Image processing device, control method of the same, and program

Abstract

To display a live view without a difference in resolution and noise feeling, regardless of the maximum display luminance of a display device.SOLUTION: An image processing device for displaying an image obtained by an imaging unit, as a live view on a display device comprises: an acquisition unit which acquires information representing the maximum display luminance of the display device; a determination unit which on the basis of the information acquired by the acquisition unit, determines a parameter for correcting a noise and / or resolution; and a correction unit which corrects the image obtained by the imaging unit in accordance with the parameter and thereby generates an image representing the live view.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an image processing device that displays captured video as a live view, and a control method and program for the same. [Background technology]

[0002] Cameras equipped with a so-called live view display function that displays an image in real time on a display such as an electronic viewfinder during shooting are becoming more and more popular. Patent Document 1 discloses a method for performing live view display with low noise even when shooting a night scene or the like with high ISO sensitivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-186363 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 compares the display colors of imaging data captured at a low ISO sensitivity with those of imaging data captured at a high ISO sensitivity to estimate the color components of the color noise and perform color correction in order to reduce color noise in an image displayed on a display device.

[0005] On the other hand, in the case of noise amount adjustment using only the ISO sensitivity of the image pickup as in Patent Document 1, the user may perceive a different sense of noise depending on the maximum display luminance of the display, which may cause a sense of incongruity to the user looking at the display. Such a sense of incongruity may also occur in a case where the maximum display luminance of the display is dynamically changed according to the brightness of the surroundings, or the maximum display luminance is changed arbitrarily.

[0006] Furthermore, Patent Document 1 does not disclose any control related to the resolution correction process such as sharpness processing, which may cause an unnatural feeling in the resolution as well as noise.

[0007] The present invention has been made in consideration of the above problems, and aims to provide a technology that allows the perception of a uniform sense of resolution or noise by adjusting the strength of the resolution correction process or noise reduction process according to not only the imaging ISO sensitivity but also the maximum display brightness of the display. [Means for solving the problem]

[0008] In order to solve this problem, for example, an image processing device according to the present invention has the following arrangement. An image processing device that displays an image obtained by an imaging means as a live view on a display device, An acquisition means for acquiring information representing a maximum display luminance of the display device; a determination means for determining a parameter for correcting at least one of noise and perceived resolution based on the information acquired by the acquisition means; and a correction unit that corrects the image obtained by the imaging unit in accordance with the parameters to generate an image representing the live view. Effect of the Invention

[0009] According to the present invention, it is possible to display a live view without differences in resolution and noise, regardless of the maximum display brightness of the display device. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram of a digital camera to which an embodiment is applied. [Diagram 2] FIG. 11 is a diagram illustrating comparison conditions according to the embodiment and the modified example. [Diagram 3] 11A to 11C are diagrams illustrating examples of images displayed on a display device according to the embodiment and the modified example. [Figure 4] 11A and 11B are diagrams illustrating examples of luminance values ​​of a display image according to the embodiment and the modified example. [Diagram 5] 11A to 11C are diagrams illustrating examples of the perceived amount of luminance values ​​of a display image according to the embodiment and modified examples. [Figure 6] 11A to 11C are diagrams illustrating the perceived amount of overshoot and undershoot in a display image according to an embodiment and a modification example. [Figure 7] FIG. 4 is a functional configuration diagram of an image processing unit according to the embodiment and a modification example. [Figure 8] 5 is a flowchart showing the processing content of a control unit in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0012] [First embodiment] In the first embodiment, an example of application of the present invention to a digital camera having a display capable of operating as an electronic viewfinder will be described as an example of an image processing device. However, the present invention is applicable to electronic devices capable of generating images for display. For example, the applicable devices may be digital video cameras, personal computers, tablet terminals, mobile phones, game consoles, see-through goggles used for presenting AR (Augmented Reality) or MR (Mixed Reality), and the like, and any type of device may function as an electronic viewfinder.

[0013] The configuration of a digital camera 100 to which the first embodiment is applied is shown in Fig. 1. As shown in the figure, the digital camera 100 has a control unit 101, a recording medium 102, a memory 103, an imaging unit 104, an image processing unit 105, a display 106, an operation unit 107, and a lens 110, which are connected to a system bus so as to be able to communicate with each other.

