JP4362094B2 - Focus control device and focus control method - Google Patents

Description

  The present invention relates to a focus control device and a focus control method, and more particularly to a focus control device that performs focus control based on image information obtained by imaging and a focus control method in the focus control device.

  In recent years, the demand for digital cameras has been rapidly increasing with the increase in resolution of imaging devices such as CCD (Charge Coupled Device) area sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors.

  By the way, this type of digital camera is generally provided with an automatic exposure function (AE function) for adjusting the brightness of a captured subject image and an automatic focusing function (AF function) for adjusting the focus. These functions automate complicated imaging adjustments.

  For example, the automatic focusing function can employ a contrast detection method for obtaining an optimum focus position based on the contrast of the imaging signal. As the position control of the imaging lens by the contrast detection method, for example, a high frequency component of the object scene image corresponding to the position of the imaging lens is extracted, and the imaging lens is positioned at a position where the evaluation value is maximized. Thus, a so-called hill-climbing control method in which a subject image is formed on the imaging surface of the imaging element can be applied.

  In such image adjustment using the automatic exposure function and the automatic focusing function, predetermined areas of the image capture screen are set as a photometry area and a focus area, respectively, and an image signal in the areas is detected, and a shutter speed, an aperture value, and the like are set. It was for adjusting and controlling the focal position of the imaging lens.

Conventionally, control of multiple imaging processing functions when performing imaging for the purpose of enabling detailed adjustment of imaging such as the automatic exposure function and automatic focusing function as described above with a simple configuration. A plurality of generating means each for generating an evaluation value for selecting, a selecting means for selecting and outputting any of the evaluation values generated by the plurality of generating means for each unit time according to an imaging signal, and the unit An integration unit configured to set a common integration region shared by the plurality of imaging processing functions in an image range formed by an imaging signal of time, and to integrate an evaluation value at a timing corresponding to the common integration region among outputs of the selection unit; In addition, there is a technology including a control unit that inputs an integrated value by the integrating unit and controls the imaging process according to the integrated value corresponding to the imaging processing function (see, for example, Patent Document 1).
JP 11-239291 A

  By the way, in order to realize the automatic focusing function, it is necessary to derive an evaluation value for focusing control in the focus area of the imaging screen in real time, and for this purpose, an image showing a captured image corresponding to the focus area. A memory for storing information in real time was required. As the memory, a line memory having a small storage capacity is generally used in order to avoid an increase in the cost of the apparatus.

  However, in this case, an evaluation value for only the horizontal direction of the subject image is derived, and a good focus state may not be obtained depending on the state of the subject. For example, when shooting is performed in a state where a subject with little change in the horizontal direction, such as a single color blind or a horizontal striped clothing, enters the focus area.

  On the other hand, in the conventional technique for controlling the plurality of imaging processing functions described above, the maximum value of the integrated value of the image signal in one horizontal scanning period is set for focus control in the vertical direction of the subject image. There are provided a peak hold circuit that holds every plural horizontal scanning periods, an evaluation value integration circuit that integrates the values held by the peak hold circuit, and outputs the integration result as an evaluation value representing contrast information in the vertical direction. It was done.

  However, this technique has a problem that it is necessary to newly provide a circuit such as a peak hold circuit that is not required when deriving an evaluation value in the horizontal direction, and the configuration is not necessarily simple. It was.

  The present invention has been made to solve the above-described problems, and a focusing control device and a focusing device capable of performing focusing control in the vertical direction of a subject image with a simple configuration without providing a new circuit. An object is to provide a control method.

  In order to achieve the above object, an in-focus control device according to claim 1, imaging means for continuously generating an analog image signal indicating a subject image by continuous imaging, and the analog image signal as digital image data. Conversion means for converting, a line memory for storing one line of a predetermined number of pixels of digital image data corresponding to an imaging region to be focused in the digital image data, and the line memory for the digital image data For each subject image continuously captured by the imaging means, the storage order is switched between a storage order that is continuous in the horizontal direction of the subject image and a storage order that is continuous in the vertical direction of the subject image. Switching means; derivation means for deriving a focus control evaluation value used in focus control based on the digital image data stored in the line memory; and And and a control unit for performing focus control based on focus control evaluation value derived by.

