JP2005142829A - Image data corrector, image processor, image data correcting method, control program, and memory medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image data corrector which exactly decides the conditions that the dark image photography is necessary in practice to possibly lessen the dark image photography causing a shutter release time lag and prevents the deterioration of the image quality. <P>SOLUTION: After finishing a photographing process, the dark output level (DL) is calculated from data corresponding to DL detection regions of an imaging element 14 (S121) and compared with a specified value DLt in S122, and, if DL is less than DLt, the step immediately proceeds to a developing process. In this case no dark fetching process (dark image photography) is made but the data fetched in S120 in the developing process are corrected according to horizontal dark shading correction data. If DL exceeds the specified value, noise components due to the dark current of the imaging element 14 with a shutter 12 closed are accumulated for the same time as a regular photography, and the dark fetching process for reading out noise image signals finished with the accumulation is executed (S123) and then proceeds to the developing process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention executes an image data correction apparatus and an image data correction method for correcting image data obtained by an image sensor or the like, an image processing apparatus such as an electronic camera provided with the image data correction apparatus, and the image data correction method. And a storage medium for storing the control program.

  Conventionally, for example, as an imaging device that captures, records, and plays back still images and moving images, a memory card having a solid-state memory element is used as a recording medium, and still images and moving images captured by a solid-state imaging element such as a CCD or CMOS are recorded. An imaging device such as an electronic camera for reproduction is already known.

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

  In addition, when imaging using a solid-state image sensor, 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 after charge accumulation is performed with the image sensor exposed. Dark noise correction processing can be performed by performing arithmetic processing using the read main image data. 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 imaging apparatus such as the above-described conventional electronic camera, in the case of performing the main shooting after executing the shooting operation (hereinafter referred to as dark image shooting) for obtaining the dark image data by accumulating the charge without exposing the image sensor, The shutter release time lag increased by the dark image shooting time, and there was a risk of missing a valuable photo opportunity.

  On the other hand, when dark image shooting is performed after the actual shooting, the shutter release time lag can be reduced, but the interval to the next shooting is increased by the dark image shooting time, and the immediacy of the shutter release operation is impaired. There was a problem of being.

  In addition, photographing conditions and environmental conditions when exposure was not performed at long seconds or exposure at high temperatures 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.

Therefore, depending on the shooting conditions and environmental conditions, dark image shooting is performed under conditions where a dark current is expected to be large, and dark image shooting is not performed under other conditions, and fixed patterns are stored using correction data stored in advance. There has been proposed an imaging apparatus that can prevent deterioration of image quality while correcting the noise while reducing the shooting of a dark image that causes a shutter release time lag as much as possible (see, for example, Patent Document 1).
JP 2003-264736 A

  However, in the above-mentioned Patent Document 1, dark image shooting is performed only under shooting conditions / environmental conditions in which it is assumed in advance that image quality deterioration due to dark current will exceed an allowable amount. However, among several factors that influence the amount of dark current, such as charge accumulation time and temperature, the predetermined conditions are not always optimal.

  In addition, the dark current amount of the image sensor has a large individual difference, and when it is determined whether or not to perform dark image capturing under the same conditions, the dark image capturing is actually unnecessary in an image sensor with a small dark current amount. That is also the case in shooting, and in an image pickup device with a large amount of dark current, there is a possibility that the image quality deteriorates because it is not performed in shooting that should originally perform dark image shooting.

  In view of the above-described conventional problems, the present invention accurately determines conditions under which dark image shooting is actually necessary, and reduces image quality deterioration while minimizing dark image shooting that causes a shutter release time lag. It is an object of the present invention to provide a correction device, an image processing device, an image data correction method, a control program, and a storage medium.

  In order to achieve the above object, in the image data correction apparatus of the present invention, the first image data obtained in the first imaging mode in which charge accumulation is performed in a non-exposure state of an imaging means for converting an optical image into an electrical signal. , And an image data correction apparatus capable of correcting the second image data obtained in the second imaging mode in which charge is accumulated in the exposure state of the imaging means, wherein the second image data Dark output calculation means for calculating a dark output value from the light shielding area, determination means for determining whether the dark output value calculated by the dark output calculation means is a predetermined value or more, and the dark output value by the determination means Correction means for correcting the second image data using the first image data when it is determined that the value is equal to or greater than a predetermined value.

