The operation of the fill processing unit 7 when resetting the subject information will be described with reference to FIG. In the figure, a subject area 7E is obtained via the binarization processing unit 5 and the logical filter 6, and the subject area 7E is obtained.
Is performed, the center of gravity of the subject area 7E is predicted in order to set the starting point of the fill processing (the prediction point 7).
F). The predicted point 7F is determined by a function that satisfies or approximates the locus 7H (dot-dash line) of the center-of-gravity position information by sequentially accumulating the center-of-gravity position information of the subject area 7E obtained for each frame. Then, the above-described fill processing is performed with the predicted point 7F as a starting point. Further, since the color information (color information including the hue, color, and lightness constituting the prediction point 7F) of the subject area 7E is obtained from the obtained subject area 7E, the previous color information (the previous frame screen) is obtained. Of the subject area 7
E is updated to the color information of E (the color information of the current frame screen), and the subject area 7 to be changed in the future through the data calculation unit 8 described above.
In order to predict the movement of E, the control signal generator 9 stores and holds the color information of the current frame screen.

Further, when the subject candidate area does not exist at the above-mentioned predicted point 7F (for example, when the subject moves rapidly or is large), the center of gravity 7 determined in the initial setting state is used.
The coordinate data of a point in the subject area 7E closest to the coordinate data of D is obtained (a point in the subject area 7E located at the shortest distance from the center of gravity 7D), and the above-described fill processing may be performed with the point 7G as a starting point. . Further, when the center of gravity 7D of the subject area 7C in the "initial setting state" is included in the current subject area 7E, for example, the subject in the "initial setting state" When the motion of the subject hardly changes, such as when the center of gravity 7D of the area 7C is included in the subject area 7E, the center of gravity 7D may be used as the starting point of the fill processing.

The subject area 7E is filled with the predicted point (start point) 7F or the point 7G obtained as described above.
Similarly, since the area information and the barycentric position information are obtained by the data calculating section 8, the area information signal and the barycentric position information signal are updated with the control signal generating section 9 in order to update these information together with the color information as the latest subject information. Supply each. Then, the subject information of the previous frame screen stored in the control signal generator 9 is replaced with the subject information. In the control signal generator 9, the value (current area) of the area information signal of the subject area 7E with respect to the value of the area information signal of the subject area 7C in the “initial setting state” (the value of the reference area information signal and the reference value). Value). The increase / decrease ratio of the current area value is obtained from the difference value, and when the increase / decrease ratio of the current area value decreases, the distance of the subject away from the position where the subject was in the “initial setting state” is calculated from the ratio of the value of the area information signal. calculate. When the increase / decrease ratio of the current area value increases, the distance from the position where the subject is in the “initial setting state” is calculated from the ratio of the value of the area information signal. (5) Zoom control From the increase / decrease ratio of the value of the area information signal thus calculated, a magnification for setting the current area value, which is the value of the current object area information signal, to the same value as the reference value is obtained. Since the enlargement / reduction magnification for making the current area value equal to the reference value is determined, a zoom lens magnification control signal corresponding to this is obtained and supplied to the zoom lens drive control unit 10.
The zoom lens drive control section 10 supplies a motor rotation drive control signal to the motor 11 based on the zoom lens magnification control signal. The motor 11 transmits power corresponding to the rotation angle and the number of revolutions based on the motor rotation drive control signal to the lens barrel drive unit of the zoom lens 12 according to the motor rotation drive control signal. Perform automatic adjustment of. For example, when the size of the subject on the current frame screen is smaller than the size of the subject on the previous frame screen (1/4 times the reference value in terms of area value), the size of the subject is equal to the size of the subject on the previous screen. To this end, the control signal generator 9 supplies a zoom lens magnification control signal to the zoom lens drive controller 10 to instruct the magnification of the zoom lens to be four times.

In the above-described fill processing, when an image having no correlation with the previous frame screen is obtained on the current frame screen (for example, a person wearing blue clothes up to the previous frame screen has been recognized as a subject. , When this subject suddenly holds a red doll on the current frame screen),
Since the color information of the subject is different from the color information of another object inside the subject, a region corresponding to a hole is generated in the subject region obtained by the above-described binarization process. Since the shape of the hole or the movement of the doll changes the area of the hole obtained by the fill process, the calculated position of the center of gravity changes. For this reason, the prediction of the position of the center of gravity is erroneous, or the change in the area amount is erroneously detected, which may cause a malfunction of the zoom. However, it is assumed that the different area described above occurs inside the object area.

Therefore, when there is an area (another area) having different color information inside the object area, it is necessary to perform the fill processing with priority on the object without being affected by the other area. As this method, the above-described fill processing is performed stepwise as described below. First, after the above-described fill processing is performed on the subject area excluding another area (fill processing 1),
A fill process is performed on the entire area of the screen other than the subject area (fill processing 2). At this time, the start point of the fill process 2 is, for example, a point in an area other than the subject area that is the shortest distance from the start point of the fill process 1. At this point, another area inside the object area has not been filled. Then, a fill process is performed on an area other than the area on which the fill process has been performed by the above-described fill process 2 (referred to as a fill process 3). In the filling process 3, a subject region is specified by performing a filling process on the entire region including another region inside the subject region. Therefore, by performing the above-described fill process 1 to fill process 3, even when the above-described another region exists inside the subject region, it is possible to perform the fill process with priority given to the subject region while absorbing the influence of the another region. If the predicted point 7E of the center of gravity of the subject is obtained from the area and the center of gravity of the subject area calculated by the data calculation unit 8 at the same time as the above-described fill processing 3, the automatic zoom control for the subject area can be performed. Can be improved.