  According to the focusing control device of the first aspect, an analog image signal indicating a subject image is continuously generated by continuous imaging by the imaging unit, and the analog image signal is converted into digital image data by the conversion unit. Of the digital image data, digital image data corresponding to the imaging region to be focused is stored for one line of a predetermined number of pixels by the line memory. The imaging means includes a solid-state imaging device such as a CCD area sensor or a CMOS image sensor. The line memory includes all line buffers of the FIFO (First In First Out) system.

  Here, in the present invention, the switching unit stores the digital image data in the line memory in the horizontal direction of the subject image for each subject image continuously captured by the imaging unit. The focus control evaluation value used in focus control is derived based on the digital image data stored in the line memory by the deriving means. Further, the control means performs focus control based on the focus control evaluation value derived by the deriving means.

  As described above, according to the focusing control device of the first aspect, the storage order of the digital image data in the line memory is determined for each subject image continuously captured by the imaging unit. Since switching is performed between the storage order that is continuous in the direction and the storage order that is continuous in the vertical direction of the subject image, the focus control evaluation values for the horizontal direction and the vertical direction are derived without providing a new circuit. As a result, focusing control in the vertical direction of the subject image can be performed with a simple configuration without providing a new circuit.

  Note that, as in the invention described in claim 2, the present invention further includes determination means for determining whether or not the focus control evaluation value derived by the deriving means is equal to or greater than a predetermined value, and the switching is performed. When the determination means determines that the focus control evaluation value is equal to or greater than a predetermined value, the means is in the storage order of the digital image data stored in the line memory when the focus control evaluation value is derived. The storage order in the line memory may be fixed. As a result, the storage order of the digital image data in the line memory can be fixed at a storage order in which the focusing control can be performed at a predetermined level or more, and the processing load required for switching the storage order by unnecessary switching means is reduced. can do.

  According to a third aspect of the present invention, as in the third aspect of the present invention, the information processing apparatus further includes an acquisition unit that acquires designation information that specifies a storage order of the digital image data in the line memory, and the switching unit includes the acquisition unit. The storage order of the digital image data in the line memory may be fixed in the storage order designated by the designation information acquired by the means. As a result, the storage order of the digital image data in the line memory can be fixed to the storage order specified by the user, and the processing load required for switching the storage order by the unnecessary switching means can be reduced. .

  On the other hand, in order to achieve the above object, the focus control method according to claim 4 includes an imaging unit that continuously generates an analog image signal indicating a subject image by continuous imaging, and the analog image signal is converted into a digital image. Conversion means for converting to data, a line memory for storing digital image data corresponding to an imaging area to be focused in the digital image data for one line of a predetermined number of pixels, and stored in the line memory Deriving means for deriving a focus control evaluation value used in focus control based on the digital image data, and control means for performing focus control based on the focus control evaluation value derived by the deriving means. In the focus control method in the focus control apparatus, the storage order of the digital image data in the line memory is continuously captured by the imaging unit. For each object image, in which switching between a horizontally contiguous storage order and vertically contiguous storage order of the subject image of the subject image.

  Therefore, according to the focus control method described in claim 4, since it operates in the same manner as the invention described in claim 1, as in the invention described in claim 1, a simple circuit can be provided without providing a new circuit. With the configuration, focus control in the vertical direction of the subject image can be performed.

  According to the present invention, the storage order of the digital image data in the line memory is determined for each subject image continuously picked up by the image pickup means and the storage order continuous in the horizontal direction of the subject image and the vertical direction of the subject image. Since switching is performed between consecutive memory orders in the direction, it is possible to derive a focus control evaluation value for each of the horizontal direction and the vertical direction without providing a new circuit. As a result, a new circuit is obtained. The effect that the focusing control in the vertical direction of the subject image can be performed with a simple configuration without providing the above is obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, the case where the focus control device and the focus control method according to the present invention are applied to a digital camera that captures a still image will be described.

