JP2008182486A - Photographing device, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photographing device capable of reducing color moire and false color without deteriorating image quality, and to provide an image processing method. <P>SOLUTION: Photographing is performed two times when an S2 is turned on, and one photographing of two times of photographings is performed in such a state that an optical blur correction controller 30A intentionally blurs an image. A luminance and color difference converting device 102 generates a luminance signal Y and color difference signals Cr and Cb from R, G and B signals acquired from a CCD 32. A luminance holding memory 104 temporarily stores a luminance signal Y1 acquired by the first photographing. A luminance and color difference composition device 106 composes the luminance signal Y1 and color difference signals Cr2 and Cb2 and outputs the resultant signals. The luminance signal Y1 and the color difference signals Cr2 and Cb2 outputted from the luminance and color difference combining device 106 are respectively subjected to predetermined processing and subsequently stored in a RAM 20. The luminance signal Y1 and the color difference signal Cr2 and Cb2 stored in the RAM 20 are compressed according to a predetermined format by a compression/decompression processing part 46 and recorded in a recording medium 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image capturing apparatus and an image processing method, and more particularly to an image capturing apparatus that captures an image by receiving light from a subject with an image sensor and an image processing method applied to processing of an image captured by the image capturing apparatus.

Conventionally, it has been disclosed that an optical low-pass filter (optical LPF) is inserted on the incident side of an image sensor to prevent high-frequency components higher than the Nyquist frequency in incident light to prevent occurrence of color moire (for example, Patent Document 1). Japanese Patent Application Laid-Open No. 2004-228561 reduces moire using a first image signal obtained by imaging in a focused state and a second image signal obtained by imaging in a non-focused state. Is disclosed.
JP 2001-45506 A

  It is known that when high-frequency light exceeding the Nyquist frequency is incident on the image pickup device, a false signal called moire is generated by folding the high-frequency component of the light. In addition, when a color filter is arranged on a single CCD and a color is interpolated by signal processing, a false signal called color moiré or false color is generated, and an original color may appear in an image.

  In the method of inserting the optical LPF on the incident side of the image sensor described in Patent Document 1, there is a problem that the resolution is lowered and the cost of the apparatus is increased due to the addition of the optical LPF. Further, in the method using the image signal in the in-focus state and the out-of-focus state, there is a problem that the color reproducibility is deteriorated and the image quality is deteriorated because the subject blur differs depending on the subject distance. Furthermore, when photographing a subject with a large amount of motion, if the photographing is performed twice in the in-focus state and the out-of-focus state, the position of the subject is shifted, and the image signal obtained by the two photographings is obtained. There has been a problem that luminance and color shift occur in the combined image and the image quality deteriorates.

  SUMMARY An advantage of some aspects of the invention is that it provides a photographing apparatus and an image processing method capable of reducing color moire and false color without degrading image quality.

  In order to solve the above-described problems, an imaging apparatus according to the first aspect of the present invention receives an image from an object by receiving light from a subject, acquires an image signal, and optical blur in an image captured by the imaging element. Obtained in the first state without optical blur, the first state without optical blur, the shooting control means for shooting an image in the second state with optical blur, and the first state without optical blur. Image generation means for generating an image by synthesizing the luminance signal and the color difference signal acquired in the second state causing optical blurring.

  According to the present invention 1, since the image can be uniformly blurred using the optical blur generating means, the luminance signal without optical blur and the intentional optical blur are caused, and the color moire and the false color are generated. By combining the color difference signals photographed so as not to occur, color moiré and false color can be reduced without degrading the image quality.

  An imaging device according to the present invention 2 receives light from a subject to capture an image, acquires an image signal, a first state in which the subject is in focus and there is no optical blur, Shooting control means for shooting an image in the second state where the subject is out of focus or caused optical blur, and the amount of movement of the subject in the images shot in the first and second states An image is generated by synthesizing the luminance signal acquired in the first state and the color difference signal acquired in the second state when the movement amount is equal to or less than a threshold value On the other hand, it comprises image generation means for generating an image using the luminance signal and the color difference signal acquired in the first state when the amount of motion is larger than a threshold value.

  According to the second aspect of the present invention, the luminance signal acquired in the first state and the second state are acquired when the amount of movement of the subject in the images shot in the first and second states is equal to or less than the threshold value. Since the color moiré and false color are reduced by combining the color difference signals, it is possible to avoid the image of the composite image from being deteriorated due to the subject moving out of position due to the movement of the subject.