  The image processing apparatus may further include a changing unit that changes a charge accumulation time when acquiring the first image data in the first imaging mode according to the dark output value calculated by the dark output calculating unit.

  Further, as correction data for correcting the second image data, correction data storage means storing correction data different from the first image data, and the obtained in the first imaging mode Selecting means for selecting one of the first image data and the correction data stored in the correction data storage means, wherein the correction means has a dark output value calculated by the dark output calculation means as a predetermined value. If it is above, the first image data is selected by the selection means, and the second image data is corrected based on the first image data. If the dark output value is less than a predetermined value, the selection is performed. The correction data is selected by means, and the second image data is corrected based on the correction data.

  In addition, the imaging unit is configured by an imaging device, and the first image data obtained in the first imaging mode is dark current noise data of the imaging device, and is obtained in the second imaging mode. The image data is captured image data captured by the image sensor, and the correction data is fixed pattern noise corresponding to circuit noise of the image sensor.

  The correction data is data obtained by calculation based on the first image data.

  Further, the correction data is one-dimensional data in the horizontal direction obtained by projecting the first image data in the vertical direction.

  An image processing apparatus according to the present invention includes the image data correction apparatus and the imaging unit.

  In the image data correction method of the present invention, the exposure in the imaging step is performed using the first image data obtained in the first imaging mode in which charges are accumulated in the non-exposure state of the imaging means for converting the optical image into an electrical signal. An image data correction method for correcting second image data obtained in a second imaging mode in which charge accumulation is performed in a state, wherein dark output calculation is performed to calculate a dark output value from a light-shielding region of the second image data A step of determining whether or not the dark output value calculated by the dark output calculation step is equal to or greater than a predetermined value, and when the dark output value is determined to be equal to or greater than the predetermined value by the determination step And a correction step of correcting the second image data using the first image data.

  In the control program of the present invention, the first image data obtained in the first imaging mode in which charge accumulation is performed in the non-exposure state of the imaging means for converting the optical image into an electrical signal, and in the exposure state of the imaging step. A computer-readable control program for executing an image data correction method for correcting second image data obtained in a second imaging mode for performing charge accumulation, wherein the second image data is shielded from light. A dark output calculation step for calculating a dark output value from the region; a determination step for determining whether or not the dark output value calculated by the dark output calculation step is equal to or greater than a predetermined value; and A correction step of correcting the second image data using the first image data when it is determined that the value is equal to or greater than a predetermined value. And butterflies.

  The storage medium of the present invention stores the control program.

  According to the present invention, a dark image causing a shutter release time lag is accurately determined by accurately determining a condition actually required for a shooting operation (dark image shooting) in one shooting mode in which charge accumulation is performed in a non-exposure state of the imaging unit. It is possible to prevent image quality degradation while reducing the number of shootings as much as possible.

  Embodiments of the present invention for providing an image data correction apparatus, an image processing apparatus, an image data correction method, a control program, and a storage medium according to the present invention will be described with reference to the drawings. The image processing apparatus of this embodiment is applied to an electronic camera.

<Configuration of electronic camera>
1 and 2 are block diagrams showing the configuration of an electronic camera according to an embodiment of the present invention.

  In the figure, 100 is an image processing apparatus, 12 is a shutter 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 taken 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 into 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 in accordance with 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 significantly reduced. it can.

  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 continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to 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 30. Write to.

  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 photometry information from the photometry control unit 46. Reference numeral 42 denotes a distance measurement control unit for performing AF (autofocus) processing. A diaphragm 312, lens mounts 306 and 106, a 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. Reference numeral 46 denotes a photometric control unit for performing AE (automatic exposure) processing. Light beams incident on the photographing lens 310 in the lens unit 300 are 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 captured by the image sensor 14, the system control circuit 50 performs the exposure (shutter) control unit 40, the aperture control unit 340, In addition, exposure control and AF control using the video TTL method can be performed on 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.