[First Embodiment]
First, an external configuration of the digital camera 10 according to the present embodiment will be described with reference to FIG.

  In front of the digital camera 10, a lens 21 for forming a subject image, a strobe 44 that emits light to irradiate the subject as necessary during photographing, and a finder used for determining the composition of the subject to be photographed. 20 is provided. Further, on the upper surface of the digital camera 10, a release switch (so-called shutter) 56A, a power switch 56B, and a mode changeover switch 56C that are pressed when performing shooting are provided.

  Note that the release switch 56A of the digital camera 10 according to the present embodiment is pressed down to an intermediate position (hereinafter referred to as “half-pressed state”) and to a final pressed position beyond the intermediate position. A two-stage pressing operation of a state (hereinafter referred to as a “fully pressed state”) can be detected.

  In the digital camera 10, the release switch 56A is pressed halfway to activate the AE (Automatic Exposure) function to set the exposure state (shutter speed, aperture state), and then AF (Auto Focus). , Automatic focusing) function is performed to control focusing, and then exposure (photographing) is performed when the button is fully pressed.

  The mode changeover switch 56C is rotated when setting to any one of a shooting mode that is a mode for shooting and a playback mode that is a mode for playing back a subject image on the LCD 38 described later.

  On the other hand, on the back of the digital camera 10, an eyepiece of the finder 20 described above, a liquid crystal display (hereinafter referred to as “LCD”) 38 for displaying a photographed subject image, a menu screen, and the like, and a cross cursor A switch 56D. The cross-cursor switch 56D includes four arrow keys that indicate four moving directions of up, down, left, and right in the display area of the LCD 38.

  Furthermore, on the back of the digital camera 10, a menu switch that is pressed when displaying the menu screen on the LCD 38, a determination switch that is pressed when confirming the operation content up to that point, and the previous operation content are displayed. A cancel switch that is pressed when canceling and a strobe switch that is pressed when setting the light emission state of the strobe 44 are provided.

  Next, the main configuration of the electrical system of the digital camera 10 according to the present embodiment will be described with reference to FIG.

  The digital camera 10 includes an optical unit 22 including the lens 21 described above, a charge coupled device (hereinafter referred to as “CCD”) 24 disposed behind the optical axis of the lens 21, and an input analog. And an analog signal processing unit 26 that performs various analog signal processing on the signal.

  The digital camera 10 also performs an analog / digital converter (hereinafter referred to as “ADC”) 28 that converts an input analog signal into digital data, and performs various digital signal processing on the input digital data. And a digital signal processing unit 30.

  The digital signal processing unit 30 includes a line buffer having a predetermined capacity, and also performs control to directly store the input digital data in a predetermined area of a memory 48A described later.

  In addition, the digital signal processing unit 30 directly stores digital data corresponding to an imaging area (hereinafter referred to as “AF area”) to be focused from the input digital data in a line memory 48B described later. Also controls. Here, the digital signal processing unit 30 according to the present embodiment determines the storage order of the digital data in the line memory 48B for each subject image continuously captured by the CCD 24 in accordance with an instruction input from the outside. The storage order can be switched between the storage order that is continuous in the horizontal direction of the subject image and the storage order that is continuous in the vertical direction of the subject image.

  The output terminal of the CCD 24 is connected to the input terminal of the analog signal processing unit 26, the output terminal of the analog signal processing unit 26 is connected to the input terminal of the ADC 28, and the output terminal of the ADC 28 is connected to the input terminal of the digital signal processing unit 30. . Accordingly, the analog signal indicating the subject image output from the CCD 24 is subjected to predetermined analog signal processing by the analog signal processing unit 26, converted into digital image data by the ADC 28, and then input to the digital signal processing unit 30.

