JP2006295814A - Image processing device and method therefor, and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brightness level distribution graph independent of a gamma characteristic. <P>SOLUTION: An image processing device includes an input means for inputting image data, a gamma correction means for performing a gamma correction to the image data inputted by the input means, and a generation means for generating a graph indicating a distribution of a brightness level of the image data to which the gamma correction is performed. The generation means sets a scale of the brightness level of the graph so that intervals of output values after the gamma correction corresponding to a plurality of input values of an equal interval before the gamma correction may become equal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus and method, and an imaging apparatus, and more particularly to an image processing apparatus and method, and an imaging apparatus that process electrical image data obtained by photoelectrically converting a subject optical image.

  Bar graphs and line graphs representing frequency distributions (histograms) for each luminance level, with the horizontal axis representing the luminance level and the vertical axis representing the frequency of pixels, etc., for the purpose of making it easy to check the appropriateness of exposure during shooting A technique for displaying (hereinafter referred to as “brightness level distribution graph”) on a liquid crystal monitor or the like is known (see, for example, Patent Document 1).

  In the conventional luminance level distribution graph, for example, in the case of 8 bits, a graph is created by counting the number of pixels for each luminance level from 0 to 255.

JP 2003-125240 A

  However, generally, the image signal is subjected to gamma correction, and the brightness of the image signal after image processing is not linear.

  FIG. 10 is a conceptual diagram for explaining a conventional example. FIG. 10A shows a gamma curve, with the horizontal axis indicating input and the vertical axis indicating output. When a general S-shaped gamma correction as shown in FIG. 10A is applied to an image having a brightness level distribution as shown in FIG. 10B, the brightness level distribution after the gamma correction is as shown in FIG. As shown in (c). That is, by performing the gamma characteristic correction as shown in FIG. 10A, the interval between the luminance values after gamma correction corresponding to the luminance values that were equally spaced before the gamma correction is wide at the center, Becomes narrower and disappears at equal intervals. However, in the conventional example, regardless of changes in luminance values before and after gamma correction, a luminance level distribution graph of the image signal after gamma correction is generated using equally-spaced scales as shown in FIG. .

  As described above, when the luminance level distribution graph after the gamma correction is generated, the shape of the graph is different before and after the gamma correction, as is apparent from FIGS. 10 (b) and 10 (c). Specifically, for example, when a mountain near the center in the luminance level distribution graph before gamma correction moves toward the end in the luminance level distribution graph after gamma correction, the width of the mountain becomes narrower.

  When it is determined whether or not exposure is appropriate at the time of shooting by looking at such a conventional luminance level distribution graph, and the exposure correction is to be performed, it is difficult for the photographer to determine the exposure correction amount. This is because gamma correction is normally performed on an image signal that has been exposure-corrected. For example, in the case of an image that has been subjected to general gamma correction, the distribution near the center of the luminance level distribution graph has a slight exposure correction amount. However, although the horizontal axis moves greatly, the distribution at the end does not move much even if the exposure correction amount is increased. As a specific example, FIG. 10 (d) shows a luminance level distribution graph when exposure correction is performed so that the image signal shown in the luminance level distribution graph of FIG. 10 (b) becomes bright, and the image signal is subjected to gamma correction. A later conventional luminance level distribution graph is shown in FIG.

  As can be seen from a comparison between FIG. 10C and FIG. 10E, the shape of the graph changes greatly before and after exposure correction. Therefore, an appropriate exposure correction amount is determined from the conventional luminance level distribution graph. It was difficult.

  The present invention has been made in view of the above problems, and an object thereof is to provide a luminance level distribution graph that is not affected by gamma characteristics.

  Furthermore, another object is to make it possible to determine the used gamma characteristic from the luminance level distribution graph.