  The imaging device according to the third aspect of the present invention includes an imaging device that receives light from a subject to capture an image and obtains an image signal, a still object photographing mode for photographing a subject with little motion, and a subject with motion A shooting mode switching means for switching a shooting mode between an action object shooting mode for shooting an object, a first state in which the subject is in focus and no optical blur is present, and the subject is not in focus. Or a photographing control means for photographing an image in the second state in which optical blurring occurs, a luminance signal acquired in the first state when the photographing mode is a stationary object photographing mode, and the second The color difference signals acquired in the state are combined to generate an image, while in the shooting mode operation object shooting mode, an image is generated using the luminance signal and color difference signals acquired in the first state. Image generation means and Characterized in that it comprises.

  According to the third aspect of the present invention, when the shooting mode is the stationary object shooting mode, the color moire and the false color are obtained by combining the luminance signal acquired in the first state and the color difference signal acquired in the second state. Since it is reduced, it can be avoided that the subject is shifted due to the movement of the subject and the image quality of the composite image is deteriorated.

  The image processing method according to the fourth aspect of the present invention uses an imaging device to receive light from a subject to capture an image and acquire an image signal, and causes an optical blur in an image captured by the imaging device. An optical blur generating step, a first state without optical blur, a shooting control step for shooting an image in a second state causing optical blur, and luminance acquired in the first state without optical blur And an image generation step of generating an image by combining the signal and the color difference signal acquired in the second state causing the optical blur.

  The image processing method according to the fifth aspect of the present invention is a method of capturing an image by receiving light from a subject using an imaging device to acquire an image signal, focusing on the subject, and without optical blurring. A shooting control step of shooting an image in a first state, a second state where the subject is out of focus or optical blurring, and in the images shot in the first and second states A movement amount acquisition step of acquiring a movement amount of the subject in step S3, a luminance signal acquired in the first state and a color difference signal acquired in the second state when the movement amount is equal to or less than a threshold value. An image generating step of generating an image using the luminance signal and the color difference signal acquired in the first state when the amount of motion is larger than a threshold value while generating an image by combining. To do.

  The image processing method according to the sixth aspect of the present invention includes a step of capturing an image by receiving light from a subject using an imaging element to acquire an image signal, and a stationary object photographing mode for photographing a subject with little movement A shooting mode switching step of switching a shooting mode between a moving object shooting mode for shooting a moving subject, a first state in which the subject is in focus and no optical blur occurs, and the subject And a brightness control acquired in the first state when the shooting mode is the stationary object shooting mode. The signal and the color difference signal acquired in the second state are combined to generate an image. On the other hand, in the shooting mode operation object shooting mode, the luminance signal and the color difference signal acquired in the first state are generated. Use to generate images Characterized in that it comprises a that image generation process.

  According to the present invention, since the image can be uniformly blurred using the optical blur generating means, the luminance signal without optical blur and the intentional optical blur are generated to generate color moire and false color. By synthesizing the color difference signals photographed in such a manner, color moiré and false colors can be reduced without degrading the image quality.

  Further, according to the present invention, in consideration of the movement of the subject, whether to synthesize the luminance signal acquired in the first state and the color difference signal acquired in the second state is selected. Therefore, it is possible to avoid the deterioration of the image quality of the composite image due to the subject moving out of position due to the movement of the subject.

  Hereinafter, preferred embodiments of a photographing apparatus and an image processing method according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 2 is a block diagram showing the main configuration of the photographing apparatus according to the first embodiment of the present invention. As shown in FIG. 2, the CPU 12 is connected to each unit in the photographing apparatus 10 (hereinafter referred to as the camera 10) via a bus 14, and based on an operation input from the operation unit 16 or the like, This is the overall control unit that controls the operation. The CPU 12 controls each unit of the camera 10 based on an input signal from the operation unit 16, for example, driving control of the lens unit 28, shooting operation control, image processing control, image data recording / reproduction control, image display unit 42. Display control.

  The operation unit 16 includes a power switch, an operation mode switching switch, a shooting mode switching switch, a face detection function on / off switch, a release button, a menu / OK key, a cross key, and a cancel key.

  The power switch is an operation means for controlling the power on / off of the camera 10.

  The operation mode switching switch is an operation means for switching the operation mode of the camera 10 between the shooting mode and the reproduction mode.

  The shooting mode switching switch functions as a switch for switching the shooting mode of the camera 10. In addition to the pre-shutter mode, which will be described later, the shooting mode of the camera 10 can be set according to the scene position (for example, natural photo, person, landscape, night view, portrait, sport, underwater, close-up (flowers, etc.) or text text). It is possible to switch to a scene position mode for optimizing exposure for shooting, an auto mode for automatically setting focus and exposure, a manual mode for manually setting focus and exposure, or a moving image shooting mode.

