JP7614798B2 - Display control device and control method thereof - Google Patents

Description

The present invention relates to a display control device and a control method thereof, and in particular to a technology for displaying information related to photography.

The F-number and T-number are known as indicators of the brightness of a photographic lens. The F-number is a value obtained when the light transmittance of the optical components in the optical path is assumed to be 100%. On the other hand, the T-number is a value that reflects the actual light transmittance of the optical components in the optical path. In environments that require strict exposure control, such as television and movie shooting, not only the F-number but also the T-number is important.

Patent document 1 discloses that a lens information display device connected to a lens device displays the F-number and T-number side by side as information about the lens device.

JP 2003-101835 A

In a photographic lens, the difference between the T-number and the F-number affects the degree of blurring of the image (blurred image) of the out-of-focus part (hereinafter referred to as bokeh). However, if the T-number and F-number are displayed as is, as in Patent Document 1, it is difficult to easily grasp the degree of blurring of the captured image.

The object of the present invention is to provide a display control device and a control method thereof that allows a user to easily grasp the blur of a captured image before recording it.

The above-mentioned object is achieved by a display control device having a setting means capable of setting at least one of the F value and the T value, an acquisition means capable of acquiring information regarding the deviation between the F value and the T value, and a control means for controlling the display so that a first item indicating the setting value set by the setting means is displayed together with a second item indicating information acquired by the acquisition means that corresponds to the current setting value.

The present invention provides a display control device and a control method thereof that allow a user to easily grasp the blur of a captured image before recording it.

FIG. 1 is a block diagram showing an example of the functional configuration of a digital camera as an example of a display control device according to an embodiment; FIG. 2 is a perspective view showing an example of the appearance of the digital camera shown in FIG. FIG. 1 is a block diagram showing an example of the functional configuration of a lens unit according to an embodiment; FIG. 4 is a diagram showing an example of the transmittance characteristic of the APD in FIG. 3 and an example of the relationship between the F value and the T value. Schematic diagram of the effect of APD FIG. 1 is a diagram showing an example of a live view screen in the first embodiment; 1 is a flowchart showing an operation of acquiring a blur index according to a first embodiment; FIG. 13 is a diagram showing a blur index and a display example used in the second embodiment. FIG. 13 is a diagram illustrating a display control of blur index items in the third embodiment. 11 is a flowchart for controlling the display of blur index items in the second embodiment. Flowchart regarding a lens unit discrimination operation in the third embodiment FIG. 23 is a diagram showing a display example of blur index items in the sixth embodiment; Flowchart regarding the generation operation of blur index items in the sixth embodiment Flowchart of bokeh effect generation operation in the seventh embodiment Schematic diagram of blur effect image generation in the seventh embodiment. FIG. 23 is a diagram showing an example of a method for presenting a bokeh effect to a user in the seventh embodiment; FIG. 23 is a diagram showing an example of a method for presenting a bokeh effect to a user in the seventh embodiment;

The present invention will be described in detail below based on an exemplary embodiment with reference to the attached drawings. Note that the following embodiment does not limit the invention according to the claims. In addition, although multiple features are described in the embodiment, not all of them are necessarily essential to the invention, and multiple features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicate explanations are omitted.

In the following embodiment, the present invention will be described with respect to a case where the present invention is implemented in a digital camera with interchangeable lenses. However, the present invention can be implemented in any electronic device capable of acquiring information about a photographing lens. Such electronic devices include electronic devices equipped with an imaging device and electronic devices serving as external devices capable of communicating with an imaging device. More specifically, the present invention can be implemented in digital video cameras, computer devices (personal computers, tablet computers, media players, PDAs, etc.), mobile phones, smartphones, game consoles, robots, drones, etc. Note that these are merely examples of electronic devices in which the present invention can be implemented, and do not prevent the present invention from being implemented in other electronic devices.

● (First embodiment)
<Digital Camera Configuration>
1 is a block diagram showing an example of the functional configuration of a digital camera 100 (camera body) as an example of a display control device according to this embodiment. The shutter 101 is a focal plane shutter. The imaging unit 22 is an imaging element in which a plurality of pixels are arranged two-dimensionally and converts an optical image into a group of analog electrical signals, and may be a CCD or CMOS image sensor.

The A/D converter 23 converts the analog electrical signals output from the imaging unit 22 into digital signals (image data). The imaging unit 22 may have the A/D converter 23.
The image processing unit 24 applies predetermined image processing to image data supplied from the A/D converter 23 or the memory control unit 15, generates signals and image data, and acquires and/or generates various information. The image processing circuit 824 may be a dedicated hardware circuit such as an ASIC designed to realize a specific function, or may be configured to realize a specific function by a programmable processor such as a DSP executing software.

Here, the image processing applied by the image processing unit 24 includes preprocessing, color interpolation, correction, data processing, evaluation value calculation, special effect processing, etc. Preprocessing includes signal amplification, reference level adjustment, defective pixel correction, etc. Color interpolation is a process of interpolating the values of color components not included in the image data read from the pixel, and is also called demosaic processing or synchronization processing. Correction processing includes white balance adjustment, gradation correction (gamma processing), processing to correct the effects of optical aberration and peripheral light reduction of the shooting optical system, color correction, etc. Data processing includes synthesis processing, scaling processing, encoding and decoding processing, header information generation processing, etc. Evaluation value calculation processing includes generation of signals and evaluation values used for automatic focus detection (AF), calculation of evaluation values used for automatic exposure control (AE), etc. Special effect processing includes addition of blur, change of color tone, relighting processing, etc. Note that these are examples of image processing that the image processing unit 24 can apply, and do not limit the image processing applied by the image processing unit 24.

Image data output by the A/D converter 23 and image processing unit 24 is stored in memory 32 via memory control unit 15. Memory 32 is used as a buffer memory for temporarily storing data being processed by image processing unit 24. A part of memory 32 is used as video memory (VRAM) for display unit 28. Memory 32 has a capacity for storing a predetermined number of still images and a predetermined period of moving images and audio.

Under the control of the system control unit 50, the OSD drawing unit 25 generates image data for on-screen display using font data, icon data, etc. stored in the non-volatile memory 56, and stores the image data in the VRAM area of the memory 32. The image data generated by the OSD drawing unit 25 may be a GUI screen such as a menu screen, an image showing the status or setting values of the digital camera 100, a guidance screen for user operations, etc.

The display control unit 13 generates a video signal based on the display image data stored in the VRAM area of the memory 32, and supplies the signal to the display unit 28. The display unit 28 displays an image on a display device such as a liquid crystal display (LCD) or an organic light-emitting display (OLED) in response to the video signal from the display control unit 13. The display unit 28 may be a touch display. The display unit 28 may be an external device connected to the digital camera 100 so as to be able to communicate with the digital camera 100.

By shooting video and sequentially processing each frame by the image processing unit 24 and the display control unit 13, the display unit 28 functions as an electronic viewfinder (EVF). The image displayed to make the display unit 28 function as an EVF is called a live view image or a through image.