  In order to achieve the above object, an image processing apparatus of the present invention includes an input unit for inputting image data, a gamma correction unit for performing gamma correction on the image data input from the input unit, and the gamma-corrected image data. Generating means for generating a graph indicating a distribution of luminance levels, wherein the generating means is configured such that intervals between the output values after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction are equal intervals. The scale of the luminance level of the graph is set so that

  The image processing method of the present invention includes an input step of inputting image data, a gamma correction step of performing gamma correction on the image data input in the input step, and a luminance level distribution of the gamma corrected image data. A generating step for generating a graph, wherein in the generating step, the intervals between the output values after the gamma correction corresponding to the plurality of input values at the equal intervals before the gamma correction are equal intervals. A scale of the luminance level of the graph is set.

  According to another configuration, the image processing apparatus of the present invention includes an input unit that inputs image data, a gamma correction unit that performs gamma correction on the image data input from the input unit, and the gamma-corrected image. Generating means for generating a graph showing a distribution of luminance levels of data, the generating means on the generated graph after the gamma correction corresponding to a plurality of equally spaced input values before the gamma correction An index indicating the output value of is displayed.

  The image processing method of the present invention includes an input step of inputting image data, a gamma correction step of performing gamma correction on the image data input in the input step, and a luminance level distribution of the gamma corrected image data. A generating step for generating a graph, and in the generating step, an index indicating an output value after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction is provided on the generated graph. indicate.

  According to the present invention, it is possible to provide a luminance level distribution graph independent of gamma characteristics.

  In addition, the used gamma characteristic can be determined from the luminance level distribution graph.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a block diagram showing a schematic configuration of an imaging apparatus such as a digital camera according to the first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a photographic lens, and reference numeral 2 denotes an AF (autofocus) drive circuit, which is composed of, for example, a stepping motor. The focus is adjusted by changing the focus lens position in the photographic lens 1 under the control of a microcomputer 16 to be described later. Match. The defocus amount used for the focus calculation is calculated by using the video signal processing circuit 10 for an output from a specific area of the image sensor 6 to be described later.

  The zoom drive circuit 3 is constituted by, for example, a stepping motor, and changes the focal length of the photographic lens by changing the position of the zoom lens in the photographic lens 1 under the control of the microcomputer 16. The aperture driving circuit 4 is constituted by, for example, an auto iris or the like, and changes the optical aperture value of the aperture 5 under the control of the microcomputer 16.

  Reference numeral 6 denotes an image sensor, which uses a photoelectric conversion element such as a CCD or a MOS, and photoelectrically converts an optical image such as a subject incident on the light receiving surface by the photographing lens 1 through an aperture 5. Outputs electrical signals.

  A clamp / CDS (Correlated Double Sampling) circuit 7 and an AGC (Auto Gain Controller) 8 perform basic analog processing before A / D conversion. The microcomputer 16 can change the clamp level and the AGC reference level.

  The A / D converter 9 converts the analog signal output from the image sensor 6 and processed by the clamp / CDS circuit 7 and the AGC 8 into a digital signal. The video signal processing circuit 10 performs image processing based on development parameters such as filter processing, color conversion processing, and gamma / knee processing on the digitized image data, and outputs the processed image data to the memory controller 13. Further, the video signal processing circuit 10 generates a graph (luminance level distribution graph) indicating the distribution of luminance levels of image data after image processing including gamma / knee processing. The gamma / knee can be switched by an instruction from the microcomputer 16, and an optimum one is selected and instructed according to the photographing mode. The video signal processing circuit 10 also includes a D / A converter, which converts the video signal input from the A / D converter 9 and the image data input from the memory controller 13 into an analog signal, and outputs an EVF ( It is also possible to output to the EVF 12 through the Electrical View Finder) drive circuit 11.

  The function switching of these video signal processing circuits 10 is performed by exchanging data with the microcomputer 16, and the exposure information, focus information, white balance information and autofocus information of the image signal are output to the microcomputer 16 as necessary. Is also possible. Based on the information obtained from the video signal processing circuit 10, the microcomputer 16 adjusts the white balance correction value and the gain. Further, the focus information is evaluated and communicated to the AF drive circuit 2 to drive the focus lens in the photographing lens 1.