  The face detection function on / off switch controls on / off of a face detection function for detecting a face from a captured image.

  The release button is an operation button for inputting an instruction to start photographing, and includes a two-stroke switch having an S1 switch that is turned on when half-pressed and an S2 switch that is turned on when fully pressed.

  The menu / OK key is an operation having both a function as a menu button for instructing to display a menu on the screen of the image display unit 42 and a function as an OK button for instructing confirmation and execution of selection contents. Key.

  The cross key is an operation unit for inputting instructions in four directions, up, down, left, and right, and functions as a button (cursor moving operation means) for selecting an item from the menu screen or instructing selection of various setting items from each menu. To do. The up and down keys of the cross key function as a zoom switch in shooting mode or a playback zoom switch in playback, and the left and right keys function as frame advance (forward / reverse feed) buttons in playback mode. Function.

  The cancel key is used to delete a desired object such as a selection item, cancel an instruction content, or return to the previous operation state.

  The ROM 18 stores programs processed by the CPU 12 and various data necessary for control. The RAM 20 includes a work area and an image processing area where the CPU 12 performs various arithmetic processes.

  The camera 10 has a media socket (media mounting portion), and can mount a recording medium 22. The form of the recording medium 22 is not particularly limited. A semiconductor memory card represented by an xD picture card (registered trademark), an SD card (registered trademark), a smart media (registered trademark), a portable small hard disk, a magnetic disk, an optical disk, Various media such as a magneto-optical disk can be used. The media controller 24 performs necessary signal conversion in order to deliver an input / output signal suitable for the recording medium 22.

  The camera 10 also includes a communication interface unit (communication I / F) 26 as communication means for connecting to a public network such as the Internet or a mobile phone communication network.

  Next, the shooting function of the camera 10 will be described. In the shooting mode, power is supplied to the image pickup unit including the image pickup device 32, and an image can be shot. In the present embodiment, a single-plate color CCD solid-state image sensor is employed as the image sensor 32, and is simply referred to as the CCD 32 in the following description. As the image sensor 32, another image sensor such as a CMOS sensor may be used.

  The lens unit 28 is an optical unit including a photographing lens including a focus lens and a zoom lens, and a diaphragm. The lens driving unit 28A includes a focus lens, a zoom lens, a motor for moving the diaphragm, a sensor for detecting the position of the lens, and the like. The CPU 12 outputs a control signal to the lens driving unit 28A, and performs focusing, zooming, and aperture control of the photographing lens.

  The optical blur correction device (anti-vibration lens) 30 is arranged so as to be movable up and down (vertical direction) and left and right (horizontal direction) in a plane perpendicular to the optical axis. The optical blur correction control device 30A detects an angular velocity of vibration applied to the lens unit 28, outputs an angular velocity signal (angular velocity signal) detected, and an angular velocity signal output from the angular velocity sensor. Calculating means for calculating the movement target position of the vibration-proof lens 30 for displacing the image in the direction and size to cancel the optical blur (image blur) caused by the vibration of the lens unit 28; And a motor for moving to a position. When vibration is generated in the lens unit 28, the anti-vibration lens 30 moves to a position for correcting image blur by the optical blur correction control device 30A (position for canceling image blur due to vibration).

  Note that the image blur correction method is not limited to the above. For example, a method in which the image is intentionally displaced by displacing the CCD 32 to cancel the image blur, a recording from a photographed image taken by the CCD 32, or Other methods such as a method of canceling image blur by intentionally displacing an image by changing a range to be cut out as an image signal for reproduction can be used.

  The light that has passed through the lens unit 28 forms an image on the light receiving surface of the CCD 32. A number of light receiving elements (photodiodes) are two-dimensionally arranged on the light receiving surface of the CCD 32, and red (R), green (G), and blue (B) primary color filters are predetermined for each photodiode. Arranged in an array structure. The subject image formed on the light receiving surface of the CCD 32 is converted into a signal charge of an amount corresponding to the amount of incident light by each photodiode. The signal charges are sequentially read out as R, G, and B voltage signals (image signals) corresponding to the charge amount. The CCD 32 has an electronic shutter function for controlling the charge accumulation time (shutter speed) of each photodiode. The CPU 12 controls the signal charge readout timing from the CCD 32 and the charge accumulation time of each photodiode via the imaging control unit 32A.