  Reference numeral 50 denotes a system control circuit that controls the entire image processing apparatus 100 and incorporates a known CPU and the like. Reference numeral 52 denotes a memory for storing 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 for displaying an operation state and a message with characters, images, voices, and the like in accordance with execution of a program in the system control circuit 50. It is installed in a single or a plurality of locations 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, and a display showing a connection state with an external computer.

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

  Furthermore, 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 to be described later, and 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 for creating this one-dimensional correction data, for example, a method of generating data for one horizontal line by projecting an image obtained by capturing a dark image can be considered.

  In addition, as correction data, the dark image imaged in the production process may be directly stored as two-dimensional data. 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 cause of generation of the fixed pattern noise, as shown in FIG. 3, there is a large difference (variation) in the readout path where the signal of the pixel unit 500 reaches the final output stage 511 when the signal is read from the circuit system of the image sensor. . This point will be described with reference to FIG. FIG. 3 is a diagram showing mixing of fixed pattern noise in the horizontal and vertical directions.

  The fixed pattern noise in the horizontal direction depends on the difference (T1) between the readout path of the vertical line a and the readout path of the vertical line b shown in FIG. Further, the fixed pattern noise in the vertical direction depends on the difference (T2) between the readout path of the horizontal line c and the readout path of the horizontal line d shown in FIG. For example, as shown in FIG. 3, each horizontal line shares a readout circuit (510), and imaging with a small amount of noise mixed when signals of each horizontal line are transferred to the common readout circuit 510 by devising a circuit layout or the like. In the case of an element, 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.

  1 and 2, reference numerals 60, 62, 64, 66, 68, and 70 are operation units for inputting various operation instructions of the system control circuit 50, and are switches, dials, touch panels, pointing by gaze detection, And a single or a plurality of combinations such as a voice recognition device. 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 used for exposure processing for writing a signal read from the image sensor 12 to the memory 30 via the A / D converter 16 and the memory control circuit 22, and for the image processing circuit 20 and the memory control circuit 22. An instruction is given to start a series of processing operations such as a development process using computation and a recording process in which image data is read from the memory 30, compressed by the compression / decompression circuit 32, and written to the recording media 200 and 201.

  Reference numeral 66 denotes a playback switch, which instructs to start a playback operation in which an image shot in the shooting mode is read from the memory 30 or the recording medium 200 or 210 and displayed 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, which can set the ISO sensitivity by changing the gain setting in the image sensor 14 or the image processing circuit 20.

  Reference numeral 70 denotes an operation unit composed of 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, 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, 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 for JPEG compression, or a switch for selecting a CCD RAW mode for digitizing an image signal and recording it on a recording medium. In addition to a playback switch that can set each function mode such as a compression mode switch, playback mode, multi-screen playback / erase mode, and PC connection mode, autofocus operation starts when the shutter switch SW1 is pressed. There is an AF mode setting switch that can set a one-shot AF mode that keeps the in-focus state when in focus 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 / off modes of the image processing apparatus 100. In addition, the power on / off setting of various accessory devices in the lens unit 300, the external strobe, the recording media 200, 210, etc. connected to the image processing apparatus 100 can also be switched.

  Reference numeral 80 denotes a power control unit, which includes a battery detection circuit, a DC-DC converter, and a switch circuit that switches a block to be energized, and 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 an instruction from the system control circuit 50, and a necessary voltage is supplied to each unit 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 a 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 and a hard disk, 92 and 96 are connectors for connecting to a recording medium such as a memory card and a hard disk, and 98 is a recording medium 200 and 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 the present embodiment, two interfaces and connectors for attaching the recording medium are provided. However, the interfaces and connectors for attaching the recording medium may be provided by a single or an arbitrary number of systems. Further, as interfaces and connectors of different standards, those compliant with standards such as PCMCIA cards and CF (compact flash (registered trademark)) cards may be used.