[0014] The control unit 101 is a control unit consisting of at least one processor or circuit. The control unit 101 reads out an operating program from a recording medium 102, expands it into a memory 103, and executes it to control each component and cause it to function as a digital camera.

[0015] The recording medium 102 is a non-volatile recording device, such as a Flash-ROM, that is configured to be electrically erasable and recordable. The recording medium 102 holds information such as constants and parameters required for the operation of each block in addition to the operation programs of each block of the digital camera 100. The recording medium 102 may also serve as a configuration (semiconductor memory card) for recording images (RAW data, developed images, etc.) obtained by imaging. On the other hand, the memory 103 is a volatile recording device, such as an SRAM or DRAM, and is used as a development area and work area for the operation programs of each block. The memory 103 is also used as a VRAM when displaying images on a display 106, which will be described later.

[0016] Lens 110 is a unit equipped with a group of imaging lenses, and is configured to be detachable from digital camera 100. Note that lens 110 is usually composed of multiple lenses, but for simplicity, only one lens is shown in FIG. 1. Lens 110 has a control circuit (not shown). This control circuit changes the state of the lens, for example, moves the focus lens, etc., based on a drive signal input from control unit 101.

[0017] The imaging unit 104 is an imaging element such as a CCD or CMOS sensor, and obtains an analog image signal by converting an optical image formed on an imaging surface by the lens 110 into an electrical signal. The obtained analog image signal is converted into a digital image signal (hereinafter referred to as RAW data) by an A / D converter (not shown). In this embodiment, the imaging unit 104 is described as a single-plate color imaging element equipped with a general primary color filter. Here, the primary color filter is configured by arranging three types of color filters having main transmission wavelength bands in the vicinity of 650 nm, 550 nm, and 450 nm in a mosaic pattern (Bayer array). By applying the primary color filter, each pixel of the single-plate color imaging element captures a color plane corresponding to one of the bands of R (red), G (green), or B (blue). In other words, the photoelectric conversion elements constituting the single-plate color imaging element can only obtain light intensity related to a single color plane. The imaging unit 104 may also include peripheral circuits such as an amplifier circuit that processes signals obtained from the pixels.

[0018] The image processing unit 105 performs various image processing such as pixel interpolation, resizing, and color conversion on the RAW data from the imaging unit 104 or the RAW data read from the recording medium 102 (described in detail later). The image processing unit 105 also performs arithmetic processing on the RAW data obtained by imaging to derive information required for exposure control and distance measurement control. The digital camera 100 of this embodiment performs TTL (through-the-lens) type AF (autofocus) processing, AE (autoexposure) processing, and EF (flash pre-flash) processing based on the information. The image processing unit 105 also performs TTL type AWB (auto white balance) processing by performing arithmetic processing on the image data obtained by imaging.

[0019] The display 106 is a display device such as a liquid crystal display, and displays information such as settings of the digital camera 100, messages, GUIs such as menu screens, captured images, etc. The display 106 may be an electronic viewfinder (EVF) or a rear liquid crystal display built into the digital camera 100, or an external display detachably connected to the digital camera 100. In the following explanation, in order to explain display control of the electronic viewfinder while the digital camera 100 is capturing images, the explanation will be given assuming that the display 106 functions as an electronic viewfinder.

[0020] The display 106 includes a display control circuit (not shown) and is configured to be able to change its maximum display luminance. In the embodiment, when the display 106 is a liquid crystal display, the maximum display luminance itself depends on the drive control of the backlight. The maximum display luminance (backlight drive control) of the display 106 is dynamically controlled according to, for example, a Bv value (luminance value) obtained by the photometry result of the imaging scene. Alternatively, the maximum display luminance may be obtained by estimating the brightness of the scene according to the imaging mode set. That is, the maximum display luminance in this embodiment does not refer to the brightest luminance that the display can display, but refers to the maximum display luminance that can be output in the current display setting in a display whose luminance setting can be changed. Here, the photometry of the imaging scene may be performed based on an image signal obtained by imaging, or may be performed based on the output of a separately provided photometry sensor. In this embodiment, information on which the maximum display luminance of the display 106 is is obtainable, and the information is supplied to at least the image processing unit 105.

