Imaging device and control method thereof

Abstract

To provide an imaging apparatus capable of smooth LV display while suppressing deterioration of visibility even if LV images cannot be photographed by still image photographing.SOLUTION: When an instruction to photograph a still image is detected while live-view display is being executed, the imaging apparatus causes an image element to give priority to photographing a still image. In addition, the imaging apparatus repeatedly displays the same image for a period when the live-view display cannot be updated due to the photographing of a still image. In this case, the imaging apparatus reduces the brightness of the image to be repeatedly displayed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an imaging apparatus and a control method thereof. [Background technology]

[0002] Some imaging devices using an imaging element have a live view (hereinafter referred to as LV) display function. The live view display function allows the user to check the current shooting range by performing shooting and display at high speed and continuously. The LV display is performed on a display device provided on the back of the housing of the imaging device or in the viewfinder. The image used for LV display (LV image) has a different resolution (number of pixels) from a still image for recording. Therefore, the drive control (also called drive mode) of the imaging element differs between shooting a video for display (LV image) and shooting a still image for recording. Hereinafter, for convenience, the drive mode when shooting an image for LV is called the video mode, and the drive control when shooting a still image for recording is called the still image mode. A switching operation is required to switch between the video mode and the still image mode.

[0003] For example, consider a case where LV display is performed for still image shooting in a configuration where LV images and recording images are shot with the same image sensor. It is desirable to have a constant update interval for the LV image, but depending on the timing of starting shooting the still image and the exposure time, the still image drive period may overlap with the planned display drive period.

[0004] When still image shooting is prioritized and LV image shooting is skipped, the LV image shot immediately before is repeatedly displayed, or a black image is displayed instead of the LV image (blackout). Patent Document 1 proposes that in a configuration in which a black image is displayed outside the LV display period, the display luminance of the LV image is made higher than normal to improve the perceived darkness of the LV image displayed between black images. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-006827 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a configuration in which a black image is displayed when an LV image cannot be captured, the luminance difference between the black image and the LV image is large, which reduces visibility and makes the eyes more tired. This problem becomes even more serious when the LV image is displayed at a luminance higher than normal as in Patent Document 1. Furthermore, when past LV images are repeatedly displayed instead of a black image, the movement of a moving subject in the LV display becomes unnatural.

[0007] The present invention has been made to alleviate such problems of the conventional technology, and aims to provide an imaging device and a control method thereof that are capable of smooth LV display while suppressing a decrease in visibility even when LV images cannot be captured by still image capture. [Means for solving the problem]

[0008] The above object is to provide a camera having an image sensor, and a control means that, when an instruction to shoot a still image is detected while live view display is being performed by shooting a moving image by the image sensor and displaying the moving image obtained by shooting, causes the image sensor to prioritize shooting of a still image, and controls the image sensor to repeatedly display the same image during a period in which the live view display cannot be updated due to shooting of the still image, and the control means: Based on the length of exposure time for still photography, Reduce the brightness of images that are displayed repeatedly, The control means determines the amount of reduction in luminance such that the amount of reduction in luminance increases as the length of the exposure time in capturing a still image increases. The object is achieved by an imaging device comprising: Effect of the Invention

[0009] According to the present invention, it is possible to provide an imaging device and a control method thereof that are capable of providing a smooth LV display while suppressing a decrease in visibility even when an LV image cannot be captured by still image capture. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of a functional configuration of an imaging apparatus according to an embodiment; [Diagram 2] 1 is a timing chart showing the operation of capturing a still image during video capture in the first embodiment; [Diagram 3] 1 is a flowchart showing the brightness adjustment operation of an LV image in the first embodiment; [Figure 4] Flowchart for brightness adjustment operation of LV image in the second embodiment [Diagram 5] Flowchart for brightness adjustment operation of LV image in the third embodiment [Figure 6] FIG. 11 is a block diagram showing another example of the functional configuration of an imaging apparatus according to an embodiment; [Figure 7] Flowchart for adjusting an LV image in the fourth embodiment [Figure 8] Flowchart for adjusting an LV image in the fifth embodiment [Figure 9] Flowchart for adjusting an LV image in the sixth embodiment [Figure 10] Flowchart for adjusting an LV image in the seventh embodiment [Figure 11] Flowchart for adjusting an LV image in the eighth embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below based on its exemplary embodiments with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. In addition, although multiple features are described in the embodiments, not all of them are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numbers are used for the same or similar configurations, and duplicated explanations are omitted.

[0012] In the following embodiments, an example in which the present invention is applied to an imaging device such as a digital camera will be described. However, the present invention can be applied to any electronic device having an imaging function capable of capturing still images while capturing video using one imaging sensor. Such electronic devices include video cameras, computer devices (personal computers, tablet computers, media players, PDAs, etc.), mobile phones, smartphones, game consoles, robots, drones, and drive recorders. These are merely examples, and the present invention can be applied to other electronic devices.

[0013] ●(First embodiment) FIG. 1 is a block diagram showing an example of the functional configuration of a digital camera 1 as an example of an imaging device according to the present invention. The image sensor 100 is, for example, a CCD image sensor or a CMOS image sensor, and has an array of pixels each having a photoelectric conversion unit. The image sensor 100 converts an optical image formed on an imaging surface by an imaging lens 120 into an electrical signal using a plurality of pixels, and generates image data consisting of a plurality of pixel data. The image data generated by the image sensor 100 is written into a temporary storage unit (buffer memory) 107 via a data transfer unit 105.

[0014] The image processing unit 101 applies predetermined image processing to the video data and still image data to generate image data for display or recording (live view image data, still image data for recording and display). The image processing unit 101 applies various image processing to the image data stored in the temporary storage unit 107. Image processing applied to image data when capturing still images includes pre-processing, color interpolation processing, correction processing, data processing, and the like. Pre-processing includes noise reduction, signal amplification, reference level adjustment, defective pixel correction, and the like. Color interpolation processing is processing for interpolating values ​​of color components not included in image data read from pixels, and is also called demosaic processing. Correction processing includes white balance adjustment, processing for correcting the luminance of an image, processing for correcting aberrations of the optical system of the imaging lens 120, processing for correcting colors, and the like. Data processing includes scaling processing, encoding and decoding processing, header information generation processing, and the like. Note that these are examples of image processing that can be performed when capturing still images, and do not limit the image processing performed by the image processing unit 101. The image processing unit 101 writes the generated image data into the temporary storage unit 107. When the LV image data is generated, the image processing unit 101 outputs the data to the display unit 102 via the data transfer unit 105.

[0015] The image processing unit 101 may apply detection processing and evaluation value calculation processing to the generated LV image data. The detection processing is detection of characteristic regions (for example, face regions and human body regions) and their movements, person recognition processing, etc. The evaluation value calculation processing is processing for calculating evaluation values ​​used in the operation of the control unit 104, such as a pair of image signals for phase difference AF (autofocus detection), an evaluation value for contrast AF, and an evaluation value used for automatic exposure control (AE). Note that these are examples of image processing that the image processing unit 101 can perform, and do not limit the image processing performed by the image processing unit 101.

[0016] The display unit 102 receives the LV image data from the temporary storage unit 107 via the data transfer unit 105. The display unit 102 applies processing to the LV image data as necessary for display on the display device 103. Processing includes, for example, edge processing (such as letterbox processing) when the aspect ratio of the display screen of the display device differs from that of the LV image. Processing also includes synthesis of auxiliary information such as shooting time, synthesis of GUI images such as OSD images, and signal format conversion.

[0017] The display unit 102 outputs the LV image data, to which necessary processing has been applied, to the display device 103. The display device 103 is, for example, an LCD (Liquid Crystal Display) or an OLED (Organic Light Emitting Diode) display. The display device 103, which displays the LV image data (moving image data), functions as an electronic viewfinder (EVF).

[0018] The photographing instruction unit 111 is an input member that allows the user to give instructions for photographing a still image to the digital camera 1. The photographing instruction unit 111 may be a release button provided on the digital camera 1, or may be another input member such as a remote control. User instructions given through the photographing instruction unit 111 are detected by the control unit 104.

[0019] The control unit 104 has a CPU, and for example, reads a program stored in a ROM 113 into a RAM 112 and executes it. Note that a programmable processor, such as an FPGA (field-programmable gate array), may be used instead of the CPU. The control unit 104 realizes the functions of the digital camera 1 by controlling the operation of each functional block. The ROM 113 is, for example, a rewritable non-volatile memory, and stores programs executable by the CPU of the control unit 104, setting values, GUI data, and the like. The RAM 112 is used to read the programs executed by the CPU of the control unit 104 and to store values ​​required during the execution of the programs. The control unit 104 also mainly controls the read operation from the image sensor 100, which will be described later. The control unit 104 also includes a system timer, and measures the time used for various controls and the time of a built-in clock.

[0020] The data transfer unit 105 is composed of, for example, a plurality of DMA (Direct Memory Access) controllers (DMAC). Various image data are temporarily stored in a temporary storage unit 107 by the DMAC via a bus 106. In addition, the image data stored in the temporary storage unit 107 is read out to the bus 106 by the DMAC and supplied to each unit connected to the data transfer unit 105.

[0021] Furthermore, the data transfer unit 105 generates a vertical synchronization signal (imaging display V synchronization signal) 110 used by the image sensor 100 to capture and read moving image data (here, LV image data for display), and supplies it to the image sensor 100. For example, when the frame rate of the moving image is 60 frames / second, the data transfer unit 105 generates an imaging display V synchronization signal with a cycle of 1 / 60 seconds.

[0022] When an instruction to shoot a still image is detected during shooting of a moving image, the control unit 104 temporarily stops the generation of an imaging display V synchronization signal by the data transfer unit 105, and then switches the read mode of the image sensor 100 from a moving image read mode to a still image read mode. The control unit 104 then generates a synchronization signal (still image synchronization signal) according to the timing of shooting the still image and supplies it to the image sensor 100.

[0023] When shooting of one frame of still image is completed, the control unit 104 switches the read mode of the image sensor 100 from the still image read mode to the moving image read mode. Then, the control unit 104 causes the data transfer unit 105 to resume generating the image display V synchronization signal 110.