  Further, under the instruction of the microcomputer 16, the image data sent from the A / D converter 9 is subjected to compression encoding processing such as lossless compression without performing image processing with the development parameters by the video signal processing circuit 10, and the memory It is also possible to store in the buffer memory 19 through the controller 13. Such image data is called RAW image data. The video signal processing circuit 10 also has a function of performing compression processing such as JPEG. In the case of continuous shooting, RAW image data is temporarily stored in the buffer memory 19, and when there is processing time, the RAW image data is read from the buffer memory 19 through the memory controller 13, and image processing and compression processing are performed by the video signal processing circuit 10. And you can earn continuous shooting speed. The number of images that can be continuously shot depends on the capacity of the buffer memory 19.

  In the memory controller 13, RAW image data input from the video signal processing circuit 10 is stored in the buffer memory 19, a processed digital image is stored in the memory 14, and conversely, image data from the buffer memory 19 or the memory 14 is stored. Are output to the video signal processing circuit unit 10. The memory controller 13 can also control the image sent from the external interface 15 to be stored in the memory 14 or output the image stored in the memory 14 via the external interface 15. . As the memory 14, an internal memory or a removable storage medium can be used.

  The power supply unit 17 supplies power necessary for each IC and drive system.

  The operation member 18 transmits the state of the operation member 18 to the microcomputer 16, and the microcomputer 16 controls each part according to the change of the operation member 18.

  20 (a) is an input switch (SW1) of the operation member 18 that is turned on when a release button (not shown) is half-pressed, and 20 (b) is an operation switch 18 that is turned on when the release button (not shown) is fully pressed. Input switch (SW2). The release button (not shown) is constituted by a two-stage switch, and the input switch (SW2) 20 (b) is turned on via the ON state of the input switch (SW2) 20 (a). In this case, the captured image is held. And recorded.

  Reference numeral 21 denotes a liquid crystal drive circuit which drives the external liquid crystal display unit 22 and the in-finder liquid crystal display unit 23 in accordance with a display content command of the microcomputer 16. The in-finder liquid crystal display unit 23 is provided with a backlight such as an LED (not shown), and the LED is also driven by the liquid crystal drive circuit 21.

  Next, the operation of the imaging apparatus having the above configuration will be described with reference to the flowchart of FIG.

  When the process is started, the microcomputer 16 determines whether or not a power-off timer (not shown) has timed out in step S101. If it is determined that the time-out has occurred, the microcomputer 16 proceeds to step S118 for power-off processing. If not timed out, the process proceeds to step S102.

  In step S102, various settings are performed. Various settings such as a camera mode are set according to the input content of the operation member 18. In step S103, the state set in step S102 and various setting states are displayed on the external liquid crystal display member 22 or the like.

  In step S104, it is determined whether or not the input switch (SW1) 20 (a) is on, that is, whether or not a release button (not shown) is in a half-pressed state. If the input switch (SW1) 20 (a) is off, the process returns to step S101. If the input switch (SW1) 20 (a) is on, the process proceeds to step S105 to update the power-off timer (reset to 0 or set to a predetermined value).

  Next, the image signal read from the image sensor 6 in step S <b> 106 is taken in via the clamp / CDS circuit 7, AGC 8, and A / D converter 9. In step S107, the lens drive amount is calculated and determined based on the focus information that is the output of the video signal processing circuit 10, and the focus lens in the lens 1 is driven using the AF drive circuit 2 to adjust the focus. In step S108, the gain value sent to the AGC 8 and the aperture value sent to the aperture drive circuit 4 and the image sensor 6 are set so as to obtain appropriate brightness based on the exposure condition information output from the video signal processing circuit 10. The electronic shutter value for control is calculated and controlled. Further, in step S109, based on the white balance information output from the video signal processing circuit 10, the video signal processing circuit 10 calculates and determines the R and B gains used for white balance correction so as to obtain an appropriate color. ,Control.