The system control unit 50 is, for example, a CPU (also called an MPU or microprocessor). The system control unit 50 controls the operation of each part of the digital camera 100 and realizes the functions of the digital camera 100 by expanding a program stored in the non-volatile memory 56 into the system memory 52 and executing it. The system control unit 50 also communicates with the lens control unit 301 of the lens unit 300 via the lens communication unit 92 and controls the operation of the lens unit 300.

The non-volatile memory 56 is an electrically rewritable ROM (EEPROM) that stores the programs executed by the system control unit 50, various settings of the digital camera 100, GUI data, etc. The system memory 52 is a memory (RAM) used to expand the programs executed by the system control unit 50 and to store information necessary for executing the programs. Note that the memory 32 and the system memory 52 may be separate areas within the same memory space.

The system timer 53 generates timing signals used for various controls and measures time using an internal clock.
The mode changeover switch 60, the first shutter switch (SW1) 61, the second shutter switch (SW2) 62, the operation unit 70, and the power switch 72 are input devices that allow the user to input instructions to the digital camera 100. The first shutter switch (SW1) 61 is turned on when the release button is half-pressed, and the second shutter switch (SW2) 62 is turned on when the release button is fully pressed. The system control unit 50 recognizes the first shutter switch (SW1) 61 being turned on as an instruction to prepare for shooting a still image, and the second shutter switch (SW2) 62 being turned on as an instruction to start shooting a still image.

When the first shutter switch (SW1) 61 is turned ON, the system control unit 50 performs AF processing, AE processing, AWB (auto white balance) processing, EF (pre-flash) processing, etc. as preparation operations for shooting, and waits for an instruction to start shooting.

When the second shutter switch (SW2) 62 is turned ON, the system control unit 50 drives the shutter 101 according to the exposure conditions determined by the AE processing, exposing the imaging unit 22. The system control unit 50 then reads out a group of analog signals from the imaging unit 22, causes the image processing unit 24 to generate a still image data file for recording, and starts a series of shooting processing operations up to recording on the recording medium 200.

The operation unit 70 includes multiple input devices, each of which has a name according to the assigned function. For example, the operation unit 70 includes a menu button, directional keys, and a determination key. Multiple functions may be assigned to the same input device. The input device may also be a software button/key using a touch panel. For example, when the menu button is pressed, a menu screen in which various settings can be made is displayed on the display unit 28. The user can input various settings and instructions to the digital camera 100 by operating the menu screen displayed on the display unit 28 using the directional keys and the determination key. Note that the operation unit 70 may also include an input device that inputs instructions without contact, such as voice input or eye contact input.

The mode change switch 60 is a dial switch for switching the operation mode of the digital camera 100. There are no particular limitations on the operation modes, but they can be broadly divided into, for example, a still image recording mode, a video recording mode, and a playback mode, and each mode can have multiple modes.

The power switch 72 switches the power of the digital camera 100 ON and OFF. In this embodiment, when the power switch 72 is used to turn the power ON, the digital camera 100 goes into a standby state for still image capture. In this state, the system control unit 50 continuously executes control operations to cause the display unit 28 to function as an EVF.

The power supply control unit 80 is composed of a battery detection circuit, a DC-DC converter, a switch circuit that switches between blocks to which electricity is applied, and other components, and detects whether a battery is installed, the type of battery, and the remaining battery power. The power supply control unit 80 also controls the DC-DC converter based on the detection results and instructions from the system control unit 50, and supplies the necessary voltage to each unit, including the recording medium 200, for the necessary period of time.

The power supply unit 30 is a primary battery, a secondary battery, an AC adapter, etc. The recording medium I/F 18 is a communication interface with the recording medium 200. The recording medium 200 may be a memory card, a hard disk, etc.

The lens connection unit 91 is a mechanism for attaching and detaching the lens unit, and is also called a lens mount. The lens unit, which is mechanically connected to the lens connection unit 91, is electrically connected to the digital camera 100 through contacts provided on the lens connection unit 91, and receives power from the digital camera 100 and communicates with the digital camera 100. The lens communication unit 92 is a communication interface with the lens unit.

The system control unit 50 communicates with the lens unit through the lens communication unit 92 to obtain information about the lens unit and provide commands to control the operation of the lens unit.

Figure 2 is a perspective view showing an example of the appearance of the digital camera 100, with the same reference numerals used for the same components as in Figure 1. Figure 2(a) is a front perspective view, and (b) is a rear perspective view. Figure 2 shows the state in which the lens unit 300 is attached to the lens connection portion 91.

The menu button 73, directional keys 74, and decision key 75 are input devices included in the operation unit 70. The directional key 74 is a four-way key that can be pressed up, down, left, and right. The decision key 75 is mainly used to instruct the user to confirm a selected item. The menu button 73 is used to instruct the display unit 28 to display a menu screen. By operating the menu screen, the user can check and change the current settings of the digital camera 100.

The viewfinder 16 is an EVF with an in-finder display inside. The viewfinder 16 may be an optical viewfinder.

<Lens unit configuration>
3 is a block diagram showing an example of the functional configuration of a lens unit 300 that can be connected to the digital camera 100. The lens unit 300 is an image capturing optical system of the digital camera 100. A lens control unit 301 is, for example, a CPU, and controls the operation of each part of the lens unit 300 by loading a program stored in a ROM 302 into a RAM 306 and executing the program.

The camera connection part 303 mechanically engages with the lens connection part 91 of the digital camera 100 to connect the lens unit 300 to the digital camera 100. When the lens unit 300 is connected to the digital camera 100, the contacts on the camera connection part 303 and the lens connection part 91 come into contact with each other, and the lens unit 300 and the digital camera 100 are also electrically connected.

This enables the lens control unit 301 and the system control unit 50 to communicate with each other, and when establishing a connection, the lens control unit 301 transmits information about the lens unit 300 to the system control unit 50. Following commands from the system control unit 50, the lens control unit 301 controls the operation of the focus adjustment unit 304 and the aperture adjustment unit 305, and transmits information such as position information of the focus lens (front lens group 310) and aperture value information of the aperture 312 to the system control unit 50.

The front lens group 310 and the rear lens group 311 are arranged on the optical axis 314 of the lens unit 300, and form an optical image of the subject on the imaging plane of the imaging section 22. The focus adjustment section 304 drives the front lens group 310 in the direction of the optical axis 314 to change the focal distance of the lens unit 300. This changes the degree of focus of the image formed on the imaging plane. The focus adjustment section 304 is, for example, a motor. The front lens group 310 is arranged closer to the subject than the aperture 312, and the rear lens group 311 is arranged closer to the digital camera 100 than the aperture 312. Position information of the front lens group 310 can be detected by the lens control section 301.

The aperture 312 is disposed on the optical axis 314, and the aperture diameter is adjusted by the aperture adjustment unit 305. The aperture adjustment unit 305 is, for example, an actuator. The aperture 312 may be manually operable, in which case the aperture adjustment unit 305 has, for example, an aperture ring operated by the user, and an aperture opening adjustment mechanism that works in conjunction with the aperture ring. Also, although the aperture adjustment unit 305 here adjusts the F-number, it may also adjust the T-number.