  The R, G, B image signals read from the CCD 32 are amplified by sampling and holding (correlated double sampling processing) for each pixel of the CCD 32 by the analog processing unit (CDS / AMP) 34, and then A / It is added to the D converter 36 and converted into digital R, G, B signals. The R, G, and B signals converted into digital signals by the A / D converter 36 are stored in the RAM 20 via the image input control unit 38.

  The image signal processing unit 40 includes an offset correction unit, a white balance adjustment circuit, a gamma correction circuit, an RGB interpolation processing device (synchronization circuit, reference numeral 100 in FIG. 1), a luminance / color difference conversion device (reference numeral 102 in FIG. 1), a noise filter. , Functions as image processing means including a contour correction circuit, a color difference matrix, and the like, and performs predetermined signal processing using the RAM 20 in accordance with instructions from the CPU 12. That is, the image signal processing unit 40 reads out digital R, G, and B signals stored in the RAM 20, performs predetermined signal processing such as offset correction, white balance adjustment, and gamma correction, and performs R, G, and B signals. The signal is converted into a luminance signal (Y signal) and a color difference signal (Cr, Cb signal) and stored in the RAM 20.

  When the captured image is output to the image display unit 42 (for example, a liquid crystal monitor), the luminance / color difference signal (Y / C signal) stored in the RAM 20 is read and displayed via the bus 14. 44. The display control unit 44 converts the input Y / C signal into a predetermined video signal for display (for example, an NTSC color composite image signal) and outputs the video signal to the image display unit 42.

  When displaying a live view image (through image), the image data in the RAM 20 is periodically rewritten by the image signal output from the CCD 32, and the image signal generated from the image data is supplied to the image display unit 42. Is done. Thereby, the video (through image) being shot is displayed on the image display unit 42 in real time. The photographer can confirm the shooting angle of view by the through image displayed on the image display unit 42.

  When the release button is pressed halfway (S1 ON), the image signal output from the CCD 32 is input to the CPU 12 via the image input control unit 38 after A / D conversion, and AE and AF processes are started.

  The CPU 12 divides one screen into a plurality of divided areas (for example, 8 × 8 or 16 × 16), and integrates R, G, and B image signals for each divided area. The CPU 12 detects the brightness of the subject (subject brightness) based on the integrated value, calculates an exposure value (shooting EV value) suitable for shooting, and aperture value according to the exposure value and a predetermined program diagram. The shutter speed is determined and the electronic shutter and the aperture of the CCD 32 are controlled to obtain an appropriate exposure amount.

  Further, the CPU 12 calculates an average integrated value for each color of the R, G, and B image signals for each divided area during automatic white balance adjustment, and obtains the ratio of R / G and B / G for each divided area. , R / G, and B / G values are discriminated based on the distribution in the color space of the R / G and B / G axis coordinates. Then, the CPU 12 controls the gain value (white balance gain) for the R, G, and B image signals according to the determined light source type, and corrects the image signals of the R, G, and B color channels.

  For example, contrast AF that moves the focus lens so that the high-frequency component of the G signal of the image signal is maximized is applied to the AF control in the camera 10. That is, the CPU 12 cuts out a signal in the AF area set in advance in a part of the effective pixel area of the CCD 32 (for example, the central part of the effective pixel area), and uses a high-pass filter to generate a high-frequency component of the G signal in the AF area. Only the absolute value data of the high-frequency component is integrated, and a focus evaluation value (AF evaluation value) relating to the subject image in the AF area is calculated.

  The CPU 12 calculates a focus evaluation value at a plurality of AF detection points while moving the focus lens by controlling the lens driving unit 28A, and determines a lens position where the focus evaluation value is maximized as a focus position. Then, the CPU 12 controls the lens driving unit 28A to move the focus lens to the determined focus position. The calculation of the focus evaluation value is not limited to the aspect using the G signal, and a luminance signal (Y signal) may be used.

  After the release button is pressed halfway (S1 on) and AE / AF processing is performed, when the release button is fully pressed (S2 on), the recording operation for recording starts.

  Hereinafter, the photographing operation according to the present embodiment will be described with reference to the block diagram of FIG. In the present embodiment, photographing is performed twice when S2 is on. One of the two shootings is performed while the optical blur correction control device 30A intentionally blurs the image. The R, G, and B image signals obtained by the above two imaging operations are subjected to A / D conversion after being subjected to predetermined processing, and are stored in the RAM 20 as digital R, G, and B signals. The image signal processing unit 40 reads out digital R, G, and B signals from the RAM 20 in accordance with a command from the CPU 12, performs predetermined signal processing, and inputs them to the RGB interpolation processing device 100.