  In step S110, the image signal captured and processed in step S106 is sent to the EVF drive circuit 11 and displayed on the EVF 12. Further, the photographing information (AF, AE, WB) determined in steps S107, S108, and S109 is sent to the liquid crystal drive circuit 21 and displayed on the external liquid crystal display 22 and the finder liquid crystal display 23. At this time, the backlight of the in-finder liquid crystal display 23 is also turned on.

  Also, a luminance level distribution graph of the image signal after gamma correction is generated and displayed on the EVF. The luminance level distribution graph generated here will be described later in detail.

  The user determines whether the image configuration, brightness, and the like are desired from the image signal displayed on the EVF 12, the luminance level distribution graph displayed together with the image, and the shooting information displayed on the external liquid crystal display 22. Can be confirmed.

  Next, the process proceeds to step S111, where it is determined whether or not the input switch (SW2) 20 (b) is turned on. If it is on, the process proceeds to step S112 to record an image. If not, the process proceeds to step S104. Return.

  In step S112, photographing processing is performed under the conditions set in steps S107, S108, and S109, and the obtained image signal is sent to the memory controller 13 and temporarily stored in the buffer memory 19. Details of the imaging process performed in step S112 will be described later with reference to FIG. When continuous shooting is set, the imaging process is repeated at predetermined time intervals while the input switch (SW2) 20 (b) is on. However, since the captured image is temporarily stored in the buffer memory 19, as described above, the maximum number of images that can be recorded by one continuous shooting depends on the capacity of the buffer memory 19, and the input switch (SW2) 20 (b When the maximum number of images is reached, the shooting process ends.

  In step S113, the image stored in the buffer memory 19 is processed and compressed when the load on the video signal processing circuit 10 is at a level at which image processing is possible, and the operation of storing in the memory 14 is started. If the load on the video signal processing circuit 10 is so high that images are continuously stored in the buffer memory 19 such as continuous shooting, the image processing may be stopped when the image processing level is not sufficient.

  In step S114, the storable area of the memory 14 is checked to determine the recordable number of sheets. Note that when making the determination, the determination is performed in consideration of an unprocessed image on the buffer memory 19.

  In step S115, it is determined whether or not further photographing is possible as a result of the determination in step S114. If photographing is possible, the process returns to step S104 to determine the input switch (SW1) 20 (a) described above. repeat. On the other hand, if the photographing is not possible, the process proceeds to step S117 to display a warning display indicating that the memory 14 has insufficient free space or that the next photographing cannot be performed, and then returns to step S101.

  In step S101, when a power-off timer (not shown) times out as described above, the process proceeds to step S118, the EVF drive circuit 11 turns off the EVF 12, and the backlight of the in-finder liquid crystal display unit 23 is also turned off. When the external liquid crystal display unit 22 is on, the external liquid crystal display unit 22 is also turned off. Further, in step S119, the image processing and compression started in step S113 and the storage in the memory 14 are all completed, and the buffer memory 19 is waited for. When the processing is completed and the buffer memory 19 is empty, Then, the power supply circuit 17 is instructed to turn off unnecessary power, and the process is terminated.

  Next, details of the photographing processing operation performed in step S112 will be described with reference to FIG.

  First, in step S201, a mirror (not shown) is moved to the mirror up position, and in step S202, the aperture 5 is driven to a predetermined aperture value based on the photometric data obtained by the photometric processing in step S108 of FIG. In step S203, the charge clear operation of the image sensor 6 is performed, and charge accumulation is started in step S204. After the start of charge accumulation, a shutter (not shown) is opened in step S205, and exposure of the image sensor 6 is started (step S206).