[0021] The operation unit 107 is a user interface provided in the digital camera 100 of this embodiment that accepts various operational inputs. When the operation unit 107 detects that an operational input has been made to each user interface, it outputs a corresponding control signal to the control unit 101. The operation unit 107 includes a release switch for instructing the start of a shooting preparation operation and the start of shooting (main shooting), an imaging mode selection switch for selecting an imaging mode, direction keys, an enter key, and the like. The operation unit may also include a touch panel.

[0022] In this embodiment, the processing according to the invention will be described as being realized by circuits and processors corresponding to each block of the hardware provided in the digital camera 100. However, the embodiment of the present invention is not limited to this, and the processing of each block may be realized by a program that performs the same processing as that of each block.

[0023] <Image generation control for electronic viewfinder> Next, a detailed description will be given of the generation of images (display images) to be displayed on the electronic viewfinder in the digital camera 100 of this embodiment. The digital camera 100 of this embodiment sequentially displays captured images acquired by the imaging unit 104 (for example, with an imaging frame rate of 30 frames per second) on the display 106.

[0024] The digital camera 100 of this embodiment is configured so that, in at least some of the imaging modes in which developed images are recorded, contrast correction, exposure correction, saturation correction, and the like that are performed during the development process can be set in advance.

[0025] The generation of a display image by the image processing unit 105 includes at least a gradation conversion that assigns a gradation value to the signal intensity indicated in the RAW data. The gradation conversion is performed based on the input / output characteristics that indicate the relationship between the signal value of the RAW data and the gradation value after development processing. For example, if each component of the RAW data is 14 bits and the developed data is 8 bits, the gradation conversion is a conversion of the 14-bit gradation value to an 8-tone value.

[0026] The maximum display luminance of the display 106 is controlled to be different depending on whether the image capture scene is a bright place or a dark place (extremely, whether it is a sunny daytime scene or indoors) in consideration of the visibility of the electronic viewfinder. Specifically, if the image capture scene is a bright scene such as a sunny daytime scene, it is set to 450 nit, and if the image capture scene is a relatively dark scene such as indoors, it is set to 150 nit. However, the value of the maximum display luminance in each scene is not limited to this, and other values ​​may be set. Note that the user selects whether it is a sunny daytime scene or indoors via the operation unit, but a sensor that detects brightness may be used.

[0027] Here, the difference in human visual perception that appears between sunny daytime and indoors, where the maximum display luminance is different, will be described.

[0028] According to the Weber-Fechner law, the amount of sensation that humans perceive is proportional to the logarithm of the amount of stimulation given to the sensory receptors. In this specification, based on this relationship between the amount of sensation and the amount of stimulation, the perceived resolution and noise of a displayed image are evaluated as a perceived amount using the final display luminance, which takes into account the maximum display luminance of the display 106, to explain the differences in perceived resolution and noise through an electronic viewfinder.

[0029] In the following, the relationship between the resolution and noise of a display image and the absolute luminance is shown by using the luminance component value of a perceptually uniform color space conforming to the human visual characteristics. In this embodiment, the I value of the ICtCp color space defined in ITU-R BT.2100 is used as the luminance component value of the perceptually uniform color space, and the Ct and Cp values ​​are used as the color component values. The I value can be derived from the RGB value by using the inverse characteristic (Inverse EOTF) of the EOTF (Electro-Optical Transfer Function) of the PQ (Perceptual Quantization) method standardized in SMPTE ST 2084. The PQ method determines the absolute luminance independent of the display characteristics specific to the display device, and is suitable for defining the sensory amount because bits are efficiently allocated based on the human visual characteristics.

[0030] 2 shows an example of comparison conditions in this embodiment. Consider a case where the lens aperture is narrowed down to F64 on a sunny day and the sensitivity of the image sensor is set to ISO 3200. Since the scene is bright at this time, the maximum display brightness of the electronic viewfinder is 450 nit. In contrast, consider a case where the lens aperture is narrowed down to F2 indoors and the sensitivity of the image sensor is set to ISO 3200. Since the scene is dark at this time, the maximum display brightness of the electronic viewfinder is 150 nit.