  Further, when the interfaces 90 and 94 and the connectors 92 and 96 are configured using a standard conforming to a PCMCIA card or a CF (Compact Flash (registered trademark)) card, a LAN card, a modem card, a USB card, and an IEEE 1394 card are used. By connecting various communication cards such as communication cards such as P1284 card, SCSI card, and PHS, image data and management information attached to image data can be exchanged with other computers and peripheral devices such as printers. It is possible to transfer.

  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, and forms an optical image for display by a single-lens reflex system. 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. Also, some functions of the display unit 54 are provided in the optical viewfinder 104, for example, focus display, camera shake warning display, flash charge display, shutter speed display, aperture value display, exposure correction display, and the like. .

  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 performing 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. Whether or not the lens unit 300 is attached to the lens mount 106 and / or the connector 122 is detected by a lens attachment / detachment detection unit (not shown).

  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. Further, 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 an electrical signal but also an optical signal, an audio signal, 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 photometry 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 unique number of the lens unit 300, management information, function information such as an open aperture value, a minimum aperture value, and a focal length. Also, it has a function of a non-volatile memory that holds each setting value of the present and past.

<Operation of electronic camera>
The operation of the electronic camera having the above configuration will be described with reference to FIGS.

  4 and 5 are flowcharts showing the shooting operation processing procedure of the image processing apparatus 100. FIG. 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). Subsequently, the system control circuit 50 determines the set 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. The power control unit 80 performs a predetermined end process such as shutting off unnecessary power of each unit of the image processing apparatus 100 including the image display unit 28 (step S103), and then 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 and the operation status have 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 on the display unit 54 or outputting sound (step S105), and then the process returns to step S102. 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.

  When the mode dial switch 60 is set to the shooting mode, it is determined whether or not the recording media 200 and 201 are attached, acquisition of management information of the image data recorded on the recording media 200 and 201, and recording It is determined whether or not the operation state of the mediums 200 and 201 has a problem in the operation of the image processing apparatus 100, particularly 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 / continuous shooting switch 68, when the shutter switch SW2 is pressed, a single shooting mode in which one frame is shot and the camera is 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 of the system control circuit 50 or the memory 52.

  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 by an image or sound using the image display unit 28.

  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 further performs a photometry process to determine an aperture value and a shutter speed. Distance measurement / photometry 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.

  In subsequent step S <b> 115, the system control circuit 50 reads the one-dimensional correction data used for the horizontal dark shading correction from the nonvolatile memory 56 and develops it in a predetermined area of the memory 30. After the development of the correction data is completed, the process proceeds to step S116.

  Here, FIG. 6 shows a conceptual diagram of correction of the main image by horizontal dark shading correction or blackening correction. As shown in the figure, in the horizontal dark shading correction, the one-dimensional correction data (horizontal one line data 601) developed in step S115 is repeatedly subtracted for each horizontal line, so that a horizontal circuit system from the main image 600 is obtained. It is possible to obtain a corrected image 602 from which noise, that is, fixed pattern noise is removed. Blackening correction by the black image 603 will be described later.

  Then, it is determined whether or not the shutter switch SW2 is pressed (step S116). If the shutter switch SW2 is not pressed, it is determined whether or not the shutter switch SW1 is released (step S117), and the shutter switch SW1. Steps S116 and S117 are repeated until is released or the shutter switch SW2 is pressed. If the shutter switch SW1 is released in step S117, the process proceeds to step S102.

  On the other hand, when the shutter switch SW2 is pressed in step S116, the system control circuit 50 determines whether or not the memory 30 has an image storage buffer area capable of storing captured image data (step S118). When 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 by displaying an image on the display unit 54 or outputting sound (step S119). The process returns to step S102. The case where there is no area where new image data can be stored in the image storage buffer area is, for example, immediately after the maximum number of continuous shots that can be stored in the image storage buffer area of the memory 30 is taken. The first image to be read from and written to the storage media 200 and 210 is still unrecorded in the storage media 200 and 210, and one free area cannot be secured in the image storage buffer area of the memory 30 yet. Such as the case.

  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 in the process of step S118.

