JP2006109162A - Imaging apparatus, imaging method, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of preventing deterioration in the image quality under various environments while reducing the photographing of dark images causing a shutter release time lag to the utmost. <P>SOLUTION: The imaging apparatus captures no dark image data under ordinary photographing and environmental conditions in the case of photographing, uses linear correction data stored in advance in a nonvolatile memory 56 in a production step to carry out horizontal dark shading correction in the development processing. In the case of needing the dark image data depending on the photographing condition such as the ISO sensitivity and a shutter time and the environmental condition such as ambient temperature, the imaging apparatus captures the dark image data, uses linear correction data newly produced from the obtained dark data to carry out the horizontal dark shading correction. The linear correction data by one line in the horizontal direction used when the horizontal dark shading correction is carried out are produced by applying projection arithmetic operations to the image obtained by dark photographing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to, for example, an imaging apparatus, an imaging method, a program, and a storage medium that capture, record, and reproduce a still image and a moving image.

  Conventionally, as this type of imaging device, there has already been an imaging device such as an electronic camera that records and reproduces still images and moving images captured by a solid-state imaging device such as a CCD or CMOS, using a memory card having a solid-state memory element as a recording medium. It is commercially available.

  In this electronic camera, by selecting a shooting mode, single-shot shooting for shooting one frame each time the shutter button is pressed and continuous shooting for continuous shooting while pressing the shutter button are performed. Can be switched.

  Also, when imaging using a solid-state image sensor such as a CCD or CMOS, the dark image data read after charge accumulation is performed in the same manner as in the main photographing without exposing the image sensor and the charge with the image sensor exposed. Dark noise correction processing can be performed by performing arithmetic processing using the actual captured image data read after accumulation.

  As a result, it is possible to obtain a high-quality image by correcting the captured image data against image quality degradation such as pixel current loss due to dark current noise generated in the image sensor and minute scratches inherent to the image sensor.

  In particular, since dark current noise increases with the charge accumulation time and the temperature rise of the image sensor, a large image quality improvement effect can be obtained when performing exposure at long seconds or exposure at high temperatures. For this, the dark noise correction processing is a useful function.

  However, in the image pickup apparatus using the first correction means, when performing the main shooting after shooting the dark image data, the shooting frame interval can be made constant during continuous shooting, but the dark image is shot during single shooting. The shutter release time lag increased by the shooting time, and there was a possibility of missing a valuable photo opportunity.

  On the other hand, when dark image data is taken after the actual shooting, the shutter release time lag can be reduced during single shooting, but the shooting interval between the first frame and the second frame is increased by the dark image shooting time during continuous shooting. Therefore, there is a problem that the interval between the photographing frames cannot be made constant.

  In addition, photographing conditions and environmental conditions when exposure was not performed at a long time or exposure at a high temperature were not considered at all. That is, there is circuit system noise other than image quality deterioration such as pixel current loss due to dark current noise generated in the image sensor and minute scratches specific to the image sensor, but this has not been considered. Here, the circuit system noise is fixed pattern noise as dark offset generated due to voltage non-uniformity or element variation due to the resistance component of the power supply line in the sensor.

  Furthermore, the above imaging apparatus is effective for correcting fixed pattern noise that does not change for each shooting, but rather increases random noise components generated in different patterns for each shooting. There was also a problem. As a result, under conditions where random noise is more dominant than fixed pattern noise components, it is a cause of degradation of image quality.

  Further, as a second correction means for correcting the photographed image data, a correction means for preparing correction data such as a horizontal mapping of a dark image at the time of factory adjustment in advance and correcting the image data photographed using the correction data is provided. is there.

  The advantage of this second correction means is that it is not necessary to capture and read out a black image again at the time of photographing one screen, so that the time required for one photographing can be shortened. Further, the random noise component is not increased as in the case of using the first correction means.

  However, the second correction means has the following problems.

  That is, if the shape of dark noise to be corrected changes depending on the surrounding environment such as temperature, the correction performed using correction data prepared in advance may not be corrected properly depending on the surrounding environment. It may not be.

  Further, as a third correction method, there is a correction unit that generates correction data from a part of a dark image at the time of imaging and performs dark noise correction processing using the correction data.

  According to the present correcting means, only a part of the black image is less affected by the surrounding environment as in the second correcting means, and compared to the first correcting means that performs correction using the entire black image range. Therefore, the time required for one imaging can be shortened.

  However, the time required for imaging becomes longer compared to the second correction means that does not require imaging of a new dark image at the time of imaging.

  As described above, the various image correction means as described above have both advantages and disadvantages, and it is difficult to perform appropriate image correction in shooting under various shooting environments using one correction means. there were.

JP-A-10-155100

  SUMMARY An advantage of some aspects of the invention is that it provides an imaging apparatus, an imaging method, a program, and a storage medium that can prevent the degradation of image quality while reducing the dark image capturing that causes the shutter release time lag as much as possible.

  In order to achieve the above object, an imaging apparatus according to the present invention includes a first imaging mode and an exposure for obtaining first image data by performing imaging in a non-exposure state in an imaging apparatus that records a captured image on a recording medium. Imaging means capable of imaging in a second imaging mode for capturing second image data by imaging in a state, and correction data for correcting the second image data obtained in the second imaging mode are stored Correction data storage means, correction data generation means for generating second correction data from a part of the first image data obtained in the first imaging mode, first correction data and second correction data Selection means for selecting any of the correction data, and correction means for correcting the second image data obtained in the second imaging mode using the correction data selected by the selection means. It is characterized by.

  The imaging method of the present invention is an imaging method in which a captured image is recorded on a recording medium, a first imaging step in which imaging is performed in an unexposed state to obtain first image data, and imaging is performed in an exposed state. A second imaging step for obtaining second image data, a correction data storing step for storing correction data for correcting the second image data, and a first image obtained in the first imaging step. A correction data generation step of generating second correction data from a part of the image data of one, a selection step of selecting either the first correction data or the second correction data, and the selection means selected And a correction step of correcting the obtained second image data using correction data.

  According to the present invention, when correction is performed by selecting correction data stored in advance, since it is not necessary to capture dark image data, the shutter release time lag can be reduced, and the photographer can take a photo opportunity by the release time lag. Never miss it.

  If the amount to be corrected is expected to be significantly different from previously stored correction data due to shooting conditions such as ISO sensitivity and shutter speed, and environmental conditions such as ambient temperature, it is obtained in the first imaging mode. By performing correction using horizontal dark shading correction data newly generated from the obtained dark image data, it is possible to prevent the image quality from deteriorating.

  Further, by making the correction data stored in advance one-dimensional correction data, the processing becomes simple and at the same time, the memory for storing the correction data can be reduced.