[0024] The bus 106 includes, for example, an independent system bus and a data bus. The functional blocks connected to the bus 106 are capable of bidirectional communication. The temporary storage unit 107 is composed of a memory control unit and a memory, and writes data to the memory or reads and outputs data from the memory in response to instructions from the control unit 104 or the data transfer unit 105. The temporary storage unit 107 is also used as a buffer for video data and still image data.

[0025] The recording unit 108 records the still image data and video data for recording generated by the image processing unit 101 on a recording medium such as a memory card under the control of the control unit 104. The recording unit 108 also reads and outputs the image data recorded on the recording medium under the control of the control unit 104. The control unit 104 stores the read image data in the temporary storage unit 107.

[0026] When the digital camera of this embodiment is started up by the power switch, it enters a shooting standby state. In the shooting standby state, the control unit 104 continuously executes LV display and waits for an instruction to shoot a still image or a video to be input through the operation unit 109. In the shooting standby state, the control unit 104 can execute exposure control and focus adjustment based on an evaluation value obtained from the image processing unit 101. When an instruction to shoot a still image is input in the shooting standby state, the control unit 104 starts shooting processing of the still image. Data of the still image obtained by shooting is stored in the temporary storage unit 107 after processing by the image processing unit 101.

[0027] Furthermore, the control unit 104 recognizes the continuous input of the instruction to shoot still images as an instruction to shoot continuous still images, and executes the shooting process of still images repeatedly until the input of the shooting instruction is finished or the number of continuous shots reaches a predetermined upper limit. Note that the continuous input of the instruction to shoot still images may be recognized as the shooting process of continuous still images only when the continuous shooting mode is set by the mode selection dial.

[0028] When the input of the instruction to shoot a still image is finished, the control unit 104 records the still image data stored in the temporary storage unit 107 in a data file of a predetermined format on a memory card or the recording unit 108. The time from when the instruction to shoot a still image is input in the shooting standby state until the still image shooting actually starts is called the release time (or release time lag). Moreover, the control unit 104 calls the interval between two consecutive shooting timings when shooting still images continuously the continuous shooting interval.

[0029] 2 is a timing chart showing the operation of continuous still image shooting and live view display (LV display) in the digital camera of this embodiment, with time proceeding to the right. The exposure time during still image shooting is different between FIG. 2(a) and FIG. 2(b).

[0030] Fig. 2 is a diagram showing a schematic diagram of timing control of shooting and display operations when shooting still images while performing live view display (moving image display). The horizontal axis is the time axis, and time progresses from left to right in the drawing. Here, the case of continuous shooting in which instructions to shoot still images are input continuously is shown.

[0031] The imaging display V sync (signal) indicates the output timing of a vertical synchronization signal that indicates the timing to start exposure and data readout of an LV image from the imaging element 100. As described above, the vertical synchronization signal is output at a period corresponding to the frame rate of the LV image (moving image).

[0032] The still image synchronization (signal) is a signal indicating the timing at which still image data is read out by the image sensor 100. The control unit 104 generates a still image synchronization signal at a predetermined timing while an instruction to shoot a still image is being input from the shooting instruction unit 111. In this embodiment, when an instruction to shoot a still image is detected for the first time, the control unit 104 outputs a still image synchronization signal after a certain time (release time) T0. Thereafter, if instructions to shoot still images are continuously input, the control unit 104 outputs a still image synchronization signal at a predetermined continuous shooting interval T1.

[0033] The sensor output image indicates a period during which imaging and image data (LV image data, still image data) are captured in the imaging element 100, and a period during which LV image (moving image) readout and still image readout are switched over (readout mode switching period). Display 1 to display 9 indicate the LV image imaging and readout period (moving image drive period or first drive period), and still image 1 to still image 2 indicate the still image imaging and readout period (still image drive period or second drive period). Also, 201 and 202 indicate the drive mode switching period of the imaging element 100. 201 indicates the switching period from the drive mode for acquiring LV images (moving image) (moving image mode) to the drive mode for acquiring still images (still image mode), and 202 indicates the switching period from the still image mode to the moving image mode. The drive mode of the imaging element 100 is switched by, for example, the control unit 104 changing the settings of the imaging element 100.

[0034] The LV image, which is a moving image for display, and the still image for recording have different resolutions and exposure times. In particular, the resolution of the LV image is lower than that of the still image data, so the amount of image data to be read out is small. Also, in the example of FIG. 2, the exposure time T2 of the still image is longer than the exposure time of the moving image. Therefore, the moving image drive period is shorter than the still image drive period. Note that, among displays 1 to 9, the moving image drive periods shown in displays 5 and 8 are marked with diagonal lines because LV image data is not actually read out during these periods.

[0035] Image processing indicates the image processing period in image processing unit 101. Indications 1, 2, 3, 4, 6, 7, and 9 and still images 1 and 2 indicate sensor output images to be processed. The image processing period is the period from when image data read from image sensor 100 is supplied to image processing unit 101 via temporary storage unit 107 to when the image data is stored again in temporary storage unit 107 after image processing.

[0036] For LV images, supply to the image processing unit 101 is started before all image data for one screen is stored in the temporary storage unit 107. On the other hand, for still images, supply to the image processing unit 101 is started after all still image data for one screen read from the imaging element 100 is stored in the temporary storage unit 107. However, this is not essential, and similarly to the LV images, the storage operation from the imaging element 100 to the temporary storage unit 107 and the supply operation from the temporary storage unit 107 to the image processing unit 101 may be performed in parallel. Note that the data transfer unit 105 supplies only the image data stored in the temporary storage unit 107 to the image processing unit 101. There is no image data supplied to the image processing unit 101 without being stored in the temporary storage unit 107.

[0037] The display V sync is a vertical synchronization signal for the display device 103. By shortening the delay of the display V sync with respect to the imaging display V sync, the real-time performance of the LV display is improved.

[0038] The display indicates the display period and the image displayed on the display device 103. Note that the reason why display 4 and display 7 are each output for two consecutive frames is because LV image data corresponding to displays 5 and 8 is not generated.

[0039] Next, FIG. 2(b) will be described. Whereas in FIG. 2(a) the exposure time T2 of the still image falls within one cycle of the capture-display V sync and display V sync, in FIG. 2(b) it is longer, spanning two cycles. Due to the effect of the longer exposure time T2 of the still image, the image processing period of still image 1 is delayed from 203 to 213. As a result, in FIG. 2(b), display 6 cannot be displayed, and three frames of display 4 are displayed consecutively. In this way, the number of consecutive display frames of the LV image changes depending on the exposure time of the still image.

[0040] 2 shows an example in which the exposure time T2 of the still image falls within one period of the image capture display V synchronization and the display V synchronization, and a case in which it spans two periods. However, if the exposure time T2 of the still image becomes longer, the number of consecutively displayed frames of the LV image increases to four or more.

[0041] Fig. 3 is a flowchart related to the luminance adjustment operation when the same LV image is displayed for two or more consecutive frames. The luminance adjustment of the LV image may be performed when the LV image is generated by the image processing unit 101, or may be performed when the LV image is processed by the display unit 102. The operation shown in Fig. 3 is executed by the control unit 104.

[0042] 3A is a flowchart showing an operation of adjusting the brightness of an LV image to be repeatedly displayed during a period when the LV display cannot be updated. The control unit 104 repeatedly executes this operation, for example, every time a still image capturing operation is started.

[0043] In S301, the control unit 104 determines whether or not the LV image can be updated. For example, the control unit 104 may determine that the LV image can be updated if the image processing in the image processing unit 101 or the processing in the display unit 102 has been completed to a predetermined stage for an LV image captured after the currently displayed LV image. Alternatively, the control unit 104 may determine that the LV image cannot be updated if the exposure period for still image capture or the image processing period for still image data overlaps with the timing of the next display V synchronization. There is no particular limit to the determination method, and any other method may be adopted. If the control unit 104 determines that a newer LV image than the currently displayed LV image can be displayed, the process proceeds to S302, and if not, the process proceeds to S303.

[0044] In S302, the control unit 104 causes a new LV image to be displayed on the display device 103 via the display unit 102. This is similar to the LV image update process in the shooting standby state. In this embodiment, the control unit 104 determines that still image shooting (for one frame) has ended when the LV image is ready to be updated after still image shooting has started, and ends the brightness adjustment operation of the LV image. However, it may also be determined that still image shooting (for one frame) has ended based on other conditions, such as completion of reading of still image data from the image sensor 100.

[0045] In S303, the control unit 104 adjusts the luminance of the LV images to be displayed continuously. In this embodiment, the luminance of the same LV image is not adjusted for the first display, and the luminance of the same LV image is lower for the second and subsequent displays. For example, the luminance is adjusted by multiplying the pixel values ​​(RGB values ​​or luminance values) of the original image (LV image whose luminance has not been adjusted) by a predetermined Gain (for example, a coefficient equal to or greater than a lower limit value less than 1 and greater than 0). As described above, the luminance may be adjusted by the image processing unit 101 or the display unit 102. For example, when the original image data (the most recent LV image data) is held in the display unit 102, or when the image data after the image processing unit 101 provides the processing is held in the temporary storage unit 107, the luminance adjustment may be performed by the display unit 102. The control unit 104 instructs the image processing unit 101 or the display unit 102 to perform luminance adjustment (reduction) for the LV image to be displayed next. The gain value may be specified by the control unit 104, or may be held or determined by the image processing unit 101 or the display unit 102.

[0046] In S304, the control unit 104 controls the display unit 102 so that the luminance-adjusted LV image is displayed from the next display V synchronization. Then, the control unit 104 returns the process to S301, and repeatedly executes the processes of S303 and S304 until it is determined that the LV image can be updated. Note that in the example of FIG. 3(a), the amount of reduction in luminance with respect to the original image is constant regardless of the number of consecutively displayed frames. Therefore, when luminance-adjusted LV image data is already present, such as when the most recent LV image data is held in the display unit 102, the process of S303 may be skipped.

[0047] On the other hand, Fig. 3(b) to Fig. 3(d) show an example in which the gain applied to the original image is dynamically changed. The control unit 104 can execute any one of the operations shown in Fig. 3(b) to Fig. 3(d) instead of the operation of S303 in Fig. 3(a).

[0048] In S311 of Fig. 3(b), the control unit 104 acquires the number of frames (number of times) N (N ≥ 1) during which the LV image cannot be updated due to still image shooting and the most recent LV image is continuously displayed. Here, the second display corresponds to N = 1. The control unit 104 can acquire N as the number of display V synchronizations since the start of still image shooting, for example, but it may also be acquired by other methods.