[0031] Here, consider a case where a high-contrast subject as shown in FIG. 3(a) is displayed on an electronic viewfinder. Generally, noise occurs when capturing an image at a high ISO sensitivity. For this reason, a well-known technique is used to adjust the strength of perceived resolution correction processing such as sharpness processing according to the ISO sensitivity in order to suppress an increase in noise. FIG. 4 shows a line profile of luminance value Y in the area shown by the dashed line 301 in FIG. 3(b) when perceived resolution correction processing is performed only according to the ISO sensitivity. The depression shown by reference numeral 401, which is generated by perceived resolution correction processing such as sharpness processing, is called an undershoot, and the bulge shown by reference numeral 402 is called an overshoot. Generally, the larger the width of the undershoot and overshoot, the higher the perceived resolution.

[0032] <Adjusting the resolution> As mentioned above, in Fig. 4, the perceived resolution is corrected according to only the ISO sensitivity at which the image was taken, so when comparing images on displays with different maximum display luminance settings, the perceived amount of resolution is not uniform. By using the I value of the ICtCp color space described above, an evaluation is made in accordance with visual characteristics. Fig. 5 shows the line profile in Fig. 4 converted into an I value to convert the perceived amount of resolution when the maximum display luminance of the display is set to 150 nit or 450 nit. Reference numeral 501 indicates the I value when the maximum display luminance is 150 nit, and reference numeral 502 indicates the I value when the maximum display luminance is 450 nit. The overshoot when the maximum display luminance is 150 nit is ΔIo501, and the undershoot ΔIu501. The overshoot when the maximum display luminance is 450 nit is ΔIo502, and the undershoot ΔIu502. The respective values ​​in this case are shown in Fig. 6.

[0033] As shown in Fig. 6, ΔIo502 is larger than ΔIo501, and similarly ΔIu502 is larger than ΔIu501, so the perceived resolution when the maximum display luminance is set to 450 nit is higher than when the maximum display luminance is set to 150 nit. Even though both images are captured at the same ISO sensitivity, the perceived resolution is different depending on the viewing environment, i.e., the maximum display luminance of the electronic viewfinder, which may cause discomfort to the user. Therefore, by using 150 nit as the standard and weakening the sharpness processing when displayed at 450 nit so that ΔIo501 and ΔIo502, as well as ΔIu501 and ΔIu502, are equal, it is possible to realize a display with a uniform perceived resolution depending on the scene luminance.

[0034] It is also possible to strengthen the sharpness processing when displaying at 150 nit with 450 nit as the standard, or to adjust the strength of the sharpness processing for 450 nit and 150 nit with a different luminance as the standard. In other words, by adjusting the sharpness processing (selecting the sharpness filter to be used) according to not only the imaging ISO sensitivity but also the maximum display luminance of the display, it is possible to realize a display with a uniform sense of resolution perceived according to the scene luminance.

[0035] Furthermore, although sharpness processing has been given as an example of perceived resolution adjustment, any perceived resolution correction processing such as diffraction correction processing may be used, or a combination of these may be used.

[0036] <Adjusting noise level> As with the resolution, the ICtCp value is used to calculate the noise level. The I value is used for luminance noise, and the Ct and Cp values ​​are used for chrominance noise, allowing the amount of noise to be calculated according to the perception characteristics. As with the resolution, if the same level of noise reduction processing is performed on 150 nit and 450 nit, it is easy to imagine that the 450 nit display will be perceived as having more noise, which may cause discomfort to the user. Here, by using the characteristics of 150 nit as the standard and strengthening the noise reduction processing so that the perceived amount of luminance noise and chrominance noise at 450 nit is equal to the perceived amount at 150 nit, a display with a uniform noise level according to the scene luminance can be realized.

[0037] The reference brightness may be either 150 nit or 450 nit, as in the case of adjusting the resolution, or may be a different brightness. In addition, a number of noise reduction filters are prepared in advance for use in the noise reduction process, and one of them is appropriately selected to perform the noise reduction process.