  Thereafter, in step S207, the process waits for the end of exposure according to the photometric data, and the shutter is closed in step S208. In step S209, the aperture is driven to the open aperture value, and in step S210, the mirror is driven to the mirror down position. In step S211, it waits until the set charge accumulation time elapses, and the charge accumulation of the image sensor 6 is terminated (step S212). Finally, in step S213, the signal of the image sensor 6 is read out, and a series of processes is terminated and the process returns to the main process.

  Next, the luminance level distribution graph in the first embodiment displayed in step S110 of FIG. 2 will be described with reference to FIG.

  FIG. 4A is a diagram illustrating a gamma correction curve, where the horizontal axis indicates an input value and the vertical axis indicates an output value. As can be seen from FIG. 4 (a), the interval between the output values with respect to the input value at equal intervals is not equal. For example, as shown in FIG. 4A, in a general S-shaped gamma characteristic, the interval between the output values with respect to the equally spaced input values is wide at the central portion and narrow at the periphery.

  Conventionally, in the luminance level distribution graph of the image signal after the gamma processing, as shown in FIG. 4B, the interval between the output values after the gamma correction with respect to the input values at the same interval before the gamma correction becomes an unequal interval. In the graph, the shape of the graph was different before and after the gamma treatment. On the other hand, in the first embodiment, when the luminance level distribution graph after gamma correction is created, the scale of the luminance level is equal to the input value after gamma correction with respect to the input value at equal intervals before gamma correction. Set to be. That is, the scale on the horizontal axis (luminance level) as shown in FIG. 4B is set to the scale on the horizontal axis (luminance level) as shown in FIG. Thereby, even when the exposure correction is performed and the peak of the luminance level distribution moves to the left and right, the shape of the peak of the luminance level distribution after the gamma correction does not change.

  5A and 5B are diagrams showing luminance level distribution graphs before and after exposure correction in the first embodiment. FIG. 5A shows a state before exposure correction, and FIG. 5B shows a state after applying +0.5 EV exposure correction. It is a luminance level distribution graph. As described above, it can be seen that the shape of the graph of the luminance level distribution graph does not change even after the gamma correction, and the graph has just moved to the left by the exposure correction amount.

  FIG. 6 is a diagram showing another example of gamma characteristics. Even with such gamma characteristics, when exposure correction is performed, the shape of the graph of the luminance level distribution graph does not change, and the graph moves to the left or right by the exposure correction amount.

  Thus, according to the first embodiment, it is possible to provide a luminance level distribution graph that is not affected by the gamma characteristic. Thereby, the relationship between the exposure correction amount and the movement of the luminance level distribution is clarified, and the exposure correction amount can be easily determined from the luminance level distribution graph, so that the operability is improved.

  In the first embodiment, it has been described that the luminance level distribution graph is always generated and displayed in step S110 of FIG. 2, but the luminance level distribution graph display mode is provided and the mode is set. Only in this case, it may be controlled to generate and display a luminance level distribution graph.

  The scale of the brightness level shown in FIG. 4C may be actually displayed on the brightness level distribution graph. In that case, it is preferable to set the interval between input values before gamma correction to an integral multiple of the exposure correction amount. For example, by setting the exposure correction width × 1 times, for example, by changing the exposure correction amount by one step, it is known in advance that the graph moves by one scale in the left or right direction. Easy to judge.

  The luminance level distribution graph after gamma conversion shown in FIGS. 4 to 6 is set so that the luminance level value increases toward the left side of the graph, but the luminance level value increases toward the right side of the graph. It goes without saying that the graph may be as follows.

<Second Embodiment>
Next, a second embodiment of the present invention will be described.

  In the second embodiment, a case where an index indicating the gamma characteristic used by the video signal processing circuit 10 is displayed on the luminance level distribution graph when generating the luminance level distribution graph of the image will be described. Note that the imaging apparatus and the operation thereof in the second embodiment are the same as those described with reference to FIGS. 1 to 3 in the first embodiment, and thus the description thereof is omitted here.