  On the other hand, if it is determined in step S118 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 The photographed image data is written in a predetermined area of the memory 30 via the A / D converter 16, the image processing circuit 20 and the memory control circuit 22, or directly from the A / D converter 16 via the memory control circuit 22. An imaging process is executed (step S120). Details of this photographing process will be described later.

  When the photographing process in step S120 is completed, the system control circuit 50 calculates DL from data corresponding to the dark output level (hereinafter referred to as DL) detection area of the image sensor 14 among the image data written in the memory 30 (step S120). S121). The DL detection area is the whole or a part of a light-shielded area (light-shielded area) in the image sensor 14 where light is not incident. FIG. 7 is a diagram schematically illustrating the pixel region 700 of the image sensor 14. Although the DL detection region 703 is provided in the light shielding region 702 adjacent to the opening region 702 in the horizontal direction in the figure, the light shielding region adjacent to the vertical direction may be used. Any DL calculation method may be used, but here, the average value of data in the DL detection area is used. This DL increases as the dark current component in the signal increases during long-second imaging. In particular, at a high temperature, the amount of dark current generated increases, and therefore increases more remarkably. Further, if the photographing conditions such as the charge accumulation time and the environmental temperature are the same, the dark current amount itself is the same regardless of the ISO sensitivity setting, but in the case of high sensitivity (such as ISO 1600), Since the dark current component is amplified together with the other components, the DL at the time of long-second shooting becomes larger than that in the case of low sensitivity.

  In subsequent step S122, the system control circuit 50 compares DL with a predetermined value DLt. If DL is less than DLt, the system control circuit 50 immediately proceeds to processing in step S124. Therefore, in this case, the dark capturing process is not performed, and the image data captured in step S120 is corrected by the horizontal dark shading correction data in the developing process in step S124. When DL is small, dark current is small, and noise components other than dark current such as fixed pattern noise are dominant, and sufficient correction is possible with horizontal dark shading correction data.

  On the other hand, when DL is large, the dark current is large, and noise components caused by dark current such as pixel defects due to minute flaws and dark current unevenness cannot be ignored, and horizontal dark shading correction data cannot be sufficiently corrected. . Therefore, if DL is greater than or equal to a predetermined value in step S122, the system control circuit 50 accumulates the noise component due to the dark current of the image sensor 14 for the same time as the main photographing with the shutter 12 closed, and the noise image that has been accumulated. A dark capturing process (dark image capturing) for reading a signal is performed (step S123), and the process proceeds to step S124.

  In step S124, the system control circuit 50 reads a part of the image data written in the predetermined area of the memory 30 via the memory control circuit 22 and performs a WB (white balance) integration calculation process necessary for development processing. , OB (optical 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 the memory 52 of the system control circuit 50. Are used to perform various development processes including AWB (auto white balance) processing, gamma conversion processing, and color conversion processing.

  In this development process, the dark image data is used when the dark capturing process (step S123) is performed, and the horizontal dark shading correction data developed in step S115 is used when the dark capturing process is not performed. By performing the subtraction process, dark correction calculation processing for canceling fixed pattern noise, 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, the dark capturing process at the time of shooting is not performed with respect to the image quality deterioration due to the horizontal fixed pattern noise generated in the image sensor 14. Can be corrected. Further, when the correction calculation process is performed using the dark image data captured in the dark capture process, not only the horizontal fixed pattern noise generated in the image sensor 14 but also the pixel defect or dark current due to the minute scratch inherent in the image sensor 14. The captured image data can be corrected for image quality deterioration due to noise caused by dark current such as unevenness.

  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 photographed and completed a series of processing is written into the portion (step S125).

  Then, the system control circuit 50 reads the image data stored in the image storage buffer area of the memory 30 and records it on a memory card, a compact flash (registered trademark) card or the like via the interfaces 90 and 94 and the connectors 92 and 96. Recording processing for writing the read image data on the media 200 and 210 is started (step S126). This recording start process is performed on the image data every time new image data that has been shot and finished a series of processes is newly written in the empty image portion of the image storage buffer area of the memory 30.

  Note that 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 to indicate that the writing operation is being performed.