[0038] <Peaking processing threshold adjustment> Peaking processing is widely known as one of the auxiliary functions for focus adjustment in manual focusing, etc. This is a function that uses a predetermined threshold value to determine whether or not a displayed image is an edge area, and colors the obtained edge area with a predetermined color to make the focused area easier to see. If the coloring during peaking processing, i.e., the determination result of whether or not an area is an edge area, changes as a result of adjusting the sharpness intensity based on the maximum display brightness, it may cause a deterioration in usability.

[0039] By varying the threshold value in conjunction with the adjustment amount of the sharpness intensity and maintaining the coloring results obtained during peaking processing, it is possible to prevent deterioration of the usability.

[0040] <Functional configuration of image processing unit 105> Next, the functional configuration and operation of the image processing unit 105 related to the generation of an image for display will be described with reference to Fig. 7. Fig. 7 shows the configuration of the image processing unit 105 related to the development processing related to the image for display.

[0041] In the imaging unit 104, it is assumed that three types of color filters, R, G, and B, are arranged in a mosaic pattern (typically a Bayer array) on the imaging surface of the imaging element. Therefore, the RAW data 701 can be said to be color mosaic image data represented by one component (either R, G, or B) per pixel. The image processing unit 105 reads the RAW data 701 from the memory 103, applies development processing, and generates a display image 707 in which one pixel is composed of three components.

[0042] First, the white balance unit 702 performs white balance processing on the RAW data 701, which converts the image of the subject, which is originally white, into white. More specifically, the white balance unit 702 plots the RGB data of each pixel constituting the RAW data 701 in a predetermined color space, such as an xy color space. The white balance unit 702 then integrates R, G, and B of the data plotted in the color space near the locus of blackbody radiation, which is likely to be the light source color, and derives white balance coefficients (G / R and G / B) for the R and B components from the integral value. The white balance unit 702 performs white balance processing using the obtained white balance coefficients, thereby correcting color casts caused by the light source and reproducing white.

[0043] The color interpolation unit 703 performs noise reduction processing and processing to interpolate pixel values ​​of color components not included in each pixel on the image data converted by the white balance unit 702. Through this processing, a synchronized image is generated in which R, G, and B color information (pixel values ​​of color components) are complete for all pixels.

[0044] A matrix conversion unit 704 performs a matrix conversion process on the synchronized image generated by the color interpolation unit 703 to convert it into a color image that is the basis of the process. Furthermore, a color and brightness adjustment unit 706 applies an adjustment process to this color image to adjust the color and brightness, thereby generating a display image 707 as a live view.

[0045] Here, the adjustment by the color brightness adjustment unit 706 includes adjustment performed by referring to color brightness adjustment parameters 705 that describe settings for contrast correction, exposure correction, saturation correction, sharpness correction, etc., to be applied to the recorded image according to the current maximum display brightness of the display 106 (information indicating the driving status of the backlight, since an LCD display is used in this embodiment).

[0046] The display image 707 thus generated is displayed on the display 106 whose maximum display luminance is controlled in accordance with the captured scene, thereby realizing an electronic viewfinder.

[0047] Next, the process of obtaining the color brightness adjustment parameter 705 by the control unit 101 in this embodiment will be described with reference to the flowchart in Fig. 8. The program in this figure is loaded from the storage medium 102 to the memory 103 and executed. This program is not executed for every frame by the imaging unit 104, but at appropriate frame intervals (for example, every few seconds).

[0048] In S100, the control unit 101 obtains current RAW data from the imaging unit 104 and determines the scene currently being photographed. To give a specific example, the control unit 104 obtains a Bv value from the photographing conditions of the RAW data. The control unit 101 then compares the Bv value with a pre-stored threshold value Th. If the control unit 101 determines that the Bv value is equal to or greater than the threshold value Th, it determines that photographing is currently being performed during the day under clear skies. If the control unit 101 determines that the Bv value is below the threshold value Th, it determines that photographing is currently being performed indoors.