  In this way, it is possible to prevent deterioration of image quality while reducing the dark image capturing that causes the shutter release time lag as much as possible.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the imaging apparatus according to the present embodiment is applied to an electronic camera.

  FIG. 1 is a block diagram illustrating a configuration of an electronic camera according to an embodiment.

  In FIG. 1, 100 is an image processing apparatus, 12 is a shutter having a diaphragm function for controlling the exposure amount of the image sensor 14, and 14 is an image sensor for converting an optical image into an electrical signal.

  The light beam incident on the photographing lens 310 in the lens unit 300 forms an optical image on the image sensor 14 guided by the single-lens reflex system through the diaphragm 312, the lens mounts 306 and 106, the mirror 130, and the shutter 12.

  Reference numeral 16 denotes an A / D converter that converts an analog signal output from the image sensor 14 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16 and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control circuit 50.

  An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 16 or the data from the memory control circuit 22. The image processing circuit 20 performs predetermined calculation processing using image data captured as necessary, and the system control circuit 50 controls the exposure (shutter) control unit 40 and the distance measurement control unit 42 based on the obtained calculation result. TTL (through-the-lens) AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash dimming) processing for control are performed. The image processing circuit 20 performs predetermined arithmetic processing using the captured image data, and performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

  In the present embodiment, since the distance measurement control unit 42 and the photometry control unit 46 are provided exclusively, the system control circuit 50 uses the distance measurement control unit 42 and the photometry control unit 46 to perform AF (autofocus) processing. , AE (automatic exposure) processing and EF (flash dimming) processing are performed, and the image processing circuit 20 is used for AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash dimming) processing. It is good also as a structure which does not perform each process.

  Further, the AF (autofocus) process, the AE (automatic exposure) process, and the EF (flash dimming) process are performed using the distance measurement control unit 42 and the photometry control unit 46, and the image processing circuit 20 is used. The AF (autofocus) process, the AE (automatic exposure) process, and the EF (flash dimming) process may be performed.

  A memory control circuit 22 controls the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32.

  Data from the A / D converter 16 is written to the image display memory 24 or the memory 30 via the image processing circuit 20 and the memory control circuit 22 or directly via the memory control circuit 22.

  Reference numeral 24 is an image display memory, and 26 is a D / A converter. Reference numeral 28 denotes an image display unit comprising a TFT type LCD. The display image data written in the image display memory 24 is displayed on the image display unit 28 via the D / A converter 26. When the captured image data is sequentially displayed on the image display unit 28, an electronic viewfinder function can be realized. Further, the image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the image processing apparatus 100 can be greatly reduced. Can do.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a sufficient storage capacity to store a predetermined number of still images and a predetermined time of moving images. Therefore, even in the case of continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, a large amount of image writing can be performed on the memory 30 at high speed. The memory 30 can also be used as a work area for the system control circuit 50.

  A compression / decompression circuit 32 compresses and decompresses image data by adaptive discrete cosine transform (ADCT) or the like, reads an image stored in the memory 30, performs compression processing or decompression processing, and stores the processed data in the memory. Write to 30.

  Reference numeral 40 denotes a shutter control unit that controls the shutter 12 in cooperation with an aperture control unit 340 that controls the aperture 312 based on photometric information from the photometry control unit 46. Reference numeral 42 denotes a distance measurement control unit for performing AF (autofocus) processing. A light beam incident on the photographing lens 310 in the lens unit 300 is used to stop the aperture 312, the lens mounts 306 and 106, the mirror 130, and a distance measurement sub-mirror (see FIG. The in-focus state of the image formed as an optical image is measured by entering with a single-lens reflex system via a not-shown).

  A thermometer 44 detects the ambient temperature in the photographing environment. When the thermometer is in the image sensor (sensor) 14, it is possible to predict the dark current of the sensor more accurately.

  Reference numeral 46 denotes a photometric control unit for performing AE (automatic exposure) processing. A light beam incident on the photographing lens 310 in the lens unit 300 is converted into an aperture 312, lens mounts 306 and 106, a mirror 130, and a photometric sub-mirror (not shown). The exposure state of the image formed as an optical image is measured. The photometry control unit 46 also has an EF (flash dimming) processing function in cooperation with the flash unit 48. A flash unit 48 has an AF auxiliary light projecting function and a flash light control function.

  As described above, based on the calculation result calculated by the image processing circuit 20 using the image data picked up by the image pickup device 14, the system control circuit 50 includes the exposure (shutter) control unit 40, the aperture control unit 340, It is possible to perform exposure control and AF (autofocus) control using the video TTL system for the distance measurement control unit 342.

  Further, AF (autofocus) control may be performed using a measurement result obtained by the distance measurement control unit 42 and a calculation result obtained by calculating the image data captured by the image sensor 14 by the image processing circuit 20. Further, exposure control may be performed using the measurement result obtained by the photometry control unit 46 and the calculation result obtained by calculating the image data captured by the image sensor 14 by the image processing circuit 20.

  A system control circuit 50 controls the entire image processing apparatus 100, and incorporates a known CPU and the like. A memory 52 stores constants, variables, programs, and the like for operating the system control circuit 50. Reference numeral 54 denotes a display unit having a liquid crystal display device, a speaker, and the like that display an operation state and a message by characters, images, voices, and the like in accordance with execution of a program in the system control circuit 50. It is installed at one or a plurality of places that are easily visible in the vicinity. The display unit 54 is configured by a combination of an LCD, an LED, a sound generating element, and the like. Some functions of the display unit 54 are provided in the optical viewfinder 104.

  Among the display contents of the display unit 54, what is displayed on the LCD or the like includes single shot / continuous shooting display, self-timer display, compression rate display, recording pixel number display, recording number display, remaining image number display, shutter Speed display, Aperture value display, Exposure compensation display, Flash display, Red-eye reduction display, Macro shooting display, Buzzer setting display, Clock battery level display, Battery level display, Error display, Multi-digit number information display and recording There are an attachment / detachment state display of the media 200 and 210, an attachment / detachment state display of the lens unit 300, a communication I / F operation display, a date / time display, a display showing a connection state with an external computer, and the like.

  Among the display contents of the display unit 54, what is displayed in the optical viewfinder 104 includes in-focus display, photographing preparation completion display, camera shake warning display, flash charge display, flash charge completion display, shutter speed display, aperture value. Display, exposure correction display, recording medium writing operation display, and the like.

  Further, among the display contents of the display unit 54, what is displayed on the LED or the like includes, for example, in-focus display, shooting preparation completion display, camera shake warning display, flash charge display, flash charge completion display, recording medium writing operation display, Macro shooting setting notification display, secondary battery charge display, and the like.

  Among the display contents of the display unit 54, what is displayed on a lamp or the like includes, for example, a self-timer notification lamp. This self-timer notification lamp may be shared with AF auxiliary light.

  Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory storing a program and the like which will be described later. An EEPROM or the like is used as the nonvolatile memory. The nonvolatile memory 56 stores various parameters, setting values such as ISO sensitivity, setting mode, and one-dimensional correction data used when performing horizontal dark shading correction. This one-dimensional correction data is created and written at the time of adjustment in the production process. As a method of creating the one-dimensional correction data, for example, a method of generating data for one horizontal line by projecting an image obtained by performing dark photographing can be considered.

  In addition, as correction data, the dark image imaged in the production process may be stored as two-dimensional data as it is. However, some image pickup devices have a small fixed pattern noise in the vertical direction and need only be corrected in the horizontal direction.

  Here, as a generation factor of the fixed pattern noise, there is a large difference (variation) in the readout path where the signal of the pixel portion reaches the final output stage when the signal is read out from the circuit system of the image sensor.

  FIG. 2 is a diagram illustrating mixing of fixed pattern noise in the horizontal and vertical directions.

  The fixed pattern noise in the horizontal direction depends on the difference between the readout path of the vertical line a and the readout path of the vertical line b in the figure. Also, the fixed pattern noise in the vertical direction depends on the difference between the readout path of the horizontal line c and the readout path of the horizontal line d in the figure. For example, as shown in FIG. 2, in the case of an image sensor in which each horizontal line shares a readout circuit, and noise that is mixed when transferring the signal of each horizontal line to the common readout circuit due to circuit layout improvements, etc. The fixed pattern noise in the vertical direction is small and does not need to be corrected. In an imaging apparatus using such an imaging element, fixed pattern noise can be removed by correcting the main image using one-dimensional correction data in the horizontal direction.

  Reference numerals 60, 62, 64, 66, 68 and 70 are operation units for inputting various operation instructions of the system control circuit 50. One or a plurality of switches, dials, touch panels, pointing by line-of-sight detection, voice recognition devices, etc. Consists of Details of these operation units are shown below.

  Reference numeral 60 denotes a mode dial switch, which is an automatic shooting mode, program shooting mode, shutter speed priority shooting mode, aperture priority shooting mode, manual shooting mode, depth of focus priority (depth) shooting mode, portrait shooting mode, landscape shooting mode, and close-up shooting. Each function shooting mode such as a shooting mode, a sports shooting mode, a night view shooting mode, and a panoramic shooting mode can be switched and set.

  A shutter switch (SW1) 62 is turned on during the operation of a shutter button (not shown), and AF (auto focus) processing, AE (automatic exposure) processing, AWB (auto white balance) processing, EF (flash adjustment). Instructs the start of operation such as (light) processing.

  Reference numeral 64 denotes a shutter switch (SW2) which is turned on when a shutter button (not shown) is operated. The shutter switch (SW2) 64 is an exposure process for writing image data into the memory 30 via the A / D converter 16 and the memory control circuit 22 through the signal read from the image sensor 12, the image processing circuit 20 and the memory control circuit 22 The development processing using the calculation in the above, the image data is read out from the memory 30, compressed by the compression / decompression circuit 32, and the start of a series of processing operations such as recording processing for writing the image data to the recording media 200 and 201 is instructed.

  Reference numeral 66 denotes a playback switch, which instructs to start a playback operation for reading an image shot in the shooting mode state from the memory 30 or the recording medium 200, 210 and displaying it on the image display unit 28.

  Reference numeral 68 denotes a single / continuous shooting switch. When the shutter switch SW2 is pressed, a single shooting mode in which one frame is shot to be in a standby state, and shooting is continuously performed while the shutter switch SW2 is being pressed. The continuous shooting mode can be set.

  Reference numeral 69 denotes an ISO sensitivity setting switch. The ISO sensitivity can be set by changing the gain setting in the image sensor 14 or the image processing circuit 20.

  Reference numeral 70 denotes an operation unit including various buttons, a touch panel, etc., a menu button, a set button, a macro button, a multi-screen playback page break button, a flash setting button, a single shooting / continuous shooting / self-timer switching button, a menu movement + (plus ) Button, menu movement-(minus) button, playback image movement + (plus) button, playback image-(minus) button, shooting image quality selection button, exposure compensation button, date / time setting button, panorama mode shooting and playback A selection / switching button for setting selection and switching of various functions when executing the function, a determination / execution button for setting determination and execution of various functions when performing shooting and playback in panorama mode, etc. Image display ON / OFF switch to set ON / OFF, image data taken immediately after shooting Quick review ON / OFF switch for setting a quick review function for automatic playback, a switch for selecting a compression rate of JPEG compression, or a switch for selecting a CCD RAW mode in which an image sensor signal is digitized and recorded on a recording medium. Auto-focus operation starts when the shutter switch SW1 is pressed, a playback switch that can set each function mode such as compression mode switch, playback mode, multi-screen playback / erase mode, and PC connection mode. In this case, there is an AF mode setting switch or the like that can set a one-shot AF mode that keeps the focused state and a servo AF mode that keeps autofocusing continuously while the shutter switch SW1 is pressed.

  In addition, the functions of the plus button and the minus button can be selected more easily by providing a rotary dial switch.

  Reference numeral 72 denotes a power switch, which can be set to switch between power-on and power-off modes of the image processing apparatus 100. In addition, the power on and power off settings of various accessory devices such as the lens unit 300, the external strobe, and the recording media 200 and 210 connected to the image processing apparatus 100 can be switched.

  Reference numeral 80 denotes a power supply control unit, which includes a battery detection circuit, a DC-DC converter, a switch circuit for switching a block to be energized, and the like, detects whether or not a battery is installed, the type of battery, and the remaining battery level. The DC-DC converter is controlled based on the detection result and the instruction of the system control circuit 50, and a necessary voltage is supplied to each part including the recording medium for a necessary period.

  Reference numerals 82 and 84 denote connectors, 86 denotes a primary battery such as an alkaline battery or lithium battery, a secondary battery such as a NiCd battery, NiMH battery, or Li battery, an AC adapter, or the like.

  90 and 94 are interfaces with a recording medium such as a memory card or a hard disk, 92 and 96 are connectors for connecting to a recording medium such as a memory card or a hard disk, and 98 is a recording medium 200 or 210 attached to the connectors 92 and 96. It is a recording medium attachment / detachment detection unit that detects whether or not the recording medium is present.

  In this embodiment, two interfaces and connectors for attaching a recording medium are provided. However, a single or an arbitrary number of interfaces and connectors for attaching a recording medium may be provided. Also, as interfaces and connectors with different standards, PCMCIA cards, CF (compact flash) cards and other standards compliant may be used.