[0049] In S312, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-An×N. An is a fixed coefficient, and for example, the value of An can be determined based on a predetermined maximum number of N so that the value of Gain is equal to or greater than the lower limit and less than 1. Alternatively, when the actual value of An×N exceeds 1, the maximum value less than 1 may be set. The larger N is, the smaller the value of Gain is (the greater the amount of reduction in brightness). Therefore, the more the number of times the same LV image is continuously displayed, the darker the image is adjusted to be darker than the original image. The lower limit of Gain may be any value greater than 0, and may be, for example, about 0.2 to 0.3. The lower limit can be determined experimentally in advance.

[0050] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0051] 3(c), the control unit 104 acquires a period Tc [msec] during which the LV image cannot be updated due to still image shooting and the most recent LV image is continuously displayed. The control unit 104 can acquire the period Tc by, for example, measuring the elapsed time from the first display V synchronization that occurs after the start of still image shooting, but may acquire the period Tc by other methods.

[0052] In S322, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-Ac×Tc. Ac is a fixed coefficient, and for example, the value of Ac can be determined based on a predetermined maximum number of Tc so that the value of Gain is equal to or greater than a lower limit and less than 1. Alternatively, when the actual value of Ac×Tc exceeds 1, the maximum value less than 1 may be set. The longer (larger) Tc is, the smaller the Gain value becomes (the amount of reduction in brightness becomes greater). Therefore, the longer the time during which the LV image cannot be updated due to still image shooting, the darker the brightness is adjusted to be than the original image.

[0053] In S323, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0054] 3D, the control unit 104 acquires the exposure time Ts [sec] for still image shooting. The control unit 104 can acquire the exposure time Ts by, for example, measuring the time from the start of exposure, but may acquire it by other methods.

[0055] In S332, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-As×Ts. As is a fixed coefficient, and for example, the value of As can be determined based on a predetermined maximum number of Ts so that the value of Gain is equal to or greater than the lower limit and less than 1. Alternatively, when the actual value of As×Ts exceeds 1, the maximum value less than 1 may be set. Also, when 1-As×Ts is below the lower limit of Gain, Gain is set to the lower limit. The longer the exposure time Ts, the smaller the value of Gain becomes (the greater the amount of reduction in luminance). Therefore, the longer the exposure time Ts for still image shooting, the darker the image is than the original image, and luminance adjustment is performed.

[0056] In S323, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0057] The Gain value in the operations described in Fig. 3(b) to Fig. 3(d) may be fixed for the period from the start to the end of still image capture for one frame. In this case, in S311 in Fig. 3(b) and S321 in Fig. 3(c), the control unit 104 can obtain N and Tc based on, for example, the exposure time for still image capture, the expected image processing period, the timing of display V synchronization, and the display cycle. In addition, in S331 in Fig. 3(d), the exposure time Ts obtained as the reciprocal of the shutter speed determined as the exposure condition may be used.

[0058] As described with reference to FIG. 3, the digital camera of this embodiment repeatedly displays the most recent LV image instead of a black image during the period when the LV display cannot be updated due to still image shooting. Therefore, there is no large change in luminance of the LV image as occurs when a black image is displayed. Furthermore, by lowering the luminance of the repeatedly displayed LV image from its original luminance, the difference in the state of the moving subject when the LV image is next updated becomes less noticeable. Therefore, it is possible to improve the visibility of the LV display when updating of the LV image is stopped or when updating is resumed.

[0059] ●(Second embodiment) Next, a second embodiment of the present invention will be described. In this embodiment, the Gain value used for adjusting the brightness of the original image is determined in consideration of the number of consecutively displayed frames N of the LV image as well as other information such as information obtained from the LV image to be displayed.

[0060] Figures 4(a) to 4(f) are flowcharts relating to the operation of determining the Gain value according to this embodiment. In Figures 4(a) to 4(f), steps that perform the same processes as in Figure 3(b) are given the same reference numerals.

[0061] FIG. 4(a) shows an example of determining the Gain value in consideration of the luminance information of the LV image. In S311, the control unit 104 acquires the number N of consecutively displayed frames of the LV image. Then, in S402, the control unit 104 acquires the luminance Y of the entire LV image (before luminance correction) to be consecutively displayed. The luminance Y may be luminance information obtained from the image processing unit 101 as an evaluation value for exposure control. The luminance Y may be, for example, the average luminance of the entire image. The luminance Y may also be information such as a luminance histogram of the entire image. In this case, the control unit 104 can generate luminance information to be reflected in the determination of the Gain value from the luminance histogram by a predetermined method. The range of values ​​that the luminance Y can take may be from 0 to 255, or may be normalized from 0 to 1.

[0062] In S403, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-An×N×By×Y. An is a fixed coefficient, and for example, the value of An can be determined based on a predetermined maximum number of N so that the value of An×N is greater than 0 and less than 1. Alternatively, when the actual value of An×N exceeds 1, the value of By may be set to a maximum value less than 1. Also, By is a fixed coefficient, and for example, the value of By can be determined based on a predetermined maximum value of luminance Y so that the value of By×Y is greater than 0 and less than 1. Alternatively, when the actual value of By×Y exceeds 1, the value of By may be set to 1. Note that, when 1-An×N×By×Y is less than the lower limit of Gain, Gain is set to the lower limit. The larger N is, and the larger the luminance Y is, the smaller the value of Gain is (the greater the amount of reduction in luminance is).

[0063] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0064] FIG. 4(b) shows another example of determining the Gain value in consideration of the luminance information of the LV image. In S311, the control unit 104 acquires the number N of consecutively displayed frames of the LV image. Then, in S412, the control unit 104 acquires the luminance Yt of the main subject region of the LV image (before luminance correction) to be continuously displayed. The luminance Yt may be luminance information obtained from the image processing unit 101 as an evaluation value for exposure control. For example, the luminance Yt may be the average luminance of the main subject region (a region that matches a predetermined characteristic, such as a face region or a human body region) detected in the LV image. The luminance Yt may also be information such as a luminance histogram of the main subject region. In this case, the control unit 104 can generate luminance information to be reflected in the determination of the Gain value from the luminance histogram by a predetermined method. The range of values ​​that the luminance Yt can take may be from 0 to 255, or may be normalized from 0 to 1.

[0065] In S413, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-An×N×Bt×Yt. An is the same as in FIG. 4(a). Bt is a fixed coefficient, and for example, the value of Bt can be determined based on a predetermined maximum value of luminance Yt so that the value of Bt×Yt is greater than 0 and equal to or less than 1. Alternatively, the maximum value of Bt×Yt may be set to 1, and when the actual value exceeds 1, it may be set to 1. Note that when 1-An×N×Bt×Yt is below the lower limit value of Gain, Gain is set to the lower limit value. The larger N is, and the larger the luminance Yt is, the smaller the value of Gain is (the greater the amount of reduction in luminance).

[0066] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0067] 4(c) shows an example in which the Gain value is determined taking into consideration the movement of the main subject. In S311, control unit 104 acquires the number N of consecutively displayed frames of the LV image. Then, in S422, control unit 104 acquires the amount of motion Vt relating to the main subject region of the LV images (before brightness correction) to be consecutively displayed. Here, the amount of motion Vt is the positional change of the main subject region detected between the LV image to be consecutively displayed and the LV image immediately preceding it, and can be obtained by image processing unit 101. Therefore, control unit 104 can acquire the amount of motion Vt of the main subject from image processing unit 101.

[0068] In S423, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-An×N×Bv×Vt. An is the same as in FIG. 4(a). Bv is a fixed coefficient, and for example, the value of Bv can be determined based on the maximum value of a predetermined amount of motion Vt so that the value of Bv×Vt is greater than 0 and equal to or less than 1. Alternatively, the maximum value of Bv×Vt may be set to 1, and when the actual value exceeds 1, it may be set to 1. Note that when 1-An×N×Bv×Vt is below the lower limit value of Gain, the lower limit value is set. The larger N is, and the larger the amount of motion Vt is, the smaller the value of Gain is (the greater the amount of reduction in luminance is).

[0069] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0070] 4(d) shows an operation for determining a Gain value when it is possible to display an LV image generated from a still image. For example, when an LV image cannot be captured by still image capture, it is possible to generate an LV image from a still image obtained by still image capture. In this case, the image processing unit 101 or the display unit 102 generates an LV image (original image) from the still image data stored in the temporary storage unit 107.

[0071] In S311, the control unit 104 acquires the number of consecutive display frames N of the LV image. Then, in S432, the control unit 104 determines the type of the LV image to be displayed. Specifically, the control unit 104 determines whether the LV image to be displayed is generated from a still image. Note that whether to repeatedly display the most recent LV image (captured in video mode) or display the LV image generated from a still image captured later can be determined by the control unit 104 according to predetermined conditions. For example, if the image processing for the still image data is completed by a predetermined ratio or more, the control unit 104 can determine to display the LV image generated from the still image, and if not completed, display the most recent LV image (captured in video mode).

[0072] Then, the control unit 104 determines the value of the coefficient Bs used when determining the value of Gain. Here, when the control unit 104 displays the LV image generated from a still image, the coefficient Bs is set to a fixed value predetermined in the range of 0 < Bs < 1, and when displaying the LV image not generated from a still image (captured in video mode), the coefficient Bs = 1.

[0073] In S433, the control unit 104 determines the value of Gain to be applied to the original image. Here, it is assumed that the control unit 104 determines the value of Gain as Gain = 1 - An × N × Bs. An is the same as in the case of Fig. 4(a). Note that when 1 - An × N × Bs is below the lower limit value of Gain, Gain is set to the lower limit value. The larger N is, the smaller the value of Gain becomes (the larger the amount of luminance decrease). Also, when repeatedly displaying the LV image captured in video mode rather than when the LV image to be displayed is generated from a still image, the value of Gain becomes even smaller. This is because the still image used for generating the LV image is captured later than the LV image captured in video mode.

[0074] In S313, as described with reference to Fig. 3(a), the control unit 104 adjusts the luminance of the continuously displayed LV images.

[0075] 4(e) shows an example of determining the Gain value in consideration of the still image shooting mode. Here, the still image shooting mode is assumed to be one of single shooting (single shot), low-speed continuous shooting, and high-speed continuous shooting. In S311, the control unit 104 acquires the number N of continuous display frames of the LV image.