The APD 313 is also called an apodization filter or a smooth transfer focus, and is an optical element whose transmittance changes according to the distance from the optical axis. Here, the APD 313 is disposed on the optical axis 314 between the aperture 312 and the rear lens group 311. The APD 313 can also be said to be an optical element that modulates the transmittance distribution in the radial direction of the pupil of the light beam passing through the pupil of the lens unit 300. The APD 313 may be an optical element in which a film having optical properties that modulate the transmittance distribution in the radial direction of the pupil is provided on the surface of optical glass by deposition or the like. Note that instead of providing the APD 313, a film having similar optical properties may be provided by deposition or the like on a part of the optical elements that constitute the front lens group 310 and the rear lens group 311. In this case, the lens corresponds to a configuration that also serves as an APD. The APD 313 has the effect of realizing a soft blurred image by making the blurred image smoother. Details will be described later.

In addition, the lens control unit 301 may determine the drive amount and drive direction of the front lens group 310 instead of instructing the lens control unit 301 from the system control unit 50. In this case, the system control unit 50 may supply information for calculating the defocus amount to the lens control unit 301. In addition, a part of the front lens group 310 or a part of the rear lens group 311 may function as a focus lens.

<Configuration and characteristics of apodization filter>
Next, the optical characteristics of the APD 313 will be described. Fig. 4A is a diagram showing an example of the relationship between the normalized pupil radius and transmittance (transmittance characteristics) of the APD 313. The pupil radius is 0 at the intersection of the optical axis and the APD 313, and 1 at the maximum pupil radius. Also, a transmittance of 1 indicates 100%. In other words, Fig. 4A shows that the APD 313 has optical characteristics in which the light transmittance decreases as the radial distance from the optical axis increases.

4A is expressed by the following formula (1): In formula (1), t is the transmittance (0≦t≦1), and r is the normalized pupil radius (0≦r≦1).
t = exp ( -r ² /r ₀ ² ) (1)

On the other hand, the F value and the T value have the relationship expressed by formula (2).
√(I ₀ )*√I = F / T (2)
Here, _I0 indicates the transmittance (0≦ _I0 ≦1) of the lens group excluding the APD 313. The transmittance _I0 may be obtained by actual measurement or simulation. Also, I is the ratio of the amount of light between when there is no APD 313 and when there is. The amount of light can be obtained, for example, by integrating equation (1). Specifically, I can be expressed by the following equation (3).

Here, an example is shown in which the light intensity ratio I is analytically calculated, but it is also possible to actually measure the light intensity ratio I for each F-number, and store the F-number and the light intensity ratio I in correspondence with each other in the form of a table in ROM 302.

FIG. 4B shows an example of the relationship between the F-number and the T-number when _I0 is 0.9. The horizontal axis shows the F-number, and the vertical axis shows the T-number. _Fmin indicates the minimum F-number (full F-number) of the lens unit 300, which is 2.2 in this example. The dashed line shows the relationship between the F-number and the T-number when the APD 313 is disposed on the optical axis 314, and the T-number changes nonlinearly with respect to the change in the F-number, especially in the range where the F-number is small. This is because in the small F-number region, the influence of the modulation of the radial transmittance by the APD 313 appears in the T-number. Moreover, _Tmin is the minimum T-number corresponding to the minimum F-number of 2.2, and is obtained from formula (2).

4B shows the relationship between the F-number and the T-number when there is no APD 313. When there is no APD 313, the T-number changes linearly with respect to the change in the F-number, as expressed by the following formula (4).
√(I ₀ ) = F / T' (4)

4B represents the difference or deviation between the T value obtained by formula (4) and the T value in the presence of the APD 313, for the same F value. Δ can be calculated by the following formula (5) using formulas (4) and (2).
Δ=F / T' - F / T = √(I ₀ ) - F / T (5)

4 indicates the T value at the minimum F value F _min when there is no APD _313. Also, Δ _MAX indicates the maximum deviation amount of the T value for the same F value when there is and when there is no APD 313, and is expressed by the following formula (6).

When the APD 313 has a transmittance modulation characteristic in which the transmittance t monotonically decreases with an increase in the pupil radius r as expressed by equation (1), equations (2), (3), and (5) show that the T value also monotonically decreases and Δ monotonically increases with an increase in the pupil radius r. As mentioned above, the degree of blurring (the degree of blurring or the amount of blurring) of an image of an out-of-focus portion (a blurred image) is affected by the difference between the T value and the F value. Because the magnitude of Δ affects the magnitude of the difference between the T value and the F value, the magnitude of Δ can also be used as an index of the degree of blurring.

<Effect of apodization filter>
Fig. 5 is a schematic diagram showing the change in blurred image, i.e., the change in blur caused by the APD 313. Fig. 5(a) to Fig. 5(c) are images captured of the same scene, and all of them include a circular blurred image. Here, Fig. 5(a) is assumed to be an image captured without the APD 313. Fig. 5(b) is a schematic diagram of an image captured with the APD 313 and the aperture value set to maximum (F _min ), and Fig. 5(c) is a schematic diagram of an image captured with the APD 313 and the aperture value set to a value greater than maximum.

In the image in FIG. 5(b), where the effect of the APD 313 is greatest, the interior and edges of the circular blurred image become smoother, resulting in a soft blurred image. Increasing the F-number makes the pupil of the photographing optical system smaller, suppressing the decrease in light transmittance caused by the APD 313, and thus making the edges of the blurred image clearer.

FIG. 6 is a diagram showing an example of a live view screen that is displayed on the display unit 28 of the digital camera 100 when the lens unit 300 having the APD 313 is attached.
The live view screen 400 is an image obtained by combining a captured image 401 captured by the imaging unit 22 with an image of the auxiliary information for photography. Here, items 410 to 418 and 430 are illustrated as examples of the auxiliary information for photography. The F-number information item 410 indicates the currently set F-number. The WB item 411 indicates the currently set white balance. The ND item 412 indicates the stage number of the ND filter currently used. The ISO item 413 indicates the currently set shooting sensitivity. The shutter item 414 indicates the currently set shutter speed. The power item 415 indicates the current remaining battery level. The media information item 416 indicates the remaining capacity of the recording medium and which slot the recording medium is used for recording. The frame rate item 417 and the time code item 418 indicate the frame rate and time code of the video. The blur index item 430 indicates the degree of effect of the APD 313 on the blurred image (the degree of smoothness of the blurred image) in the current shooting settings.

6, the ratio or proportion of Δ corresponding to the current F-number to _ΔMAX described in FIG. 4B is shown as a blur index as a numerical value in the blur index item 430. The effect of the APD 313 on the blurred image is maximum when Δ= _ΔMAX , and the blurred image is smoothest. Therefore, the value of the blur index calculated as the ratio of the two (0≦Δ/ _ΔMAX ≦1) is an index of the degree of effect of the APD 313 on the blurred image (smoothness of the blurred image), and the effect is maximum when the blur index is 1, and no effect when the blur index is 0. Note that in FIG. 6, the blur index item 430 is displayed as a value of Δ for convenience of screen display, but the displayed value is Δ/ _ΔMAX .

Figure 7 is a flowchart of the operation of calculating the blur index executed by the digital camera 100. The operation shown in the flowchart in Figure 7 is realized by the system control unit 50 expanding a program recorded in the non-volatile memory 56 into the system memory 52 and executing the program. This process can be executed as part of the live view display operation in the digital camera 100.