[0049] In S110, the control unit 101 determines the maximum display luminance of the display unit 106. In the above embodiment, if the control unit 101 determines that shooting is currently taking pictures under clear skies during the day, the control unit 101 determines the maximum display luminance of the display unit 106 to be 450 nits. On the other hand, if the control unit 101 determines that shooting is currently taking pictures indoors, the control unit 101 determines the maximum display luminance of the display unit 106 to be 150 nits.

[0050] Then, in S120, the control unit 101 drives the backlight of the display unit 106 so as to achieve the determined maximum display luminance. This backlight driving state is maintained until the next time this process is performed.

[0051] In S130, the control unit 101 determines the color luminance adjustment parameter 705 in order to perform the display described above according to the determined maximum display luminance.

[0052] As described above, according to this embodiment, it is possible to generate a display image that gives the perception of uniform resolution and noise, regardless of the maximum display luminance of the display.

[0053] In the above embodiment, the display 106 has been described as a liquid crystal display using a backlight. However, the type of display is not limited to this, and the display may be a self-luminous organic EL device, for example. In this case, the device itself emits light, so the maximum display luminance can be achieved by adjusting the drive signal for the device.

[0054] In the above embodiment, the maximum display brightness of the display device 106 is described as 450 nits and 150 nits, but the maximum display brightness is not limited to these values. Also, the maximum display brightness of the display device 106 can be changed in more than two stages instead of two stages.

[0055] In the above embodiment, the scene is determined from the captured image data, but the user may select the type of scene by operating the operation unit 107. In other words, the maximum display brightness of the display 106 may be changed by the user's operation.

[0056] In the above, the resolution adjustment process is performed in accordance with the ISO sensitivity and maximum display brightness settings for the live view display image, but on the other hand, the resolution adjustment process may be performed only in accordance with the ISO sensitivity for the image to be recorded.

[0057] In the above embodiment, the resolution adjustment process is based on the first display luminance of the display device, and when the display is performed at a second display luminance higher than the first display luminance, the noise reduction process is strengthened or the resolution correction process is weakened so that the difference in the perceived amount is reduced. Furthermore, when the display is performed at a third display luminance lower than the first display luminance, the noise reduction process may be weakened or the resolution correction process may be strengthened so that the difference in the perceived amount is reduced.

[0058] In the above embodiment, the image processing unit 105 has been described as having the configuration shown in Fig. 7. However, if the processing capacity of the control unit 101 is sufficiently high, each configuration shown in Fig. 7 may be realized by the control unit 101 executing a program.

[0059] In the above embodiment, the generation of video data for live view display has been described, but when recording the video on a recording medium, processing is performed that is unrelated to the maximum display brightness of the display. For example, in live view display, processing is performed according to the exposure such as ISO sensitivity in addition to the maximum display brightness of the display. However, for the video to be recorded, the maximum display brightness may not be used, and only processing according to ISO sensitivity may be performed.

[0060] [Variation 1] This embodiment can be realized by any device that generates an image that presents a sense of resolution and a sense of noise that are uniformly perceived regardless of the change in the maximum display luminance of a display device that can change the maximum display luminance. At this time, information on the maximum display luminance that has been set may be obtained from the display device via a signal formulated according to a standard adopted for connection with the display device 106, or may be obtained from another device that controls the operation of the display device. That is, unlike the first embodiment, it does not have to be determined based on the photometry results of the image capture scene.

[0061] [Variation 2] This embodiment may also be applied when generating an image to be displayed on an external display detachably connected to the digital camera 100. That is, the sense of resolution and the sense of noise may be adjusted according to information on the maximum display luminance obtained from the external display. In addition, it may be possible to switch whether or not to comply with the maximum display luminance information when displaying on the external display, based on a user instruction or the like.

[0062] [Variation 3] This embodiment may also be applied to the case where a display image is displayed simultaneously on an external display and an electronic viewfinder or rear LCD display built into the digital camera 100. In other words, the resolution and noise may be adjusted according to the maximum display luminance of the external display and the electronic viewfinder or rear LCD display, respectively, or may be configured to correspond to the maximum display luminance of only one of them.

