JP4985251B2 - Imaging apparatus, focus control method, and focus control program - Google Patents

Description

  The present invention relates to an imaging device having an autofocus function, a focus control method, and a focus control program.

  2. Description of the Related Art Conventionally, there are cameras that automatically adjust sensitivity and shutter speed in order to prevent deterioration of image quality of captured images.

  Here, during normal shooting (when shooting other than panning), the sensitivity is automatically adjusted to prevent degradation of image quality, and on the other hand, the camera is moved to shoot the moving main subject. In this case, there is a case where it is desired to express the feeling of speed and dynamic of the main subject by intentionally degrading only the image quality of the background image.

  However, with the conventional camera described above, even during panning, the sensitivity and shutter speed are automatically adjusted to prevent deterioration of the image quality of the photographed image, so that only an image without a sense of speed can be obtained.

  As a technology related to this, for example, in Patent Document 1 below, a motion vector of each area portion in an image is detected from a plurality of images taken continuously in time, while focusing is performed within an angle of view. Determining the shooting situation based on the motion vector of the main subject region and the motion vector of the other background region with the face portion of the person detected by the vicinity of the position or the face detection function as the main subject region, A technique for setting shooting conditions such as a shutter speed according to a shooting situation is described.

According to such a technique, the sensitivity and the shutter speed are automatically adjusted in order to prevent deterioration of the image quality of the captured image during normal shooting. On the other hand, if the photographer shakes the camera to bring the desired subject into the focus area for focus detection (for example, the center of the angle of view), the subject in focus is identified as the main subject. It is also possible to increase the sensitivity by increasing the shutter speed according to only the motion vector of the main subject. As a result, it is considered that only the image quality of the background image is degraded and a sense of speed can be expressed in the captured image.
JP 2006-157428 A

  However, in the technique disclosed in Patent Document 1, when the main subject is specified, the photographer shakes the camera so that the desired main subject is in the focus detection focus area (for example, the center in the angle of view). Need to do. Therefore, it takes time to identify the main subject. As a result, there is a problem that it takes time to obtain a speedy image during panning.

  The present invention has been made in view of such conventional problems, and an imaging apparatus, a focus control method, a focus, and the like that can easily acquire an image having a sense of speed at the time of panning using a digital camera or the like. An object is to provide a control program.

In order to solve the above-described problem, the imaging apparatus according to the first aspect of the present invention includes an imaging unit that captures an image of a subject and obtains an image, and a plurality of detection blocks in the image obtained by the imaging unit. Detecting means for detecting the amount of movement of each part of the subject in the camera, and a second detecting block other than the first detecting block of the plurality of detecting blocks, wherein the detecting means detects substantially the same moving amount. the specific area as the main subject area formed by the control means and a said control means for controlling the photographing conditions of the imaging means, the smallest movement among the movement amount detection blocks constituting the main subject area A shutter speed is determined based on the amount, and the shooting condition is adjusted to a shooting condition including the determined shutter speed .

Further, in the imaging apparatus according to the invention of claim 2, wherein the control means is characterized by comprising a focus control means for setting to focus control the focus detecting area in the main main subject region .

In the image pickup apparatus according to the third aspect of the present invention, the detection means includes a movement amount and a movement direction of each part of the subject within the angle of view from a plurality of detection blocks in the image obtained by the imaging means. The control means detects a second of the plurality of detection blocks other than the first detection block in which the detection means detects the substantially same movement amount and the substantially same movement direction. wherein the main subject area and to Rukoto within angle the specific region configured by the detection block.

In the imaging device according to the fourth aspect of the present invention, the imaging device further includes an acquisition unit that acquires a ratio of the second detection block in a predetermined region surrounding the specific region, and the control unit includes the acquisition unit. ratio obtained is if more than a predetermined criterion, characterized by the main subject area and to Rukoto in the second field angle in a specific area including a detection block by.

  Moreover, in the imaging device according to the fifth aspect of the invention, the detection means includes a plurality of detection blocks in an image taken by the imaging means on condition that a predetermined operation mode is set. The amount of movement of each part of the subject within the angle of view is detected.