[0076] In S442, the control unit 104 acquires the set still image shooting mode, for example, from the RAM 112. Also, the coefficient Gm for each still image shooting mode is stored in advance in the ROM 113, for example, as a table. The control unit 104 acquires the value of Gm corresponding to the current still image shooting mode from the table stored in the ROM 113. The coefficient Gm is a value greater than 0 and equal to or less than 1, and is set so that, when single shooting is regarded as the slowest continuous shooting, the value of the coefficient Gm remains unchanged or decreases with a decrease in the continuous shooting speed. As an example, the coefficient Gm is set to 0.4 for single shooting, 0.6 for low-speed continuous shooting, and 0.8 for high-speed continuous shooting.

[0077] In S443, the control unit 104 determines the Gain value to be applied to the original image. Here, the control unit 104 determines the Gain value as Gain = 1 - An x N x Gm. An is the same as in the case of FIG. 4(a). If 1 - An x N x Gm is below the lower limit of Gain, Gain is set to the lower limit. The larger N is and the higher the continuous shooting speed is, the smaller the Gain value will be (the greater the amount of reduction in brightness will be).

[0078] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG.

[0079] Fig. 4(f) shows an example of determining the Gain value taking into consideration the movement of the digital camera 1. Fig. 6 is a block diagram showing a configuration in which a motion measurement unit 114 that measures the movement of the digital camera 1 is provided in the digital camera 1, and the same reference numerals are used to designate the same components as in Fig. 1. The motion measurement unit 114 outputs a signal indicating the motion of the digital camera 1 to the control unit 104. The motion measurement unit 114 may be, for example, a gyro sensor that measures the magnitude of the angular velocity as the motion of the digital camera 1. The motion measurement unit 114 may be a motion sensor provided for camera shake correction. in It's fine.

[0080] In S311, the control unit 104 acquires the number N of consecutively displayed frames of the LV image. Then, in S452, the control unit 104 acquires a signal indicating the angular velocity Ωm [deg / sec] as the movement of the digital camera 1 from the movement measurement unit 114. The angular velocity Ωm is updated at the timing of updating the LV image. When the movement measurement unit 114 outputs angular velocities for multiple rotation axes, the control unit 104 determines one representative angular velocity from the multiple angular velocities using a predetermined method. For example, the representative angular velocity may be the maximum of the multiple angular velocities, or may be the average value or total value of the multiple angular velocities. When the movement measurement unit 114 outputs angular velocities for multiple rotation axes, the angular velocity Ωm in the following will mean the representative angular velocity.

[0081] In S453, the control unit 104 determines the value of Gain to be applied to the original image. Here, the control unit 104 determines the value of Gain as Gain=1-An×N×Bp×Ωm. An is the same as in FIG. 4(a). Bp is a fixed coefficient, and for example, the value of Bp can be determined so that the value of Bp×Ωm is greater than 0 and equal to or less than 1 within a range of values ​​that the angular velocity Ωm can take in advance. Alternatively, if Bp×Ωm exceeds the upper limit value of 1, the value may be corrected (clipped) to 1. If 1-An×N×Bp×Ωm is less than the lower limit value of Gain, Gain is set to the lower limit value. The larger N is, or the larger the angular velocity Ωm is, the smaller the value of Gain is (the greater the amount of reduction in luminance).

[0082] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG. Although the motion of digital camera 1 is measured using motion measurement unit 114 here, the motion of digital camera 1 may be measured from an LV image. For example, the motion of the entire image may be detected in the same manner as the motion of the main subject region is detected in S412, and used as the motion of digital camera 1.

[0083] In addition, the operation shown in Fig. 3(b) of the first embodiment has been described here in Fig. 4(a) to (f) in which the Gain value is determined taking other information into consideration. However, the configuration of this embodiment can also be implemented in combination with the configurations of Fig. 3(c) and Fig. 3(d).

[0084] According to this embodiment, in addition to the effects of the first embodiment, the Gain value is determined taking other information into consideration, so that more detailed brightness adjustment can be performed. Therefore, it is possible to realize more effective brightness adjustment by improving visibility.

[0085] ●(Third embodiment) Next, a third embodiment of the present invention will be described. This embodiment is configured to change the amount of luminance reduction as the number of consecutively displayed frames increases, and can be combined with the configurations of the first and second embodiments (configurations in which the luminance of the LV image during consecutive display is fixed). Here, a configuration combined with Fig. 3(b) of the first embodiment will be described. In Fig. 5, steps that perform the same processes as those in Fig. 3(b) are given the same reference numerals.

[0086] In S311, the control unit 104 acquires the number N of consecutively displayed frames of the LV image. In S503, the control unit 104 initializes the loop count K to 1.

[0087] In S504, the control unit 104 obtains the value of Gain. Here, the control unit 104 determines the value of Gain as Gain=1-Ck×K. Ck is a fixed coefficient, and for example, the value of Ck can be determined based on a predetermined maximum number of N so that the value of Ck×N is greater than 0 and less than 1. Alternatively, when the actual value of Ck×K exceeds 1, the maximum value less than 1 may be set. When 1-Ck×K is less than the lower limit value of Gain, Gain is set to the lower limit value. The larger K is, the smaller the value of Gain is (the greater the amount of reduction in luminance). Therefore, during a period in which the same LV image is repeatedly displayed, the display luminance is reduced for each frame.

[0088] In S313, the control unit 104 adjusts the brightness of the LV images to be continuously displayed, as described with reference to FIG. S506: Control unit 104 determines whether K is equal to N, and if it is determined that K is equal to N, the process ends, and if not, the process proceeds to S507. In S507, the control unit 104 increments K by 1, and returns the process to S504. In this manner, the luminance of the LV image is reduced for each frame until the number of times the LV image is repeatedly displayed reaches N obtained in S311.

[0089] In this embodiment, the operation shown in FIG. 3(b) is described as changing the Gain value as the number of consecutive displays increases. However, the configuration of this embodiment can be implemented in combination with the configurations of FIG. 3(c) and FIG. 3(d). In this case, if the period Tc or the exposure time Ts spans multiple frames, the amount of reduction can be adjusted for each frame.

[0090] According to this embodiment, in addition to the effects of the first and second embodiments, the Gain value is gradually changed (decreased) each time the same LV image is repeatedly displayed, thereby enabling finer brightness adjustment. Therefore, it is possible to realize more effective brightness adjustment by improving visibility.

[0091] ●(Fourth embodiment) Next, a fourth embodiment of the present invention will be described. This embodiment is configured to control the brightness of continuously displayed LV images in consideration of the movement of the digital camera 1, and can be implemented in a digital camera 1 having a movement measurement unit 114 shown in Fig. 6. In this embodiment, the angular velocity Ωm [deg / sec] described in Fig. 4(f) (second embodiment) is used as the movement of the digital camera 1.

[0092] Fig. 7 is a flowchart relating to the brightness adjustment operation of an LV image in this embodiment. Note that as the image brightness adjustment process executed in S607 in Fig. 7, the control unit 104 can execute either the process shown in the flowchart in Fig. 3(a) or Fig. 5. In this case, the control unit 104 executes the operation shown in the flowchart in Fig. 4(f) as the operations in Fig. 3(a), S303, and S313 in Fig. 5.

[0093] In this embodiment, a reference angular velocity Ωp [deg / sec] is set, and a reference value ( threshold The Gain value is determined in response to the fact that an angular velocity Ωm exceeding a reference angular velocity Ωp (value) is continuously obtained for a predetermined period of time. The reference angular velocity Ωp is set to 0 or more, and is set to 50 [deg / sec] as an example here. The reference angular velocity Ωp can be stored in the ROM 113, for example.

[0094] In S601, the control unit 104 starts the operation of a timer. The timer may be one built into the control unit 104, or one that exists external to the control unit 104. The timer may be, for example, a counter that counts the number of pulses of a clock signal used by the digital camera 1. In addition, the timer may actually acquire the current time from the system clock and store it in the RAM 112.

[0095] In S602, the control unit 104 acquires the angular velocity Ωm from the motion measurement unit 114. The angular velocity Ωm is updated at the same time that the LV image is updated. In S603, the control unit 104 determines whether the acquired angular velocity Ωm is greater than a reference angular velocity Ωp (threshold value). If it is determined that the angular velocity Ωm is greater than the reference angular velocity Ωp, the control unit 104 executes S605, and if it is not determined that the angular velocity Ωm is greater than the reference angular velocity Ωp, the control unit 104 executes S604.

[0096] In S604, the control unit 104 initializes the timer. This ends the measurement of the period during which the angular velocity Ωm is greater than the reference angular velocity Ωp. Thereafter, the control unit 104 executes S601 again. Note that if the timer is a free-running counter, the control unit 104 may set the counter value to an initial value (for example, 0) in S604 and execute the process again from S602.

[0097] In S605, the control unit 104 acquires the measured time T by the timer. The control unit 1045 can acquire the count value, the elapsed time, or the like as the measured time T depending on the type of timer.

[0098] In S606, the control unit 104 judges whether the measured time T is greater than a predetermined reference time T3. If the control unit 104 judges that the measured time T is greater than the predetermined reference time T3, it executes S607, and if the control unit 104 judges that the measured time T is not greater than the predetermined reference time T3, it executes S602. The reference time T3 is set to 0 or more, and is set to 500 [msec] as an example here. The reference time T3 can be stored in the ROM 113, for example.

[0099] In this manner, in this embodiment, when the digital camera 1 continues to move for a certain period of time while capturing a still image, the brightness of the LV image is adjusted. More specifically, when it is considered that the digital camera 1 is panning while capturing a still image, the brightness of the LV image is adjusted. On the other hand, when the digital camera 1 is not panning and is capturing a normal still image, the brightness of the LV image is not adjusted. This allows effective brightness adjustment to be performed only while capturing a moving object, thereby improving visibility.

[0100] Considering that panning is generally a movement in a fixed direction, in addition to the magnitude of the angular velocity, a condition for continuing time measurement by a timer may be added that the main direction of the movement does not reverse.

[0101] ●(Fifth embodiment) Next, a fifth embodiment of the present invention will be described. In this embodiment, hysteresis is provided to the reference angular velocity Ωp in the fourth embodiment. Fig. 8 is a flow chart relating to the luminance adjustment operation of the LV image in this embodiment, and the same reference numerals are used for steps that perform the same processes as in Fig. 7.