In S501, the system control unit 50 acquires at least one of the current F-number and T-number. The system control unit 50 can acquire the current F-number (T-number) by, for example, inquiring of the lens control unit 301. The system control unit 50 stores the acquired current F-number (T-number) in the system memory 52. Note that the lens control unit 301 may actively transmit the current F-number (T-number) to the system control unit 50 via the camera connection unit 303, and the system control unit 50 may constantly update the current F-number (T-number) stored in the system memory 52. Note that, when the system control unit 50 controls the aperture 312 of the lens unit 300, the system control unit 50 can acquire the current F-number by, for example, referring to the last set aperture value stored in the system memory 52. In this case, the system control unit 50 does not need to communicate with the lens control unit 301.

In S502, the system control unit 50 acquires the deviation amount Δ of the T value corresponding to the current F value of the lens unit 300. The deviation amount Δ can be acquired in various ways. For example, information (e.g., a table) that associates the T value deviation value Δ with each F value (T value) is registered in the ROM 302 of the lens unit 300. The system control unit 50 then acquires the table from the lens unit 300 at some timing (e.g., immediately after the lens unit 300 is connected and communication with the lens control unit 301 is established) and stores it in the system memory 52. In S502, the system control unit 50 can acquire the deviation amount Δ by referring to the table in the system memory 52 based on the F value (T value) acquired in S501.

Alternatively, the deviation amount Δ may be obtained by the system control unit 50 making an inquiry to the lens control unit 301. In this case, the lens control unit 301 obtains the deviation amount Δ by referring to a table registered in the ROM 302 based on the current F-number (T-number), and transmits it to the system control unit 50.

When the lens control unit 301 is configured to transmit the current F-number (T-number) to the system control unit 50 in S501, the deviation amount Δ corresponding to the current F-number (T-number) may also be transmitted. This can reduce the number of communications between the system control unit 50 and the lens control unit 301.

The system control unit 50 may store in the non-volatile memory 56 the unique information of the lens unit 300 acquired from the lens unit 300, such as information associating the T-value deviation value Δ with each F-value (T-value), in association with the lens unit's identification information. This eliminates the need to acquire the unique information again from the lens unit 300 when the same lens unit is reconnected.

In S503, the system control unit 50 calculates the blur index Δ/ _ΔMAX . If the deviation amount Δ obtained in S502 is used as the blur index as it is, S503 does not need to be executed. By setting the blur index to Δ/ _ΔMAX , a blur index is obtained in which the state where the maximum effect is obtained is set to 1, making it easier to grasp the magnitude of the effect.

Then, based on the acquired blur index, the system control unit 50 causes the image processing unit 24 to generate an image of the shooting auxiliary information including the image of the blur index 430. The image of the shooting auxiliary information is stored in the VRAM area of the memory 32, combined with the captured image for display, and displayed on the display unit 28 by the display control unit 13.

In this manner, in this embodiment, an index showing the smoothness of the blurred image in the captured image obtained under the shooting conditions is presented based on the difference in the T value corresponding to the same F value depending on the presence or absence of an optical member that modulates the light transmittance. This allows the user to easily grasp the smoothness of the blurred image obtained with the current settings before shooting, and allows the user to change the settings as necessary. This allows the user to easily shoot an image with the desired blur.

● (Second embodiment)
Next, a second embodiment will be described. In the first embodiment, an index based on the deviation amount Δ of the T value is used as an index indicating the smoothness of the blurred image. However, other indexes may be used. This embodiment may be similar to the first embodiment except for the method of presenting the blur index and the blur index item 430, so the configuration and operation of the device common to the first embodiment will not be described.

8A is a diagram showing an example of the relationship between Δ/ _ΔMAX and the normalized transmittance modulation amount, which has a value between 0 and 1 and is a value obtained by normalizing the light transmittance according to the size (radius r) of the pupil region of the photographing optical system by the light transmittance when the size of the pupil region is maximum (radius r ₀ ).

As shown in Fig. 8A, the normalized transmittance modulation amount and Δ/ _ΔMAX are in a corresponding relationship, so the normalized transmittance modulation amount can be used as an index showing the smoothness of a blurred image. When the normalized transmittance modulation amount is used as an index showing the smoothness of a blurred image, the effect of the APD (smoothness of a blurred image) can be grasped as a change in luminance value.

In addition, the effect of the APD (smoothness of a blurred image) may be expressed in a number of categories. In the example of Fig. 8A, the value of the normalized transmittance modulation amount is divided into five categories at intervals of 0.2 as shown below.
・Range 601 greater than 0.8 and less than or equal to 1: Level A
Range 602 greater than 0.6 and less than or equal to 0.8: Level B
- Range 603 greater than 0.4 and equal to or less than 0.6: Level C
- Range 604 greater than 0.2 and equal to or less than 0.4: Level D
・0.2 or less, 0 or more range 605: Level E

Then, the system control unit 50 causes the display unit 28 to display an image corresponding to each level as the blur index item 430. FIG. 8(b) shows an example of the blur index item 430 corresponding to each level, and FIG. 8(c) shows an example of the blur index item 430 displayed in live view. In FIG. 8(c), the same reference numerals as in FIG. 6 are used for the configurations similar to those in the first embodiment, and the description thereof will be omitted.

In the example shown in FIG. 8(b), the levels are represented using a number of bar patterns equal to the number of levels (number of divisions) minus 1. 611 to 615 in FIG. 8(b) are examples of blur index items 430 corresponding to levels A to E, respectively. At level E, which has the lowest effect, no bar patterns are displayed, and instead the text "OFF" is displayed. From level D to level A, the number of bar patterns displayed increases with each increase in level, and at level A, which is the highest level, all patterns are displayed. In the example shown in FIG. 8(b), the lengths of the bar patterns are made different and are displayed in order from the shortest to the oldest, so that the level is indicated not only by the number of patterns displayed but also by their length. To indicate the total number of bar patterns, only the outlines of patterns that are not displayed may be displayed.

In this embodiment, the index of the bokeh effect is presented in a stepped manner, which has the advantage that it is easier to immediately grasp the magnitude of the effect compared to the first embodiment, in which the index is presented in a numerical manner. Note that, although the range of values of the normalized transmittance modulation amount is divided into five in the example of FIG. 8(b), it may be expressed in two categories, with level E being the category of no effect and the other categories being the category of effective effect. This is effective when the user only wants to know whether or not there is an effect.

The number of divisions of the normalized transmittance modulation amount may be a predetermined value, or may be set by the user from a menu screen (an integer of 2 or more). Note that, instead of the normalized transmittance modulation amount, the range of Δ/ _ΔMAX may be divided and presented in the same manner as in this embodiment.

Also, taking into consideration human visual recognition, the transmittance modulation amount may be converted to a logarithm before classification. Furthermore, in this embodiment, an example is shown in which the level is represented by varying the number of patterns displayed according to the classification, but a presentation method that represents the level using other expressions such as color tone, gradation, and item size may also be adopted.

(Third embodiment)
Next, a third embodiment will be described. This embodiment may be similar to the first embodiment except for the method of presenting the blur index item 430, so a description of the configuration and operation of the device common to the first embodiment will be omitted.