  Further, when the interfaces 90 and 94 and the connectors 92 and 96 are configured using a PCMCIA card, a CF (compact flash) card, or the like, a LAN card, a modem card, a USB card, an IEEE 1394 card, a P1284 card, By connecting various communication cards such as SCSI cards and communication cards such as PHS, it is possible to transfer image data and management information attached to image data to and from other computers and peripheral devices such as printers. It is.

  Reference numeral 104 denotes an optical viewfinder, which guides a light beam incident on the photographing lens 310 through an aperture 312, lens mounts 306 and 106, and mirrors 130 and 132 by a single-lens reflex system, and forms an optical image for display. Is possible. Accordingly, it is possible to perform shooting using only the optical viewfinder 104 without using the electronic viewfinder function of the image display unit 28. The optical finder 104 is provided with some functions of the display unit 54, such as a focus display, a camera shake warning display, a flash charge display, a shutter speed display, an aperture value display, and an exposure correction display.

  A communication unit 110 has various communication functions such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication. Reference numeral 112 denotes a connector for connecting the image processing apparatus 100 to another device by the communication unit 110, or an antenna for wireless communication.

  Reference numeral 120 denotes an interface for connecting the image processing apparatus 100 to the lens unit 300 in the lens mount 106. A connector 122 electrically connects the image processing apparatus 100 to the lens unit 300. A lens attachment / detachment detection unit 124 detects whether the lens unit 300 is attached to the lens mount 106 and / or the connector 122.

  The connector 122 communicates control signals, status signals, data signals, and the like between the image processing apparatus 100 and the lens unit 300, and also has a function of supplying currents of various voltages. The connector 122 may be configured to transmit not only electrical communication but also optical communication, voice communication, and the like.

  Reference numerals 130 and 132 denote mirrors that guide light rays incident on the photographing lens 310 to the optical viewfinder 104 by a single-lens reflex system. The mirror 132 may be either a quick return mirror or a half mirror.

  Reference numeral 200 denotes a recording medium such as a memory card or a hard disk. The recording medium 200 includes a recording unit 202 composed of a semiconductor memory, a magnetic disk, or the like, an interface 204 with the image processing apparatus 100, and a connector 206 for connecting with the image processing apparatus 100. Reference numeral 210 denotes a recording medium such as a memory card or a hard disk, similar to the recording medium 200. The recording medium 210 includes a recording unit 212 composed of a semiconductor memory, a magnetic disk, or the like, an interface 214 with the image processing apparatus 100, and a connector 216 for connecting with the image processing apparatus 100.

  Reference numeral 300 denotes an interchangeable lens type lens unit. A lens mount 306 mechanically couples the lens unit 300 to the image processing apparatus 100. The lens mount 306 includes various functions for electrically connecting the lens unit 300 to the image processing apparatus 100.

  Reference numeral 310 denotes a photographing lens, and 312 denotes an aperture. Reference numeral 320 denotes an interface for connecting the lens unit 300 to the image processing apparatus 100 in the lens mount 306. A connector 322 electrically connects the lens unit 300 to the image processing apparatus 100.

  The connector 322 has a function of transmitting a control signal, a status signal, a data signal, and the like between the image processing apparatus 100 and the lens unit 300 and supplying various currents or supplying currents. The connector 322 may be configured to transmit not only electrical signals but also optical signals, audio signals, and the like.

  Reference numeral 340 denotes an aperture control unit that controls the aperture 312 in cooperation with the shutter control unit 40 that controls the shutter 12 based on photometric information from the photometry control unit 46. A distance measurement control unit 342 controls focusing of the photographing lens 310. A zoom control unit 344 controls zooming of the photographing lens 310. A lens system control circuit 350 controls the entire lens unit 300. The lens system control circuit 350 includes a memory for storing operation constants, variables, programs and the like, identification information such as a number unique to the lens unit 300, management information, function information such as an open aperture value, a minimum aperture value, a focal length, It also has a non-volatile memory function for holding current and past set values.

  The operation of the electronic camera having the above configuration will be described.

  3 to 5 are flowcharts showing the photographing operation processing procedure of the image processing apparatus 100. This processing program is stored in a storage medium such as the nonvolatile memory 56, loaded into the memory 52, and executed by the CPU in the system control circuit 50.

  Upon power-on such as battery replacement, the system control circuit 50 initializes flags, control variables, and the like, and performs necessary initial settings for each part of the image processing apparatus 100 (step S101). The system control unit 50 determines the setting position of the power switch 72 and determines whether or not the power switch 72 is set to power OFF (step S102).

  When the power switch 72 is set to power OFF, the display of each display unit is changed to the end state, and necessary parameters, setting values, and setting modes including flags and control variables are recorded in the nonvolatile memory 56. After the power control unit 80 performs a predetermined end process such as cutting off unnecessary power of each part of the image processing apparatus 100 including the image display unit 28 (step S103), the process returns to the process of step S102.

  On the other hand, when the power switch 72 is set to ON, the system control circuit 50 determines whether the remaining capacity of the power source 86 such as a battery or the operation status has a problem in the operation of the image processing apparatus 100 by the power control unit 80. Is determined (step S104). If it is determined that there is a problem, a predetermined warning is given by displaying an image or outputting sound on the display unit 54 (step S105), and then the process returns to step S102.

  On the other hand, if it is determined that there is no problem with the power supply 86, the system control circuit 50 determines the setting position of the mode dial switch 60 and determines whether or not the mode dial switch 60 is set to the shooting mode (step S106). ). When the mode dial switch 60 is set to another mode, the system control circuit 50 executes processing according to the selected mode (step S107), and returns to the processing of step S102 after execution.

  On the other hand, when the mode dial switch 60 is set to the photographing mode, it is determined whether or not the recording media 200 and 201 are attached, the management information of the image data recorded on the recording media 200 and 201 is acquired, and the recording medium It is determined whether or not the operation states 200 and 201 have a problem in the operation of the image processing apparatus 100, particularly in the recording / reproducing operation of the image data with respect to the recording medium (step S108). If it is determined that there is a problem, a predetermined warning is given by displaying an image or outputting sound on the display unit 54 (step S105), and then the process returns to step S102.

  On the other hand, when it is determined in step S108 that there is no problem, the system control circuit 50 checks the selection state of the single / continuous shooting switch 68 for selecting single shooting / continuous shooting (step S109). If single shooting is selected, the single shooting / continuous shooting flag is set to single shooting (step S110). If continuous shooting is selected, the single shooting / continuous shooting flag is set to continuous shooting (step S110). Step S111). In the single shooting / continuous shooting switch 68, when the shutter switch SW2 is pressed, a single shooting mode in which one frame is shot to be in a standby state, and continuous shooting is performed while the shutter switch SW2 is pressed. It is possible to switch the mode arbitrarily. The state of the single / continuous shooting flag is stored in the internal memory or the memory 52 of the system control circuit 50.