  In the image pickup apparatus according to the sixth aspect of the present invention, a recording means for recording an image obtained by the imaging means, and the imaging means for a user to record a subject image on the recording means Instruction means for instructing imaging preparation prior to the imaging operation, and the detection means responds to the instruction for imaging preparation from the user by the instruction means, and a plurality of images in the image captured by the imaging means It is characterized in that the amount of movement and the direction of movement of each part of the subject within the angle of view are detected from the detection block.

Further, in the imaging apparatus according to the invention of claim 7, wherein, e Bei recording means for recording the subject image picked up by the image pickup means, said control means, each part of the object detected by said detecting means a movement amount, this based on the amount of movement of the detection blocks constituting the principal object area, adjusts the imaging conditions at the time of imaging operation of said imaging means toward a recording object images to the recording means And features.

Further, in the imaging apparatus according to an eighth aspect of the present invention, the control means is a first detection block in which substantially the same movement amount is detected by the detection means among the plurality of detection blocks. The specific area formed by the second detection block in which a movement amount smaller than the substantially same movement amount is detected is set as a main subject area .

In the image pickup apparatus according to the ninth aspect of the present invention, the control unit includes a determination unit that determines whether or not substantially the same movement amount is detected by the detection unit, and the determination unit If the same the amount of movement is determined to not detected, characterized in that a shutter speed control means for controlling the imaging means to image shot with the shutter speed of the given range.

Further, the focus control method according to the invention of claim 10 is a focus control method in the imaging apparatus, wherein the movement amount of each part of the subject within the angle of view is determined from a plurality of detection blocks in the captured image. a detection step of detecting that, among said plurality of detection blocks, the main subject of the specific region configured by a first detection of the non-block second detection block in which the movement amount substantially the same is detected by the detecting step as an area, seen including a control step for controlling the photographing conditions, the control step determines the shutter speed based on the minimum amount of movement among the movement amount detection blocks constituting the main subject area, the photographing The condition is adjusted to a shooting condition including the determined shutter speed .

Further, in the focus control program according to the invention of claim 11, wherein the computer imaging device has, from a plurality of detection blocks in the captured image, detected for detecting the movement amount of each portion of the subject in the angle of view And taking a specific area constituted by a second detection block other than the first detection block in which the detection means detects the substantially same amount of movement among the plurality of detection blocks as a main subject area. to function as a control means for controlling the condition, the control means determines the shutter speed based on the minimum amount of movement among the movement amount detection blocks constituting the main subject area, the photographing condition, It characterized that you adjust the shooting conditions including a shutter speed and the determined.

  According to the present invention, an image with a sense of speed can be easily acquired at the time of panning using a digital camera or the like.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
First, the first embodiment will be described. FIG. 1 is a block diagram showing a schematic configuration of a digital camera according to the present embodiment. This digital camera has functions of AE (automatic exposure), AF (autofocus), and face detection, and mainly includes the following parts.

  That is, the digital camera has a CCD 2 as an imaging unit that photoelectrically converts an optical image of a subject imaged by the optical system 1 and outputs it as an imaging signal. The CCD 2 is driven by a drive signal generated by a CCD drive circuit 4 based on a timing signal generated by a timing generator (TG) 3. The output signal of the CCD 2 is converted into a digital signal by the A / D converter 5 and then sent to the image processing unit 6.

  The optical system 1 includes a focus lens and a lens motor for moving the focus lens on the optical axis. The focus lens is driven by a drive signal generated by the lens drive circuit 8 according to a command from the control unit 7. By being driven, the position on the optical axis is controlled.

  The image processing unit 6 performs RGB interpolation processing for generating R, G, and B color component data (RGB data) for each pixel with respect to the imaging signal after A / D conversion, and luminance signal (Y) from the RGB data. And YUV conversion processing for generating YUV data consisting of color difference signals (U, V) for each pixel, and digital signal processing for improving image quality such as auto white balance and edge enhancement. The YUV data converted by the image processing unit 6 is sequentially stored in the SDRAM 9.

