JP2013186355A - Automatic focusing apparatus, automatic focusing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a focus image properly.SOLUTION: An imaging apparatus 100 includes: a region image generation unit 2c which performs, using multiple filters that respectively have different filter coefficients corresponding to subject distances, predetermined filtering to processing target regions of an image signal converted from a subject image having passed through a predetermined optical system, and which generates multiple processed region images; an evaluation value calculation unit 2d which calculates contrast evaluation values of the respective processed region images generated; an evaluation value identification unit 2e which compares the contrast evaluation values calculated, so as to identify the highest evaluation value; and a filter selection unit 2f which selects, as a filter to be used for a focus image generation processing, a filter that corresponds to a processed region image having the highest evaluation value identified.

Description

  The present invention relates to an automatic focusing device, an automatic focusing method, and a program.

  2. Description of the Related Art Conventionally, an imaging apparatus that restores an image signal without dispersion from an image signal of a dispersion image of a subject that has passed through an optical wavefront modulation element is known (see, for example, Patent Document 1). This imaging apparatus selects a conversion coefficient corresponding to the dispersion caused by the light wavefront modulation element according to the distance to the subject, performs a convolution operation using the conversion coefficient, and restores the image signal.

JP 2007-117413 A

  However, in the case of the above-mentioned Patent Document 1, a means for measuring the distance to the subject such as a distance measuring sensor is required for selecting the conversion coefficient. Furthermore, there is a problem that when the distance measurement cannot be performed accurately, the image signal cannot be properly restored.

  Accordingly, an object of the present invention is to provide an automatic focusing apparatus, an automatic focusing method, and a program that can appropriately generate a focused image.

In order to solve the above problems, an automatic focusing device according to the present invention is
A storage unit that stores a plurality of filters having different filter coefficients corresponding to the subject distance, an acquisition unit that acquires an image signal converted from a subject image that has passed through a predetermined optical system, and acquired by the acquisition unit First generation means for applying a predetermined filter process to each predetermined area of the image signal using each of the plurality of filters stored in the storage means to generate a plurality of processed area images; The calculation unit that calculates the contrast evaluation values of the plurality of processed region images generated by the one generation unit and the plurality of contrast evaluation values calculated by the calculation unit are compared to identify the highest evaluation value And a filter corresponding to the processed area image having the highest evaluation value specified by the specifying means is used for the focus image generation process. It is characterized a selection means for selecting a filter, further comprising: a.

Moreover, the automatic focusing method according to the present invention includes:
An automatic focusing method using an automatic focusing device including a storage unit that stores a plurality of filters having different filter coefficients corresponding to a subject distance, and is converted from a subject image passing through a predetermined optical system A process of acquiring an image signal and a predetermined filter process using each of a plurality of filters stored in the storage unit for a predetermined area of the acquired image signal, and a plurality of processed area images A process of generating, a process of calculating a contrast evaluation value of each of the generated plurality of processed area images, a process of comparing the calculated evaluation values of the plurality of contrasts, and specifying the highest evaluation value; And a process of selecting a filter corresponding to the processed region image having the highest evaluation value identified as a filter used for the process of generating a focused image. That.

The program according to the present invention is
Acquiring means for acquiring an image signal converted from a subject image that has passed through a predetermined optical system, using a computer of an automatic focusing device having a storage means for storing a plurality of filters having different filter coefficients corresponding to the subject distance The predetermined region of the image signal acquired by the acquisition unit is subjected to predetermined filter processing using each of the plurality of filters stored in the storage unit to generate a plurality of processed region images. 1 generating means, calculating means for calculating the contrast evaluation values of the plurality of processed region images generated by the first generating means, respectively, comparing the plurality of contrast evaluation values calculated by the calculating means, A specifying means for specifying a high evaluation value, and a filter corresponding to the processed area image of the highest evaluation value specified by the specifying means Selecting means for selecting a filter for use in the generation process is characterized in that to function as a.

  According to the present invention, it is possible to appropriately generate a focused image.

It is a block diagram which shows schematic structure of the imaging device of Embodiment 1 to which this invention is applied. 3 is a flowchart illustrating an example of an operation related to an automatic focusing process by the imaging apparatus of FIG. 1. 3 is a flowchart illustrating an example of an operation related to a focused image generation process in the automatic focusing process of FIG. 2. It is a figure which shows typically an example of the image which concerns on the automatic focusing process of FIG. It is a block diagram which shows schematic structure of the imaging device of Embodiment 2 to which this invention is applied. 6 is a flowchart illustrating an example of an operation related to a focused image generation process in an automatic focusing process performed by the imaging apparatus of FIG. 5. 7 is a flowchart showing a continuation of the focused image generation process of FIG. 6. It is a figure which shows typically an example of the image which concerns on the automatic focusing process of FIG. It is a block diagram which shows schematic structure of the imaging device of the modification 1. It is a figure which shows typically an example of the image which concerns on the automatic focusing process by the imaging device of FIG.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

[Embodiment 1]
FIG. 1 is a block diagram illustrating a schematic configuration of an imaging apparatus 100 according to the first embodiment to which the present invention is applied.
As illustrated in FIG. 1, the imaging apparatus 100 according to the first embodiment specifically includes an imaging unit 1, an image processing unit 2, a memory 3, an image recording unit 4, a display control unit 5, and a display unit. 6, an operation input unit 7, and a central control unit 8.
The imaging unit 1, the image processing unit 2, the memory 3, the image recording unit 4, the display control unit 5, and the central control unit 8 are connected via a bus line 9.

The imaging unit 1 captures a predetermined subject and generates a frame image as an imaging unit.
Specifically, the imaging unit 1 includes an optical system 1a, an electronic imaging unit 1b, and an imaging control unit 1c.

The optical system 1a optically captures an image of a subject and has various lenses. Specifically, the optical system 1a includes a restoration processing premise optical system that forms a subject image in a form on the premise that restoration processing using a filter is performed on the image signal converted by the electronic imaging unit 1b. It is configured. That is, although not shown, the restoration precondition optical system is connected between an object-side lens exposed on the subject side and an imaging lens for forming an optical image of the subject on the electronic imaging unit 1b. An optical wavefront modulation element (wavefront forming optical element) that deforms the wavefront of the image formed on the light receiving surface of the electronic imaging unit 1b by the image lens is provided. The light wavefront modulation element is composed of, for example, a phase plate having a three-dimensional curved surface.
Further, the optical image of the subject that has passed through the reconstruction processing prerequisite optical system (phase plate) forms a dispersed image that does not fit anywhere on the light receiving surface of the electronic imaging unit 1b. In other words, the light wavefront modulation element forms a deep light flux and a flare that is a blurred portion that play a central role in image formation on the light receiving surface of the electronic imaging unit 1b, and the subject image is dispersed. As described above, since the depth of field of the optical image of the subject that has passed through the restoration processing premise optical system is extended, the restoration processing premise optical system includes a depth extension optical system that extends the depth of field. I can say that.