For the above-described stepwise fill processing, for example, by obtaining the area of the entire area of the screen other than the subject area obtained by the above-described fill processing 2, the subject area and the area other than the subject area are obtained. Since the area ratio can be calculated, the control signal generator 9 may supply a control signal to the zoom lens drive controller 10 so as to keep the area ratio constant.

According to the above-described fill process of the subject area, the fill process is performed every predetermined frame period to obtain the above-described center-of-gravity position information, which is stored in the control signal generating unit 9, thereby obtaining the center of gravity of the subject area. Since the position information is accumulated, it is possible to predict the position of the center of gravity of the subject, and when the subject region is obtained, the predicted value can be corrected because the center of gravity position information of the subject region is updated each time. In addition, the position of the subject area can be accurately captured. Therefore, it is needless to say that the automatic zoom control can be performed with high accuracy by using the center-of-gravity position information of the subject area and, at the same time, the subject that controls the pan and / or tilt of the video camera can be automatically tracked.

Further, by performing the fill process for each frame, the subject information can be obtained by following the state of the subject that changes every moment. That is, since the average value of the color information of the subject obtained up to the previous frame period is used as the color information for specifying the subject area, when the color of the subject changes gradually, for example, the sun, a light bulb, a fluorescent light Since the subject can be specified even when the same subject is imaged under various light sources such as, for example, the automatic zoom control is performed with high accuracy, and at the same time, for example, the automatic tracking of the subject which controls the pan and / or tilt of the video camera can be performed. Of course, you can do it.

In order to improve the operability of the automatic zoom control, there has been a method of performing an automatic zoom based on distance information from a subject estimated by an auto focus (automatic focus setting) mechanism. That is, a specific high-frequency component is extracted from a captured video signal, and a focus (focus) adjustment (a so-called hill-climbing servo method) is performed so that the amplitude of the high-frequency component is maximized. This zoom control was performed by estimating the distance. However, since this distance information has a large error, it is difficult to perform auto-zoom with high accuracy. Since it is possible to obtain area information and center-of-gravity position information as accurate movement information of the moved subject, the drive control of the zoom lens can be performed with high accuracy by using such information for the autofocus control.

In this embodiment, the automatic zoom control of the video camera has been described.
By adding the configuration of the present invention to a still camera or the like using an imaging element as an imaging medium, it is needless to say that the automatic zoom control of the still camera or the like can be performed.

[0042]

The video camera according to the present invention comprises: a binarization processing means for binarizing an image of a captured subject into a subject region and other regions; and a filter for filtering a binary image signal relating to the subject region. Fill processing means for processing, data calculation means for calculating the area information signal and the center of gravity position information signal of the subject region in the fill processing image signal output from the fill processing means, and the area information signal and the center of gravity position information signal, The color information signal relating to the subject area is updated and held, respectively, and the held color information signal and the center-of-gravity position information signal are output to the binarization processing unit and the fill processing unit, respectively. A control signal generating means for outputting a control signal based on a difference between the control signal and the updated and held area information signal; and a zoom lens based on the control signal. And a zoom lens drive control means for variably controlling the magnification of the object, the object is specified based on the color information signal of the imaged object, and the area information signal is obtained. Based on the value of the area information signal value, the difference between the subject and the subject other than the subject having substantially the same size and substantially the same movement as the subject can be reliably determined. Can be performed with high accuracy, so that the same subject image can be continuously captured at all times.

Further, since the subject is specified based on the color information signal of the subject picked up by the video camera of the present invention and the center-of-gravity position information signal is obtained, the movement of the subject can be quickly and reliably followed. For example, even when another image having substantially the same luminance information and having a different color (for example, the color of the original subject image is “white” but “cream” close to “white”) is instantaneously replaced. This makes it possible to maintain the subject in a specific manner, so that even if the subject is moving rapidly, the subject image can always be continuously photographed with the same size.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a video camera according to the present invention.

FIG. 2 is a diagram for explaining an operation of a binarization processing unit;

FIG. 3 is a diagram for explaining an operation of a logical filter.

FIG. 4 is a diagram for explaining the operation of a fill processing unit.

FIG. 5 is a diagram for explaining the operation of a fill processing unit.

FIG. 6 is a diagram for explaining an operation of a fill processing unit after an initial setting state.

[Explanation of symbols]

 Reference Signs List 5 Binarization processing unit 5C, 6A, 7C, 7E Subject area 6 Filter 7 Fill processing unit 8 Data calculation unit 9 Control signal generation unit 10 Zoom lens drive control unit 12 Zoom lens A Zoom lens drive control system

Claims (1)

(57) [Claims] 1. A binarization processing means for binarizing an image of a captured subject into a subject area and other areas, a fill processing means for filling a binary image signal related to the subject area, Data calculating means for outputting an area information signal and a center-of-gravity position information signal of the subject area in the fill-processed image signal output from the fill processing means, respectively; the area information signal, the center-of-gravity position information signal, and color information relating to the subject area The signals are updated and held, respectively, and the held color information signal and center-of-gravity position information signal are output to the binarization processing means and the fill processing means, respectively. Control signal generating means for outputting a control signal based on a difference from the obtained area information signal; and a variable control unit for variably controlling a magnification of the zoom lens based on the control signal. A video camera comprising a camera lens drive control means.