Figures 9(a) to 9(c) are diagrams that show a schematic diagram of the display control of the blur index item 430 in this embodiment. The same reference numerals are used for the same configurations as in Figure 6, and duplicated explanations will be omitted. Figure 10 is a flowchart relating to the display control operation of the blur index item 430 in this embodiment. The operation shown in the flowchart in Figure 10 is realized by expanding a program recorded in the non-volatile memory 56 into the system memory 52 and executing it by the system control unit 50. This processing can be executed as part of the live view display operation in the digital camera 100.

Figure 9 (a) shows an example of the display of the live view screen 400 when the digital camera 100 is powered on and in a shooting standby state. In the shooting standby state, the digital camera 100 is powered on, startup processing and the like are completed, and the camera is ready to accept user operations. When the system control unit 50 enters the shooting standby state, it continues to shoot and display video, and waits for user instructions while making the display unit 28 function as an EVF. In this embodiment, the blur index item 430 is not displayed on the live view screen 400 from when the power is turned on until the first user instruction to change the aperture setting is given.

In S1001, the system control unit 50 determines whether an operation to change the aperture value setting has been performed. If it is determined that an operation to change the aperture value setting has been performed, the system control unit 50 executes S1002, and if it is determined that an operation to change the aperture value setting has not been performed, the system control unit 50 executes S1004. Here, the operation to change the aperture value setting may be an operation of the aperture adjustment unit (e.g., aperture ring) 305 in the lens unit 300, or an operation to change the aperture value on the operation unit 70.

In S1002, the system control unit acquires a blur index corresponding to the changed aperture value (F-number or T-number). The blur index acquired here may be any of the blur indexes described in the previous embodiments.

Then, in S1003, the system control unit 50 controls the image processing unit 24 to display on the display unit 28 a blur index item 430 corresponding to the blur index acquired in S1002. The blur index acquired here may be any of the blur index items described in the previous embodiment. FIG. 9B shows a state in which the blur index item 430 of the form described in the second embodiment has been added to the live view screen 400. In the example of FIG. 9B, the display of the F-number information item 410 is inverted to emphasize on the live view screen 400 that the aperture value has been changed. In addition, the example of FIG. 9B also shows that the smoothness of the blurred image has increased because the F-number has been changed to a smaller F-number (F2.4) than in the state (F4) of FIG. 9A.

In S1004, the system control unit 50 determines whether a predetermined time (e.g., about 3 to 5 seconds; here, 4 seconds) has elapsed since detecting the change in aperture setting in S1001. The system control unit 50 can determine whether the predetermined time has elapsed, for example, by using the system timer 53. If it is determined that the predetermined time has elapsed, the system control unit 50 executes S1005, and if it is not determined that the predetermined time has elapsed, it executes S1001 again.

In S1005, the system control unit 50 hides the blur index item 430 from the display unit 28 (stops displaying the blur index item 430). FIG. 9(c) shows an example of a live view screen 400 in which it has been determined that a predetermined time has passed since the aperture value was changed, and the blur index item 430 is no longer displayed. In addition, the F-number information item 410 that was inverted in FIG. 9(b) has returned to normal display.

In S1005 to S1006, the display/hide of the blur index item is controlled based on the change in aperture value setting and the time elapsed since the setting change. However, because the blurred image also changes depending on the focal distance, the display/hide of the blur index may be controlled based on an operation that changes the focal distance and the time elapsed since the operation, similar to the change in aperture value setting. An operation that changes the focal distance may be, for example, a manual focus operation or an operation to change the focus detection area.

According to this embodiment, when the user performs an operation to change the aperture value or an operation to change the focal distance, the blur index item 430 is displayed for a certain period of time. This makes it possible to improve the visibility of the live view screen while informing the user of the smoothness of the blurred image at an appropriate time.

(Fourth embodiment)
Next, a fourth embodiment will be described. Since this embodiment may be similar to the first embodiment except for the method of presenting the blur index item 430, a description of the configuration and operation of the device common to the first embodiment will be omitted.

In the first to third embodiments, it is assumed that the lens unit 300 connected to the digital camera 100 has an APD 313 (an optical member that modulates light transmittance). However, a lens unit that does not have an APD may be connected to the digital camera 100. Therefore, in this embodiment, whether or not to display the blur index item 430 on the display unit 28 is controlled depending on whether or not the connected lens unit 300 has an optical member that modulates light transmittance.

Figure 11 is a flowchart of the lens unit discrimination operation in this embodiment. The operation shown in the flowchart in Figure 11 is realized by the system control unit 50 expanding a program recorded in the non-volatile memory 56 into the system memory 52 and executing it. This process can be executed when the digital camera 100 is turned on, or can be executed periodically when the lens unit 300 is in a detachable state.

In S1101, the system control unit 50 determines whether the lens unit 300 is connected. When S1101 is executed when the power is ON, it may be a determination as to whether the lens unit 300 is connected. The system control unit 50 can make this determination based on, for example, whether communication via the lens communication unit 92 is possible, based on the potential of the contacts of the lens connection unit 91, etc.

If the system control unit 50 determines that the lens unit 300 is connected, it executes S1102, and if it does not determine that the lens unit 300 is connected, it repeatedly executes S1101.

In S1102, the system control unit 50 acquires lens information through communication with the lens control unit 301. The lens information may include model information of the lens unit and the range in which the aperture value can be set. It may also include information such as the presence or absence of an APD and the relationship between the F-number and the T-number.

In S1103, the system control unit 50 determines whether the connected lens unit 300 is a lens unit having a transmittance modulation member such as an APD. This determination may be made based only on the lens information, or may be made based on the lens information and information previously stored in the non-volatile memory 56 (e.g., model information of the lens unit having a transmittance modulation member). If the system control unit 50 determines that the lens unit 300 is a lens unit having a transmittance modulation member, it executes S1104, and if not, it executes S1105.

In S1104, the system control unit 50 decides to display the blur index item 430. In addition, in S1105, the system control unit 50 decides not to display the blur index item 430. The system control unit 50 stores the results of the decisions in S1104 and S1105, for example, in the system memory 52, and reflects them in the subsequent display control operation of the display unit 28.

According to this embodiment, the blur index item 430 can be displayed only when a lens unit that requires display is connected. Therefore, unnecessary display does not reduce the visibility of the screen. Alternatively, the display space of the blur index item 430 can be used for other purposes.

● (Fifth embodiment)
Next, a fifth embodiment will be described. In the previous embodiment, a configuration was described in which the blur index (Δ, Δ/Δ _MAX , and normalized transmittance modulation amount) is used to control the display of the blur index item 430. However, the blur index may be used for other purposes. For example, when recording image data obtained by shooting, the blur index can be associated and recorded. For example, the system control unit 50 can record the blur index as header information or metadata of a data file that stores image data. This makes it possible to easily search for an image with a smooth blur by searching for an image data file in which the blur index has a value within a specific range, for example.

● (Sixth embodiment)
Next, a sixth embodiment will be described. In this embodiment, the configuration and operation of the device common to the first embodiment will be omitted since the present embodiment may be the same as the first embodiment except for the form and presentation method of the blur index item. In the first to fifth embodiments, an index of the smoothness of the blurred image is presented with attention to the aperture value, but the blurred image also changes depending on the focal distance (the distance of the subject to be focused on). Therefore, it is also useful for the user to present the smoothness of the blurred image in relation to the focal distance.