[0102] In this embodiment, two criteria corner Velocity Ωq1 (first threshold) and criterion corner Velocity Ωq2 (second threshold value) is used. corner The speed Ωq1 is the reference corner The speed is greater than Ωq2. corner Speed ​​Ωq1 and reference corner The velocity Ωq2 can be stored in the ROM 113 in advance.

[0103] After acquiring the angular velocity Ωm in S602, the control unit 104 executes S703. In S703, the control unit 104 determines whether or not the acquired angular velocity Ωm is greater than the reference angular velocity Ωq1. If it is determined that the angular velocity Ωm is greater than the reference angular velocity Ωq1, the control unit 104 executes S605, and if it is not determined that the angular velocity Ωm is greater than the reference angular velocity Ωq1, the control unit 104 executes S604.

[0104] The control unit 104 acquires the time T measured by the timer in S605, and determines whether the measured time T is greater than the reference time T3 in S606. If it is determined that the measured time T is greater than the reference time T3, the control unit 104 executes S707, and if it is not determined that the measured time T is greater than the reference time T3, the control unit 104 executes S601.

[0105] In S707, the control unit 104 determines whether or not the angular velocity Ωm is greater than the reference angular velocity Ωq2. If it is determined that the angular velocity Ωm is greater than the reference angular velocity Ωq2, the control unit 104 executes S711, and if it is not determined that the angular velocity Ωm is greater than the reference angular velocity Ωq2, the control unit 104 executes S709.

[0106] In S709 and S710, the control unit 104 determines whether the time T measured by the timer is greater than the reference time T3, similarly to S605 and S606. If it is determined that the measured time T is greater than the reference time T3, the control unit 104 executes S601, and if it is not determined that the measured time T is greater than the reference time T3, the control unit 104 executes S607.

[0107] On the other hand, in S711, the control unit 104 initializes the timer in the same manner as in S604, and then executes S607. After adjusting the brightness of the LV image in S607, the control unit 104 executes S712 and, similarly to S602, acquires the angular velocity Ωm from the motion measurement unit 114. Then, the control unit 104 executes S707.

[0108] In the case where there is only one reference angular velocity, if the movement of the digital camera 1 transitions near the reference angular velocity, the LV image with brightness adjustment and the LV image without brightness adjustment may frequently switch places, which may reduce the visibility of the LV image.

[0109] In this embodiment, two reference angular velocities with different magnitudes are used, and when the conditions for performing luminance adjustment of the LV image are satisfied, the smaller reference angular velocity is used to determine whether or not the luminance adjustment needs to be continued. Therefore, once the luminance adjustment is performed, the luminance adjustment is less likely to be stopped than when there is only one reference angular velocity, and it is possible to suppress a decrease in visibility when the movement of the digital camera 1 transitions near the (larger) reference angular velocity used initially.

[0110] ●(Sixth embodiment) Next, a sixth embodiment of the present invention will be described. This embodiment can be implemented by the digital camera 1 shown in FIG. 1, and therefore a description of the configuration of the digital camera 1 will be omitted. FIG. 9 is a flowchart relating to the luminance adjustment operation of the LV image in this embodiment. The sixth to eighth embodiments adjust the brightness and / or color of the LV image by combining an image of a specific color with the LV image that is repeatedly displayed during a period when the LV image cannot be updated by still image shooting. When the specific color is achromatic, this is essentially equivalent to adjusting the luminance of the LV image.

[0111] The flowchart shown in Fig. 9(a) shows the operation of adjusting the brightness and / or color of the LV image depending on whether the LV display can be updated. The control unit 104 executes this operation when the still image shooting operation starts. In Fig. 9(a), the same reference numbers as in Fig. 3(a) are used for steps that perform the same operations as in the first embodiment.

[0112] In S301, the control unit 104 determines whether or not the LV image can be updated, and if it is determined that the LV image can be updated, the process proceeds to S302, and if not, the process proceeds to S903. For example, at the timing of display V synchronization, if image processing in the image processing unit 101 or processing processing in the display unit 102 has been completed to a predetermined stage for an LV image captured after the currently displayed LV image, the control unit 104 can determine that the LV image can be updated.

[0113] In S302, the control unit 104 causes the display device 103 to display a new LV image via the display unit .

[0114] In S903, the control unit 104 adjusts the brightness and / or color tone of the LV images to be continuously displayed. In this embodiment, the brightness and / or color tone of the LV images to be continuously displayed is adjusted by displaying composite LV image data obtained by combining the LV image (original image) data to be continuously displayed with adjusted image data having a specific color (hereinafter referred to as composite color I). The adjusted image data may be an image composed only of pixels of composite color I and having the same resolution (number of pixels) as the LV image data.

[0115] The composite ratio α (0<α<1) of the adjusted image data when generating the composite LV image data may be a fixed value or may be a value that is dynamically determined based on some condition. Similarly, the composite color I may be fixed (e.g., black) or may be dynamically determined based on some condition. The composite color I may be an achromatic color or a chromatic color.

[0116] In S904, the control unit 104 controls the display unit 102 so that an LV image with adjusted brightness and / or color tone is displayed from the next display V synchronization. Then, the control unit 104 returns the process to S301, and repeatedly executes the processes of S903 and S904 until it is determined that the LV image can be updated.

[0117] In the example of Fig. 9(a), the blending ratio α is constant regardless of the number of times the same original image is continuously displayed (number of continuously displayed frames). On the other hand, Fig. 9(b) to Fig. 9(d) show examples in which the blending ratio α and the blending color I are dynamically determined. The control unit 104 can execute any of the operations of Fig. 9(b) to Fig. 9(d) in place of the operation of S903 of Fig. 9(a).

[0118] The flowchart in FIG. 9(b) shows an example in which the blending ratio α and blending color I are determined according to the number of frames during which the LV display is not updated. In S911, the control unit 104 acquires the number of times (number of frames) N to continuously display the most recent LV image (original image) when the LV image cannot be updated due to still image shooting. The control unit 104 can obtain the number of times N (hereinafter, referred to as the number of consecutively displayed frames N) based on, for example, the exposure time of the still image determined before shooting and the time expected to be required for image processing of the still image, but may also acquire the number of times N using other methods.

[0119] In S912, the control unit 104 determines a composite color I and a composite ratio α of the image of the composite color I. Here, the control unit 104 determines the composite color I=Yn×(1-An×N) and the composite ratio α=An×N. An is a fixed coefficient, and an An is used such that the composite ratio α=An×N is greater than 0 and less than or equal to 1. For example, An can be determined so that a specific composite ratio α (≦1) is obtained when N is at its maximum value. Alternatively, when An×N exceeds 1, An×N=1 may be used.

[0120] Here, the composite color I is also an achromatic color according to the composite ratio α (=An×N), but it may be a fixed color such as black. Yn is a predetermined reference luminance value. The larger N is, the closer the composite color I is to the reference luminance value Yn. Note that the composite color I may also be a chromatic color. Here, both the composite ratio α and the composite color I are determined based on the number N of consecutive display frames, but either one of them may be fixed.

[0121] In S913, the control unit 104 notifies the image processing unit 101 or the display unit 102 of the composite color I and the composite ratio α determined in S912. The image processing unit 101 or the display unit 102 composites an image having the composite color I with the most recently used LV image data (original image data) according to the composite ratio α, and generates LV image data for update. More specifically, the image processing unit 101 or the display unit 102: Image data for update = original image data × (1-α) + image of composite color I × α Then, image data for updating is generated.

[0122] For example, when the composite color I is black, the original image data is composited at a ratio of (1-α) and the black image data is composited at a ratio of α, so image data in which the original image is darkened overall is generated as update image data and displayed. In other words, when the composite color I is black, the greater the number of consecutively displayed frames N, the darker the LV images displayed consecutively. Also, when the composite color I is based on the number of frames N, the LV images displayed consecutively are displayed in a color closer to the image of the composite color I than to the original images. In other words, the greater the number of consecutively displayed frames N of the LV images, the closer the color of the LV images will be to the composite color I.

[0123] The flowchart in Fig. 9(c) shows an example in which the blending ratio α and blending color I are determined according to the length of a period during which the LV display is not updated. In S921, the control unit 104 acquires a period Tc [msec] during which the LV image cannot be updated due to still image shooting and the most recent LV image is continuously displayed. The control unit 104 can acquire the period Tc by, for example, multiplying the number of continuously displayed frames N described in S911 in Fig. 9(a) by the frame period, but may acquire the period Tc by other methods.

[0124] In S922, the control unit 104 determines a composite color I and a composite ratio α of the image of the composite color I. Here, the control unit 104 determines the composite color I=Yc×(1−Ac×Tc) and the composite ratio α=Ac×Tc. Ac is a fixed coefficient, and Ac is used such that the composite ratio α=Ac×Tc is greater than 0 and less than or equal to 1. For example, Ac can be determined so that a specific composite ratio α (≦1) is obtained when Tc is at its maximum value. Alternatively, when Ac×Tc exceeds 1, Ac×Tc=1 may be used.

[0125] Here, the composite color I is also an achromatic color according to the composite ratio α (=Ac×Tc), or it may be a fixed color such as black. Yc is a predetermined reference luminance value. The larger Tc is, the closer the composite color I is to the reference luminance value Yc. Note that the composite color I may also be a chromatic color. Here, both the composite ratio α and the composite color I are determined based on the period Tc, but either one of them may be fixed.

[0126] The operation in S913 is as described above. For example, if the composite color I is black, the longer the period Tc, the darker the continuously displayed LV images will be. Also, if the composite color I is based on the period Tc, the continuously displayed LV images will be displayed in a color closer to the image of the composite color I than to the original images. In other words, the longer the period Tc during which the most recent LV image is continuously displayed (or the period during which the LV image is not updated), the closer the color of the LV image will be to the composite color I.

[0127] 9(d) shows an example of determining the blending ratio α and blending color I according to the length of the exposure time Ts of the still image. In S931, the control unit 104 acquires the exposure time Ts [sec] of the still image capture. The control unit 104 can acquire the exposure time Ts based on the exposure conditions determined before the start of the still image capture, for example, but may acquire it by other methods.