  Further, the system control circuit 50 determines whether or not the shutter switch SW1 is pressed (step S127). 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 S128), and single shooting is set. If it is, the process returns to step S127, and the current process is repeated until the shutter switch SW1 is released. On the other hand, if continuous shooting has been set, in order to perform continuous shooting, the process returns to step S116 to prepare for the next shooting. As a result, a series of processing relating to photographing is completed.

  FIG. 8 is a flowchart showing the distance measurement / photometry processing procedure in step S114 of FIG.

  In this 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.

  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. The AF control for detecting the in-focus state using the unit 42 is executed (steps S202 and S203).

  When it is determined in step S203 that ranging (AF) is in focus, the system control circuit 50 determines a focusing point from a plurality of ranging points in the shooting screen, and together with the determined ranging point data. Ranging data and / or setting parameters are stored in the internal memory of the system control circuit 50 or the memory 52 (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 of the system control circuit 50 or the memory 52 (step S208). 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.

  Thereafter, the system control circuit 50 determines whether or not flashing is necessary based on the measurement data obtained by the photometric processing in step S206 (step S209). If flashing is necessary, the flash flag is set and charging is performed. The flash unit 48 is charged until is completed (steps S210 and S211). Then, when the charging of the flash unit 48 is completed, this process is terminated and the process returns to the main process.

  FIG. 9 is a flowchart showing the photographing processing procedure in step S120 of FIG.

  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 via the interface 120, the connector 122, the connector 322, the interface 320, and the lens system control circuit 350. Done.

  The system control circuit 50 moves the mirror 130 to the mirror up position by a mirror drive unit (not shown) (step S301), and according to the photometric data stored in the internal memory or the memory 52 of the system control circuit 50, the aperture control unit The diaphragm 312 is driven to a predetermined diaphragm value by 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 exposure of the image sensor 14 to end 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. Subsequently, 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). ).

  Then, 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 ends the charge accumulation of the image sensor 14 (step S314). ), A charge signal is read from the image sensor 14, and the memory 30 is connected via the A / D converter 16, the image processing circuit 20 and the memory control circuit 22, or directly from the A / D converter 16 via the memory control circuit 22. The photographed image data is written in the predetermined 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 capture processing procedure in step S123 of FIG.

  After performing the charge clear operation of the image sensor 14 (step S401), the system control circuit 50 starts charge accumulation in the image sensor 14 with the shutter 12 closed (step S402). Then, it is determined whether or not the set predetermined charge accumulation time has elapsed (step S403).

  When the charge accumulation time has elapsed, the system control circuit 50 reads the charge signal from the image sensor 14 after completing the charge accumulation of the image sensor 14 (step S404), and the A / D converter 16, the image processing circuit 20, and Image data (dark image data) is written into a predetermined area of the memory 30 via the memory control circuit 22 or directly from the A / D converter 16 via the memory control circuit 22 (step S405). The dark image data is used when the development process is performed in a state where the shooting process is executed first and the shot image data is read from the image sensor 14 and written in the memory 30.

  By performing development processing using this dark image data, it is possible to correct the captured image data against image quality degradation such as dark current noise generated in the image sensor 14 and pixel defects due to scratches inherent to the image sensor 14. Is possible. Thereafter, this process is terminated and the process returns to the main process.

  In the present embodiment, the charge accumulation time (Ts) of the main photographing process (step S120) and the charge accumulation time (Td) of the dark capturing process are made equal. In this case, for example, in 30-second shooting, the photographer must wait for 30 seconds again for the dark capturing process after the main shooting process, which may cause the next photo opportunity to be missed. Since Td need only be within a range where sufficient data for correcting dark current noise or the like can be obtained, in order to reduce the waiting time for such a photographer, charge accumulation different from Ts is required. It may be time.

At this time, Td may be shorter than Ts according to the value of DL. For example, when two threshold values DLt1 and DLt2 (DLt1 <DLt2) are provided in DL, and DL is DLt1 or more and less than DLt2, Td = Ts × (DL-DLt1) / (DLt2-DLt1)
And That is,
(1) DL <DLt1 → Do not perform dark capture processing (2) DLt1 ≦ DL <DLt2 → Dark capture according to the degree of DL (3) DL ≧ DLt2 → Perform dark capture processing for the same time as imaging processing Become.