Figure 12(a) is a schematic diagram showing an example of a blur comparison item 700 showing the relationship between the degree of smoothness of a blurred image by APD 313 and the in-focus distance. The blur comparison item 700 has a slider item 710, multiple distance items 701-707, and multiple blur index items 711-717. Note that the positional relationship of each item is not limited to that shown in Figure 12(a). For example, the distance items 701-707 may be displayed superimposed on the slider item 710. Also, the number of distance items may be any number greater than or equal to one.

The linear slider item 710 and the multiple distance items 701-707 arranged near the slider item 710 in the longitudinal direction of the slider item 710 represent at least a portion of the distance range in which the lens unit 300 can focus. Here, since the distance items indicate numerical values, a distance unit item 708 indicating the unit of the numerical value is also displayed. The distance unit item 708 does not have to be displayed.

An indicator item 709 indicating the current focus distance is superimposed on the slider item 710. The current focus distance can be calculated by the system control unit 50 from the position information of the focus lens (front lens group 310).

The multiple blur index items 711-717 diagrammatically represent the change in the smoothness of the blurred image in the distance range represented by the slider item 710 and the distance items 701-707. Here, the distance items 701-707 and the blur index items 711-717 are displayed in association with each other, and the blur index items 711-717 indicate the smoothness of the blurred image at the focus distance represented by each of the distance items 701-707. However, the number of distance items and blur index items may differ, and the blur index items may not be displayed in association with the focus distance indicated by the distance items.

The blur index items 711 to 717 are circular images that show a schematic representation of the blurred image of a point light source for discrete focus distances, reflecting the effect of the focus distance on the blurred image and the effect of the APD 313. From the images of the blur index items 711 to 717, the user can concretely and intuitively grasp how the smoothness of the blurred image changes as the focus distance is changed.

The bokeh index items can be generated in advance for multiple discrete focus distances for each model of lens unit 300, for example, and registered in non-volatile memory 58. In this case, the system control unit 50 can refer to the non-volatile memory 58 based on the model information acquired from the lens unit 300 and acquire the bokeh index item to be used. Alternatively, the lens unit 300 can store bokeh index items in ROM 302 in association with multiple discrete focus distances. The system control unit 50 can also acquire the bokeh index items when acquiring other information from the lens unit 300.

Figure 12 (b) is a diagram showing another example of a blur comparison item. The blur index item 700' is the same as that in Figure 12 (a) except for the blur index items 801 to 807. The blur index items 801 to 807 are images that mimic the shape of the luminance gradient of a blurred image for a point light source. The closer the shape is to a rectangle, like the blur index item 807, the steeper the luminance gradient near the edge of the blurred image, i.e., the sharper the edge of the blurred image. On the other hand, the more gently sloping the left and right sides are, like the blur index item 801, the gentler the luminance gradient near the edge of the blurred image, i.e., the smoother the edge of the blurred image.

The blur index items 711 to 717 and 801 to 807 shown in Figures 12(a) and 12(b) are images that mimic the blurred image for a point light source, but the type of light source is not limited to a point light source. However, the smoothness of the blurred image can be most easily understood when a point light source is used.

Figure 12(c) is a diagram showing an example in which the blur comparison item 700 shown in Figure 12(a) is superimposed on the live view screen shown in Figure 6. The same components as in Figure 6 are given the same reference numerals, and duplicated explanations will be omitted. The system control unit 50 can superimpose the image of the blur comparison item 700 on the live view image and display it on the display unit 28, similar to the other GUI items 411 to 418. The blur comparison item 700' can also be displayed in a similar manner.

Figure 13 is a flowchart of the operation of generating a blur index item executed by the digital camera 100. The operation shown in the flowchart in Figure 13 is realized by the system control unit 50 expanding a program recorded in the non-volatile memory 56 into the system memory 52 and executing the program. This operation can be executed as part of the live view display operation in the digital camera 100.

In S1301, the system control unit 50 determines candidates for the focus distance to be displayed in the blur comparison item. Candidates for the focus distance can be determined in various ways. For example, the system control unit 50 determines, as candidates, distances at the near end and far end that correspond to a predetermined amount of movement of the focus lens, based on the current focus distance. After that, the system control unit 50 can determine, as the remaining candidates, distances that correspond to focus lens positions obtained by equally dividing the focus lens positions at the near end and far end by a predetermined number.

Alternatively, the system control unit 50 may similarly determine a candidate focus distance based on the subject distance equivalent to infinity for the lens unit 300 and the minimum shooting distance obtained through communication with the lens control unit 301.

The focal distance may be determined, for example, by taking into consideration user operation of an input device included in the operation unit 70. For example, when the user is performing an operation to change the focal distance of the lens unit 300, a candidate focal distance may be determined so that the current focal distance is always at the center.

In S1302, the system control unit 50 determines the focus distance that is to be used as the basis for the bokeh index. The reference focus distance can be determined in various ways. For example, the system control unit 50 can present selectable reference distance candidates on the display unit 28 and determine the focus distance based on the user's selection through operation of the operation unit 70. Alternatively, the system control unit 50 may determine the subject distance equivalent to infinity of the lens unit 300, or the minimum shooting distance, as the basis for the bokeh index.

In S1303, the system control unit 50 acquires information about the smoothness of the blurred image corresponding to the focal distance of the lens unit 300. The information about the smoothness of the blurred image can be acquired in various ways. For example, information (e.g., a table) that associates each of a plurality of predetermined discrete focal distances with the smoothness of the corresponding blurred image is registered in the ROM 302 of the lens unit 300. The system control unit 50 then acquires the table from the lens unit 300 through communication with the lens control unit 301 and stores it in the system memory 52. The system control unit 50 can acquire information about the smoothness of the blurred image by referring to the table in the system memory 52 based on the focal distance candidate determined in S1301. The table can be acquired when the camera 100 is started and/or when the attachment of the lens unit 300 is detected.

Instead of acquiring the entire table, the system control unit 50 may acquire information regarding the smoothness of the blurred image for the candidate focusing distance determined in S101 and the reference focusing distance determined in S1302. The lens control unit 301 may refer to the table registered in ROM 302 in response to a request from the system control unit 50, acquire information regarding the smoothness of the blurred image for the focusing distance requested by the system control unit 50 from the table, and transmit the information to the system control unit 50.

Alternatively, the above-mentioned table may be registered in the non-volatile memory 56 in association with the identification information of the lens unit 300. In this case, the system control unit 50 identifies the table by referring to the non-volatile memory 56 using the identification information of the attached lens unit 300. The system control unit 50 can then refer to the table in the system memory 52 based on the focal distance candidate determined in S1301, and obtain information regarding the smoothness of the blurred image.

The system control unit 50 may associate the unique information of the lens unit 300 acquired from the lens unit 300, such as information associated with the smoothness of the blurred image, with the identification information of the lens unit and store it in the non-volatile memory 56. This eliminates the need to acquire the unique information again from the lens unit 300 when the same lens unit is reconnected.