[0128] In S932, the control unit 104 determines a composite color I and a composite ratio α of the image of the composite color I. Here, the control unit 104 determines the composite color I=Ys×(1-As×Ts) and the composite ratio α=As×Ts. As is a fixed coefficient, and As is used such that the composite ratio α=As×Ts is greater than 0 and is equal to or less than 1. For example, As can be determined so that a specific composite ratio α (≦1) is obtained when Ts is at its maximum value. Alternatively, when As×Ts exceeds 1, As×Ts=1 may be used.

[0129] Here, the composite color I is also an achromatic color according to the blending ratio α (=As×Ts), or it may be a fixed color such as black. Ys is a predetermined reference luminance value. The larger Ts is, the closer the composite color I is to the reference luminance value Ys. Note that the composite color I may also be a chromatic color. Here, both the blending ratio α and the composite color I are determined based on the exposure time Ts, but either one of them may be fixed.

[0130] The operation in S913 is as described above. For example, when the composite color I is black, the longer the exposure time Ts, the darker the continuously displayed LV images will be. Also, when the composite color I is based on the exposure time Ts, the continuously displayed LV images will be displayed with a color closer to the image of the composite color I than to the original images. In other words, the longer the exposure time Ts for still image shooting, the closer the color of the LV image will be to the composite color I.

[0131] The operations shown in the flowcharts of Fig. 9(b) to Fig. 9(d) have been described as being executed in place of S903 in Fig. 9(a). In this case, the LV image is adjusted for each display V synchronization. On the other hand, the operations shown in the flowcharts of Fig. 9(b) to Fig. 9(d) may be executed in response to a still image shooting instruction. In this case, the lower limit of the synthesis ratio α is set to 0 in order to accommodate cases where the LV image can be updated.

[0132] As described above, by adjusting the brightness and / or color of the frame images displayed in continuous LV as explained in Fig. 9, it is possible to avoid unnatural subject movement and a complete blackout display. This enables a smooth live view display with good visibility during periods when the LV image cannot be updated by still image capture.

[0133] ●(Seventh embodiment) Next, a seventh embodiment of the present invention will be described. In this embodiment, the composite color I and the composite ratio α of the image of the composite color I are determined in consideration of the number N of consecutively displayed frames of the LV image as well as other information such as information obtained from the LV image to be displayed.

[0134] Figures 10(a) to 10(f) are flowcharts relating to the operation of determining the composite color I and the composite ratio α according to this embodiment. Here, as an example, a configuration for determining the composite color I and the composite ratio α based on the number of consecutively displayed frames N and other information will be described. In Figures 10(a) to 10(f), the same reference numerals are used to denote steps that perform the same processes as those in Figure 9(b).

[0135] 10(a) to 10(f) can be executed in place of S903 in Fig. 9(a) in the same manner as the operation shown in Fig. 9(b). Generation of a composite LV image based on the composite color I and the composite ratio α determined according to this embodiment may be performed by either the image processing unit 101 or the display unit 102.

[0136] 10A shows an example of determining a composite color I and a composite ratio α in consideration of luminance information of an LV image. In S911, the control unit 104 acquires the number of consecutively displayed frames N of the LV image. Then, in S1002, the control unit 104 acquires a luminance Y for the entire LV image (before luminance correction) to be consecutively displayed, for example, in the same manner as in S402 in the second embodiment.

[0137] In S1003, the control unit 104 determines a composite color I and a composite ratio α to be applied to the original image. Here, the control unit 104 determines the composite color I and the composite ratio α as composite color I=Y×(1−An×N) and composite ratio α=An×N×By×Y. An is a fixed coefficient, and for example, the value of An can be determined based on a predetermined maximum number of N so that the value of An×N is greater than 0 and less than or equal to 1. Alternatively, when the actual value of An×N exceeds 1, the value of By may be set to 1. Also, By is a fixed coefficient, and for example, the value of By can be determined based on a predetermined maximum value of luminance Y so that the value of By×Y is greater than 0 and less than or equal to 1. Alternatively, when the actual value of By×Y exceeds 1, the value of By may be set to 1.

[0138] In this case, the blending ratio α increases as the luminance Y increases and as N increases. The blended color I becomes brighter as the luminance Y increases, and becomes an achromatic color darker than the luminance Y as the number N of consecutive display frames increases. Note that, although the blended color I is an achromatic color according to the luminance Y and the number N of consecutive display frames here, it may be a fixed color such as black. Note that the blended color I may also be a chromatic color. Here, both the blending ratio α and the blended color I are determined based on the luminance Y, but either one of them may be independent of the luminance Y (dependent only on the number N of consecutive display frames).

[0139] In S913, the control unit 104 notifies the image processing unit 101 or the display unit 102 of the composite color I and the composite ratio α determined in S912. The image processing unit 101 or the display unit 102 composites an image having the composite color I with the most recently used LV image data (original image data) according to the composite ratio α, and generates LV image data for update. More specifically, the image processing unit 101 or the display unit 102: Image data for update = original image data × (1-α) + image of composite color I × α Then, image data for updating is generated.

[0140] The image data for updating is closer to the image data of the composite color I than the original image data. Since the composite ratio α increases as the luminance Y increases, the LV image that is repeatedly displayed is closer to the achromatic image of the composite color I as the luminance Y of the original image increases.

[0141] 10(b) shows another example of determining the composite color I and the composite ratio α in consideration of the luminance information of the LV image. In S911, the control unit 104 acquires the number of consecutively displayed frames N of the LV image. Then, in S1012, the control unit 104 acquires the luminance Yt of the main subject region of the consecutively displayed LV images (before luminance correction) in the same manner as in S412 in the second embodiment, for example.

[0142] In S1013, the control unit 104 determines a composite color I and a composite ratio α to be applied to the original image. Here, the control unit 104 determines the composite color I and the composite ratio α as composite color I=Yt×(1-An×N) and composite ratio α=An×N×Bt×Yt. An is the same as in the case of FIG. 10(a). Also, Bt is a fixed coefficient, and for example, the value of Bt can be determined based on a predetermined maximum value of luminance Yt so that the value of Bt×Yt is greater than 0 and equal to or less than 1. Alternatively, the maximum value of Bt×Yt may be set to 1, and when the actual value exceeds 1, the value may be set to 1.

[0143] In this case, the blending ratio α increases as the luminance Yt increases and as N increases. The blended color I becomes brighter as the luminance Yt increases, and becomes an achromatic color darker than the luminance Yt as the number of consecutive display frames N increases. Note that, although the blended color I is an achromatic color according to the luminance Yt and the number of consecutive display frames N here, it may be a fixed color such as black. Note that the blended color I may be a chromatic color. Here, both the blending ratio α and the blended color I are determined based on the luminance Yt, but one of them may be independent of the luminance Yt (dependent only on the number of consecutive display frames N).

[0144] In S913, the control unit 104 notifies the blending color I and blending ratio α determined in S912 to the image processing unit 101 or the display unit 102. The image processing unit 101 or the display unit 102 generates update image data as described above.

[0145] The image data for updating is closer to the image data of the composite color I than the original image data. Since the composite ratio α increases as the luminance Yt increases, the LV image that is repeatedly displayed becomes closer to the achromatic image of the composite color I as the luminance Yt of the main subject region of the original image increases.

[0146] 10(c) shows an example of determining the composite color I and the composite ratio α in consideration of the movement of the main subject. In S911, the control unit 104 acquires the number of consecutively displayed frames N of the LV image. Then, in S1022, the control unit 104 acquires the amount of movement Vt for the main subject region of the consecutively displayed LV images (before brightness and / or color adjustment) in a manner similar to, for example, S422 in the second embodiment.

[0147] In S1023, the control unit 104 determines a composite color I and a composite ratio α to be applied to the original image. Here, the control unit 104 determines the composite color I and the composite ratio α as composite color I=Yv(1-An×N×Bv×Vt) and composite ratio α=An×N×Bv×Vt. Here, Yv is a predetermined reference luminance value. An is the same as in the case of FIG. 10(a). Also, Bv is a fixed coefficient, and for example, the value of Bv can be determined based on the maximum value of a predetermined amount of motion Vt so that the value of Bv×Vt is greater than 0 and equal to or less than 1. Alternatively, the maximum value of Bv×Vt may be set to 1, and when the actual value exceeds 1, the value may be set to 1.

[0148] In this case, the composition ratio α is amount The larger Vt and N are, the larger the composite color I is. amount The larger Vt is, the darker the color becomes, and the larger the number of consecutive display frames N is, the darker the achromatic color becomes. amount Although the color is achromatic according to Vt and the number of consecutive display frames N, it may be a fixed color such as black. The composite color I may be a chromatic color. Here, both the composite ratio α and the composite color I are determined based on the amount of motion Vt regarding the main subject region, but either one of them may be independent of the amount of motion Vt (dependent only on the number of consecutive display frames N).

[0149] In S913, the control unit 104 notifies the blending color I and blending ratio α determined in S912 to the image processing unit 101 or the display unit 102. The image processing unit 101 or the display unit 102 generates update image data as described above.

[0150] The image data for updating is closer to the image data of the composite color I than the original image data. Since the composite ratio α increases as the amount of motion Vt of the main subject region increases, the LV image that is repeatedly displayed becomes closer to the achromatic image of the composite color I as the amount of motion Vt of the main subject region of the original image increases.

[0151] FIG. 10(d) shows an example of determining the composite color I and the composite ratio α when it is possible to display an LV image generated from a still image. For example, when it is not possible to capture an LV image by still image capture, it is conceivable to generate an LV image from the still image obtained by still image capture. In this case, the image processing unit 101 or the display unit 102 generates an LV image (original image) from the still image data stored in the temporary storage unit 107.

[0152] In S911, the control unit 104 acquires the number of consecutive display frames N of the LV image. Then, in S1032, the control unit 104 determines the type of the LV image to be displayed. Specifically, the control unit 104 determines whether the LV image to be displayed is generated from a still image in the same manner as in S432 of the second embodiment.

[0153] Then, the control unit 104 determines the value of the coefficient Bs used when determining the composite color I and the composite ratio α. Here, the control unit 104 sets the coefficient Bs when displaying an LV image generated from a still image as a fixed value predetermined in the range of 0 < Bs < 1, and sets the coefficient Bs = 1 when displaying an LV image that is not generated from a still image (captured in video mode).