  The system control circuit 50 displays various setting states of the image processing apparatus 100 using images and sounds using the display unit 54 (step S112). Here, when the image display switch of the image display unit 28 is ON, various setting states of the image processing apparatus 100 may be displayed using the image display unit 28 by an image or sound.

  It is determined whether or not the shutter switch SW1 is pressed (step S113). If the shutter switch SW1 is not pressed, the process returns to step S102. On the other hand, when the shutter switch SW1 is pressed, the system control circuit 50 performs a distance measurement process to focus the photographing lens 310 on the subject, and performs a light measurement process to determine an aperture value and a shutter speed. Photometric processing is performed (step S114). In the photometric process, the flash is set if necessary. Details of the distance measurement / photometry processing will be described later.

  Thereafter, in steps S115 to S118, correction means corresponding to the selection means in claims is selected. First, the setting sensitivity of the camera is determined. That is, it is determined whether or not the sensitivity set by the ISO sensitivity setting switch 69 is less than ISO 800 (step S115). The reason for this determination is that, under ISO 800, the exposure amount is small, so that dark current noise generated in the image sensor or image quality deterioration due to pixel defects due to a small flaw unique to the image sensor is conspicuous. In the present embodiment, ISO 800 is used, but it is of course possible to use another set sensitivity such as ISO 1600. If it is ISO 800 or higher, the process proceeds to step S119. On the other hand, if it is lower than ISO 800, it is further determined whether or not the set sensitivity is lower than ISO 400 (step S116).

  When the temperature is lower than ISO 400, the process proceeds to step S122. On the other hand, when the temperature is higher than ISO 400, it is determined whether the ambient temperature Temp measured by the thermometer 44 is lower than 28 ° C. (step S117). If it is less than 28 ° C., the process proceeds to step S122. If it is 28 ° C. or more, it is determined whether or not the shutter time Tv is less than 1 second (step S118). If it is less than 1 second, the process proceeds to step S122. If it is 1 second or more, the process proceeds to step S119.

  In the condition determination in steps S116 to S118, values of ISO 400, 28 ° C., and 1 second are set as thresholds. However, depending on the characteristics of the image sensor 14, it is of course possible to use appropriate values. It is.

  Here, since the dark current noise increases with the charge accumulation time and the temperature rise of the image sensor, when performing exposure at a long time or exposure at a high temperature, the correction data stored in advance cannot be corrected. Therefore, it must be corrected using a dark image taken under the same environment as that at the time of actual photographing. At this time, since so-called “black drawing” for subtracting the entire dark image from the photographed image increases the photographing time, correction is performed using correction data created by reading out a part of the dark image. "Black drawing" is to be performed.

  Accordingly, when none of the conditions in steps S116 to S118 is satisfied, the simple blacking flag is set to 1 (step S119). Then, the setting state of the single / continuous shooting flag is checked (step S120). If single shooting is set, dark capture is performed after the actual shooting is completed, and the process directly proceeds to step S124. On the other hand, when continuous shooting is set, after dark capture for simple blacking is performed (step S121), the process proceeds to step S124. By performing the correction calculation process using the dark image data captured in the dark capture process, it is possible to correct the captured image data with respect to image quality deterioration due to dark current noise or the like generated in the image sensor 14. The dark capture process will be described later.

  If any of the conditions is satisfied in the processing in steps S116 to S118, the simple blacking flag is cleared to 0 in order to perform horizontal dark shading correction without performing simple blacking (step S122). The correction data is developed (step S123). The state of the simple black flag is stored in the internal memory of the system control circuit 50 or the memory 52.

  In step S123, the system control circuit 50 reads the one-dimensional correction data used for horizontal dark shading correction from the nonvolatile memory 56, and stores the one-dimensional data in the predetermined area of the memory 30 in the vertical direction in the same number as the actual image. Repeat as many times as the number of lines. After the expansion of the correction data, the process proceeds to step S124. FIG. 6 is a diagram showing correction of the main image by simple blackening or horizontal dark shading correction data.

  Then, it is determined whether or not the shutter switch SW2 is pressed (step S124). If the shutter switch SW2 is not pressed, it is determined whether or not the shutter switch SW1 is released (step S125), and the shutter switch SW1. Steps S124 and S125 are repeated until is released or the shutter switch SW2 is pressed. If the shutter switch SW1 is released in step S125, the process proceeds to step S102.

  On the other hand, when the shutter switch SW2 is pressed in step S124, the system control circuit 50 determines whether or not the memory 30 has an image storage buffer area in which captured image data can be stored (step S126). If it is determined that there is no area where new image data can be stored in the image storage buffer area of the memory 30, a predetermined warning is given to the display unit 54 by displaying an image or outputting sound (step S127). The process returns to step S102.

  For example, immediately after performing the maximum number of continuous shots that can be stored in the image storage buffer area of the memory 30, the first images to be read from the memory 30 and written to the storage media 200 and 210 are still storage media 200 and 210. This is a case where, for example, one blank area cannot be secured in the image storage buffer area of the memory 30.

  Note that when the captured image data is compressed and stored in the image storage buffer area of the memory 30, the area that can be stored in consideration of the fact that the amount of compressed image data varies depending on the compression mode setting. Is in the image storage buffer area of the memory 30, it is determined in the process of step S126.

  On the other hand, if it is determined in step S126 that there is an image storage buffer area capable of storing the image data captured in the memory 30, the system control circuit 50 reads out the imaging signal that has been captured and accumulated for a predetermined time from the imaging element 14, and Image data captured in a predetermined area of the memory 30 through the A / D converter 16, the image processing circuit 20 and the memory control circuit 22, or directly from the A / D converter 16 through the memory control circuit 22. A writing process for writing is executed (step S128). Details of this photographing process will be described later.

  When the photographing process in step S128 is completed, the system control circuit 50 checks the state of the simple blacking flag stored in the internal memory or the memory 52 (step S129). If the simple blacking flag is not set to 1, the process proceeds to step S132. On the other hand, when the simple blacking flag is set to the value 1, the system control circuit 50 determines the state of the single shooting / continuous shooting flag stored in the internal memory or the memory 52 (step S130). If the copy is set, the process proceeds to step S132.

  As described above, when the continuous shooting is set in step S130, the dark capture process is not performed in step S131 because the dark capture process has already been performed in step S121 prior to the execution of the continuous shooting. In addition, the development process is executed (step S132), and the continuous shooting frame interval can be made substantially constant.

  On the other hand, if single shooting is set in step S130, the system control circuit 50 accumulates noise components such as dark current of the image sensor 14 for the same time as the main photographing with the shutter 12 closed, and the noise that has been accumulated. A dark capture process for reading an image signal is performed (step S131), and the process proceeds to step S132.