  The RGB interpolation processing device 100 obtains R, G, and B signals at each pixel position of the CCD 32 by interpolation calculation (synchronization processing). In this embodiment, since the CCD 32 is a single plate type, each photodiode (pixel) of the CCD 32 outputs a signal of any one color of R, G, and B. For this reason, the RGB interpolation processing device 100 is provided, and the color that is not output from each pixel is obtained from the color signal of the surrounding pixels by interpolation calculation. For example, the extent of the G and B signals at the position of the pixel that outputs the R signal is obtained by interpolation from the G and B signals of the surrounding pixels. Since the RGB interpolation calculation is specific to a single-plate CCD, it is not necessary when using a three-plate CCD.

  The luminance / color difference conversion apparatus 102 generates a luminance signal Y and color difference signals Cr and Cb from the R, G, and B signals after the RGB interpolation calculation. In the following description, the luminance signal obtained by the first photographing is denoted as Y1, the color difference signal is represented by Cr1, Cb1, and the luminance signal obtained by the second photographing is represented by Y2, and the color difference signal is represented by Cr2, Cb2.

  The luminance holding memory 104 temporarily stores the luminance signal Y1 acquired by the first shooting.

  When the color difference signals Cr2 and Cb2 acquired by the second photographing are input from the luminance and color difference conversion device 102, the luminance and color difference synthesis device 106 receives the luminance signal Y1 and the color difference signals Cr2 and Cb2 temporarily stored in the luminance holding memory 104. Are combined and output. The luminance signal Y1 and the color difference signals Cr2 and Cb2 output from the luminance / color difference synthesis device 106 are stored in the RAM 20 after being subjected to contour correction processing and color tone correction processing, respectively.

  The luminance signal Y1 and the color difference signals Cr2 and Cb2 stored in the RAM 20 are compressed according to a predetermined format by the compression / decompression processing unit 46 and recorded on the recording medium 22. For example, a still image is recorded as a JPEG (Joint Photographic Experts Group) format, a moving image is recorded as an AVI (Audio Video Interleaving) format, and a Motion-JPEG image file.

  In the playback mode, the compressed data of the last image file (last recorded image file) recorded on the recording medium 22 is read. When the image file related to the last recording is a still image, the read compressed data is decompressed to an uncompressed Y / C signal by the compression / decompression processing unit 46, and is then processed by the image signal processing unit 40 and the display control unit 44. After being converted into a display signal, it is output to the image display unit 42. Thereby, the image content of the image file is displayed on the image display unit 42.

  During single-frame playback of a still image (including playback of the first frame of a movie), the image file to be played is switched by operating the right or left button of the cross button (forward / reverse frame advance). Can do. The image file at the frame-advanced position is read from the recording medium 22, and still images and moving images are reproduced and displayed on the image display unit 42 in the same manner as described above.

  Next, the flow of imaging processing according to the present embodiment will be described with reference to the flowchart of FIG. First, after the release button is pressed halfway (S1 on) and AE / AF processing is performed, when the release button is fully pressed (S2 on), the first shooting is performed without image blurring ( Step S10). Then, RGB interpolation processing (step S12) and luminance color difference conversion processing (step S14) are performed on the R, G, and B signals acquired by the first shooting to generate the luminance signal Y1, and the luminance holding memory 104 Is temporarily stored (step S16).

  Next, the second shooting is performed while the image is blurred by the optical blur correction control device 30A (steps S18 and S20). Then, RGB interpolation processing (step S22) and luminance color difference conversion processing (step S24) are performed on the R, G, and B signals acquired by the second shooting to generate color difference signals Cr2 and Cb2, and luminance color difference The data is input to the synthesizer 106.

  Next, the luminance signal Y1 temporarily stored in the luminance holding memory 104 is read out by the luminance / chrominance synthesizing device 106 and synthesized with the color difference signals Cr2 and Cb2 generated in step S24 (step S26). The luminance signal Y1 and the color difference signals Cr2 and Cb2 are output to the compression / decompression processing unit 46 and recorded on the recording medium 22 as an image file of a predetermined format.

  According to the present embodiment, since the image can be uniformly blurred using the optical blur correction device (anti-vibration lens) 30, the luminance signal Y1 without image blur and the image blur are intentionally caused. By synthesizing the color difference signals Cr2 and Cb2 photographed without generating color moire and false color, the color moire and false color can be reduced without degrading the image quality.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 4 is a block diagram for explaining a recording photographing operation according to the present embodiment. In the present embodiment, shooting is performed twice when S2 is on, and shooting is performed once in the focused state and once in the out-of-focus state. The image signal processing unit 40 performs predetermined signal processing on the digital R, G, and B signals obtained by the above two shootings in accordance with a command from the CPU 12, and then inputs them to the RGB interpolation processing device 100.