  On the other hand, the digital camera 10 generates a signal for displaying a subject image, a menu screen or the like on the LCD 38 and supplies the signal to the LCD 38, and a CPU (Central Processing Unit) 40 that controls the operation of the entire digital camera 10. The memory 48A for storing digital image data obtained by imaging, and the digital image data corresponding to the AF area in the digital image data obtained by imaging are set to a predetermined number of pixels (in this embodiment, the AF area A line memory 48B for storing one line (the number of pixels in the horizontal direction) and a memory interface 46 for controlling access to the memory 48A and the line memory 48B.

  Further, the digital camera 10 includes an external memory interface 50 for enabling the portable memory card 52 to be accessed by the digital camera 10, a compression / expansion processing circuit 54 for performing compression processing and expansion processing on digital image data, and AE. And an evaluation value deriving unit 60 for deriving an evaluation value for the function (hereinafter referred to as “AE evaluation value”) and an evaluation value for the AF function (hereinafter referred to as “AF evaluation value”). Has been.

  In the digital camera 10 of the present embodiment, an SDRAM (Synchronous Dynamic Random Access Memory) is used as the memory 48A, an FIFO line buffer is used as the line memory 48B, and a smart media (Smart Media (Smart Media)) is used as the memory card 52. Registered trademark)). Further, in the evaluation value deriving unit 60 according to the present embodiment, as an AE evaluation value, the AE area is determined from digital image data in an area subject to exposure control set in advance (hereinafter referred to as “AE area”). In addition to deriving information indicating the brightness, the AF evaluation value is obtained from the digital image data in the preset AF area (digital image data stored in the line memory 48B), and information indicating the height of contrast (here, a predetermined value) It is derived by extracting the high-frequency component of the band.

  The digital signal processing unit 30, the LCD interface 36, the CPU 40, the memory interface 46, the external memory interface 50, the compression / decompression processing circuit 54, and the evaluation value deriving unit 60 are connected to each other via a system bus BUS. Therefore, the CPU 40 controls the operation of the digital signal processing unit 30, the compression / decompression processing circuit 54 and the evaluation value deriving unit 60, displays various information via the LCD interface 36 to the LCD 38, the memory 48A, the line memory 48B, and the memory card. 52 can be accessed via the memory interface 46 and the external memory interface 50, respectively.

  On the other hand, the digital camera 10 includes a timing generator 32 that mainly generates a timing signal for driving the CCD 24 and supplies the timing signal to the CCD 24, and the driving of the CCD 24 is controlled by the CPU 40 via the timing generator 32.

  Further, the digital camera 10 is provided with a motor drive unit 34, and driving of a focus adjustment motor, a zoom motor, and an aperture drive motor (not shown) provided in the optical unit 22 is also controlled by the CPU 40 via the motor drive unit 34. The

  In other words, the lens 21 according to the present embodiment has a plurality of lenses, is configured as a zoom lens that can change (magnify) the focal length, and includes a lens driving mechanism (not shown). The lens drive mechanism includes the focus adjustment motor, the zoom motor, and the aperture drive motor, and these motors are each driven by a drive signal supplied from the motor drive unit 34 under the control of the CPU 40.

  When changing the optical zoom magnification, the CPU 40 drives and controls the zoom motor to change the focal length of the lens 21 included in the optical unit 22.

  In addition, the CPU 40 performs focusing control by driving and controlling the focus adjustment motor so that the AF evaluation value of the image obtained by imaging by the CCD 24 is maximized. In other words, the digital camera 10 according to the present embodiment employs a so-called TTL (Through The Lens) method in which the lens position is set so that the contrast of the read image is maximized as the focus control. .

  Further, various switches such as the release switch 56A, the power switch 56B, the mode switch 56C, the cross cursor switch 56D, and the menu switch (generically referred to as “operation unit 56” in the figure) are connected to the CPU 40. The CPU 40 can always grasp the operation state with respect to the operation unit 56.

  In addition, the digital camera 10 includes a charging unit 42 that is interposed between the strobe 44 and the CPU 40 and charges power for causing the strobe 44 to emit light under the control of the CPU 40. Further, the strobe 44 is also connected to the CPU 40, and the light emission of the strobe 44 is controlled by the CPU 40.