  The phase plate exemplified as the light wavefront modulation element is an example and is not limited to this, and can be arbitrarily changed as appropriate. For example, the optical wavefront modulation element may be any element that deforms the wavefront, such as an optical element whose thickness changes, an optical element whose refractive index changes, and a thickness and refractive index that are coded by coating on the lens surface. It may be an optical element that changes, a liquid crystal element that can modulate the phase distribution of light, or the like.

  The electronic imaging unit 1b includes, for example, an image sensor (imaging device) such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). Then, the electronic imaging unit 1b converts the optical image of the subject that has passed through the optical system 1a into a two-dimensional image signal. For example, the electronic imaging unit 1b converts a dispersed image of the subject that has passed through the optical system 1a into an image signal.

  The imaging control unit 1c controls imaging of a subject. That is, the imaging control unit 1c includes a timing generator, a driver, and the like, although not illustrated. Then, the imaging control unit 1c scans and drives the electronic imaging unit 1b with a timing generator and a driver, and the electronic imaging unit 1b converts the optical image of the subject passing through the lens into a two-dimensional image signal for each predetermined period. Then, the frame image is read out for each screen from the imaging area of the electronic imaging unit 1b and is output to the image processing unit 2.

  Note that the imaging control unit 1c may perform adjustment control of conditions when imaging a subject such as AE (automatic exposure processing) and AWB (automatic white balance).

The image processing unit 2 generates an image signal without dispersion from the image signal of the dispersion image of the subject of each frame image transferred from the electronic imaging unit 1b. Specifically, the image processing unit 2 includes an image acquisition unit 2a, a first region setting unit 2b, a region image generation unit 2c, an evaluation value calculation unit 2d, an evaluation value specification unit 2e, and a filter selection unit 2f. And a first in-focus image generation unit 2g and a filter storage unit 2h.
Note that each unit of the image processing unit 2 is configured by, for example, a predetermined logic circuit, but the configuration is an example and is not limited thereto.

The image acquisition unit 2a acquires an image signal of the subject image.
That is, the image acquisition unit 2a acquires an image signal converted by the electronic imaging unit 1b from an optical image of a subject that has passed through the optical system 1a of the imaging unit 1 as an acquisition unit. Specifically, the image acquisition unit 2a acquires the image signal of the dispersed image of the subject generated by the electronic imaging unit 1b.

The first region setting unit 2b sets a plurality of processing target regions A1 for the filter process.
In other words, the first area setting unit 2b serves as a first setting unit in the distributed image P1 corresponding to the image signal of the distributed image of the subject acquired by the image acquisition unit 2a over substantially the entire area of the image ( A plurality of predetermined areas A1 are set (see FIG. 4A). Specifically, the first region setting unit 2b sequentially sets all the pixels constituting the distributed image P1 as the processing target region A1, for example, from a predetermined position (for example, the upper left corner).
In FIG. 4A, the dispersion image P1 is schematically shown.

The region image generation unit 2c performs a predetermined filter process on the image signal of the processing target region A1 to generate a plurality of processed region images.
That is, the area image generation unit 2c serves as a first generation unit with respect to the processing target area A1 of the image signal of the dispersed image of the subject acquired by the image acquisition unit 2a. A predetermined filter process is performed using each of the filters to generate a plurality of processed area images. Specifically, the region image generation unit 2c stores each of the plurality of processing target regions A1,... Set for each pixel of the dispersed image P1 by the first region setting unit 2b in the filter storage unit 2h. The restoration processing is performed using each of the first to third filters, and three processed region images without dispersion are generated.

The evaluation value calculation unit 2d calculates the evaluation value of the contrast of the processed region image.
That is, the evaluation value calculation unit 2d calculates, as calculation means, the contrast evaluation values of the plurality of processed region images generated by the region image generation unit 2c. Specifically, the evaluation value calculation unit 2d acquires image data of each processed region image and calculates an evaluation value indicating the level of contrast of the processed region image.

The evaluation value specifying unit 2e specifies the highest evaluation value among a plurality of contrast evaluation values.
That is, the evaluation value specifying unit 2e, as specifying means, compares a plurality of contrast evaluation values calculated by the evaluation value calculating unit 2d and specifies the highest evaluation value. Specifically, the evaluation value specifying unit 2e has three processed regions generated using the first to third filters calculated by the evaluation value calculating unit 2d for each of the plurality of processing target regions A1,. By comparing the evaluation values of the contrast of the image, the highest evaluation value is specified.

The filter selection unit 2f selects a filter used for generating the focused image P2 (see FIG. 4B) from among a plurality of filters.
That is, the filter selection unit 2f serves as a filter that is used as a selection unit for the processed image of the focused image P2 that corresponds to the processed region image having the highest contrast evaluation value specified by the evaluation value specifying unit 2e. select. Specifically, the filter selection unit 2f was used for the restoration process of the processed region image having the highest contrast evaluation value specified by the evaluation value specifying unit 2e for each of the plurality of processing target regions A1,. A filter is selected from the first to third filters.

The first focused image generation unit 2g generates a focused image P2.
That is, the first focused image generation unit 2g serves as a second generation unit for each processing target area A1 in the distributed image P1 corresponding to the image signal acquired by the image acquisition unit 2a. Predetermined filter processing is performed using the filter selected by (1) to generate a focused image P2. Specifically, the first focused image generation unit 2g uses, for each pixel of the dispersed image P1, a filter selected by the filter selection unit 2f for the processing target area A1 set corresponding to the pixel. A restoration process is performed to generate an image having no dispersion, and an image corresponding to each pixel is combined to generate a focused image P2.

The filter storage unit 2h stores a plurality of filters having different filter coefficients.
That is, the filter storage unit 2h stores a plurality of filters with different filter coefficients corresponding to the distance from the apparatus main body to the subject (subject distance) as storage means.
Here, the filter coefficient is a coefficient for restoring the point spread function of the optical image of the subject passing through the optical system 1a so that the point spread function becomes a predetermined value in the restoration process. Moreover, as a filter coefficient, the coefficient which prescribes | regulates the size of the kernel of a predetermined filter is mentioned, for example.
Specifically, for example, the filter storage unit 2h includes a first filter in which “close” as the subject distance and the first filter coefficient are associated with each other, “infinity” as the subject distance, and the second filter coefficient. And a third filter in which the “intermediate” between the closest and infinity as the subject distance and the third filter coefficient are associated with each other are stored.

  Further, the image processing unit 2 generates YUV data corresponding to the YUV color space of the focused image P2, and performs various image processing, compression, and the like on the YUV data to form a file. Then, the image processing unit 2 transfers the filed image data to the image recording unit 4.