  In addition, the digital camera has a display unit 10 including a liquid crystal monitor and a driving circuit thereof. When the recording mode for photographing is set, the YUV data stored in the SDRAM 9 is sent to the image processing unit 6 every time one frame is accumulated, where it is converted into a video signal, and then the display unit 10 ( On a liquid crystal monitor). When shooting in the recording mode, the image data temporarily stored in the SDRAM 9 is compressed and encoded by the JPEG conversion unit 11 using the JPEG method, and then configured by, for example, various memory cards via the external memory I / F 12. It is recorded as a still image file in the external memory 13 which is a recording means of the present invention.

  The still image file recorded in the external memory 13 is appropriately read in accordance with the user's selection operation in the reproduction mode, is decompressed by the JPEG conversion unit 11 and developed as YUV data in the SDRAM 9, and then is statically displayed on the display unit 10. Displayed as an image.

  The key input block 14 includes a power key, a plurality of keys such as a mode switching key for switching between the recording mode and the playback mode, which are basic operation modes of the digital camera, a MENU key, and a shutter key. The state is scanned by the control unit 7 as needed. The shutter key is an instruction means of the present invention, and has a so-called half shutter function capable of two-stage operation of a half-pressed position and a full-pressed position for instructing an actual photographing operation.

  The motion detection unit 15 is a plurality of frames of image data (hereinafter referred to as frame images) that are sequentially generated and sent by the image processing unit 6 in the recording mode (a panning mode described later), that is, temporally continuous. A detection unit of the present invention that detects a motion vector of a subject from each part of an image, that is, a movement distance (number of pixels) and a movement direction, more specifically, a frame memory that temporarily stores image data for a plurality of frames, It comprises an image processing circuit for performing various image processing necessary for motion vector detection operation.

  Then, when detecting a motion vector, the motion detection unit 15 divides the image 100 into a plurality of macroblocks 101 (detection blocks) as shown in FIG. 2, and a block matching method or the like is known for each macroblock 101. The motion vector A is detected by the method described above and sent to the control unit 7. Here, the macroblock 101 does not necessarily need to be an area obtained by dividing the image 100, and an arbitrary interval smaller than the size of the macroblock 101 may be provided between the macroblocks 101. Good. The size of the macroblock 101 is arbitrary as long as the motion vector can be detected.

  The control unit 7 includes a CPU and its peripheral circuits, and performs control of each unit of the digital camera, AE control based on luminance information included in the imaging signal, AF control using a contrast detection method, and the like. Various programs for causing the control unit 7 to perform such control and various data necessary for each control are stored in a flash memory 16 which is a nonvolatile memory capable of rewriting stored data. In particular, the flash memory 16 stores a focus control program that causes the control unit 7 to function as the control means of the present invention as the various programs. The flash memory 16 also stores setting information regarding various functions of the digital camera that are appropriately rewritten as necessary.

  Next, the operation of the digital camera in this embodiment will be described. 3 and 4 show the control unit 7 when the operation in the recording mode (hereinafter referred to as the panning mode) is started in a state in which the panning function prepared in advance in the digital camera is set to the on state. It is a flowchart which shows the processing content of.

  As shown in FIG. 3, when the control unit 7 starts the operation in the panning mode, the control unit 7 immediately starts acquiring a through image at a predetermined frame rate (for example, 30 fps) and enters a shooting standby state (step SA1). In the meantime, detection of a motion vector from the through image by the motion detector 15 is started (step SA2).

  Thereafter, in the shooting standby state, whether or not the shutter key is half-pressed or fully pressed is sequentially checked. If the shutter key is fully pressed without being pressed halfway (NO in step SA3, step SA4). YES), the focus is adjusted immediately by normal AF control. In other words, focusing is performed for a predetermined focus area within the angle of view (such as the central portion within the angle of view), and ISO sensitivity and shutter speed are adjusted by normal AE control, and set as shooting conditions. (Step SA5).

  Thereafter, photographing is performed with the set ISO sensitivity and shutter speed, and the photographed image is recorded in the external memory 13 (step SA14). That is, a normal photographing operation is performed without performing so-called AF lock or AE lock, and one photographing process is completed.

  On the other hand, when the shutter key is pressed halfway in the shooting standby state (YES in step SA3), first, out of the motion vectors of all the macroblocks 101 in the image 100 detected by the motion detection unit 15 at that time. Then, it is confirmed whether or not the number of first motion vectors whose magnitudes (movement distances) are substantially the same in accordance with a predetermined reference determined in advance is greater than or equal to a predetermined number (step SA6).