[0154] In S1033, the control unit 104 determines the composite color I and the composite ratio α to be applied to the original image. Here, it is assumed that the control unit 104 determines the composite color I and the composite ratio α as composite color I = Ybs(1 - An×N×Bs) and composite ratio α = An×N×Bs. Here, Ybs is a predetermined reference luminance value. An is the same as in the case of FIG. 10(a).

[0155] In this case, the blending ratio α is larger when the LV image captured in the video mode is repeatedly displayed than when the LV image to be displayed is generated from a still image. Also, when the LV image captured in the video mode is repeatedly displayed than when the LV image to be displayed is generated from a still image, the blending color I becomes a darker achromatic color. This is because the still image used to generate the LV image is captured after the LV image captured in the video mode. Note that, although the blending color I is an achromatic color based on the reference luminance value Ybs here, it may be a fixed color such as black. Note that the blending color I may be a chromatic color. Here, both the blending ratio α and the blending color I are determined based on the coefficient Bs according to whether the LV image to be displayed is generated from a still image or a video, but either one of them may be independent of the coefficient Bs (dependent only on the number of consecutively displayed frames N).

[0156] In S913, the control unit 104 notifies the blending color I and blending ratio α determined in S912 to the image processing unit 101 or the display unit 102. The image processing unit 101 or the display unit 102 generates update image data as described above.

[0157] The image data for updating is closer to the image data of the composite color I than the original image data. Also, the composite ratio α is larger when the LV image is generated from a moving image than when it is generated from a still image. Therefore, when the LV image is generated from a moving image, the repeatedly displayed LV image is closer to the achromatic image of the composite color I than when it is generated from a still image.

[0158] 10(e) shows an example of determining the composite color I and the composite ratio α in consideration of the still image shooting mode. Here, it is assumed that the still image shooting mode is one of single shooting (single shot), low-speed continuous shooting, and high-speed continuous shooting. In S911, the control unit 104 acquires the number N of continuous display frames of the LV image.

[0159] In S1042, the control unit 104 acquires the set still image shooting mode, for example, from the RAM 112. Also, the coefficient Gm for each still image shooting mode is stored in advance, for example, as a table, in the ROM 113. Here, as in the second embodiment, it is assumed that the coefficient Gm=0.4 for single shooting, the coefficient Gm=0.6 for low-speed continuous shooting, and the coefficient Gm=0.8 for high-speed continuous shooting.

[0160] In S1043, the control unit 104 determines a composite color I and a composite ratio α to be applied to the original image. Here, the control unit 104 determines the composite color I and the composite ratio α as composite color I=Ym(1-An×N×Gm) and composite ratio α=An×N×Gm. Here, Ym is a predetermined reference luminance value. An is the same as in the case of FIG. 10(a).

[0161] In this case, the larger the coefficient Gm, i.e., the faster the continuous shooting speed, the larger the blending ratio α becomes. Also, the larger the coefficient Gm, i.e., the faster the continuous shooting speed, the darker the blended color I becomes an achromatic color. Note that although the blended color I is an achromatic color based on the reference luminance value Ym here, it may be a fixed color such as black. Note that the blended color I may also be a chromatic color. Here, both the blending ratio α and the blended color I are determined based on the coefficient Gm according to the shooting mode, but either one of them may be independent of the coefficient Gm (dependent only on the number of consecutively displayed frames N).

[0162] In S913, the control unit 104 notifies the blending color I and blending ratio α determined in S912 to the image processing unit 101 or the display unit 102. The image processing unit 101 or the display unit 102 generates update image data as described above.

[0163] The image data for updating becomes closer to the image data of the composite color I than the original image data. Also, the larger the coefficient Gm, the larger the composite ratio α becomes. In the above example, the coefficient Gm becomes larger as the shooting speed of the shooting mode increases, so that the repeatedly displayed LV image becomes closer to the achromatic image of the composite color I. Note that a similar method can be used for shooting modes other than the continuous shooting mode.

[0164] 10F shows an example of determining the composite color I and the composite ratio α in consideration of the movement of the digital camera 1. In S911, the control unit 104 obtains the number N of consecutively displayed frames of the LV image.

[0165] Then, in S1052, the control unit 104 obtains a signal indicating the angular velocity Ωm [deg / sec] as the movement of the digital camera 1 from, for example, the movement measurement unit 114 shown in FIG. 6. The angular velocity Ωm is updated at the timing of updating the LV image. When the movement measurement unit 114 outputs angular velocities for multiple rotation axes, the control unit 104 obtains one representative angular velocity from the multiple angular velocities using a predetermined method. For example, the representative angular velocity may be the maximum of the multiple angular velocities, or may be the average value or total value of the multiple angular velocities. When the movement measurement unit 114 outputs angular velocities for multiple rotation axes, the angular velocity Ωm in the following will mean the representative angular velocity.

[0166] In S1053, the control unit 104 determines a composite color I and a composite ratio α to be applied to the original image. Here, the control unit 104 determines the composite color I and the composite ratio α as composite color I=Yv(1-An×N×Ωm) and composite ratio α=An×N×Bp×Ωm. Here, Yv is a predetermined reference luminance value. An is the same as in the case of FIG. 10(a). Also, Bp is a fixed coefficient, and for example, the value of Bp can be determined so that the value of Bp×Ωm is greater than 0 and equal to or less than 1 within a predetermined range of possible values ​​of the angular velocity Ωm. Alternatively, if Bp×Ωm exceeds the upper limit value 1, the value may be corrected (clipped) to 1.

[0167] In this case, the greater the angular velocity Ωm, the greater the blending ratio α. Also, the greater the angular velocity Ωm, the darker the blended color I becomes. Note that, although the blended color I is an achromatic color based on the reference luminance value Yv here, it may be a fixed color such as black. Note that the blended color I may also be a chromatic color. Here, both the blending ratio α and the blended color I are determined based on the angular velocity Ωm, but either one of them may be independent of the angular velocity Ωm (dependent only on the number of consecutively displayed frames N).

[0168] In S913, the control unit 104 notifies the blending color I and blending ratio α determined in S912 to the image processing unit 101 or the display unit 102. The image processing unit 101 or the display unit 102 generates update image data as described above.

[0169] The image data for updating is closer to the image data of the composite color I than the original image data. In addition, since the composite ratio α increases as the angular velocity Ωm increases, the repeatedly displayed LV image becomes closer to the achromatic image of the composite color I as the angular velocity Ωm increases.

[0170] Although the motion of digital camera 1 is measured using motion measurement unit 114 here, the motion of digital camera 1 may be measured from an LV image. For example, the motion of the entire image may be detected in the same manner as the motion of the main subject region is detected in S1012, and used as the motion of digital camera 1.

[0171] 10(a) to 10(f) are used to explain the operation of the sixth embodiment shown in FIG. 9(b) in which the composite color I and the composite ratio α are determined in consideration of other information. However, the configuration of this embodiment can also be implemented in combination with the configurations of FIG. 9(c) and FIG. 9(d).

[0172] According to this embodiment, in addition to the effects of the sixth embodiment, the composite color I and the composite ratio α are determined taking other information into consideration. Therefore, the brightness and / or hue of the repeatedly displayed LV image can be adjusted more finely. Therefore, the visibility of the live view display during the period when the LV image is not updated can be further improved.

[0173] ●(Eighth embodiment) Next, the present invention 8 An embodiment will be described. This embodiment is configured to change the brightness and / or color of an LV image as the number of consecutive displays of LV images based on the same original image increases. This embodiment can be combined with the configurations of the sixth and seventh embodiments (configurations in which the brightness and / or color of an LV image during consecutive display is fixed). Here, a case in which it is combined with the configuration of FIG. 9(b) of the sixth embodiment will be described. In FIG. 11, steps that perform the same processes as those in FIG. 9(b) are given the same reference numerals. The generation of a composite LV image based on the composite color I and the composite ratio α determined according to this embodiment may be performed by either the image processing unit 101 or the display unit 102.

[0174] In S911, the control unit 104 acquires the number N of consecutively displayed frames of the LV image. In S1103, the control unit 104 initializes the loop count K to 1.

[0175] In S1104, the control unit 104 determines the composite color I and the blending ratio α. Here, the control unit 104 determines the composite color I and the blending ratio α as composite color I=Yk×(1-Ck×K) and blending ratio α=Ck×K. Here, Yk is a predetermined reference luminance value. Note that, here, the composite color I is an achromatic color based on the reference luminance value Yk, but it may be a fixed color such as black. Note that the composite color I may be a chromatic color.

[0176] Ck is a fixed coefficient, and the value of Ck can be determined so that the value of Ck×K (composite ratio α) when K=N is a target value greater than 0 and less than or equal to 1. Alternatively, when the actual value of Ck×K exceeds 1, it may be set to 1. The closer K is to N, the greater the composite ratio α becomes. Also, the composite color I becomes a dark achromatic color. Therefore, during a period in which the same LV image is repeatedly displayed, the brightness of the LV image decreases for each frame. Here, both the composite ratio α and the composite color I are made different for each frame in which an LV image based on the same original image is displayed, but either one of them may be a fixed value.

[0177] In S913, the control unit 104 notifies the blending color I and blending ratio α determined in S1104 to the image processing unit 101 or the display unit 102. The image processing unit 101 or the display unit 102 generates update image data as described above.

[0178] S1105: Control unit 104 determines whether the loop count K is equal to the number of consecutively displayed frames N obtained in S911, and ends the process if it is determined that the loop count K is equal, and advances the process to S1106 if it is not. In S1106, the control unit 104 increments the loop count K by 1 and executes again from S1104. In this manner, a different composite LV image is displayed for each frame until the number of times the LV image is repeatedly displayed reaches N obtained in S911.

[0179] In this embodiment, the operation shown in Fig. 9(b) of the sixth embodiment has been described with respect to a configuration in which the blending ratio α and / or the blended color I are changed as the number of consecutive displays increases. However, the configuration of this embodiment can also be implemented in combination with the configurations of Fig. 9(c) and Fig. 9(d). In this case, when the period Tc or the exposure time Ts spans multiple frames, it is sufficient to change the blending ratio α and / or the blended color I for each frame.

[0180] According to this embodiment, in addition to the effects of the sixth and seventh embodiments, the brightness and / or color of the LV image is gradually changed each time the same LV image is repeatedly displayed. This makes it possible to more smoothly control the change in the live view display during the period when the LV image is not updated. This makes it possible to realize a live view display of higher quality than the sixth and seventh embodiments.