  The RGB interpolation processing device 100 obtains R, G, and B signals at each pixel position of the CCD 32 by interpolation calculation. The luminance / color difference conversion apparatus 102 generates a luminance signal Y and color difference signals Cr and Cb from the R, G, and B signals after the RGB interpolation calculation.

  The luminance / color difference holding memory 108 temporarily stores the luminance signal Y1 and the color difference signals Cr1, Cb1 acquired by the first photographing.

  The motion detection device 110 compares the image signals (R, G, B signals, or Y / C signals) acquired by the first and second shootings, and calculates the amount of movement of the subject between the two shootings. And provided to the luminance / color difference synthesis apparatus 112.

  When the subject motion amount calculated by the motion detection device 110 is larger than the threshold value, the luminance / color difference synthesis device 112 receives the luminance signal Y1 and the color difference signals Cr1 and Cb1 acquired from the luminance / color difference holding memory 108 by the first shooting. Obtain and output. Further, the luminance / color difference combining device 112 combines the luminance signal Y1 acquired by the first shooting and the color difference signals Cr2 and Cb2 acquired by the second shooting when the amount of movement of the subject is equal to or less than the threshold. Output.

  The Y / C signal output from the luminance / color difference synthesizing device 112 is subjected to contour correction processing and color tone correction processing, respectively, and then compressed according to a predetermined format by the compression / decompression processing unit 46 and recorded on the recording medium 22. .

  Next, the flow of imaging processing according to the present embodiment will be described with reference to the flowchart of FIG. First, after the release button is pressed halfway (S1 on) and AE / AF processing is performed, and then the release button is fully pressed (S2 on), the focus lens control device 27A moves the focus lens 27 to the in-focus position. It is arranged (step S30), and the first shooting is performed in the focused state (step S32). Then, RGB interpolation processing (step S34) and luminance / chrominance conversion processing (step S36) are performed on the R, G, and B signals acquired by the first shooting to generate the luminance signal Y1 and the color difference signals Cr1 and Cb1. And is temporarily stored in the luminance / color difference holding memory 108 (step S38).

  Next, the focus lens 27 is shifted from the in-focus position (step S40), and the second shooting is performed in the out-of-focus state (step S42). Then, RGB interpolation processing (step S44) and luminance color difference conversion processing (step S46) are performed on the R, G, and B signals acquired by the second shooting to generate color difference signals Cr2 and Cb2, and luminance color difference The data is input to the synthesizer 106.

  Next, the amount of motion of the subject between the two images is calculated based on the image signals acquired by the first and second shootings. When the amount of movement of the subject is equal to or less than the threshold (NO in step S48), the luminance signal Y1 acquired by the first shooting and the color difference signals Cr2 and Cb2 acquired by the second shooting are combined. (Step S50). On the other hand, when the amount of motion of the subject is larger than the threshold (YES in step S48), the luminance signal Y1 and the color difference signals Cr1 and Cb1 acquired by the first shooting are read from the luminance / color difference holding memory 108 and output. (Step S52).

  Next, the Y / C signal output in step S50 or S52 is output to the compression / decompression processing unit 46 and recorded on the recording medium 22 as an image file of a predetermined format (step S54).

  According to the present embodiment, when the amount of movement of the subject between the two shootings is equal to or less than the threshold value, the luminance signal Y1 acquired in the focused state and the color difference signals Cr2 and Cb2 acquired in the out-of-focus state As shown in FIG. 6, the position of the subject is shifted due to the movement of the subject and the image quality of the composite image is prevented from being deteriorated. Can do.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the present embodiment, when the shooting mode is set to a mode for shooting a subject with little movement (for example, portrait mode, landscape mode and night view mode, hereinafter referred to as still object shooting mode), focusing is performed. A mode for photographing moving subjects such as a sports mode (hereinafter referred to as an operation) to reduce color moire and false color by combining the luminance signal acquired in the state and the color difference signal acquired in the out-of-focus state. When it is set to the object photographing mode), an image is generated using the luminance signal and the color difference signal acquired in the focused state.

  FIG. 7 is a block diagram for explaining a recording photographing operation according to the present embodiment. In the following description, the same components as those in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as in the second embodiment, shooting is performed twice when S2 is on, and one of the two shots is taken in focus and the other is taken out of focus. Done. The image signal processing unit 40 performs predetermined signal processing on the digital R, G, and B signals obtained by the above two shootings in accordance with a command from the CPU 12, and then inputs them to the RGB interpolation processing device 100.