  Here, in the situation where panning is being performed, the camera and its direction are moving following the movement of the moving main subject, and almost all the movement of the background portion excluding the main subject in the image 100 is performed. Since the vector sizes are substantially the same, if the number of the first motion vectors is not equal to or greater than the predetermined number (NO in step SA6), it is determined that no panning has been performed, and the process proceeds to step SA4 as it is and the shutter key is pressed. It is determined whether or not the button is fully pressed.

  FIG. 5 is an explanatory diagram for convenience showing a state in which images of a plurality of frames taken in a shooting standby state are combined when a skier is skiing on a background of mountains and the like. In the example, a plurality of macroblocks 101a in a background portion such as a mountain in the composite image 110 are the first detection blocks of the present invention, and the motion vector of these macroblocks 101a is the first motion vector A1.

  If the shutter key is fully pressed (YES in step SA4), the normal photographing operation is performed as described above (steps SA4 and SA5), and if the shutter key is not fully pressed (NO in step SA4). ), And returns to Step SA3.

  On the other hand, if the determination result in step SA6 is YES and the number of first motion vectors is equal to or greater than the predetermined number when the shutter key is half-pressed, it is estimated that the panning is being performed, and then Whether or not there is a second motion vector that is different (smaller) from the first motion vector (each motion vector having substantially the same size) in light of a predetermined reference having a predetermined size. (Step SA7). Here, in FIG. 5, a plurality of macroblocks 101b in the skier portion are the second detection blocks of the present invention, and the motion vector of these macroblocks 101b is the second vector A2.

  At this time, if the second motion vector does not exist (NO in step SA7), it is determined that there is no main subject within the angle of view, and a predetermined blur warning display is performed on the display unit 10 (step SA8). Then, the process proceeds to step SA4, and the process proceeds to determination of whether or not the shutter key is fully pressed.

  On the other hand, as shown in FIG. 5, when there is a second motion vector having a magnitude different from that of the first motion vector (YES in step SA7), the main subject exists within the angle of view. AF control is performed by setting a focus area F (area indicated by a double frame in FIG. 5), that is, a focus detection area, of a predetermined size in a specific area configured by the macro block 101b in which the second motion vector is detected. To focus automatically (step SA9). Note that when setting the focus area F, for example, the focus area is set at a location where many couma blocks 101 in which the second motion vector is detected are adjacent to each other. Further, a region surrounded by the outer edge of each Kumaro block 101 in which the second motion vector is detected may be used as the focus area.

  Thereafter, it waits for the shutter key to be fully pressed (step SA10). In the meantime, although not shown in the drawing, after the focus is adjusted in step SA9, if the half-pressed state is released without fully pressing the shutter key, the process immediately returns to step SA3 and the above-described processing is repeated.

  On the other hand, if the shutter key is fully pressed from the half-pressed state (YES in step SA10), first, as shown in FIG. 4, first, the second motion vector (the motion vector of the area excluding the background portion) described above is included. The size of the smallest motion vector is confirmed (step SA11).

Next, based on the magnitude of the confirmed motion vector, that is, the minimum moving amount (number of pixels) corresponding to the blurring amount of the main subject between frames, the calculated shutter speed is such that the main subject is not substantially shaken during shooting. The following formula: Shutter speed = Frame rate ÷ Minimum movement (number of pixels)
(Step SA12). That is, the shutter speed at which the movement amount of the main subject during the exposure time is 1 pixel is calculated. For example, when the frame rate is 30 fps and the minimum movement amount is 7 pixels, the calculated shutter speed is 1/210.

  If the calculated shutter speed calculated here is a settable shutter speed, it is set as a shooting condition, and in other cases, the settable shutter speed is closest to the calculated shutter speed or higher. The fastest shutter speed is set as a shooting condition. For example, if 1/210 cannot be set as the shutter speed, 1/256 or the like is set. Further, the IOS sensitivity necessary for securing the exposure is set as a photographing condition according to the shutter speed (step SA13). In other words, the IOS sensitivity is set as low as possible by setting the shutter speed at the time of shooting to a slow speed within a range where blurring of the main subject can be prevented.