  The memory 3 is composed of, for example, a DRAM (Dynamic Random Access Memory) or the like, and temporarily stores data processed by the image processing unit 2 or the central control unit 8.

The image recording unit 4 is configured by, for example, a non-volatile memory (flash memory) or the like, and is recorded by a coding unit (not shown) of the image processing unit 2 in a predetermined compression format (for example, JPEG format). Record image data for use.
Note that the image recording unit 4 may be configured, for example, such that a recording medium (not shown) is detachable and controls reading of data from the loaded recording medium and writing of data to the recording medium.

The display control unit 5 performs control to read display image data temporarily stored in the memory 3 and display it on the display unit 6.
Specifically, the display control unit 5 includes a VRAM (Video Random Access Memory), a VRAM controller, a digital video encoder, and the like. The digital video encoder reads the luminance signal Y and the color difference signals Cb and Cr read from the memory 3 and stored in the VRAM (not shown) under the control of the central control unit 8 via the VRAM controller. Are periodically read out, and a video signal is generated based on these data and output to the display unit 6.

  The display unit 6 is, for example, a liquid crystal display panel, and displays an image captured by the imaging unit 1 based on a video signal from the display control unit 5 on a display screen. Specifically, the display unit 6 sequentially updates a plurality of frame images generated by subject imaging by the imaging unit 1 and the imaging control unit 1c at a predetermined frame rate in the still image capturing mode and the moving image capturing mode. While displaying the live view image. The display unit 6 displays an image (rec view image) recorded as a still image or an image being recorded as a moving image.

  The operation input unit 7 is for performing a predetermined operation of the imaging apparatus 100. Specifically, the operation input unit 7 includes a shutter button related to an imaging instruction of a subject, a selection determination button related to an instruction to select an imaging mode and a function, a zoom button related to an instruction to adjust the zoom amount, and the like (all not shown). And outputs a predetermined operation signal to the central control unit 8 in accordance with the operation of each button of the operation unit.

  The central control unit 8 controls each unit of the imaging device 100. Specifically, although not shown, the central control unit 8 includes a CPU (Central Processing Unit) and the like, and performs various control operations according to various processing programs (not shown) for the imaging apparatus 100.

Next, automatic focusing processing by the imaging apparatus 100 will be described with reference to FIGS.
FIG. 2 is a flowchart illustrating an example of an operation related to the automatic focusing process.

  The automatic focusing process described below is executed when a focused image generation mode is selected from a plurality of operation modes displayed on the menu screen based on a predetermined operation of the operation input unit 7 by the user. Process.

<Automatic focus processing>
As shown in FIG. 2, the imaging unit 1 images a subject at a predetermined imaging frame rate (step S1), and the CPU of the central control unit 8 is based on a predetermined operation of the shutter button of the operation input unit 7 by the user. Then, it is determined whether or not an instruction to record the captured image has been input (step S2).
If it is determined that the recording instruction has not been input (step S2; NO), the CPU of the central control unit 8 returns the process to step S1 and controls the execution of the subsequent processes.

  If it is determined in step S1 that a recording instruction has been input (step S2; YES), the image acquisition unit 2a of the image processing unit 2 performs electronic imaging from the optical image of the subject that has passed through the optical system 1a of the imaging unit 1. An image signal of the dispersed image of the subject converted by the unit 1b is acquired (step S3).

Next, the image processing unit 2 performs a focused image generation process (see FIG. 3) for generating a focused image P2 (step S4).
Here, the focused image generation processing will be described in detail with reference to FIG. FIG. 3 is a flowchart illustrating an example of an operation related to the focused image generation process.

<In-focus image generation processing>
As shown in FIG. 4, the first region setting unit 2b of the image processing unit 2 is a pixel at a predetermined position in the dispersed image P1 corresponding to the image signal of the dispersed image of the subject (for example, the pixel in the upper left corner) ) Is set as the processing target area A1 (step S11).
Next, after designating any one filter (for example, the first filter) among the first to third filters stored in the filter storage unit 2h, the region image generation unit 2c (step S12). Then, the restoration process using the designated filter is performed on the pixels of the processing target area A1, and a processed area image without dispersion is generated (step S13).

Subsequently, the evaluation value calculation unit 2d calculates an evaluation value indicating the level of contrast of the processed region image generated by the region image generation unit 2c, and temporarily stores it in the memory 3 (step S14).
Next, the image processing unit 2 determines whether restoration processing has been performed on all pixels in the processing target area A1 (step S15). Here, if it is determined that the restoration process has not been performed using all the filters (step S15; NO), the region image generation unit 2c increments the filter number by +1 and includes the first through third filters. Then, after designating the next filter (for example, the second filter) different from the used filter (step S16), the process proceeds to step S13.

  In step S13, the region image generation unit 2c applies a restoration process using a designated filter (for example, the second filter) to the pixels of the processing target region A1, and generates a processed region image without dispersion. . In step S14, the evaluation value calculation unit 2d calculates an evaluation value indicating the level of contrast of the processed region image generated by the region image generation unit 2c. In step S15, the image processing unit 2 Then, it is determined whether or not the restoration process has been performed on all pixels in the processing target area A1 (step S15).

Each of the above processes is repeatedly executed until it is determined in step S15 that the restoration process has been performed using all the filters (step S15; YES).
Thereby, the evaluation value of the contrast of the processing target area A1 image using all the filters is calculated for the pixels of the processing target area A1.

If it is determined in step S15 that restoration processing has been performed using all filters (step S15; YES), the evaluation value specifying unit 2e performs an evaluation value calculation unit on the pixels in the processing target area A1. The three evaluation values of the contrast calculated by 2d are compared to identify the highest evaluation value (step S17).
Subsequently, the filter selection unit 2f selects the filter used for the restoration process of the processed region image having the highest contrast evaluation value specified by the evaluation value specifying unit 2e from the first to third filters. Information indicating the selected filter is temporarily stored in the memory 3 as selected filter information of the pixel in the current processing target area A1 (step S18).
Thereby, when the focused image P2 is generated, the filter used for the restoration process of the image signal of the pixel in the processing target area A1 is specified.

Next, the image processing unit 2 determines whether or not all the pixels of the distributed image P1 have been processed (step S19). Here, if it is determined that all the pixels are not processed (step S19; NO), the first region setting unit 2b increments the pixel number by +1, and the next pixel (for example, , The right adjacent pixel, etc.) is set as the processing target area A1 (step S20), and then the process proceeds to step S12.
Then, each process after step S12 is executed with the next pixel as the processing target area A1, and in step S18, a filter used for the image signal restoration processing of the pixel in the processing target area A1 is specified.

Each of the above processes is repeatedly executed until it is determined in step S19 that all pixels have been processed (step S19; YES).
Thereby, the filter used for a decompression | restoration process is specified about all the pixels of the dispersion | distribution image P1.