  In the area (2), the dark current component in the signal is increased as compared with the area (1), but since it is not so remarkable, it is corrected with dark image data having a shorter charge accumulation time than the imaging process. Even so, it is possible to obtain sufficient image quality.

  As described above, according to the present embodiment, it is possible to perform dark image shooting that is a factor that impedes the immediacy of the shutter release operation only under shooting conditions with a large dark current that is originally required. Under the conditions other than the above, it is possible to realize a light camera operation without performing unnecessary dark image capturing. In other words, the image correction method selection can be optimized.

  In addition, since it is determined whether it is necessary to perform blacking from actually captured image data, it is possible to optimize the selection of a correction method including individual differences in the amount of dark current generated by the image sensor.

  In this way, it is possible to accurately determine conditions actually required for dark image shooting, and to prevent deterioration of image quality while minimizing dark image shooting that causes a shutter release time lag.

  The present invention is not limited to the configurations of these embodiments, and can be applied to any configuration that can achieve the functions shown in the claims or the functions of the configurations of the embodiments. It is.

  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 (step S115) 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. Further, as shown in FIG. 11, both the one-dimensional data 601 and 605 in the horizontal and vertical directions are stored, and the correction data developing process (step S115) is not the data of the entire two-dimensional image. When developing the one-dimensional data 601 in the horizontal direction, 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 605 in the vertical direction.

  In this case, the vertical direction is further stored as a mathematical formula without being stored as one-dimensional correction data. 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.

  Further, in the above embodiment, the correction data is created at the time of adjustment in the production process and stored in the nonvolatile memory 56. However, an image obtained by photographing a dark image at any time by a user or the like can be obtained. It may be created and stored by performing a projection operation. Alternatively, it may be created when the camera is turned on or when the ISO sensitivity is changed.

  Conversely, when DL is less than the threshold value DLt and blacking is not performed, correction such as horizontal dark shading correction may not be performed. When using an image sensor with little fixed pattern noise, which is circuit system noise, correction such as horizontal dark shading correction is not necessary, and the load applied to the system control circuit 50 is reduced when the correction operation is not performed. At this time, in step S124, other development processing (AWB processing, gamma conversion processing, etc.) is performed, and the process proceeds to the next step.

  Further, in the above embodiment, the case of switching between single shooting / continuous shooting using the single shooting / continuous shooting switch 68 has been shown, but switching between single shooting / continuous shooting according to the operation mode selection in the mode dial 60. It is good also as composition which performs.

  Further, since the photographing operation cannot be performed during the execution of the dark capture processing operation in step S123, an image or sound 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.

  Further, in the present embodiment, the case where the photographing operation is performed by moving the mirror 130 between the mirror up position and the mirror down position has been described. However, the mirror 130 is configured as a half mirror so that the photographing operation is performed without moving. May be.

  Furthermore, the recording media 200 and 210 are not only memory cards such as PCMCIA cards and compact flash (registered trademark), hard disks, but also micro DAT, magneto-optical disks, optical disks such as CD-R and CD-RW, DVDs, and the like. The phase change type optical disc or the like may be used. Furthermore, 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 remain fixed to the image processing apparatus 100. There may be. 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.

  In the above embodiment, the program codes shown in the flowcharts of FIGS. 4, 5, and 8 to 10 are stored in the nonvolatile memory 56, for example. The storage medium for supplying the program code is not limited to a nonvolatile memory, and for example, a ROM, a flexible disk, a hard disk, or the like can be used.

  The present invention is not limited to the apparatus of the above-described embodiment, and may be applied to a system composed of a plurality of devices or an apparatus composed of one device. A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus reads and executes the program codes stored in the storage medium. Needless to say, it will be completed by doing.

  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. As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM is used. Can do. In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the OS running on the computer based on the instruction of the program code performs the actual processing. Needless to say, a case where the function of the above-described embodiment is realized by performing part or all of the processing is also included.