  Thereafter, photographing is performed with the set ISO sensitivity and shutter speed, and the photographed image is recorded in the external memory 13 (step SA14). As a result, a photographed image that is blurred so that the background portion flows without blurring or blurring in the main subject can be obtained. FIG. 6 is a diagram showing a photographed image 120 corresponding to FIG. 5, and when the skier was skied with a mountain in the background, the skier was blurred so that there was no blur or blur and the mountain etc. would flow. It becomes a state.

  As described above, in the digital camera according to the present embodiment, when in the shooting standby state in the panning mode, it is determined whether or not the panning is performed when the shutter key is pressed halfway. When it is determined that the focus is being performed, the area where the main subject within the angle of view exists is automatically set as the focus area and focused.

  Therefore, when performing a panning shot, the photographer moves the camera and its orientation following the movement of the main subject without having to perform a complicated task such as shaking the camera and moving the focus area to the desired main subject. However, by simply pressing the shutter key halfway, the main subject can be reliably focused regardless of the position of the main subject within the angle of view. Therefore, a captured image with a sense of speed can be easily acquired.

  In the present embodiment, when it can be determined that the panning is being performed, it is based on whether or not a second motion vector having a size different (smaller) from the first motion vector in the background portion is detected. The main subject is determined. As a result, for example, when there is only camera shake or image shaking, it is not determined that panning is being mistakenly performed, and erroneous AF operation associated therewith can be prevented in advance. Can do.

  Further, in the present embodiment, at the time of shooting when it is determined that the panning is finally performed, the shutter speed is set based on the size of the smallest motion vector among the second motion vectors. Therefore, even if the moving speed of the main subject and the moving speed of the camera and its direction do not match at the time of panning, for example, because the photographer is unfamiliar with panning, the main subject in the captured image Can be reliably prevented. Furthermore, since the shutter speed is set to a slow speed within a range that can prevent blurring of the main subject and the IOS sensitivity is set as low as possible, it is possible to prevent image quality deterioration due to unnecessary increase of the IOS sensitivity. Therefore, it is possible to acquire a high-quality captured image with a sense of speed.

  In the present embodiment, a description has been given of determining whether or not panning has been performed in response to a half-pressing operation of the shutter key. However, this determination is performed at any time regardless of the half-pressing operation of the shutter key. When it is determined that the panning is being performed, the AF control with the main subject as the target may be performed as described above.

In this case, for example, AF lock or AE lock can be performed by half-pressing the shutter key as in the general recording mode, and once the shutter key is half-pressed, AF lock or AE lock is once performed. After that , it is determined whether or not the panning is being performed. When it is determined that the panning is being performed, the AF lock and the AE lock are automatically released, and then the main subject described above is set as the target. The AF control to be performed and the AE control (setting of the shutter speed and sensitivity) based on the minimum movement amount in the second motion vector may be performed.

  In the present embodiment, the basic determination as to whether or not panning is performed in step SA6 is based on the motion vectors of all the macroblocks 101 in the image 100. Although it was performed based on the number of first motion vectors that are substantially the same, the present invention is not limited to this, and the following may be used.

  For example, the number of the first motion vectors is acquired for one or a plurality of macroblocks 101 located at the four corners of the image 100 or every other macroblock 101 in the image 100, and a panning is performed based on the number. It may be possible to simply make a basic determination as to whether or not the user is present. In that case, the processing burden required for basic judgment can be reduced.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. This embodiment relates to a digital camera in which the flash memory 16 stores a focus control program that causes the control unit 7 to function as an acquisition unit in addition to the determination unit, the focus control unit, and the adjustment unit of the present invention.

  In the first embodiment described above, when it can be determined that the panning is being performed, whether or not the second motion vector having a different size (smaller) than the first motion vector in the background portion is detected. The presence / absence of the main subject is determined based on this, but in the present embodiment, the presence / absence of the main subject is determined by a two-step determination process as will be described later.

  FIG. 7 is a flowchart corresponding to FIG. 3 showing the processing contents of the control unit 7 in the panning mode in the present embodiment. Hereinafter, differences from the first embodiment will be described. As can be seen from the figure, the processing in steps SB1 to SB8 is the same as the processing in steps SA1 to SA8.