If it is determined in step S19 that all the pixels have been processed (step S19; YES), the first focused image generation unit 2g selects each pixel of the dispersed image P1 by the filter selection unit 2f. Then, the image indicated by the selection filter information temporarily stored in the memory 3 is used to perform image signal restoration processing to generate a non-dispersed image, and a non-dispersed image corresponding to each pixel is synthesized. After generating the focused image P2 (step S21), the focused image generation process is terminated.
For example, the processed region image corresponding to all the pixels generated by the region image generation unit 2c using the first to third filters is stored in the memory 3, and the first focused image generation unit 2g is stored. May acquire the processed region image generated by using the filter selected by the filter selection unit 2f for each pixel to generate the focused image P2. This eliminates the need for the first focused image generation unit 2g to perform image signal restoration processing again using the filter selected by the filter selection unit 2f.

Returning to FIG. 2, the image processing unit 2 generates YUV data corresponding to the YUV color space of the focused image P <b> 2, performs various image processing, compression, and the like on the YUV data to form a file. The recording unit 4 records the image data of the generated focused image P2.
This completes the automatic focusing process.

As described above, according to the imaging apparatus 100 of the first embodiment, the filter coefficient is set corresponding to the subject distance for the processing target area A1 of the image signal converted from the subject image that has passed through the predetermined optical system 1a. A plurality of processed region images can be generated by performing predetermined filter processing using each of a plurality of different filters. Specifically, restoration processing is performed on the processing target area A1 of the image signal converted from the subject image that has passed through the restoration processing premise optical system that forms a subject image in a form premised on restoration processing using an image signal filter. To generate a processed region image. In particular, it is possible to generate a processed region image without dispersion by performing a restoration process on the processing target region A1 of the image signal converted from the dispersed image of the subject that has passed through a depth expanding optical system or the like that extends the depth of field. it can.
Then, the highest evaluation value is identified by comparing the contrast evaluation values of the plurality of processed area images, and the filter corresponding to the processed area image having the highest evaluation value is used for the process of generating the focused image P2. Since it is selected as a filter, it is possible to select a filter with an optimum filter coefficient corresponding to the distance to the subject without using a distance measuring means such as a distance measuring sensor, which is inappropriate due to inaccuracy of distance measurement. Execution of filter processing can be prevented. As a result, it is possible to appropriately generate the focused image P2 by performing predetermined filter processing on each of the image signals converted from the subject image using the selected filter.

  Further, for each of the plurality of processing target areas A1,... Set over substantially the entire area of the image signal, a plurality of processed area images corresponding to each of the plurality of filters are generated, and each of the plurality of processing target areas A1,. For each of the plurality of processing target areas A1,..., A filter corresponding to the processed area image with the highest evaluation value specified. Therefore, it is possible to select a filter having an optimum filter coefficient corresponding to the distance to the subject for each processing target area A1. In particular, by setting the processing target area A1 for each pixel, selecting a filter with the optimum filter coefficient for each pixel and performing a predetermined filter process, respectively, it is possible to focus on all the pixels in focus. An image P2 can be generated.

[Embodiment 2]
FIG. 5 is a block diagram illustrating a schematic configuration of the imaging apparatus 200 according to the second embodiment to which the present invention is applied.
Note that the imaging apparatus 200 according to the second embodiment has substantially the same configuration as the imaging apparatus 100 according to the first embodiment except for the details described below, and detailed description thereof is omitted.

  As illustrated in FIG. 5, the image processing unit 2 of the imaging apparatus 200 according to the second embodiment includes an image acquisition unit 2a, a region image generation unit 2c, an evaluation value calculation unit 2d, an evaluation value specification unit 2e, a filter selection unit 2f, and a filter. In addition to the storage unit 2h, a second region setting unit 2i and a second focused image generation unit 2j are provided.

The second area setting unit 2i serves as a second setting unit with a predetermined number of processing target areas (predetermined areas) B1 in the dispersion image P1 corresponding to the image signal of the dispersion image of the subject acquired by the image acquisition unit 2a ( For example, three) are set. Specifically, the second area setting unit 2i arranges the first to third processing target areas B1a to B1c having a predetermined size in the distributed image P1 in parallel in a predetermined direction (for example, a horizontal direction). Set.
Note that the positions and sizes of the first to third processing target areas B1a to B1c are merely examples and are not limited thereto, and can be arbitrarily changed as appropriate.
In FIG. 8A, the dispersion image P1 is schematically shown.

  The region image generation unit 2c generates a plurality of processed region images corresponding to each of the plurality of filters for each pixel in the predetermined number of processing target regions B1 set by the second region setting unit 2i. Specifically, the region image generation unit 2c stores, in the filter storage unit 2h, each pixel in the first to third processing target regions B1a to B1c set in the distributed image P1 by the second region setting unit 2i. The restoration processing is performed using each of the first to third filters, and three processed area images without dispersion are generated.

The evaluation value specifying unit 2e compares the plurality of contrast evaluation values calculated by the evaluation value calculating unit 2d for each pixel in the predetermined number of processing target areas B1, and specifies the highest evaluation value.
That is, the evaluation value calculation unit 2d performs the first to third filter for all the pixels in the processing target region B1 for each of the first to third processing target regions B1a to B1c generated by the region image generation unit 2c. Each of the evaluation values of the contrast of the processed region image is calculated so as to correspond to the above. Then, the evaluation value specifying unit 2e compares the contrast evaluation values calculated by the evaluation value calculating unit 2d for each pixel in each processing target area B1, and specifies the highest evaluation value.

The filter selection unit 2f adds up the highest evaluation value specified by the evaluation value specifying unit 2e for each pixel for each of the predetermined number of processing target regions B1, and uses any one filter based on the calculation result. And the filter with the shortest subject distance associated with the filter coefficient is selected from the specified filters.
That is, for each of the first to third processing target regions B1a to B1c, the filter selection unit 2f restores the processed region image having the highest contrast evaluation value specified for all the pixels in the processing target region B1. The filters used for processing are aggregated for each type of filter, and the filter with the highest aggregation result is identified. Then, the filter selection unit 2f compares the three filters specified for each of the first to third processing target areas B1a to B1c, and determines the filter having the shortest subject distance associated with the filter coefficient. It selects as a filter used for the production | generation process of the focused image P2.

The second focused image generation unit 2j generates a focused image P2 (see FIG. 8B).
That is, the second focused image generation unit 2j performs a predetermined filter process on the image signal acquired by the image acquisition unit 2a using the filter selected by the filter selection unit 2f as the second generation unit. The focused image P2 is generated. Specifically, the second focused image generation unit 2j performs a restoration process using the filter selected by the filter selection unit 2f for each pixel of the dispersion image P1, and generates an image without dispersion. A focused image P2 is generated by combining images corresponding to the respective pixels.