  Furthermore, after the program code read from the storage medium is written to the memory provided in the function expansion board inserted in the computer or the function expansion unit connected to the computer, the program code is expanded based on the instruction of the next program code. It goes without saying that the functions of the above-described embodiments may be realized by performing some or all of the actual processing by the CPU or the like provided on the expansion board or the expansion unit.

It is a block diagram which shows the structure of the electronic camera in embodiment. FIG. 2 is a continuation of FIG. 1. It is a figure explaining mixing of fixed pattern noise in the horizontal and vertical directions. 3 is a flowchart illustrating a shooting operation processing procedure of the image processing apparatus 100. FIG. 5 is a flowchart continued from FIG. 4. It is a figure which shows the correction | amendment of this image by black drawing or horizontal dark shading correction data. 3 is a diagram illustrating a configuration of a pixel region of the image sensor 14. FIG. 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 S120. It is a flowchart which shows the dark taking-in process procedure in step S123. 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 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 300 Lens unit

Claims (10)

Second charge accumulation is performed in the exposure state of the imaging means using the first image data obtained in the first imaging mode in which charge accumulation is performed in the non-exposure state of the imaging means for converting the optical image into an electrical signal. An image data correction apparatus capable of correcting the second image data obtained in the imaging mode,
Dark output calculation means for calculating a dark output value from the light shielding region of the second image data;
Determining means for determining whether the dark output value calculated by the dark output calculating means is a predetermined value or more;
And a correction unit that corrects the second image data using the first image data when the determination unit determines that the dark output value is equal to or greater than a predetermined value. Image data correction device.   The apparatus according to claim 1, further comprising a changing unit that changes a charge accumulation time at the time of acquiring the first image data in the first imaging mode according to the dark output value calculated by the dark output calculating unit. The image data correction apparatus described. Correction data storage means for storing correction data different from the first image data as correction data for correcting the second image data;
Selecting means for selecting one of the first image data obtained in the first imaging mode and the correction data stored in the correction data storage means;
The correction means includes
If the dark output value calculated by the dark output calculation means is greater than or equal to a predetermined value, the selection means selects first image data, corrects the second image data based on the first image data, and 3. The image according to claim 1, wherein when the output value is less than a predetermined value, the correction data is selected by the selection unit, and the second image data is corrected based thereon. Data correction device. 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,
The second image data obtained in the second imaging mode is captured image data captured by the imaging element,
4. The image data correction apparatus according to claim 1, wherein the correction data is fixed pattern noise corresponding to circuit system noise of the image sensor.   The image data correction apparatus according to claim 4, wherein the correction data is data obtained by calculation based on the first image data.   6. The image data correction apparatus according to claim 5, wherein the correction data is one-dimensional data in a horizontal direction obtained by projecting the first image data in a vertical direction.   An image processing apparatus comprising the image data correction apparatus according to claim 1 and the imaging unit. Second charge accumulation is performed in the exposure state of the imaging step using the first image data obtained in the first imaging mode in which charge accumulation is performed in the non-exposure state of the imaging means for converting the optical image into an electrical signal. An image data correction method for correcting second image data obtained in an imaging mode,
A dark output calculation step of calculating a dark output value from the light shielding region of the second image data;
A determination step of determining whether the dark output value calculated by the dark output calculation step is a predetermined value or more;
And a correction step of correcting the second image data using the first image data when the determination step determines that the dark output value is equal to or greater than a predetermined value. Data correction method. Second charge accumulation is performed in the exposure state of the imaging step using the first image data obtained in the first imaging mode in which charge accumulation is performed in the non-exposure state of the imaging means for converting the optical image into an electrical signal. A computer-readable control program for executing an image data correction method for correcting second image data obtained in an imaging mode,
A dark output calculation step of calculating a dark output value from the light-shielding region of the second image data;
A determination step of determining whether or not the dark output value calculated by the dark output calculation step is a predetermined value or more;
And a correction step of correcting the second image data using the first image data when the determination step determines that the dark output value is equal to or greater than a predetermined value. program.   A storage medium storing the control program according to claim 9.

Images