The information about the smoothness of the blurred image may be, for example, the coefficients of a three-dimensional function representing the shape of the smoothness, the sample values of a curve representing the shape of the smoothness, the coefficients of a nonlinear function, or a one-dimensional index. The type and expression of the function may be determined in advance.

Based on the information acquired in S1303, the system control unit 50 causes the image processing unit 24 to generate an image of the blur comparison item 700 or 700'. The system control unit 50 then stores the image generated by the image processing unit 24 in the VRAM area of the memory 32, similar to images of other shooting auxiliary information, and displays it superimposed on the live view image.

In this manner, in this embodiment, an index showing the smoothness of the blurred image in the captured image obtained under the current shooting conditions is presented for a number of different focus distances. This allows the user to easily grasp the smoothness of the blurred image, which changes depending on the distance of the subject to be focused on, before shooting. This allows the user to change the focus distance so that the desired blurred image is obtained.

(Seventh embodiment)
Next, a seventh embodiment will be described. As shown in FIG. 4B, the bokeh effect by the transmittance modulation member becomes large when the aperture value is open and in a range close to the open aperture. On the other hand, when the aperture value is open and in a range close to the open aperture, the depth of field becomes shallow. Therefore, by changing the aperture value to the open aperture side, the desired subject may be out of the depth of field, and in such a case, the focal distance must be readjusted. Furthermore, when the aperture value is changed to the open aperture side, the amount of incident light also increases, so in order to maintain the same exposure amount as before the change, it is necessary to change other shooting conditions such as the shutter speed and sensitivity.

However, because of the presence of the transmittance modulation member, the change (number of stops) in the aperture value does not immediately translate into changes in other shooting conditions. Therefore, when changing the aperture value, it is difficult to grasp the amount of correction required for other shooting conditions to maintain the exposure amount before the change.

As such, even if a user wants to check the bokeh effect when the aperture value is changed, it is not easy to check the bokeh effect because there are factors to adjust other than the aperture value. In this embodiment, it is possible to easily check the bokeh effect when the aperture value is changed. In this embodiment, other than the form and presentation method of the bokeh index item, the present embodiment may be similar to the first embodiment, so a description of the configuration and operation of the device common to the first embodiment will be omitted.

Figure 14 is a flowchart of the operation of generating and presenting a blur index executed by the system control unit 50 in this embodiment. The operation shown in the flowchart in Figure 14 is realized by the system control unit 50 expanding a program recorded in the non-volatile memory 56 into the system memory 52 and executing it. This operation can be executed as part of the live view display operation in the digital camera 100.

In S1401, the system control unit 50 generates a distance map. The distance map is also called a distance image or a depth map, and has the form of a two-dimensional image in which the value of each pixel represents distance information. The distance map can be generated by any known method, and this embodiment does not depend on the method of generating the distance map. For example, if the image sensor of the image capture unit 22 has a configuration capable of generating a pair of parallax images in one shooting, the subject distance at each pixel can be obtained based on the shift amount of corresponding pixels in the parallax images. The subject distance at each pixel may also be obtained based on the focus lens position at which the contrast of each pixel is maximized. Alternatively, a ToF distance sensor may be used. The distance map may be generated by the image processing unit 24 under the control of the system control unit 50.

In S1402, the system control unit 50 acquires information on the focus lens position and information on the focal length of the lens unit 300 from the lens control unit 301. The system control unit 50 then calculates the current focal length of the lens unit 300 based on the acquired information.

In S1403, the system control unit 50 calculates the defocus amount at each pixel from the calculated focus distance and the distance map generated in S1401. As a result, the system control unit 50 generates a defocus map in which the value of each pixel indicates the defocus amount. Note that in this embodiment, the defocus map is generated from the distance map and the current focus distance, but the defocus map may be generated by other methods. For example, if each pixel of the image sensor of the imaging unit 22 has a configuration in which it also serves as a phase difference detection pixel, the defocus amount at each pixel position can be directly obtained. In this case, it is not necessary to generate a distance map or calculate the current focus distance.

When changing from an aperture value that produces a small bokeh effect by APD313 (e.g., around F4.0) to an aperture value that produces a large bokeh effect (e.g., maximum aperture F2.2), the depth of field becomes shallower, and the amount of defocus increases for pixels outside the depth of field.

When the defocus amount increases, the image spreads. This image spread depends on the image intensity and the magnitude of the defocus amount, but can generally be determined by the point spread function (PSF). Therefore, even without driving the aperture 312 to change the aperture value, it is possible to generate a blur effect image that simulates how the change in defocus amount when the aperture value is changed affects the image of each pixel.

Note that a known PSF can be used in the simulation. Examples of known PSFs include a PSF that is approximated by a two-dimensional Gaussian function defined in an ideal optical system, a PSF that uses a Fourier transform that takes into account the aberration of the optical system, and a PSF that takes into account the effect of diffraction on the image using Huygens' principle.

In S1404, the system control unit 50 generates a bokeh effect image. FIG. 15(a) is a schematic diagram showing an example of the spread of a point light source at an aperture value with a small bokeh effect (e.g., about F4.0). FIG. 15(b) is a schematic diagram showing the results of simulating the spread of an image when the aperture value is changed to one with a large bokeh effect (e.g., open aperture F2.2), using the image shown in FIG. 15(a) and the PSF.

In this embodiment, APD313 provides the effect of smoothing the contours of the blurred image, so that a blurred image is obtained by applying the effect of ADP313 to the image shown in FIG. 15(b). The effect of ADP313 is produced by the relationship between pupil radius and transmittance shown in FIG. 4(a). Therefore, based on the relationship between pupil radius and transmittance shown in FIG. 4(a), the image shown in FIG. 15(c) can be obtained by applying the effect of APD313 to the image in FIG. 15(b).

The relationship between the pupil radius and transmittance of the APD 313 can be stored in the ROM 302 of the lens unit 300. The relationship between the pupil radius and transmittance may be stored as a function, or combinations of pupil radius and transmittance may be stored for a number of discrete pupil radii. The system control unit 50 acquires information about the relationship between the pupil radius and transmittance of the APD 313 through communication with the lens control unit 301, and stores the information in the system memory 52.

The system control unit 50 causes the image processing unit 24 to apply the SPF to each pixel of the live view image, for example, and then apply the effect of the APD 313 to generate a bokeh effect image that corresponds to the changed aperture value.

In S1405, the system control unit 50 generates a bokeh effect item. For example, the system control unit 50 extracts a difference image between the bokeh effect image generated in S1404 and the original image of the bokeh effect image. This difference image corresponds to the area that changes due to the change in aperture value. Therefore, the system control unit 50 generates a bokeh comparison item based on the difference image. For example, the system control unit 50 may convert the difference image into a specific color to create the bokeh comparison item.

Figure 16(a) shows an example in which the difference image between the original image and the bokeh effect image is converted into a specific color and displayed as a bokeh effect item superimposed on the original image. Figure 16(a) shows an example in which a bokeh effect image is generated at the widest aperture, which maximizes the bokeh effect, and a difference image with the original image is generated.