  The system control circuit 50 reads a part of image data written in a predetermined area of the memory 30 via the memory control circuit 22 and performs WB (white balance) integration calculation processing, OB (optical) necessary for development processing. (Black) Integration calculation processing is performed, and the calculation result is stored in the internal memory or the memory 52 of the system control circuit 50.

  The system control circuit 50 reads the captured image data written in a predetermined area of the memory 30 using the memory control circuit 22 and, if necessary, the image processing circuit 20, and stores the internal memory or memory of the system control circuit 50. Various development processes including an AWB (auto white balance) process, a gamma conversion process, and a color conversion process are performed using the calculation result stored in 52 (step S132).

  In the development process, a subtraction process is performed using the horizontal dark shading correction data developed in step S123 or the horizontal dark shading correction data newly generated using a part of the dark image data captured in the dark capturing process. In addition, dark correction calculation processing for canceling dark current noise and the like of the image sensor 14 is also performed.

  As described above, when the correction calculation process is performed using the horizontal dark shading correction data, it is possible to correct the image quality deterioration due to the horizontal dark current noise and the fixed pattern noise generated in the image sensor 14.

  The system control circuit 50 reads out the image data written in a predetermined area of the memory 30, performs image compression processing according to the set mode by the compression / decompression circuit 32, and free images in the image storage buffer area of the memory 30. The image data that has been shot and finished a series of processing is written in the portion (step S133).

  Then, the system control circuit 50 reads out the image data stored in the image storage buffer area of the memory 30, and the recording media 200 and 210 such as a memory card and a compact flash card via the interfaces 90 and 94 and the connectors 92 and 96. The recording process for writing the image data read out in step S134 is started (step S134). This recording start process is performed on the image data every time new image data is shot and written in the empty image portion of the image storage buffer area of the memory 30.

  In order to indicate that the writing operation is being performed while the image data is being written to the recording media 200 and 201, a recording medium writing operation display such as blinking an LED is performed on the display unit 54, for example.

  Further, the system control circuit 50 determines whether or not the shutter switch SW1 is pressed (step S135). If the shutter switch SW1 is released, the process returns to step S102. On the other hand, when the shutter switch SW1 is pressed, the state of the single / continuous shooting flag stored in the internal memory of the system control circuit 50 or the memory 52 is determined (step S136), and single shooting is set. If yes, the process returns to step S135, and the current process is repeated until the shutter switch SW1 is released. On the other hand, if continuous shooting is set, the process returns to step S124 to prepare for the next shooting in order to perform continuous shooting. As a result, a series of processing relating to photographing is completed.

  FIG. 7 is a flowchart showing the distance measurement / photometry processing procedure in step S114. In the distance measurement / photometry processing, the exchange of various signals between the system control circuit 50 and the aperture control unit 340 or the distance measurement control unit 342 includes an interface 120, a connector 122, a connector 322, an interface 320, and a lens system control circuit 350. Is done through.

  The system control circuit 50 starts an AF (autofocus) process using the image sensor 14, the distance measurement control unit 42, and the distance measurement control unit 342 (step S201).

  The system control circuit 50 causes the light beam incident on the photographing lens 310 to enter the distance measurement control unit 42 via the aperture 312, the lens mounts 306 and 106, the mirror 130, and the distance measurement sub-mirror (not shown). Then, the focusing state of the image formed as an optical image is determined, and ranging control is performed while driving the photographic lens 310 using the ranging control unit 342 until ranging (AF) is determined to be in focus. AF control for detecting the in-focus state using the unit 42 is executed (steps S202 and S203).

  When ranging (AF) is determined to be in focus in step S203, the system control circuit 50 determines a focused distance point from a plurality of distance measurement points on the shooting screen, and the determined distance measurement point. Ranging data and / or setting parameters are stored in the internal memory of the system control circuit 50 or the memory 52 together with the data (step S204).

  Subsequently, the system control circuit 50 starts an AE (automatic exposure) process using the photometry control unit 46 (step S205). The system control circuit 50 causes the light beam incident on the photographing lens 310 to enter the photometric control unit 46 via the aperture 312, the lens mounts 306 and 106, the mirrors 130 and 132, and the photometric lens (not shown). Then, the exposure state of the image formed as an optical image is measured, and photometric processing is performed using the exposure (shutter) control unit 40 until it is determined that the exposure (AE) is appropriate (steps S206 and S207).

  If it is determined in step S207 that the exposure (AE) is appropriate, the system control circuit 50 stores the photometric data and / or setting parameters in the internal memory or the memory 52 of the system control circuit 50 (step S207A).

  The system control circuit 50 determines the aperture value (Av value) and the shutter speed (Tv value) according to the exposure (AE) result detected by the photometric processing in step S206 and the shooting mode set by the mode dial switch 60. Is determined.

  Here, in accordance with the determined shutter speed (Tv value), the system control circuit 50 determines the charge accumulation time of the image sensor 14, and performs the photographing process and the dark capturing process with the determined same charge accumulation time. Do.

  Based on the measurement data obtained by the photometric processing in step S206, the system control circuit 50 determines whether or not flashing is necessary (step S208). If flashing is necessary, the flash flag is set and charging is completed. The flash unit 48 is charged until this is done (steps S209 and S210). Then, when the charging of the flash unit 48 is completed, this process is terminated and the process returns to the main process.

  8 and 9 are flowcharts showing the photographing processing procedure in step S128. In this photographing process, various signals are exchanged between the system control circuit 50 and the aperture control unit 340 or the distance measurement control unit 342 through the interface 120, the connector 122, the connector 322, the interface 320, and the lens system control circuit 350. Done through.

  The system control circuit 50 moves the mirror 130 to the mirror up position by a mirror driving unit (not shown) (step S301), and controls the aperture according to the photometric data stored in the internal memory or the memory 52 of the system control circuit 50. The diaphragm 312 is driven to a predetermined diaphragm value by the unit 340 (step S302).

  After performing the charge clear operation of the image sensor 14 (step S303), the system control circuit 50 starts charge accumulation of the image sensor 14 (step S304), and opens the shutter 12 by the shutter control unit 40 (step S305). Exposure of the image sensor 14 is started (step S306).

  Then, it is determined whether or not the flash unit 48 is necessary based on the flash flag (step S307), and if necessary, the flash unit 48 is caused to emit light (step S308).

  The system control circuit 50 waits for the end of exposure of the image sensor 14 according to the photometric data (step S309). When the exposure ends, the shutter control unit 40 closes the shutter 12 (step S310) and ends the exposure of the image sensor 14.

  The system control circuit 50 drives the aperture 312 to the open aperture value by the aperture controller 340 (step S311), and moves the mirror 130 to the mirror down position by the mirror driver (not shown) (step S312).