Next, automatic focusing processing by the imaging apparatus 200 will be described with reference to FIGS. 2 and 6 to 8.
The automatic focusing process performed by the imaging apparatus 200 according to the second embodiment is substantially the same as the automatic focusing process performed by the imaging apparatus 100 according to the first embodiment except for the details described below. To do.

<Automatic focus processing>
As shown in FIG. 2, the processes of steps S1 to S3 are performed in substantially the same manner as the automatic focusing process performed by the imaging apparatus 100 of the first embodiment. In step S4, the image processing unit 2 displays the focused image P2. A generated focused image is generated (step S4).
Here, the focused image generation processing will be described in detail with reference to FIGS. 6 and 7. 6 and 7 are flowcharts illustrating an example of an operation related to the focused image generation process.

<In-focus image generation processing>
As shown in FIG. 6, the second region setting unit 2i of the image processing unit 2 sets the first to third processing target regions B1a to B1c in the dispersion image P1 corresponding to the image signal of the subject dispersion image ( Step S31). Subsequently, after the region image generation unit 2c designates any one of the processing target regions B1 (for example, the first processing target region B1a) among the first to third processing target regions B1a to B1c (step S1). S32) One pixel at a predetermined position in the processing target area B1 (for example, a pixel at the upper left corner) is designated as the processing target pixel C (step S33).

Thereafter, the area image generation unit 2c designates any one of the filters (for example, the first filter or the like) in substantially the same manner as the focused image generation process of the first embodiment (step S12), and then designates the designated filter. Is applied to the processing target pixel C to generate a processed region image without dispersion (step S13).
Subsequently, the evaluation value calculation unit 2d calculates an evaluation value indicating the level of contrast of the processed region image generated by the region image generation unit 2c in substantially the same manner as the focused image generation processing of the first embodiment. Then, it is temporarily stored in the memory 3 (step S14).
Next, the image processing unit 2 determines whether or not the restoration processing has been performed on the processing target pixel C by using all the filters in substantially the same manner as the focused image generation processing of the first embodiment (step S <b> 1) S15). Here, if it is determined that the restoration process has not been performed using all the filters (step S15; NO), the region image generation unit 2c increments the filter number by +1 and includes the first through third filters. Then, after designating the next filter (for example, the second filter) different from the used filter (step S16), the process proceeds to step S13.

Each of the above processes is repeatedly executed until it is determined in step S15 that the restoration process has been performed using all the filters (step S15; YES).
Thereby, the evaluation value of the contrast of the processed region image using all the filters is calculated for the processing target pixel C.

If it is determined in step S15 that the restoration process has been performed using all the filters (step S15; YES), the evaluation value specifying unit 2e is substantially the same as the focused image generation process of the first embodiment. The three contrast evaluation values calculated by the evaluation value calculation unit 2d are compared with the processing target pixel C to identify the highest evaluation value (step S17).
Subsequently, the filter selection unit 2f selects the filter used for the restoration process of the processed region image having the highest contrast evaluation value specified by the evaluation value specifying unit 2e from the first to third filters. Information indicating the selected filter is temporarily stored in the memory 3 as selection filter information of the processing target pixel C in the current processing target region B1 (step S18).
As a result, the filter having the highest contrast evaluation value for the processing target pixel C is identified.

Next, the image processing unit 2 determines whether or not all the pixels in the processing target area B1 (for example, the first processing target area B1a) have been processed (step S34). Here, if it is determined that all the pixels are not processed (step S34; NO), the region image generation unit 2c increments the pixel number by +1, and within the processing target region B1, the next pixel (for example, , The right adjacent pixel, etc.) is set as the processing target pixel C (step S35), and then the process proceeds to step S12.
Then, each processing after step S12 is executed with the next pixel as the processing target pixel C, and a filter having the highest contrast evaluation value for the processing target pixel C is specified in step S18.

Each of the above processes is repeatedly executed until it is determined in step S34 that all pixels have been processed (step S34; YES).
Thereby, the filter with the highest contrast evaluation value is specified for all the pixels in the first processing target area B1a.

If it is determined in step S34 that all the pixels have been processed (step S34; YES), as shown in FIG. 7, the image processing unit 2 has processed all the processing target areas B1. Is determined (step S36). Here, if it is determined that all the processing target areas B1 have not been processed (step S36; NO), the area image generating unit 2c increments the area number by +1, and the first to third processing target areas B1a. After specifying the next processing target area B1 (for example, the second processing target area B1b) in .about.B1c (step S37), the process proceeds to step S33.
By executing each process after step S33, a filter having the highest contrast evaluation value is specified for all the pixels in the second processing target area B1b.

Each of the above processes is repeatedly executed until it is determined in step S36 that all the processing target areas B1 have been processed (step S36; YES).
As a result, the filter having the highest contrast evaluation value is specified for each pixel in all the processing target areas B1.

Next, the filter selection unit 2f specifies the selection filter information that is specified for all the pixels in each processing target region B1 and temporarily stored in the memory 3 for each of the first to third processing target regions B1a to B1c. (The filter with the highest contrast evaluation value) is aggregated for each type of filter, and one filter with the highest aggregation result is specified (step S38). Then, the filter selection unit 2f selects a filter having the shortest subject distance associated with the filter coefficient among the filters specified for each of the first to third processing target areas B1a to B1c (step S39). ).
Then, the second focused image generation unit 2j performs image signal restoration processing using one filter selected by the filter selection unit 2f for each pixel of the dispersion image P1, and generates an image without dispersion. After the non-dispersed images corresponding to the respective pixels are combined to generate the focused image P2 (step S40), the focused image generation process is terminated.

Returning to FIG. 2, the image processing unit 2 generates YUV data corresponding to the YUV color space of the focused image P2 in substantially the same manner as the automatic focusing process performed by the imaging apparatus 100 according to the first embodiment. On the other hand, after performing various image processing, compression, and the like to form a file, the image recording unit 4 records the image data of the generated focused image P2.
This completes the automatic focusing process.

As described above, according to the imaging apparatus 200 of the second embodiment, a plurality of processed region images corresponding to each of a plurality of filters are generated and calculated for each pixel in a predetermined number of processing target regions B1. The highest evaluation value among the plurality of contrast evaluation values is specified, and the highest evaluation value specified for each pixel is totaled for each of the predetermined number of processing target regions B1, and the total result is used as a reference. As one of the filters is specified, and the filter with the shortest subject distance associated with the filter coefficient is selected from among the specified filters, there is a region where the relative front-rear position with respect to the subject is shifted. In addition, by performing a predetermined filter process using a filter with the shortest subject distance, it is possible to generate a focused image P2 focused on the subject at least at the closest position. It can be.
In addition, by setting a predetermined number of processing target areas B1, it is possible to reduce the processing time compared to the case where all the pixels are set as the processing target areas B1, and an arithmetic device that does not have a high processing capability is mounted. Even in the imaging apparatus 200, it is possible to speed up the process of generating the focused image P2.