[0181] (Other embodiments) The brightness adjustment operation of the LV image described in the above embodiment may be performed when the LV image is generated by the image processing unit 101, or may be performed when the LV image is displayed on the display device 103 by the display unit 102.

[0182] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0183] 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 disclose the scope of the invention. [Explanation of symbols]

[0184] 100: sensor, 101: image processing unit, 102: display unit, 103: display device, 104: control unit, 105: data transfer unit, 106: bus, 107: temporary recording unit, 108: recording unit

Claims

1. An imaging element; a control means for, when an instruction to shoot a still image is detected while a live view display is being performed by shooting a moving image with the image sensor and displaying the moving image obtained by the shooting, causing the image sensor to preferentially shoot a still image, and for controlling the image sensor to repeatedly display the same image during a period in which the live view display cannot be updated due to the shooting of the still image, the control means reduces the luminance of the image to be repeatedly displayed based on a length of exposure time in capturing the still image; The imaging device according to claim 1, wherein the control means determines the amount of reduction in luminance such that the amount of reduction in luminance increases as the length of the exposure time in capturing the still image increases.

2. An imaging element; a control means for controlling the image pickup device to, when an instruction to shoot a still image is detected while a live view display is being performed by shooting a moving image with the image pickup device and displaying the moving image obtained by the shooting, cause the image pickup device to prioritize shooting a still image, and to repeatedly display the same image during a period in which the live view display cannot be updated due to the shooting of the still image, The control means reduces the brightness of the image to be repeatedly displayed, an imaging device characterized in that the control means determines the amount of reduction in brightness by taking into consideration not only one of the number of frames of the live view display that cannot be updated by capturing still images, the length of the period during which the live view display cannot be updated by capturing still images, and the length of the exposure time for capturing still images, but also one of information obtained from the image to be displayed, the type of image to be displayed, the still image capturing mode, and the movement of the imaging device.

3. 3. The imaging device according to claim 2, wherein information obtained from the displayed image is the brightness of the entire image or a main subject, and the control means determines the amount of reduction in brightness such that the amount of reduction in brightness increases as the brightness increases.

4. 3. The imaging device according to claim 2, wherein information obtained from the displayed image is an amount of movement of a main subject, and the control means determines the amount of reduction in luminance such that the amount of reduction in luminance increases as the amount of movement increases.

5. 3. The imaging device according to claim 2, characterized in that the type of image to be displayed is an image generated from an image obtained by still image shooting or an image generated from an image obtained by video shooting, and the control means determines the amount of luminance reduction so that the amount of luminance reduction is greater when the image to be displayed is an image generated from an image obtained by video shooting than when the image is generated from an image obtained by still image shooting.

6. 3. The imaging device according to claim 2, wherein the still image shooting modes include a plurality of still image shooting modes having different continuous shooting speeds, and the control means determines the amount of reduction in brightness so that the amount of reduction in brightness is increased for a second still image shooting mode having a higher continuous shooting speed than the first still image shooting mode.

7. 3. The image pickup apparatus according to claim 2, wherein the control means determines the amount of reduction in luminance such that the amount of reduction in luminance increases as the movement of the image pickup apparatus increases.

8. 3. The imaging device according to claim 2, wherein the control means reduces the luminance of the repeatedly displayed image when the movement of the imaging device exceeds a threshold value for a predetermined continuous period of time.

9. 3. The imaging device according to claim 2, wherein the control means starts reducing the brightness of the repeatedly displayed image when the movement of the imaging device exceeds a first threshold for a predetermined continuous period of time, and stops reducing the brightness of the repeatedly displayed image when the movement of the imaging device falls below a second threshold that is smaller than the first threshold for a predetermined continuous period of time.

10. 10. The imaging device according to claim 2, wherein the motion of the imaging device is an angular velocity of the imaging device.

11. An imaging element; a control means for, when an instruction to shoot a still image is detected while a live view display is being performed by shooting a moving image with the image sensor and displaying the moving image obtained by the shooting, causing the image sensor to preferentially shoot a still image, and for controlling the image sensor to repeatedly display the same image during a period in which the live view display cannot be updated due to the shooting of the still image, the control means changes a color tone of the repeatedly displayed image by combining an adjustment image having a specific color with the repeatedly displayed image based on a length of exposure time in capturing the still image; the control means determines a blending ratio of the specific color and / or the adjusted image based on the length of the exposure time in capturing the still image; The imaging device according to claim 1, wherein the control means determines a blending ratio of the adjusted image such that the blending ratio of the adjusted image increases as the length of the exposure time in capturing the still image increases.

12. An imaging element; a control means for controlling the image pickup device to, when an instruction to shoot a still image is detected while a live view display is being performed by shooting a moving image with the image pickup device and displaying the moving image obtained by the shooting, cause the image pickup device to prioritize shooting a still image, and to repeatedly display the same image during a period in which the live view display cannot be updated due to the shooting of the still image, the control means changes a color tone of the image to be repeatedly displayed by combining an adjustment image having a specific color with the image to be repeatedly displayed; The control means determines a blending ratio of the specific color and / or the adjusted image based on a length of exposure time in capturing the still image, The imaging device according to claim 1, wherein the control means determines the blending ratio of the adjusted image by taking into consideration information obtained from the image to be displayed, the type of image to be displayed, a still image shooting mode, and the movement of the imaging device.

13. The imaging device according to claim 12, characterized in that the information obtained from the displayed image is the brightness of the entire image or the main subject, and the control means determines a synthesis ratio of the adjustment image so that the synthesis ratio of the adjustment image increases as the brightness increases.

14. The imaging device according to claim 12, characterized in that information obtained from the displayed image is the amount of movement of a main subject, and the control means determines a synthesis ratio of the adjustment image so that the synthesis ratio of the adjustment image increases as the amount of movement increases.

15. The imaging device according to claim 12, characterized in that the type of image to be displayed is an image generated from an image obtained by still image shooting or an image generated from an image obtained by video shooting, and the control means determines a combination ratio of the adjustment image so that when the image to be displayed is an image generated from an image obtained by video shooting, the combination ratio of the adjustment image is larger than when the image to be displayed is an image generated from an image obtained by still image shooting.

16. The imaging device according to claim 12, characterized in that the still image shooting modes include a plurality of still image shooting modes having different continuous shooting speeds, and the control means determines a combination ratio of the adjustment image so that a combination ratio of the adjustment image is increased for a second still image shooting mode having a higher continuous shooting speed than the first still image shooting mode.

17. 13. The imaging device according to claim 12, wherein the control means determines a blending ratio of the adjustment image such that the blending ratio of the adjustment image increases as the movement of the imaging device increases.

18. 12. The imaging device according to claim 11, wherein the specific color is black or an achromatic color, and when the specific color is an achromatic color, the imaging device has a brightness based on the length of the exposure time in capturing the still image.

19. 12. The imaging device according to claim 11, wherein the specific color is black or an achromatic color, and if the specific color is an achromatic color, the brightness is based on the luminance of the entire image or a main subject, the amount of movement of the main subject, whether the image to be displayed is an image generated from an image obtained by still image shooting or an image obtained by video shooting, and the still image shooting mode.

20. A control method executed by an imaging device having an imaging element, comprising: When an instruction to shoot a still image is detected while a live view display is being performed by shooting a moving image by the image sensor and displaying the moving image obtained by the shooting, causing the imaging device to take a still image with priority; and controlling the display of the same image repeatedly during a period during which the live view display cannot be updated due to the capture of the still image; The controlling comprises: reducing the luminance of the repeatedly displayed image based on a length of exposure time in capturing the still image; determining an amount of reduction in luminance such that the amount of reduction in luminance increases as the length of the exposure time in capturing the still image increases; 13. A method for controlling an imaging apparatus comprising:

21. A control method executed by an imaging device having an imaging element, comprising: When an instruction to capture a still image is detected while a live view display is being performed by capturing a moving image using the image sensor and displaying the captured moving image, causing the imaging device to take a still image with priority; controlling the display of the live view to be repeatedly displayed during a period during which the live view display cannot be updated due to capturing the still image; and reducing the brightness of the repeatedly displayed image. a control method for an imaging device, characterized in that the step of reducing the brightness includes determining an amount of reduction in the brightness by taking into consideration not only one of the number of frames of the live view display that cannot be updated by capturing still images, the length of a period during which the live view display cannot be updated by capturing still images, and the length of the exposure time for capturing still images, but also one of information obtained from the image to be displayed, the type of image to be displayed, the still image capturing mode, and the movement of the imaging device.

22. A control method executed by an imaging device having an imaging element, comprising: When an instruction to capture a still image is detected while a live view display is being performed by capturing a moving image using the image sensor and displaying the captured moving image, causing the imaging device to take a still image with priority; and controlling the display of the same image repeatedly during a period during which the live view display cannot be updated due to the capture of the still image; The controlling comprises: changing a color tone of the repeatedly displayed image by synthesizing an adjustment image having a specific color with the repeatedly displayed image based on a length of exposure time in capturing the still image; determining a blending ratio of the specific color and / or the adjustment image based on the length of the exposure time in capturing the still image; determining a blending ratio of the adjustment image such that the blending ratio of the adjustment image increases as the length of the exposure time in capturing the still image increases; 23. A method for controlling an imaging apparatus comprising the steps of:

23. A control method executed by an imaging device having an imaging element, comprising: When an instruction to capture a still image is detected while a live view display is being performed by capturing a moving image using the image sensor and displaying the captured moving image, causing the imaging device to take a still image with priority; and controlling the display of the same image repeatedly during a period during which the live view display cannot be updated due to the capture of the still image; The controlling comprises: changing a color tone of the repeatedly displayed image by synthesizing an adjustment image having a specific color with the repeatedly displayed image; determining a blending ratio of the specific color and / or the adjusted image based on a length of exposure time in capturing the still image; and determining a blending ratio of the adjusted image taking into consideration information obtained from the image to be displayed, the type of image to be displayed, a still image shooting mode, and the movement of the imaging device.

23. A method for controlling an imaging apparatus comprising the steps of:

24. A program for causing a computer included in an imaging apparatus to function as a control unit for the imaging apparatus according to any one of claims 1 to 19.

Images