  Next, an overall operation at the time of shooting of the digital camera 10 according to the present embodiment will be briefly described.

  First, the CCD 24 performs imaging through the optical unit 22 and sequentially outputs analog signals for R (red), G (green), and B (blue) indicating the subject image to the analog signal processing unit 26. The analog signal processing unit 26 performs analog signal processing such as correlated double sampling processing on the analog signal input from the CCD 24 and then sequentially outputs the analog signal to the ADC 28.

  The ADC 28 converts the R, G, and B analog signals input from the analog signal processing unit 26 into 12-bit R, G, and B signals (digital image data) and sequentially outputs them to the digital signal processing unit 30. To do.

  The digital signal processing unit 30 accumulates digital image data sequentially input from the ADC 28 in a built-in line buffer and temporarily stores the digital image data directly in a predetermined area of the memory 48A. At this time, the digital signal processing unit 30 performs AF in the storage order (storage order continuous in the horizontal direction of the subject image or storage order continuous in the vertical direction of the subject image) according to the instruction input from the outside. Digital image data corresponding to the area is directly stored in the line memory 48B. In the digital signal processing unit 30 according to the present embodiment, for the sake of simplification, a storage order that is continuous in the horizontal direction of the subject image is applied when no instruction is input regarding the storage order from the outside. Only when an instruction input for instructing storage in the continuous storage order in the vertical direction is performed from the outside, the storage order continuous in the vertical direction is applied to only one image frame.

  On the other hand, the digital image data stored in the predetermined area of the memory 48A is read by the digital signal processing unit 30 in accordance with control by the CPU 40, and white balance adjustment is performed by applying a digital gain corresponding to a predetermined physical quantity. Then, gamma processing and sharpness processing are performed to generate 8-bit digital image data.

  The digital signal processing unit 30 performs YC signal processing on the generated 8-bit digital image data to generate a luminance signal Y and chroma signals Cr and Cb (hereinafter referred to as “YC signal”), and the YC signal. Is stored in an area different from the predetermined area of the memory 48A.

  The LCD 38 is configured to display a moving image (through image) obtained by continuous imaging by the CCD 24 and can be used as a finder. When the LCD 38 is used as a finder, the LCD 38 is generated. The YC signals thus output are sequentially output to the LCD 38 via the LCD interface 36. As a result, a through image is displayed on the LCD 38.

  Here, at the timing when the release switch 56A is half pressed by the user, after the AE function is activated and the exposure state is set as described above, the AF function is activated and the focus control is performed, and then the fully pressed state is continued. The YC signal stored in the memory 48A at that time is compressed in a predetermined compression format (in this embodiment, JPEG format) by the compression / expansion processing circuit 54, and then the external memory interface 50 is And recorded as an electronic file in the memory card 52. When the above AE function and AF function are activated, the AE evaluation value and AF evaluation value sequentially derived by the evaluation value deriving unit 60 are used.

  Incidentally, the digital camera 10 according to the present embodiment is equipped with an AF setting function for controlling the derivation of the AF evaluation value by the evaluation value deriving unit 60 when the shooting mode is set.

  Next, the operation of the digital camera 10 when the AF setting function is executed will be described with reference to FIG. Note that FIG. 3 shows an AF setting executed by the CPU 40 every predetermined period (here, each time a subject image for one frame (one image) is captured by the CCD 24) when the shooting mode is set. It is a flowchart which shows the flow of a process of a processing program.

  In step 100 of the figure, the variable F for counting the number of frames is incremented by 1. In the next step 102, it is determined whether or not the value of the variable F is an even number. The process proceeds to step 104.

  In step 104, an instruction input for instructing the digital signal processing unit 30 to store data in the storage order continuous in the vertical direction is performed, and then the process proceeds to step 106. In response to the instruction input by the process of step 104, the digital signal processing unit 30 applies a storage order continuous in the vertical direction as the storage order of the digital image data to the line memory 48B, and corresponds to the AF area in the storage order. Digital image data is stored in the line memory 48B.