  In this embodiment, among the motion vectors acquired when the shutter key is half-pressed, the number of first motion vectors that are substantially the same in size is equal to or greater than a predetermined number, and the motion vector If there is a second motion vector that is different (smaller) in magnitude from the first motion vector (both YES in steps SB4 and SB5), the following determination is further performed.

That the second motion vector, the area where the second motion vector is detected, i.e. 50% or more of all macro blocks 101 in the rectangular region surrounding the plurality of bear b block 101 detects a second motion vector It is determined whether or not it has been detected. If the determination result is YES (YES in step SB9), it is determined that the main subject exists within the angle of view, and AF control is performed with the main subject as the target as described above (step SB10). ). On the other hand, when the ratio of the second motion vector detected is less than 50% (NO in step SB9), it is determined that there is no main subject, and a predetermined blur warning display is performed on the display unit 10 (step SB8). ). The processing after step SB11 is the same as that of the first embodiment although not shown in the figure.

  In the present embodiment described above, whether or not the main subject exists within the angle of view is not determined based only on whether or not the second motion vector is detected, but the second motion vector is further determined. The detection is performed based on whether or not 50% or more of all the Coumaro blocks 101 in the rectangular area surrounding the plurality of Coumaro blocks 101 that have detected it are detected. That is, the presence or absence of the main subject within the angle of view is determined based on whether the ratio of the second motion vector to the rectangular area is equal to or greater than a predetermined value, or in other words, whether the detection density of the second motion vector is equal to or greater than the predetermined value. I made it.

(Embodiment 3)
Next, a third embodiment of the present invention will be described. The present embodiment relates to a digital camera in which the flash memory 16 is recorded with a program that causes the control unit 7 to function as a determination unit and a shutter speed control unit of the present invention.

  In the first and second embodiments described above, when it can be determined that panning is being performed, shooting conditions are set based on the second motion vector whose magnitude is different from the first motion vector in the background portion. did. On the other hand, in this embodiment, when it can be determined that panning is being performed, the ISO sensitivity and the shutter speed are adjusted by AE control with a small adjustment range of the ISO sensitivity and the shutter speed regardless of the motion vector. Shooting is performed by setting it as a shooting condition.

  FIG. 8 is a flowchart showing the processing contents of the control unit 7 in the panning mode in the present embodiment.

  In this embodiment, as shown in FIG. 8, when the control unit 7 starts the operation in the panning mode, it immediately starts acquiring a through image at a predetermined frame rate (for example, 30 fps) and enters a shooting standby state. (Step SC1) In the meantime, the motion detection unit 15 starts detecting a motion vector from the through image (Step SC2). Up to step SC2, the process is the same as in the first embodiment.

  Thereafter, in the photographing standby state, the control unit 7 sequentially confirms whether or not the number of substantially the same first motion vectors has been detected. That is, the control unit 7 compares the magnitudes (movement distances) of the motion vectors of all the macroblocks 101 in the image 100 detected by the motion detection unit 15 with a predetermined reference determined in advance. It is sequentially confirmed whether or not the number of substantially identical first motion vectors is equal to or greater than a predetermined number (step SC3).

  When it is determined that the number of first motion vectors that are substantially the same is not more than a predetermined number (NO in step SC3), if the shutter key is fully pressed (YES in step SC4), immediately. Transition to shooting operation. First, the ISO sensitivity and the shutter speed are adjusted by normal AE control. That is, the ISO sensitivity and the shutter speed are calculated by the same calculation as steps SA4 and SA5 in the first embodiment and steps SB4 and SB5 in the second embodiment. Then, the calculated ISO sensitivity and shutter speed are set as shooting conditions (step SC5). Thereafter, photographing is performed with the set ISO sensitivity and shutter speed, and the photographed image is recorded in the external memory 13 (step SC8).

  On the other hand, in the shooting standby state, when it is determined that a predetermined number or more of first motion vectors having substantially the same size have been detected (YES in step SA3), the shutter key is fully pressed (YES in step SC6), the process immediately proceeds to the photographing operation. In this case, unlike the first and second embodiments, the ISO sensitivity and the shutter speed are adjusted by the AE control with a small adjustment range of the ISO sensitivity and the shutter speed, regardless of the magnitude of the motion vector, and the photographic conditions are set. (Step SC7). Here, AE control with a small adjustment range is a state in which the shutter speed that can be set is limited to a predetermined speed (such as 1/125) based on the brightness information of the entire image, This is AE control that ensures proper exposure by combining with the ISO sensitivity accordingly.