  7 and 8 are diagrams for explaining a luminance level distribution graph in the second embodiment.

  As described above, when gamma correction is performed by a general S-shaped gamma characteristic as shown in FIG. 7A, as shown in FIG. 7B, the input values are equally spaced before gamma correction. The interval between the output values after the gamma correction is not equal, but is wide near the center and narrow in the peripheral region. In the second embodiment, the index indicating the non-equal interval output values is displayed so as to be superimposed on the luminance level distribution graph. Accordingly, when the gamma characteristic shown in FIG. 8A is different from that shown in FIG. 7A, an index is displayed at a position of a luminance level different from that shown in FIG. 7B as shown in FIG. 8B. Will be. FIG. 9 shows a luminance level distribution graph before exposure correction and when +0.5 EV exposure correction is applied.

  In the second embodiment as well, it is preferable to set the interval between input values before gamma correction to an integral multiple of the exposure correction amount. In this way, the index shown on the luminance level distribution graph is an integral multiple of the exposure correction amount. Therefore, for example, if the exposure correction width × 1 is set, for example, by changing the exposure correction amount by one step, it is known in advance that the graph moves by one scale in the left or right direction. It becomes easier to judge.

  Thus, since the index is displayed on the luminance level distribution graph, it is easy to determine the exposure correction amount. Further, since the index position of the displayed luminance level differs depending on the gamma characteristic to be used, it is possible to roughly determine what gamma characteristic is used for the gamma correction from the displayed index.

<Other embodiments>
In the first and second embodiments, the case has been described where, in the imaging apparatus, the luminance level distribution graph is displayed on the EVF 12 together with the captured image in step S111 before the imaging process in step S112 of FIG. 2 is performed. The image may be displayed on an external liquid crystal display 22 or the like different from EVF, and the present invention is not limited to this.
For example, in addition, the image condition information (RAW image data) before development processing, which is captured by the image capturing apparatus, is recorded in the memory 14 as it is, the recorded RAW image data is read on the PC, and the image capturing condition information attached to the RAW image data is included. Based on the above, when image processing such as development processing is performed on the PC application software, the same applies to the case where the luminance level distribution graph of the read image is displayed.

  Further, the imaging devices in the first and second embodiments are not limited to digital cameras, but also include digital video cameras, mobile phones with digital cameras, scanners, and the like. In addition, there is also included an apparatus in which imaging is performed by a remote operation in which a release instruction is issued from the PC in a state where the imaging apparatus and the PC are connected by wire or wireless, and a monitor display on the PC is used.

  Furthermore, the present invention can also be applied to an image processing apparatus that inputs an image signal from an external imaging device and performs various image processing such as development processing on the input image signal. In that case, if the input image signal is obtained by performing gamma correction, the luminance level distribution graph is generated and displayed based on the obtained image signal as described in the first and second embodiments. Good.

  Also, a software program for realizing the functions of the above-described embodiment for an apparatus connected to the various devices or a computer in the system so as to operate various devices to realize the functions of the above-described embodiments. What was implemented by supplying the code and operating the various devices in accordance with a program stored in a computer (CPU or MPU) of the system or apparatus is also included in the scope of the present invention. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included. Examples of the storage medium for storing the program code include a flexible disk, hard disk, ROM, RAM, magnetic tape, nonvolatile memory card, CD-ROM, CD-R, DVD, optical disk, magneto-optical disk, MO, and the like. Can be considered. Also, a computer network such as a LAN (Local Area Network) or a WAN (Wide Area Network) can be used to supply the program code.