In the second embodiment, three (multiple) processing target areas B1 are set in the distributed image P1, but the number of setting of the processing target areas B1 is merely an example, and is not limited thereto. It can be arbitrarily changed as appropriate.
For example, the second region setting unit 2i sets one processing target region B1 at a predetermined position (for example, approximately the center, face detection unit, etc.) of the dispersed image P1, and then performs the focused image generation process of the second embodiment. In substantially the same manner, the filter selection unit 2f specifies a filter having the highest contrast evaluation value for all the pixels in the processing target area B1. Then, the filter selection unit 2f aggregates the identified filters for each type of filter, and identifies one filter having the highest aggregation result. As a result, the second focused image generation unit 2j performs image signal restoration processing using one filter selected by the filter selection unit 2f for each pixel of the dispersion image P1, and generates an image without dispersion. Then, the image data of the focused image P2 may be generated by synthesizing non-dispersed images corresponding to the respective pixels.
Therefore, with such a configuration, a function substantially equivalent to so-called “spot AF” can be realized, and at least a focused image P2 focused on a subject existing in the processing target area B1 can be generated. Can do.
Further, for example, the second area setting unit 2i can set substantially the entire area of the distributed image P1 as the processing target area B1.

<Modification 1>
Further, as described above, when one processing target region B1 is set in the distributed image P1, the filter coefficient of one filter selected by the filter selection unit 2f is set according to the distance from the processing target region B1. It may be corrected.
Hereinafter, an imaging apparatus according to Modification 1 will be described with reference to FIGS. 9 and 10.
FIG. 9 is a block diagram illustrating a schematic configuration of the imaging apparatus 300 according to the first modification.

  As illustrated in FIG. 9, the image processing unit 2 of the imaging apparatus 300 according to the first modification includes an image acquisition unit 2a, a region image generation unit 2c, an evaluation value calculation unit 2d, an evaluation value specification unit 2e, a filter selection unit 2f, and a filter. In addition to the storage unit 2h, a third region setting unit 2k and a third focused image generation unit 21 are provided.

The third area setting unit 2k sets one processing target area (predetermined area) B1 in the distributed image P1 corresponding to the image signal of the distributed image of the subject acquired by the image acquisition unit 2a as a third setting unit. To do. Specifically, the third region setting unit 2k sets a processing target region B1 having a predetermined size at a predetermined position (for example, a substantially central portion) of the distributed image P1.
Here, the image processing unit 2 includes a face detection unit (not shown) that detects the face of the subject from the dispersed image P1, and sets the processing target region B1 at the position of the face detected by the face detection unit. You may do it.
Note that the position and size of the processing target area B1 are merely examples, and the present invention is not limited thereto, and can be arbitrarily changed as appropriate.
Further, in FIG. 10A, the dispersion image P1 is schematically shown.

  The filter selection unit 2f specifies a filter having the highest contrast evaluation value for all the pixels in one processing target region B1 set by the third region setting unit 2k. Then, the filter selection unit 2f aggregates the identified filters for each type of filter, and identifies one filter having the highest aggregation result.

The third focused image generation unit (second generation unit) 21 calculates a filter coefficient obtained by correcting the filter coefficient of the filter selected by the filter selection unit 2f according to the distance from the processing target region B1. That is, in general, the optical system 1a is likely to generate various aberrations on the end side of the central portion. For example, the filter coefficient is set according to the distance from the processing target region B1 set in the substantially central portion. By correcting, the influence of aberration can be reduced. Furthermore, the region where the front and rear positions relative to the main subject are shifted is corrected by using the correction value that is changed according to the distance from the processing target region B1 to correct the approximate image of the focused image P2. This makes it easy to achieve a state of focus throughout the entire area.
For example, the third focused image generation unit 2l uses the subject distance of the filter (for example, the “closest” first filter) selected by the filter selection unit 2f as a reference around the one processing target region B1. A region B2 to be processed using a filter adjacent to the subject distance segment (for example, an “intermediate” third filter) is set, and a filter adjacent to the subject distance segment (for example, “infinite” By setting the region B3 to be processed using a “far” second filter or the like, the corrected filter coefficient may be specified as a result (see FIG. 10A).
At this time, the boundary portion between the region B1 processed using the “closest” first filter selected by the filter selection unit 2f and the region B2 processed using the “middle” third filter is the first and Similarly, the region B2 processed using the “intermediate” third filter and the region B3 processed using the “infinity” second filter so that the filter coefficient of the third filter becomes an intermediate value. The filter coefficient may be corrected so that the boundary portion has an intermediate value between the filter coefficients of the second and third filters.

  Then, the third focused image generation unit 21 performs restoration processing (predetermined filter processing) on the image signal acquired by the image acquisition unit 2a by using the calculated corrected filter coefficient, and performs dispersion. An image with no image is generated, and an image corresponding to each pixel is combined to generate a focused image P2 (see FIG. 10B).

  Therefore, a filter coefficient obtained by correcting the filter coefficient of the selected filter according to the distance from the processing target area B1 is calculated using the one processing target area B1 as a reference, and the corrected filter coefficient is used as an image signal. On the other hand, a predetermined filter process is performed to generate the focused image P2, so that the focused image P2 can be generated in consideration of various aberrations of the optical system 1a and relative front and rear positions with respect to the main subject.

The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, in the above embodiment, the filter used to generate the focused image P2 is specified based on the evaluation value of the contrast of the processed region image. For example, the high frequency component of the processed region image is specified. Alternatively, the resolution may be calculated according to a predetermined arithmetic expression, and the filter may be specified based on the resolution.

  Moreover, in the said embodiment, although the restoration process premise optical system was illustrated and demonstrated as the optical system 1a, it is an example and is not restricted to this, It can change arbitrarily arbitrarily. For example, a plurality of microlenses for receiving light rays from a plurality of directions are arranged in an array on the light receiving surface side of the electronic imaging unit 1b so that the angle and luminance information of the light rays can be recorded. good. By adopting such a configuration, it is possible to restore a plurality of images according to the imaging distance. However, since the plurality of images according to the imaging distance include an image that is not in focus in almost the entire area. When generating a focused image P2 in focus from the image, by selecting a filter with an optimal filter coefficient according to the distance to the subject as in the first and second embodiments, The focused image P2 can be generated appropriately.

  Furthermore, the configurations of the imaging apparatuses 100, 200, and 300 are merely examples as illustrated in the above-described embodiment, and are not limited thereto. Further, although the imaging devices 100, 200, and 300 are illustrated as the automatic focusing device, the present invention is not limited to this, and any configuration can be used as long as the automatic focusing processing according to the present invention can be performed. good.