  The RGB interpolation processing device 100 obtains R, G, and B signals at each pixel position of the CCD 32 by interpolation calculation. The luminance / color difference conversion apparatus 102 generates a luminance signal Y and color difference signals Cr and Cb from the R, G, and B signals after the RGB interpolation calculation.

  The luminance / color difference holding memory 108 temporarily stores the luminance signal Y1 and the color difference signals Cr1, Cb1 acquired by the first photographing.

  The shooting mode setting device 15 sets the shooting mode in response to an input from the shooting mode switching switch of the operation unit 16.

  The luminance / color difference combining device 112 combines the luminance signal Y1 acquired by the first shooting and the color difference signals Cr2 and Cb2 acquired by the second shooting when the shooting mode is set to the stationary object shooting mode. Output. Further, the luminance / color difference synthesis device 112 acquires the luminance signal Y1 and the color difference signals Cr1, Cb1 acquired by the first shooting from the luminance / color difference holding memory 108 when the shooting mode is set to the operation object shooting mode. Output.

  The Y / C signal output from the luminance / color difference synthesizing device 112 is subjected to contour correction processing and color tone correction processing, respectively, and then compressed according to a predetermined format by the compression / decompression processing unit 46 and recorded on the recording medium 22. .

  Next, the flow of imaging processing according to the present embodiment will be described with reference to the flowchart of FIG. First, after the release button is pressed halfway (S1 on) and AE / AF processing is performed, and then the release button is fully pressed (S2 on), the focus lens control device 27A moves the focus lens 27 to the in-focus position. Arranged (step S60), the first shooting is performed in the focused state (step S62). Then, RGB interpolation processing (step S64) and luminance / chrominance conversion processing (step S66) are performed on the R, G, and B signals acquired by the first shooting to generate the luminance signal Y1 and the color difference signals Cr1 and Cb1. And is temporarily stored in the luminance / color difference holding memory 108 (step S68).

  Next, the focus lens 27 is shifted from the in-focus position (step S70), and the second shooting is performed in the out-of-focus state (step S72). Then, RGB interpolation processing (step S74) and luminance / color difference conversion processing (step S76) are performed on the R, G, and B signals acquired by the second shooting to generate the color difference signals Cr2 and Cb2, and the luminance / color difference The data is input to the synthesizer 106.

  Next, when the shooting mode is the stationary object shooting mode (NO in step S78), the luminance signal Y1 acquired by the first shooting and the color difference signals Cr2 and Cb2 acquired by the second shooting are combined. (Step S80). On the other hand, when the shooting mode is the action object shooting mode (YES in step S78), the luminance signal Y1 and the color difference signals Cr1 and Cb1 acquired by the first shooting are read out from the luminance color difference holding memory 108 and output. (Step S82).

  Next, the Y / C signal output in step S80 or S82 is output to the compression / expansion processing unit 46 and recorded on the recording medium 22 as an image file of a predetermined format (step S84).

  According to the present embodiment, when the shooting mode is the stationary object shooting mode, the luminance signal Y1 acquired in the in-focus state and the color difference signals Cr2 and Cb2 acquired in the out-of-focus state are combined to generate color moire and Since false colors are reduced, it can be avoided that the subject is shifted due to the movement of the subject and the image quality of the composite image is deteriorated.

  It should be noted that when the shooting mode is the stationary object shooting mode, it is possible to perform only the shooting in the focused state.

  In the second and third embodiments, the luminance signal Y1 acquired in the focused state and the color difference signals Cr2 and Cb2 acquired in the out-of-focus state are combined to reduce color moire and false color. However, as in the first embodiment, the luminance signal acquired without image blur and the color difference signal acquired with image blur may be combined.

  In each of the above embodiments, for example, the image signal (color difference signal) acquired by the first and second imaging is compared to extract a region where color moire or false color occurs, and the region When the image signal of the other region is generated using the luminance signal acquired by the first shooting and the color difference signal acquired by the second shooting, You may make it use the luminance signal and color difference signal which were acquired by imaging | photography.