  Furthermore, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function is based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion card or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

1 is a block diagram illustrating a schematic configuration of an imaging apparatus according to an embodiment of the present invention. It is a flowchart which shows operation | movement of the imaging device in embodiment of this invention. It is a flowchart which shows the imaging process in embodiment of this invention. It is a figure explaining the luminance level distribution graph in the 1st Embodiment of this invention. It is a figure which shows an example of the luminance level distribution graph before and after exposure correction | amendment in the 1st Embodiment of this invention. It is a figure which shows the luminance level distribution graph after correct | amending by the different gamma characteristic in the 1st Embodiment of this invention. It is a figure which shows the luminance level distribution graph in the 2nd Embodiment of this invention. It is a figure which shows the luminance level distribution graph after correct | amending by the different gamma characteristic in the 2nd Embodiment of this invention. It is a figure which shows an example of the luminance level distribution graph before and after exposure correction | amendment in the 2nd Embodiment of this invention. It is a figure explaining the conventional luminance level distribution graph.

Explanation of symbols

1: Shooting lens 2: AF driving circuit 3: Zoom driving circuit 4: Aperture driving circuit 5: Aperture 6: Image sensor 7: Clamp / CDS circuit 8: AGC
9: A / D converter 10: Video signal processing circuit 11: EVF drive circuit 12: EVF
13: Memory controller 14: Memory 15: External interface 16: Microcomputer 17: Power supply 18: Operation member 19: Buffer memory 20 (a): Input switch (SW1)
20 (b): Input switch (SW2)
21: Liquid crystal drive circuit 22: External liquid crystal display unit 23: Liquid crystal display unit in the viewfinder

Claims (13)

Input means for inputting image data;
Gamma correction means for performing gamma correction on the image data input from the input means;
Generating means for generating a graph showing a distribution of luminance levels of the gamma-corrected image data;
The generating means sets the scale of the luminance level of the graph so that intervals between the output values after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction become equal intervals. A featured image processing apparatus.   2. The image processing according to claim 1, wherein the generation unit displays an index indicating an output value after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction on the graph. apparatus. Input means for inputting image data;
Gamma correction means for performing gamma correction on the image data input from the input means;
Generating means for generating a graph showing a distribution of luminance levels of the gamma-corrected image data;
The image processing apparatus, wherein the generation unit displays an index indicating the output value after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction on the generated graph. Prior to the gamma correction, further comprising exposure correction means for performing exposure correction,
The image processing apparatus according to claim 1, wherein an interval between the plurality of input values is an integral multiple of a correction width of the exposure correction.   The image processing apparatus according to claim 1, further comprising display means for displaying a graph generated by the generation means. Imaging means for converting an incident subject optical image into image data of an electrical signal;
Including the image processing apparatus according to claim 1,
The input device of the image processing device is the image pickup device. An input process for inputting image data;
A gamma correction step for performing gamma correction on the image data input in the input step;
Generating a graph showing a distribution of luminance levels of the gamma-corrected image data,
In the generation step, the scale of the luminance level of the graph is set so that intervals between the output values after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction become equal intervals. A featured image processing method.   The image processing according to claim 7, wherein in the generation step, an index indicating the output value after the gamma correction corresponding to a plurality of input values at equal intervals before the gamma correction is displayed on the graph. Method. An input process for inputting image data;
A gamma correction step for performing gamma correction on the image data input in the input step;
Generating a graph showing a distribution of luminance levels of the gamma-corrected image data,
In the generating step, an index indicating an output value after the gamma correction corresponding to a plurality of equally spaced input values before the gamma correction is displayed on the generated graph. Prior to the gamma correction, the method further comprises an exposure correction step for performing exposure correction,
The image processing method according to claim 7, wherein an interval between the plurality of input values is an integral multiple of a correction width of the exposure correction.   The image processing method according to claim 7, further comprising a display step of displaying the graph generated by the generation step.   12. A program executable by an information processing apparatus, comprising program code for realizing the image processing method according to claim 7.   13. A storage medium readable by an information processing apparatus, wherein the program according to claim 12 is stored.

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