  If the determination at step 102 is affirmative, the process proceeds to step 106 without executing the process at step 104.

  In step 106, an instruction input for instructing the derivation of the AF evaluation value is performed to the evaluation value deriving unit 60, and then the present AF setting processing program is terminated. In response to the instruction input by the processing in step 106, the evaluation value deriving unit 60 derives an AF evaluation value using the digital image data stored in the line memory 48B.

  As shown in FIG. 4 as an example by this AF setting processing program, in the digital signal processing unit 30, the storage order of the digital image data in the line memory 48B in the AF area 70 of the subject image is horizontal in every frame. The continuous storage order (FIG. 4A) and the continuous storage order in the vertical direction (FIG. 4B) are alternately applied. As a result, the evaluation value deriving unit 60 determines the subject image for each frame. The AF evaluation value for the horizontal direction and the AF evaluation value for the vertical direction in the AF area are alternately derived, and the focus control is performed by applying these AF evaluation values.

  As described above in detail, in the present embodiment, the storage order of the digital image data in the line memory (line memory 48B) is determined for each subject image continuously captured by the imaging means (CCD 24). Since switching is performed between a storage order that is continuous in the horizontal direction of the subject image and a storage order that is continuous in the vertical direction of the subject image, focusing control in each of the horizontal direction and the vertical direction is performed without providing a new circuit. An evaluation value (AF evaluation value) can be derived. As a result, focusing control in the vertical direction of the subject image can be performed with a simple configuration without providing a new circuit.

[Second Embodiment]
In the second embodiment, when the AF evaluation value derived by the evaluation value deriving unit 60 is equal to or greater than a predetermined value, the digital image data stored in the line memory 48B when the AF evaluation value is derived is stored. A description will be given of an example in which the storage order in the line memory 48B is fixed in the storage order. Since the configuration of the digital camera according to the second embodiment is the same as that of the first embodiment, description thereof is omitted here.

  Hereinafter, the operation of the digital camera 10 according to the second embodiment at the time of executing the AF setting function will be described with reference to FIG. Note that FIG. 5 shows the processing of the AF setting processing program executed by the CPU 40 every predetermined period (here, each time a subject image for one frame is captured by the CCD 24) when the shooting mode is set. It is a flowchart which shows the flow.

  In step 200 in the figure, an instruction input for instructing the derivation of the AF evaluation value is performed to the evaluation value deriving unit 60, and in the next step 202, the AF evaluation value derived in accordance with the instruction input is used as the evaluation value. Obtained from the deriving unit 60.

  In the next step 204, it is determined whether or not the acquired AF evaluation value is greater than or equal to a predetermined value. If the determination is negative, it is assumed that the AF evaluation value cannot be focused and the process proceeds to step 206. Transition. In the digital camera 10 according to the present embodiment, the minimum value of the AF evaluation value that is regarded as being focused on the digital camera 10 is applied as the predetermined value. However, the present invention is not limited to this. For example, the predetermined value may be specified by the user.

  In step 206, an instruction is input to the digital signal processing unit 30 to instruct storage in the storage order continuous in the vertical direction. In the next step 208, the AF evaluation value is derived to the evaluation value deriving unit 60. An instruction input for instructing is performed, and then the AF setting processing program is terminated. In response to the instruction input in the process of step 208, the evaluation value deriving unit 60 derives the AF evaluation value using the digital image data stored in the line memory 48B in the storage order continuous in the vertical direction.

  On the other hand, if the determination in step 204 is affirmative, it is considered that the AF evaluation value acquired in step 202 can be focused, and the processing in steps 206 and 208 is not performed. The AF setting processing program is terminated with the storage order of the image data in the line memory 48B fixed.

  According to the AF setting processing program, when the AF evaluation value is equal to or greater than the predetermined value, the AF evaluation value is applied. When the AF evaluation value is less than the predetermined value, the line memory 48B is stored in the storage order continuous in the vertical direction. The AF evaluation value derived using the digital image data stored in is applied to perform focus control.