[0063] [Variation 4] In this embodiment, an image is generated that presents a sense of resolution and noise that is perceived equally regardless of the change in maximum display brightness for a display device that can change the maximum display brightness. Since the present invention aims to reduce discomfort when shooting, it is sufficient to apply it only to the image for display, that is, it does not have to be applied to the recorded image. In other words, the adjustment of the sense of resolution and noise for the recorded image may be configured to correspond only to the shooting ISO sensitivity.

[0064] (Other Examples) 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.

[0065] The disclosure of this specification includes the following image processing device, its control method, and program. (Item 1) An image processing device that displays an image obtained by an imaging means as a live view on a display device, An acquisition means for acquiring information representing a maximum display luminance of the display device; a determination means for determining a parameter for correcting at least one of noise and perceived resolution based on the information acquired by the acquisition means; a correction means for generating an image representing the live view by correcting the image obtained by the imaging means in accordance with the parameters; 13. An image processing device comprising: (Item 2) The display is an external display device, The acquiring means acquires information representing a maximum display luminance of the display device by communicating with the display device. 2. The image processing device according to item 1, (Item 3) a scene determination means for determining a scene represented by the image based on the luminance of the image data obtained from the imaging means; an adjustment means for adjusting the brightness of the display in accordance with the scene determined by the scene determination means; 2. The image processing device according to item 1, wherein the acquisition means acquires the maximum display luminance of the display device adjusted by the adjustment means as the maximum display luminance. (Item 4) 4. The image processing device according to any one of items 1 to 3, wherein the correction means performs noise reduction or correction of perceived resolution using an ICtCp color space. (Item 5) A method for controlling an image processing device that displays an image obtained by an imaging means as a live view on a display device, comprising the steps of: acquiring information representing a maximum display luminance of the display; a determination step of determining a parameter for correcting at least one of noise and perceived resolution based on the information acquired in the acquisition step; a correction step of generating an image representing the live view by correcting the image obtained by the imaging means in accordance with the parameters; 13. A method for controlling an image processing apparatus comprising the steps of: (Item 6) A program that, when read and executed by a computer, causes the computer to function as each of the means possessed by the device described in any one of items 1 to 4.

[0066] The 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. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0067] 100... digital camera, 101... control unit, 104... imaging unit, 105... image processing unit, 106... display unit, 701... RAW data, 705... color luminance adjustment parameter, 706... color luminance adjustment unit, 707... image for display

Claims

1. An image processing device that generates video to be displayed as a live view on a display device, An acquisition means for acquiring information representing the current maximum display brightness of the aforementioned display device, A determination means that determines parameters for correcting at least one of the noise and resolution of an image based on the information acquired by the acquisition means, Correction means for generating an image to be displayed as a live view by correcting the acquired image according to the parameters, An image processing apparatus characterized by having

2. The aforementioned display is an external display device, The acquisition means acquires information representing the maximum display brightness of the display device by communicating with the display device. The image processing apparatus according to feature 1.

3. A scene determination means for determining the scene represented by the acquired video based on its brightness, The device has an adjustment means for adjusting the maximum display brightness of the display unit according to the scene determined by the scene determination means, The acquisition means acquires information representing the maximum display brightness adjusted by the adjustment means as information representing the maximum display brightness. The image processing apparatus according to feature 1.

4. The image processing apparatus according to claim 1, characterized in that the correction means performs noise reduction or resolution correction using the ICtCp color space.

5. The image processing apparatus according to claim 1, wherein the correction means corrects the acquired image so as to suppress changes in the imaging sensitivity of the acquired image and the maximum display brightness of the display that affect the noise and resolution perceived from the image displayed on the display.

6. A control method for an image processing device that generates video to be displayed as a live view on a display device, An acquisition step of acquiring information representing the current maximum display brightness of the display device, A determination step, based on the information acquired in the acquisition step, determines parameters for correcting at least one of the noise and resolution of the image. A correction step is performed to correct the acquired video according to the parameters to generate the video to be displayed as the live view. A control method for an image processing apparatus, characterized by having the following features.

7. A program that, when read and executed by a computer, causes the computer to perform each step of the method according to claim 6.

Images