  It is determined whether or not the set charge accumulation time has elapsed (step S313). If the set charge accumulation time has elapsed, the system control circuit 50 finishes the charge accumulation of the image sensor 14 (step S314), and then performs imaging. A charge signal is read out from the element 14, and a predetermined memory 30 is stored in the memory 30 via the A / D converter 16, the image processing circuit 20, the memory control circuit 22, or directly from the A / D converter 16. The photographed image data is written in the area (step S315). When the series of processes is completed, the present process is terminated and the process returns to the main process.

  FIG. 10 is a flowchart showing the dark capturing process and the pre-dark correction data generation procedure in steps S121 and S131. After performing the charge clear operation of the image sensor 14 (step S401), the system control circuit 50 starts charge accumulation of the image sensor 14 with the shutter 12 closed (step S402).

  It is determined whether or not a predetermined charge accumulation time that has been set has elapsed (step S403). When the charge accumulation time has elapsed, the system control circuit 50 finishes the charge accumulation of the image sensor 14 (step S404), and then reads a predetermined number of rows of charge signals from the image sensor 14 to perform A / D conversion. The image data (dark image data) is written in a predetermined area of the memory 30 via the device 16, the image processing circuit 20, and the memory control circuit 22 (step S405). At this time, the image processing circuit 20 generates one-dimensional correction data used for horizontal dark shading correction from the read dark data of several rows, and the one-dimensional data is vertically displayed in a predetermined area of the memory 30. Repeats the same number of lines as the actual image.

  By performing development processing using this dark capture data, it is possible to correct captured image data in a form that conforms to the imaging environment against image quality degradation such as dark current noise generated in the image sensor 14. Thereafter, this process is terminated and the process returns to the main process.

  FIG. 11 is a diagram showing the flow of the photographing operation of the present embodiment.

  As shown in FIG. 11A, when the simple black flag is set, in single shooting, when the shutter switch SW1 is pressed, AF (auto focus) operation and AE (auto exposure) operation are performed. After that, when the shutter switch SW2 is pressed, dark capture is performed after shooting. In continuous shooting, when the shutter switch SW1 is pressed, AF (autofocus) operation and AE (automatic exposure) operation are performed, and then dark capture is performed. When the shutter switch SW2 is pressed, continuous shooting is performed. To shoot.

  On the other hand, as shown in FIG. 11B, when the simple blacking flag is not set and horizontal dark shading correction is performed, dark capture is not performed in both single shooting and continuous shooting, and the shutter is not used. When the switch SW1 is pressed, AF (autofocus) operation and AE (automatic exposure) operation are performed, and then when the shutter switch SW2 is pressed, shooting is performed.

  As described above, in the imaging apparatus according to the present embodiment, when selecting and correcting the pre-stored horizontal dark shading correction data, it is not necessary to capture dark image data, so that the shutter release time lag can be reduced, The release time lag prevents the photographer from missing a photo opportunity.

  In addition, noise that does not change depending on shooting conditions and environmental conditions, such as fixed pattern noise corresponding to circuit noise of the image sensor, can be corrected with correction data stored in advance. As the image quality deteriorates due to dark current noise generated in the case of noise, the amount of noise converted by the shooting conditions and environmental conditions may not be corrected with the data stored in advance. In order to correct such noise, the amount to be corrected is expected to differ greatly from the pre-stored horizontal dark shading correction data depending on shooting conditions such as ISO sensitivity and shutter speed, and environmental conditions such as ambient temperature. If dark capture processing is performed, horizontal dark shading correction data newly generated from the obtained dark image data is used. By performing the correction, it is possible to prevent the image quality.

  Furthermore, when using an image sensor that has a small fixed pattern noise in one of the horizontal and vertical directions and need not be corrected, the correction data stored in advance is, for example, one-dimensional horizontal dark shading correction data. Thus, the processing becomes simple and at the same time, the memory for storing correction data can be reduced.

  The above is the description of the embodiments of the present invention, but the present invention is not limited to the configurations of these embodiments, and the functions shown in the claims or the functions of the configurations of the embodiments are included. Any configuration that can be achieved is applicable.

  For example, in the above embodiment, when horizontal dark shading correction is performed, correction data is expanded in the memory 30. However, without performing this expansion processing, correction is performed sequentially from the main image while capturing image data from the image sensor 14. It is also possible to correct so that the data is subtracted.

  In this embodiment, the horizontal dark shading correction data expansion process (S123) is performed after the shutter switch SW1 is pressed. However, the correction data may be expanded when the camera is turned on. good.

  Further, although the correction data is one-dimensional data in the horizontal direction, it may be one-dimensional data or two-dimensional data in the vertical direction. In addition, as shown in FIG. 12, both horizontal and vertical one-dimensional data are stored in the correction data development process (S123), even if it is not data for the entire two-dimensional image. When developing the dimension data, the dark shading in both the horizontal and vertical directions can be corrected by adjusting the correction amount for each line using the one-dimensional data in the vertical direction. FIG. 12 is a diagram showing correction of the main image using one-dimensional data in both the vertical and horizontal directions. In this case, further, the vertical direction is stored as a mathematical formula without being stored as one-dimensional correction data, and when developing the one-dimensional data in the horizontal direction, this formula is applied to darkness in the vertical direction. You may make it correct | amend shading.

  In the above embodiment, the correction data is created at the time of adjustment in the production process and stored in the non-volatile memory 56. However, the user or the like projects an image obtained by performing dark photographing at an arbitrary time. It may be created and stored by calculation, and the correction data is automatically created and updated when the power is turned on or when a predetermined period has elapsed since the last generation of the correction data. May be.

  Furthermore, in the above-described embodiment, the case of switching between single shooting / continuous shooting using the single shooting / continuous shooting switch 68 has been described. However, according to the operation mode selection in the mode dial 60, single shooting / continuous shooting is performed. It is good also as a structure which switches.

  In the above embodiment, the case where the charge accumulation time of the main photographing process and the charge accumulation time of the dark capturing process are made equal is shown. However, if the data is sufficient to correct the dark current noise and the like. The charge accumulation time may be different.

  Further, since the photographing operation cannot be performed during the execution of the dark capture processing operations in steps S121 and S131, an image indicating that the image processing apparatus 100 is busy is displayed by the display unit 54 and / or the image display unit 28. You may make it alert | report an audio | voice.

  Further, in the present embodiment, the case where the shooting operation is performed by moving the mirror 130 between the mirror-up position and the mirror-down position is described. However, the mirror 130 is configured as a half mirror so that the shooting operation is performed without moving. Anyway.

  Further, the recording media 200 and 210 are not only memory cards such as PCMCIA cards and compact flash, hard disks, etc., but also micro DAT, magneto-optical disks, optical disks such as CD-R and CD-RW, and phase change optical disks such as DVDs. Or the like. Further, the recording media 200 and 210 may be composite media in which a memory card and a hard disk are integrated. In this case, a part of the composite medium may be detachable.