  Thereafter, photographing is performed with the set ISO sensitivity and shutter speed, and the photographed image is recorded in the external memory 13 (step SC8).

  At the time of panning, if shooting is performed by AE control with a small adjustment range of ISO sensitivity and shutter speed, blur and blur occur in the background portion. However, since there is a high possibility that the moving speed of the main subject to be recorded matches the moving speed of shaking the camera, the possibility that the main subject will blur is low. For this reason, as in the present embodiment, during panning, even if the main subject is shot by AE control with a small adjustment range of ISO sensitivity and shutter speed, the main subject is not blurred or blurred, and the background portion is blurred. A photographed image with a sense of speed can be obtained.

  As long as the shutter key is not fully pressed (YES in step SC4 or YES in step SC8), the process returns to step SA3, and the control unit 7 has detected whether or not the number of substantially identical first motion vectors is greater than or equal to a predetermined number. Continue checking.

  In the present embodiment described above, when it is determined that panning is being performed, the ISO sensitivity and the shutter speed are not adjusted based on the motion vector as in the first and second embodiments. The ISO sensitivity and shutter speed are adjusted by AE control with a small adjustment range of ISO sensitivity and shutter speed, and these are set as shooting conditions.

  As a result, when performing panning, there is no need to manually set the automatic sensitivity adjustment function in advance in order to obtain a speedy image, and a speedy image can be obtained with an easy operation. be able to. Further, the amount of calculation of the control unit 7 can be reduced.

  In this embodiment, when it is determined that panning is being performed, the above-described AE control with a small adjustment range is performed based on the brightness information of the entire image. Good. For example, when the shutter key is fully pressed, the second motion vector is detected in the same manner as in the first embodiment. If the second motion vector cannot be detected, the above-described step SC7 is executed to detect the second motion vector. If it is possible, AE control with a small adjustment range may be performed based on the brightness information of only the specific area constituted by the macroblock 101b in which the second motion vector is detected.

  Further, although not shown in FIG. 8, focusing may be performed automatically or manually. Further, specific AF control in the case of automatically performing focus adjustment is arbitrary. For example, when a shutter key is fully pressed, a normal area within the angle of view (such as a central area) is set as a focus area. AF control may be performed.

  In the first to third embodiments, the digital camera having the configuration in which the motion detection unit 15 detects the motion vector in each part of the subject has been described. However, the present invention is not limited to this, and the motion detection unit 15 is abolished. The motion vector may be detected by the control unit 7. In this case, the control unit 7 and the motion detection unit 15 detect only the movement amount of each part of the subject, not the motion vector, and perform the above-described processing based on the detected movement amount in the panning mode. You may do it.

  In the above description, the case where the present invention is applied to a general digital camera has been described. However, the present invention is an image pickup apparatus that acquires a still image by an image pickup device such as a CCD and has an autofocus function. For example, the present invention can be applied to other imaging apparatuses such as a digital video camera, a mobile phone terminal with a camera, and a PDA with a camera.

It is a block diagram of the digital camera common to each embodiment of this invention. It is the elements on larger scale of the picture which shows a macroblock. It is the flowchart which showed the operation | movement in the panning mode in 1st Embodiment. It is a flowchart following FIG. It is explanatory drawing which showed the state which synthesize | combined the image for several frames imaged in the imaging | photography standby state for convenience. It is the figure which showed the picked-up image corresponding to FIG. FIG. 6 is a flowchart corresponding to FIG. 3 illustrating an operation in a panning mode in the second embodiment. It is the flowchart which showed the operation | movement in the panning mode in 3rd Embodiment.