  As described above in detail, in the present embodiment, it is determined whether or not the focus control evaluation value (AF evaluation value) derived by the deriving unit (evaluation value deriving unit 60) is equal to or greater than a predetermined value. When it is determined that the value is equal to or greater than the predetermined value, the storage order of the digital image data stored in the line memory (line memory 48B) when the focus control evaluation value is derived is set in the storage order of the line memory. Since it is fixed, the storage order of the digital image data in the line memory can be fixed in the storage order in which the focusing control can be performed at a predetermined level or more, and the processing load required for switching the unnecessary storage order can be increased. Can be reduced.

[Third Embodiment]
In the third embodiment, an acquisition unit (here, an AF changeover switch 56E described later) that acquires designation information that specifies the storage order of digital image data in the line memory 48B is provided, and is acquired by the acquisition unit. An example in which the storage order of the digital image data in the line memory 48B is fixed in the storage order specified by the specified information will be described.

  As shown in FIG. 6, the configuration of the digital camera according to the third embodiment is the same as that of the first embodiment except that the AF changeover switch 56E is provided on the back surface.

  The AF changeover switch 56E according to the present embodiment belongs to the operation unit 56 (see also FIG. 2), and each time the pressing operation is performed, the AF evaluation value is obtained for both the horizontal and vertical directions of the subject image. The bi-directional AF mode that is sequentially derived and the normal mode that derives the AF evaluation value as being in the horizontal direction of the subject image are alternately switched. Note that the CPU 40 according to the present embodiment monitors the operation state with respect to the AF changeover switch 56E, and always grasps the mode set by the user.

  Hereinafter, the operation of the digital camera 10 according to the third embodiment at the time of executing the AF setting function will be described with reference to FIG. FIG. 7 shows the processing of the AF setting process program executed by the CPU 40 every predetermined period (here, every time a subject image for one frame is captured by the CCD 24) when the shooting mode is set. It is a flowchart which shows the flow.

  In step 300 of the figure, it is determined whether or not the bidirectional AF mode is set by the user. If the determination is affirmative, the process proceeds to step 302 and the variable F for counting the number of frames is incremented by 1. Then, the process proceeds to step 306.

  On the other hand, if the determination in step 300 is negative, it is assumed that the normal mode has been set by the user, and the process proceeds to step 304. After an even number (here, 2) is substituted for the variable F, the process proceeds to step 306. Transition.

  In step 306, it is determined whether or not the value of the variable F is an even number. If a negative determination is made, the process proceeds to step 308.

  In step 308, an instruction is input to the digital signal processing unit 30 to instruct storage in the storage order continuous in the vertical direction, and then the process proceeds to step 310. In response to the instruction input by the processing in step 308, the digital signal processing unit 30 applies a storage order continuous in the vertical direction as the storage order of the digital image data in the line memory 48B, and corresponds to the AF area in the storage order. Digital image data is stored in the line memory 48B.

  If the determination in step 306 is affirmative, the process proceeds to step 310 without executing the process in step 308.

  In step 310, an instruction input for instructing the evaluation value deriving unit 60 to derive the AF evaluation value is performed, and then the present AF setting processing program is terminated. In response to the instruction input in the process of step 310, the evaluation value deriving unit 60 derives an AF evaluation value using the digital image data stored in the line memory 48B.

  When the bidirectional AF mode is set by the user according to this AF setting processing program, the AF evaluation values are sequentially derived as those for the horizontal and vertical directions of the subject image, and the normal mode is set. In this case, the AF evaluation value is derived with respect to the horizontal direction of the subject image, and the derived AF evaluation value is applied to perform focusing control.

  As described above in detail, the present embodiment further includes acquisition means (AF switch 56E) for acquiring designation information for designating the storage order of digital image data in the line memory (line memory 48B), Since the storage order of the digital image data in the line memory is fixed in the storage order specified by the specification information acquired by the acquisition means, the storage order of the digital image data in the line memory is designated by the user The storage order can be fixed, and the processing load required for switching the unnecessary storage order can be reduced.