FIG. 3 is a block diagram for explaining a photographing operation according to the first embodiment of the present invention. 1 is a block diagram showing the main configuration of a photographing apparatus according to a first embodiment of the present invention. 6 is a flowchart showing a flow of imaging processing according to the first embodiment of the present invention. Block diagram for explaining a photographing operation according to the second embodiment of the present invention 7 is a flowchart showing a flow of imaging processing according to the second embodiment of the present invention. The figure which shows the example of the image acquired by the 1st time and 2nd imaging | photography, and its synthesized image Block diagram for explaining a photographing operation according to the third embodiment of the present invention A flowchart showing a flow of photographing processing according to the third embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Imaging device (camera), 12 ... CPU, 14 ... Bus, 16 ... Operation part, 18 ... ROM, 20 ... RAM, 22 ... Recording medium, 24 ... Media controller, 26 ... Communication interface part (communication I / F) 28 ... Lens unit, 28A ... Lens drive unit, 30 ... Optical blur correction device, 30A ... Optical blur correction control device, 32 ... Imaging device (CCD), 32A ... Shooting control unit, 34 ... Analog processing unit (CDS / AMP) , 36... A / D converter, 38... Image input control unit, 40... Image signal processing unit, 42... Image display unit, 44. , 102: Luminance color difference conversion device, 104: Luminance holding memory, 106 ... Luminance color difference synthesizing device, 108 ... Luminance color difference holding memory, 110 ... Motion detection device, 112 ... Luminance color difference Equipment

Claims (6)

An image sensor that receives light from a subject to capture an image and obtain an image signal;
Optical blur generating means for causing optical blur in an image captured by the image sensor;
Photographing control means for photographing an image in a first state without optical blur and in a second state in which optical blur is caused;
Image generation means for generating an image by combining the luminance signal acquired in the first state without optical blur and the color difference signal acquired in the second state causing optical blur;
An imaging apparatus comprising: An image sensor that receives light from a subject to capture an image and obtain an image signal;
Shooting control means for shooting an image in a first state in which the subject is in focus and no optical blur and in a second state in which the subject is out of focus or caused optical blur;
A movement amount acquisition means for acquiring a movement amount of the subject in the images photographed in the first and second states;
When the amount of motion is less than or equal to a threshold value, the luminance signal acquired in the first state and the color difference signal acquired in the second state are combined to generate an image, while the amount of motion is less than the threshold value. An image generating means for generating an image using the luminance signal and the color difference signal acquired in the first state when they are large;
An imaging apparatus comprising: An image sensor that receives light from a subject to capture an image and obtain an image signal;
A shooting mode switching means for switching a shooting mode between a stationary object shooting mode for shooting a subject with little movement and a moving object shooting mode for shooting a moving subject;
Shooting control means for shooting an image in a first state in which the subject is in focus and no optical blur and in a second state in which the subject is out of focus or caused optical blur;
When the shooting mode is the stationary object shooting mode, the luminance signal acquired in the first state and the color difference signal acquired in the second state are combined to generate an image, while the shooting mode operation Image generation means for generating an image using the luminance signal and color difference signal acquired in the first state in the case of the object photographing mode;
An imaging apparatus comprising: Using an imaging device to receive light from a subject to capture an image and obtain an image signal;
An optical blur generation step for causing optical blur in an image captured by the imaging device;
A shooting control step of shooting an image in a first state without optical blur and a second state in which optical blur has occurred;
An image generation step of generating an image by combining the luminance signal acquired in the first state without optical blur and the color difference signal acquired in the second state causing optical blur;
An image processing method comprising: Using an imaging device to receive light from a subject to capture an image and obtain an image signal;
A shooting control step of shooting an image in a first state in which the subject is in focus and no optical blur and in a second state in which the subject is out of focus or optical blur is caused;
A movement amount acquisition step of acquiring a movement amount of the subject in the images taken in the first and second states;
When the amount of motion is less than or equal to a threshold value, the luminance signal acquired in the first state and the color difference signal acquired in the second state are combined to generate an image, while the amount of motion is less than the threshold value. An image generating step for generating an image using the luminance signal and the color difference signal acquired in the first state when the image is large;
An image processing method comprising: Using an imaging device to receive light from a subject to capture an image and obtain an image signal;
A shooting mode switching step for switching a shooting mode between a stationary object shooting mode for shooting a subject with little movement and an action object shooting mode for shooting a moving subject;
A shooting control step of shooting an image in a first state in which the subject is in focus and no optical blur and in a second state in which the subject is out of focus or optical blur is caused;
When the shooting mode is the stationary object shooting mode, the luminance signal acquired in the first state and the color difference signal acquired in the second state are combined to generate an image, while the shooting mode operation An image generation step of generating an image using the luminance signal and the color difference signal acquired in the first state in the case of the object photographing mode;
An image processing method comprising:

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