  In the above embodiment, the recording media 200 and 210 are separated from the image processing apparatus 100 and can be arbitrarily connected. However, any or all of the recording media are fixed to the image processing apparatus 100. It may be left alone. Further, the image processing apparatus 100 may be configured such that a single or a plurality of recording media 200 and 210 can be connected.

  It goes without saying that the present invention can also be applied to a case where the present invention is achieved by supplying software program codes for realizing the functions of the above-described embodiments to a system or apparatus. In this case, the program code itself realizes the novel function of the present invention, and the program itself and the storage medium storing the program constitute the present invention.

  In the above embodiment, the program codes shown in the flowcharts of FIGS. 3 to 5 and FIGS. 7 to 10 are stored in the ROM that is a storage medium. The storage medium for supplying the program code is not limited to the ROM, and for example, a flexible disk, a hard disk, a nonvolatile memory card, or the like can be used.

It is a block diagram which shows the structure of the electronic camera in embodiment. It is a figure which shows mixing of the fixed pattern noise in a horizontal and vertical direction. 3 is a flowchart illustrating a shooting operation processing procedure of the image processing apparatus 100. FIG. 4 is a flowchart illustrating a photographing operation processing procedure of the image processing apparatus 100 subsequent to FIG. 3. FIG. 5 is a flowchart illustrating a shooting operation processing procedure of the image processing apparatus 100 subsequent to FIGS. 3 and 4. FIG. It is a figure which shows the correction | amendment of this image by simple black drawing or horizontal dark shading correction data. It is a flowchart which shows the ranging / photometry processing procedure in step S114. It is a flowchart which shows the imaging | photography process sequence in step S128. It is a flowchart which shows the imaging | photography process procedure in step S128 following FIG. It is a flowchart which shows the dark taking-in process procedure in step S121 and step S131. It is a figure which shows the flow of the imaging | photography operation | movement of this embodiment. It is a figure which shows correction | amendment of this image using the one-dimensional data of the vertical and horizontal directions.

Explanation of symbols

14 Image sensor 44 Thermometer 50 System control circuit 56 Non-volatile memory 60 Mode dial 62 Shutter switch SW1
64 Shutter switch SW2
69 ISO sensitivity setting switch 100 Image processing apparatus

Claims (28)

In an imaging device that records a captured image on a recording medium,
Imaging means capable of imaging in a first imaging mode in which imaging is performed in a non-exposure state to obtain first image data and a second imaging mode in which imaging is performed in an exposure state to obtain second image data; Correction data storage means storing first correction data for correcting the second image data obtained in the second imaging mode, and a part of the first image data obtained in the first imaging mode The correction data generation means for generating the second correction data from, the selection means for selecting either the first correction data or the second correction data, and the correction data selected by the selection means, An image pickup apparatus comprising: an image correction unit that corrects the second image data obtained in the second image pickup mode.   The imaging apparatus according to claim 1, wherein the correction data is stored in the correction data storage unit in a production process.   The imaging apparatus according to claim 1, wherein the selection unit selects based on an imaging condition and an environmental condition.   The imaging apparatus according to claim 3, wherein the photographing condition includes a shutter speed and ISO sensitivity.   The imaging apparatus according to claim 3, wherein the environmental condition includes an ambient temperature.   4. The imaging apparatus according to claim 1, wherein when the use of the first correction data is selected by the selection unit, imaging in the first imaging mode is not performed. 5.   A comparison unit that compares the first image data obtained in the first imaging mode and the first correction data is provided, and as a result of comparison by the comparison unit, it is determined that the difference between the two data is small 2. The imaging apparatus according to claim 1, wherein the correction data generation unit does not generate second correction data, and the selection unit selects the first correction data.   The imaging apparatus according to claim 7, wherein the comparison unit performs comparison periodically.   9. The imaging apparatus according to claim 8, wherein the comparison unit performs comparison when the imaging apparatus is powered on.   9. The imaging apparatus according to claim 8, wherein the comparison unit performs comparison when a predetermined time has elapsed since the last comparison.   The imaging means is composed of an imaging device, and the first image data obtained in the first imaging mode is dark current noise data of the imaging device, and the second image data obtained in the second imaging mode. The image pickup apparatus according to claim 1, wherein the image pickup image data picked up by the image pickup device, and the correction data is fixed pattern noise corresponding to circuit system noise of the image pickup device.   The imaging apparatus according to claim 1, wherein the first and second correction data are one-dimensional correction data.   13. The imaging apparatus according to claim 12, wherein the one-dimensional correction data is horizontal data obtained by projecting image data obtained in the first imaging mode in the vertical direction. In an imaging method for recording a captured image on a recording medium,
A first imaging step for obtaining first image data by imaging in a non-exposure state, a second imaging step for obtaining second image data by imaging in an exposure state, and the second image data A correction data storing step for storing correction data for correction, a selection step for selecting one of the obtained first image data and the stored correction data, and the selected first And a correction step of correcting the obtained second image data using image data or correction data.   The imaging method according to claim 14, wherein the correction data storing step is performed in a production process of the imaging device.   16. The imaging method according to claim 14 or 15, wherein in the selection step, the selection is made based on a photographing condition and an environmental condition.   The imaging method according to claim 16, wherein the photographing condition includes shutter speed and ISO sensitivity.   The imaging method according to claim 16, wherein the environmental condition includes an ambient temperature.   The imaging method according to claim 14 or 16, wherein when the use of the first correction data is selected in the selection step, the imaging in the first imaging step is not performed.   A comparison step of comparing the first image data obtained in the first imaging step and the first correction data, and the comparison result of the comparison step determines that the difference between the two data is small 15. The imaging method according to claim 14, wherein the correction data generation step does not generate second correction data, and the selection step selects first correction data.   21. The imaging method according to claim 20, wherein the comparison step performs comparison periodically.   The imaging method according to claim 21, wherein the comparison step performs comparison when the imaging method is powered on.   The imaging method according to claim 21, wherein the comparison step performs comparison if a predetermined time has elapsed since the last comparison.   The first image data is dark current noise data of the image sensor, the second image data is photographed image data captured by the image sensor, and the correction data is a circuit system of the image sensor. The imaging method according to claim 14, wherein the imaging method is fixed pattern noise corresponding to noise.   The imaging method according to claim 14, wherein the correction data is one-dimensional correction data obtained from the first image data.   26. The imaging method according to claim 25, wherein the one-dimensional correction data is horizontal data obtained by projecting the image data obtained in the first imaging mode in the vertical direction.   27. A storage medium having computer-readable program code for realizing the imaging method according to claim 14.   27. A program comprising computer-readable program code for implementing the imaging method according to claim 14.

Images