Figure 16 (b) is a diagram showing an example in which a frame-shaped indicator surrounding the corresponding area is generated as a bokeh effect item and superimposed as an indicator for emphasizing the difference area between the original image and the bokeh effect image. The difference area from the original image may be an area showing the difference in size of the bokeh image, or an area where the difference in pixel value is equal to or greater than a threshold. Furthermore, the frame-shaped bokeh effect item may be displayed only for the difference area where the difference in size or value is the largest, or for all difference areas where the degree of difference is equal to or greater than a certain level. Furthermore, the display form of the bokeh effect item may be changed depending on the degree of difference. Furthermore, the display form is not limited to the method shown in the figure.

Since the magnitude and fineness of the bokeh effect largely depends on the subject and the area, as shown in FIG. 16, the area in which the bokeh effect is to be confirmed may be specified by a touch operation on the display unit 28 by the user. In this case, the system control unit 50 may generate a bokeh effect image for the entire live view image, or may generate a bokeh effect image for only the specified area.

When the bokeh effect image is generated only for a specified area, the bokeh effect image may be enlarged and displayed as shown in FIG. 16. It is also effective to configure the system so that the user can specify the aperture value when generating the bokeh effect image, so that the bokeh effect resulting from changing the aperture value can be confirmed in detail and easily. The example in FIG. 16 shows an example in which the aperture value can be changed continuously by sliding the display unit 28 after the area is specified. This allows the user to easily specify the aperture value required to obtain the desired bokeh effect.

In the above example, a configuration was described in which an SPF is applied and then an APD effect is applied. However, because the original image is affected by the APD, a certain degree of blurring effect can be obtained by applying the SPF. Therefore, it is not essential to apply an APD effect after applying the SPF.

As described above, in the seventh embodiment, a bokeh effect image showing the bokeh effect obtained when the aperture value is changed is generated using the point spread function and the characteristics of the APD, and bokeh effect items based on the bokeh effect image are presented. Therefore, it is possible to accurately check the bokeh effect obtained at the changed aperture value without actually changing the aperture value.

Other Embodiments
In the above-mentioned first to fifth embodiments, the blur index is calculated using the difference or deviation Δ between the T value for the same F value when there is an APD and when there is no APD. However, the blur index may be calculated using the difference or deviation between the F value and the T value corresponding to the F value when there is no APD. This is because the difference between the F value when there is no APD and the T value corresponding to the F value does not depend on the F value. In other words, when there is an APD, the difference between a certain F value and the T value corresponding to that F value is the sum of the difference that exists even when there is no APD and the difference caused by the presence of the APD. Since the difference that exists even when there is no APD does not depend on the F value, when there is an APD, the change in the difference between a certain F value and the T value corresponding to that F value reflects the change in the difference caused by the presence of the APD. Therefore, even if the maximum value of the difference between the F value and the corresponding T value is used as Δ _MAX and the difference between the current F value and the corresponding T value is used as Δ, a value that can be used as the blur index can be obtained.

Note that the operations described in this specification as being performed by the system control unit 50 may be realized by a single piece of hardware, or may be realized by sharing the processing among multiple pieces of hardware.

Although the present invention has been described in detail based on exemplary embodiments, the present invention is not limited to these specific embodiments, and various forms that do not deviate from the gist of the invention are also included in the present invention. Furthermore, the above-mentioned embodiments can be combined as appropriate to the extent that there are no inhibiting factors.

In the above-mentioned embodiment, the present invention has been described as being applied to a digital camera. However, the present invention can be implemented in any electronic device capable of acquiring information about a photographing lens. Such electronic devices include electronic devices equipped with an imaging device and electronic devices serving as external devices capable of communicating with an imaging device. Such electronic devices include personal computers, personal digital assistants (PDAs), mobile phone terminals, media players, printer devices equipped with displays, digital photo frames, and game consoles. The present invention can also be implemented in electronic book readers, tablet terminals, projection devices, home appliance devices equipped with displays, and in-vehicle devices.

The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that realizes one or more of the functions.

The present invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, the following claims are appended to clarify the scope of the invention.

24: image processing unit, 28: display unit, 50: system control unit, 100: digital camera, 300: lens unit, 301: lens control unit

Claims (16)

A setting means capable of setting at least one of the F value and the T value;
an acquisition means for acquiring information regarding the amount of blur that changes based on the setting value set by the setting means;
When a predetermined lens having a transmittance modulation member is connected to the camera, the amount of blur acquired by the acquisition means is displayed based on the setting value set by the setting means;
and a control means for controlling so as not to display the amount of blur when the specified lens is not connected to the camera. The display control device according to claim 1, characterized in that the acquisition means is capable of acquiring a table showing the correspondence between F values and T values. The display control device according to claim 2, characterized in that the table is changed according to the focal distance. The display control device according to claim 1, characterized in that the acquisition means acquires the difference between the F-number and T-number at the current setting value, or the ratio of the difference to the maximum value of the difference, as information regarding the amount of blur. the predetermined lens has an optical member that modulates light transmittance,
The display control device according to claim 1 , wherein the acquisition means acquires information regarding the amount of blur based on a difference in T value between when the optical member is present and when the optical member is not present, corresponding to a current F value. The display control device according to claim 5, characterized in that the acquisition means acquires the difference in T values as information relating to the amount of blur, or acquires the ratio of the difference in T values to the maximum value of the difference in T values as information relating to the amount of blur. the predetermined lens has an optical member that modulates light transmittance,
The display control device according to claim 1, characterized in that the acquisition means acquires a value obtained by normalizing the light transmittance of the optical member corresponding to the current F-number by the maximum value of the light transmittance of the optical member corresponding to the minimum F-number of the specified lens as information regarding the amount of blur. The display control device according to claim 1 or 7, characterized in that the control means displays a numerical value acquired as information relating to the amount of blur as the amount of blur. The display control device according to claim 1 or 7, characterized in that the control means displays, as the amount of blur, an item that represents a category according to a numerical value acquired as information related to the amount of blur. The display control device according to any one of claims 1 and 7 to 9, characterized in that the control means displays the amount of blur until a predetermined time has elapsed since the lens aperture setting was changed, and stops displaying the amount of blur when the predetermined time has elapsed. The display control device according to any one of claims 1 and 7 to 9, characterized in that the control means displays the amount of blur until a predetermined time has elapsed since the setting of the focal distance of the lens has been changed, and stops displaying the amount of blur when the predetermined time has elapsed. The display control device according to any one of claims 1 and 7 to 10, further comprising a recording means for recording information indicating information on the amount of blur corresponding to the F-number at the time of capturing the image, in association with image data obtained by capturing the image. The display control device according to any one of claims 1 and 7 to 11, characterized in that the control means displays the amount of blur on a live view screen. A control method executed by a display control device, comprising:
Obtaining a setting value for either the F value or the T value;
acquiring information regarding the amount of blur that changes based on the setting value;
A control method for a display control device, comprising: when a specified lens having a transmittance modulation member is connected to a camera, displaying the amount of bokeh based on the set value; and when the specified lens is not connected to the camera, controlling so as not to display the amount of bokeh. A program for causing a computer to function as each of the means included in the display control device according to any one of claims 1 to 13 . A computer-readable storage medium storing a program for causing a computer to function as each of the means included in the display control device according to any one of claims 1 to 13 .

Images