  Note that the configuration of the digital camera 10 according to each of the above-described embodiments (see FIGS. 1, 2, and 6) is merely an example, and it is needless to say that the configuration can be changed as appropriate without departing from the gist of the present invention. .

  For example, in each of the above embodiments, the digital signal processing unit 30 stores the digital image data in the storage order in the line memory 48B as an instruction input when the instruction input is not performed. The case where the order is applied and the storage order continuous in the vertical direction is applied only when the instruction input for instructing the storage in the storage order continuous in the vertical direction is performed from the outside has been described. However, the present invention is not limited to this form. For example, even when a storage order that is continuous in the horizontal direction is applied, a form that is performed in response to an instruction input from the outside may be employed. Also in this case, the same effects as those of the above embodiments can be obtained.

  Further, the flow of processing of the AF setting processing program described in each of the above embodiments (see FIGS. 3, 5, and 7) is also an example, and can be appropriately changed without departing from the gist of the present invention. Needless to say.

  Further, although cases have been described with the above embodiments where the present invention is applied to a digital camera, the present invention has a photographing function such as a PDA (Personal Digital Assistant), a cellular phone, a personal computer, etc. It goes without saying that any information processing apparatus can be applied.

It is an external view which shows the external appearance of the digital camera 10 which concerns on embodiment. It is a block diagram which shows the main structures of the electric system of the digital camera 10 which concerns on embodiment. It is a flowchart which shows the flow of a process of AF setting process program which concerns on 1st Embodiment. It is the schematic which shows the switching state of the memory | storage order to the line memory 48B of the digital image data by the AF setting process program which concerns on embodiment. It is a flowchart which shows the flow of a process of AF setting process program which concerns on 2nd Embodiment. It is an external view (back view) which shows the external appearance of the digital camera 10 which concerns on 3rd Embodiment. It is a flowchart which shows the flow of a process of AF setting process program which concerns on 3rd Embodiment.

Explanation of symbols

10 Digital camera 24 CCD (Imaging means)
28 ADC (conversion means)
40 CPU (switching means, control means, determination means)
48B line memory 56E AF selector switch (acquisition means)
60 Deriving unit (derivation means)

Claims (4)

Imaging means for continuously generating an analog image signal indicating a subject image by continuous imaging;
Conversion means for converting the analog image signal into digital image data;
A line memory for storing digital image data corresponding to an imaging region to be focused in the digital image data for one line of a predetermined number of pixels;
The storage order of the digital image data in the line memory is continuously stored in the horizontal order of the subject image and in the vertical direction of the subject image for each subject image continuously captured by the imaging unit. Switching means for switching between the stored storage orders;
Derivation means for deriving a focus control evaluation value used in focus control based on the digital image data stored in the line memory;
Control means for performing focus control based on the focus control evaluation value derived by the derivation means;
Focus control device with A determination unit for determining whether or not the focus control evaluation value derived by the deriving unit is equal to or greater than a predetermined value;
The switching means stores digital image data stored in a line memory when the focusing control evaluation value is derived when the determining means determines that the focusing control evaluation value is equal to or greater than a predetermined value. The focusing control device according to claim 1, wherein the order of storage in the line memory is fixed in order. An acquisition means for acquiring designation information for designating a storage order of the digital image data in the line memory;
The focus control device according to claim 1, wherein the switching unit fixes the storage order of the digital image data in the line memory in the storage order specified by the specification information acquired by the acquisition unit. Imaging means for continuously generating an analog image signal indicating a subject image by continuous imaging, conversion means for converting the analog image signal into digital image data, and a focus control target of the digital image data A line memory that stores digital image data corresponding to an imaging area for one line for a predetermined number of pixels, and a derivation for deriving a focus control evaluation value used in focus control based on the digital image data stored in the line memory A focus control method in a focus control device comprising: means and a control means for performing focus control based on the focus control evaluation value derived by the derivation means,
The storage order of the digital image data in the line memory is continuously stored in the horizontal order of the subject image and in the vertical direction of the subject image for each subject image continuously captured by the imaging unit. Switch between remembered order,
Focus control method.

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