Explanation of symbols

1 Optical system 2 CCD
4 CCD drive circuit 5 A / D converter 6 Image processing unit 7 Control unit 8 Lens drive circuit 9 SDRAM
10 Display unit 11 JPEG conversion unit 12 External memory I / F
13 External Memory 14 Key Input Block 15 Motion Detection Unit 16 Flash Memory 101 Macroblock F Focus Area

Claims (11)

Imaging means for capturing an image of a subject and obtaining an image;
Detection means for detecting the amount of movement of each part of the subject within the angle of view from a plurality of detection blocks in the image obtained by the imaging means;
Among the plurality of detection blocks, a specific area constituted by a second detection block other than the first detection block in which substantially the same movement amount is detected by the detection means is used as the main subject area, and the imaging means and control means for controlling the shooting conditions,
The control means determines a shutter speed based on a minimum movement amount among the movement amounts of the detection blocks constituting the main subject region, and adjusts the photographing condition to a photographing condition including the determined shutter speed. An imaging apparatus characterized by that. It said control means, the image pickup apparatus according to claim 1, further comprising a focus control means for setting to focus control the focus detecting area on the main principal object area. The detection means detects a movement amount and a movement direction of each part of the subject within the angle of view from a plurality of detection blocks in the image obtained by the imaging means,
The control means is constituted by a second detection block other than the first detection block in which the substantially same movement amount and substantially the same movement direction are detected by the detection means among the plurality of detection blocks. imaging device according to claim 1 or 2, wherein the shall be the main subject area of the specific region in the angle of view within to be. Obtaining means for obtaining a ratio of the second detection block in a predetermined area surrounding the specific area;
Said control means, said the percentage obtained by the obtaining means in the case where more than the predetermined reference shall be the second detection block by the main subject region in the angle of view certain areas constituted The imaging apparatus according to claim 1 . The detection means detects a movement amount of each part of a subject within an angle of view from a plurality of detection blocks in an image taken by the imaging means on condition that a predetermined operation mode is set. The imaging apparatus according to claim 1. Recording means for recording an image obtained by the imaging means;
An instruction means for instructing a user to prepare for shooting prior to an imaging operation of the imaging means for recording a subject image on the recording means;
The detection means responds to an instruction to prepare for shooting from the user by the instruction means, and the movement amount and movement of each part of the subject within the angle of view from a plurality of detection blocks in the image taken by the imaging means. 6. The imaging apparatus according to claim 1, wherein a direction is detected. E Bei recording means for recording the subject image picked up by the image pickup means,
Wherein said control means is a movement amount of each portion of the object detected by said detecting means, based on the amount of movement of the detection blocks constituting the Principal object area, to the recording of the object image to said recording means Adjusting the shooting conditions during the imaging operation of the imaging means
This an imaging device according to any one of claims 1 to 5, characterized in. The control means has a movement amount smaller than the substantially the same movement amount other than the first detection block in which the detection means detects the substantially same movement amount among the plurality of detection blocks. The imaging device according to any one of claims 1 to 7, wherein the specific area formed by the detected second detection block is a main subject area . The control means includes
Determination means for determining whether or not substantially the same movement amount is detected by the detection means;
If it is determined that the moving amount of approximately the same is not detected by the determination means, wherein, characterized in that a shutter speed control means for controlling the imaging means to image shot with the shutter speed of the given range Item 2. The imaging device according to Item 1. A focus control method in an imaging apparatus,
A detection step of detecting a movement amount of each part of the subject within the angle of view from a plurality of detection blocks in the captured image;
Among the plurality of detection blocks, a specific area constituted by a second detection block other than the first detection block in which the substantially same amount of movement is detected by the detection step is used as a main subject area, and imaging conditions are set. and a control step of controlling seen including,
The control step determines a shutter speed based on a minimum movement amount among the movement amounts of the detection blocks constituting the main subject area, and adjusts the photographing condition to a photographing condition including the determined shutter speed. A focus control method characterized by the above. A computer included in the imaging apparatus;
Detection means for detecting the amount of movement of each part of the subject within the angle of view from a plurality of detection blocks in the captured image;
Among the plurality of detection blocks, a specific area constituted by a second detection block other than the first detection block in which substantially the same amount of movement is detected by the detection means is used as a main subject area, and imaging conditions are set. Control means to control
And then allowed to function,
The control means determines a shutter speed based on a minimum movement amount among the movement amounts of the detection blocks constituting the main subject area, and adjusts the photographing condition to a photographing condition including the determined shutter speed. A focus control program.

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