In addition, in the above-described embodiment, the functions of the acquisition unit, the first generation unit, the calculation unit, the specifying unit, and the selection unit are controlled by the central control unit 8, and the image acquisition unit 2a, the region image generation The unit 2c, the evaluation value calculation unit 2d, the evaluation value specifying unit 2e, and the filter selection unit 2f are configured to be driven. However, the configuration is not limited to this, and a predetermined program or the like is executed by the central control unit 8. It is good also as a structure implement | achieved by performing.
That is, a program including an acquisition process routine, a first generation process routine, a calculation process routine, a specific process routine, and a selection process routine is stored in a program memory (not shown) that stores the program. Then, the CPU of the central control unit 8 may function as an acquisition unit that acquires the image signal converted from the subject image that has passed through the predetermined optical system 1a by the acquisition processing routine. Further, the CPU of the central control unit 8 performs predetermined filter processing on each of the plurality of filters stored in the storage unit with respect to the predetermined region of the image signal acquired by the acquisition unit by the first generation processing routine. May be performed to function as a first generation unit that generates a plurality of processed region images. Further, the CPU of the central control unit 8 may function as a calculation unit that calculates the contrast evaluation values of the plurality of processed region images generated by the first generation unit by the calculation processing routine. In addition, the CPU of the central control unit 8 may be caused to function as a specifying unit that compares a plurality of contrast evaluation values calculated by the calculation unit and specifies the highest evaluation value by a specific processing routine. In addition, the CPU of the central control unit 8 selects the filter corresponding to the processed region image with the highest evaluation value specified by the specifying unit as a filter used for the generation processing of the focused image P2 by the selection processing routine. You may make it function as a means.

  Similarly, the first setting unit, the second generation unit, the second setting unit, and the third setting unit may be realized by executing a predetermined program or the like by the CPU of the central control unit 8.

  Furthermore, as a computer-readable medium storing a program for executing each of the above processes, a non-volatile memory such as a flash memory or a portable recording medium such as a CD-ROM is applied in addition to a ROM or a hard disk. Is also possible. A carrier wave is also used as a medium for providing program data via a predetermined communication line.

Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and equivalents thereof.
The invention described in the scope of claims attached to the application of this application will be added below. The item numbers of the claims described in the appendix are as set forth in the claims attached to the application of this application.
[Appendix]
<Claim 1>
Storage means for storing a plurality of filters having different filter coefficients corresponding to the subject distance;
Acquisition means for acquiring an image signal converted from a subject image passing through a predetermined optical system;
A first filter that generates a plurality of processed region images by subjecting a predetermined region of the image signal acquired by the acquisition unit to a predetermined filter process using each of the plurality of filters stored in the storage unit. Generating means;
Calculation means for calculating the contrast evaluation values of the plurality of processed region images generated by the first generation means;
A plurality of contrast evaluation values calculated by the calculation means, and a specifying means for specifying the highest evaluation value;
Selection means for selecting a filter corresponding to the processed region image of the highest evaluation value specified by the specifying means as a filter used for the process of generating a focused image;
An automatic focusing device characterized by comprising:
<Claim 2>
The predetermined optical system includes a restoration processing premise optical system that forms a subject image in a form premised on restoration processing using a filter of the image signal,
The automatic focusing apparatus according to claim 1, wherein the first generation unit generates the processed region image by performing the restoration process on a predetermined region of the image signal acquired by the acquisition unit.
<Claim 3>
The predetermined optical system includes a depth extension optical system that extends a depth of field,
The acquisition means acquires an image signal converted from a dispersed image of a subject that has passed through the depth extension optical system,
The said 1st production | generation means performs the said restoration process to the predetermined area | region of the image signal of the dispersion | distribution image of the object acquired by the said acquisition means, and produces | generates the processed area image without dispersion | distribution. The automatic focusing device described.
<Claim 4>
A first setting means for setting a plurality of the predetermined areas over substantially the entire area of the image signal;
The first generation unit generates a plurality of processed region images corresponding to the plurality of filters for each of the plurality of predetermined regions set by the first setting unit,
The specifying unit compares a plurality of contrast evaluation values calculated by the calculating unit for each of the plurality of predetermined areas, and specifies the highest evaluation value;
The said selection means selects the filter corresponding to the processed area image of the highest evaluation value specified by the said specification means for each of the plurality of predetermined areas. The automatic focusing device according to one item.
<Claim 5>
The image processing apparatus further includes second generation means for generating a focused image by performing predetermined filter processing on each predetermined area of the image signal acquired by the acquisition means using the filter selected by the selection means. The automatic focusing device according to claim 4, wherein:
<Claim 6>
A second setting means for setting a predetermined number of the predetermined areas;
The first generation unit generates a plurality of processed region images corresponding to each of the plurality of filters for each pixel in a predetermined number of predetermined regions set by the second setting unit,
The specifying unit compares a plurality of contrast evaluation values calculated by the calculation unit for each pixel in the predetermined number of predetermined regions, and specifies the highest evaluation value;
The selecting means, for each of the predetermined number of predetermined areas, totalize the highest evaluation value specified by the specifying means for each pixel, specify any one filter based on the total result, The automatic focusing device according to any one of claims 1 to 3, wherein a filter having the shortest subject distance associated with a filter coefficient is selected from among the identified filters.
<Claim 7>
A second setting means for setting one of the predetermined areas;
The first generation means generates a plurality of processed area images corresponding to each of the plurality of filters for each pixel in one predetermined area set by the second setting means,
The specifying unit compares a plurality of contrast evaluation values calculated by the calculation unit for each pixel in the predetermined region, and specifies the highest evaluation value;
The selection means totals the highest evaluation value specified by the specifying means for each pixel for the predetermined area, and selects any one filter based on the total result. Item 4. The automatic focusing device according to any one of Items 1 to 3.
<Claim 8>
The image processing apparatus further includes a second generation unit configured to perform a predetermined filter process on the image signal acquired by the acquisition unit using a filter selected by the selection unit and generate a focused image. Item 8. The automatic focusing device according to Item 6 or 7.
<Claim 9>
Third setting means for setting one of the predetermined areas;
Using the one predetermined area set by the third setting means as a reference, a filter coefficient obtained by correcting the filter coefficient of the filter selected by the selection means according to the distance from the predetermined area is calculated, 4. A second generation unit configured to generate a focused image by performing a predetermined filter process on the image signal acquired by the acquisition unit using a filter coefficient. The automatic focusing device according to any one of the above.
<Claim 10>
An automatic focusing method using an automatic focusing device including a storage unit that stores a plurality of filters having different filter coefficients corresponding to the subject distance,
A process of acquiring an image signal converted from a subject image passing through a predetermined optical system;
A process of performing a predetermined filter process on each of a plurality of filters stored in the storage unit and generating a plurality of processed area images with respect to a predetermined area of the acquired image signal;
A process of calculating contrast evaluation values of the generated plurality of processed area images,
A process for comparing the calculated evaluation values of a plurality of contrasts to identify the highest evaluation value,
A process of selecting a filter corresponding to the processed region image having the highest evaluation value identified as a filter used for the process of generating a focused image;
An automatic focusing method comprising:
<Claim 11>
A computer of an automatic focusing apparatus comprising storage means for storing a plurality of filters having different filter coefficients corresponding to the subject distance,
An acquisition means for acquiring an image signal converted from a subject image passing through a predetermined optical system;
A first filter that generates a plurality of processed region images by subjecting a predetermined region of the image signal acquired by the acquisition unit to a predetermined filter process using each of the plurality of filters stored in the storage unit. Generating means,
Calculating means for respectively calculating contrast evaluation values of the plurality of processed region images generated by the first generating means;
A plurality of contrast evaluation values calculated by the calculation means, and a specifying means for specifying the highest evaluation value;
Selection means for selecting a filter corresponding to the processed region image of the highest evaluation value specified by the specifying means as a filter used in the process of generating a focused image;
A program characterized by functioning as

100, 200, 300 Imaging device 1 Imaging unit 2 Image processing unit 2a Image acquisition unit 2b First region setting unit 2c Region image generation unit 2d Evaluation value calculation unit 2e Evaluation value identification unit 2f Filter selection unit 2g First focused image generation Unit 2h filter storage unit 2i second region setting unit 2j second focused image generating unit 2k third region setting unit 21 l third focused image generating unit 8 central control unit

Claims (11)

Storage means for storing a plurality of filters having different filter coefficients corresponding to the subject distance;
Acquisition means for acquiring an image signal converted from a subject image passing through a predetermined optical system;
A first filter that generates a plurality of processed region images by subjecting a predetermined region of the image signal acquired by the acquisition unit to a predetermined filter process using each of the plurality of filters stored in the storage unit. Generating means;
Calculation means for calculating the contrast evaluation values of the plurality of processed region images generated by the first generation means;
A plurality of contrast evaluation values calculated by the calculation means, and a specifying means for specifying the highest evaluation value;
Selection means for selecting a filter corresponding to the processed region image of the highest evaluation value specified by the specifying means as a filter used for the process of generating a focused image;
An automatic focusing device characterized by comprising: The predetermined optical system includes a restoration processing premise optical system that forms a subject image in a form premised on restoration processing using a filter of the image signal,
The automatic focusing apparatus according to claim 1, wherein the first generation unit generates the processed region image by performing the restoration process on a predetermined region of the image signal acquired by the acquisition unit. The predetermined optical system includes a depth extension optical system that extends a depth of field,
The acquisition means acquires an image signal converted from a dispersed image of a subject that has passed through the depth extension optical system,
The said 1st production | generation means performs the said restoration process to the predetermined area | region of the image signal of the dispersion | distribution image of the object acquired by the said acquisition means, and produces | generates the processed area image without dispersion | distribution. The automatic focusing device described. A first setting means for setting a plurality of the predetermined areas over substantially the entire area of the image signal;
The first generation unit generates a plurality of processed region images corresponding to the plurality of filters for each of the plurality of predetermined regions set by the first setting unit,
The specifying unit compares a plurality of contrast evaluation values calculated by the calculating unit for each of the plurality of predetermined areas, and specifies the highest evaluation value;
The said selection means selects the filter corresponding to the processed area image of the highest evaluation value specified by the said specification means for each of the plurality of predetermined areas. The automatic focusing device according to one item.   The image processing apparatus further includes second generation means for generating a focused image by performing predetermined filter processing on each predetermined area of the image signal acquired by the acquisition means using the filter selected by the selection means. The automatic focusing device according to claim 4, wherein: A second setting means for setting a predetermined number of the predetermined areas;
The first generation unit generates a plurality of processed region images corresponding to each of the plurality of filters for each pixel in a predetermined number of predetermined regions set by the second setting unit,
The specifying unit compares a plurality of contrast evaluation values calculated by the calculation unit for each pixel in the predetermined number of predetermined regions, and specifies the highest evaluation value;
The selecting means, for each of the predetermined number of predetermined areas, totalize the highest evaluation value specified by the specifying means for each pixel, specify any one filter based on the total result, The automatic focusing device according to any one of claims 1 to 3, wherein a filter having the shortest subject distance associated with a filter coefficient is selected from among the identified filters. A second setting means for setting one of the predetermined areas;
The first generation means generates a plurality of processed area images corresponding to each of the plurality of filters for each pixel in one predetermined area set by the second setting means,
The specifying unit compares a plurality of contrast evaluation values calculated by the calculation unit for each pixel in the predetermined region, and specifies the highest evaluation value;
The selection means totals the highest evaluation value specified by the specifying means for each pixel for the predetermined area, and selects any one filter based on the total result. Item 4. The automatic focusing device according to any one of Items 1 to 3.   The image processing apparatus further includes a second generation unit configured to perform a predetermined filter process on the image signal acquired by the acquisition unit using a filter selected by the selection unit and generate a focused image. Item 8. The automatic focusing device according to Item 6 or 7. Third setting means for setting one of the predetermined areas;
Using the one predetermined area set by the third setting means as a reference, a filter coefficient obtained by correcting the filter coefficient of the filter selected by the selection means according to the distance from the predetermined area is calculated, 4. A second generation unit configured to generate a focused image by performing a predetermined filter process on the image signal acquired by the acquisition unit using a filter coefficient. The automatic focusing device according to any one of the above. An automatic focusing method using an automatic focusing device including a storage unit that stores a plurality of filters having different filter coefficients corresponding to the subject distance,
A process of acquiring an image signal converted from a subject image passing through a predetermined optical system;
A process of performing a predetermined filter process on each of a plurality of filters stored in the storage unit and generating a plurality of processed area images with respect to a predetermined area of the acquired image signal;
A process of calculating contrast evaluation values of the generated plurality of processed area images,
A process for comparing the calculated evaluation values of a plurality of contrasts to identify the highest evaluation value,
A process of selecting a filter corresponding to the processed region image having the highest evaluation value identified as a filter used for the process of generating a focused image;
An automatic focusing method comprising: A computer of an automatic focusing apparatus comprising storage means for storing a plurality of filters having different filter coefficients corresponding to the subject distance,
An acquisition means for acquiring an image signal converted from a subject image passing through a predetermined optical system;
A first filter that generates a plurality of processed region images by subjecting a predetermined region of the image signal acquired by the acquisition unit to a predetermined filter process using each of the plurality of filters stored in the storage unit. Generating means,
Calculating means for respectively calculating contrast evaluation values of the plurality of processed region images generated by the first generating means;
A plurality of contrast evaluation values calculated by the calculation means, and a specifying means for specifying the highest evaluation value;
Selection means for selecting a filter corresponding to the processed region image of the highest evaluation value specified by the specifying means as a filter used in the process of generating a focused image;
A program characterized by functioning as