JP5474653B2 - Imaging apparatus and imaging method - Google Patents

Description

  The present invention relates to an imaging apparatus and an imaging method, and more particularly, to an imaging apparatus and an imaging method that include an illuminating unit and can capture a moving image even under conditions where natural light is insufficient.

  Conventionally, when shooting a moving image with a video camera or the like, if the surroundings are dark, shooting is performed while illuminating the subject with auxiliary light by illumination means such as a video light that can continuously illuminate with a large amount of light. Conventionally, incandescent bulbs have been generally used as video lights, but recently, with the development of LEDs (Light Emitting Diodes) and the like, many of them are low in power consumption and small in size.

  For example, Patent Document 1 discloses a strobe device that can shoot a subject by irradiating a subject by continuous light emission of LEDs. Patent Document 2 discloses a camera system in which a single shot is taken with a flash (flash light source) and a continuous shot is taken by emitting a continuous light source using an LED. Patent Document 3 discloses an imaging device that takes a still image with a flash (flash light source), and continuously and moving images by emitting light from a continuous light source using an LED.

JP 2003-233108 A International PCT / JP2005 / 001955 JP 2005-107240 A

  As described above, various continuous light emitting devices using LEDs or the like have been proposed. However, when driven by a battery that can be built in a portable device, the amount of light is limited, and the reaching distance is short and not sufficient. In addition, even when the subject is a short distance, compared to a flashlight device using a xenon tube, the amount of reflected light from the irradiated subject is insufficient, so it is necessary to increase the sensitivity of the image sensor, In that case, there is a problem that noise becomes conspicuous and image quality deteriorates.

  On the other hand, a flash light emitting device using a xenon tube can obtain an order of magnitude light amount in one frame of imaging compared with the above-mentioned video light and the like, and the sensitivity of the imaging device may be low. Good image quality. However, it is necessary to shoot a large number of frames in a short cycle, such as 30 frames per second, for example, and if a flash light emitting device is used for all frames, the capacitor for illuminating the xenon tube cannot be charged in time. For this reason, moving image shooting can be performed only for an extremely short time. In addition, when the xenon tube is used excessively continuously, there is a concern that the vicinity of the light emitting portion is overheated.

  The present invention has been made in view of such circumstances, and an imaging apparatus provided with an illuminating unit that can shoot with good image quality even in a dark place, has less power required for illumination, and does not worry about overheating of the illumination unit, and An object is to provide an imaging method.

In order to achieve the above object, an image pickup apparatus according to a first aspect of the present invention includes an image pickup unit capable of shooting a moving image by performing continuous image pickup, and an illuminating unit that complements the light amount at the time of image pickup in conjunction with the image pickup unit. In the imaging apparatus, the illuminating means may be a first illumination mode that illuminates by flash light emission, or a second illumination mode that continuously illuminates a plurality of frames with a light amount per frame smaller than that of the flash light emission. The image pickup apparatus corrects the color tone and noise of the image shot in the second illumination mode with the image shot in the first illumination mode, and the image quality of all frames is corrected. Are provided with image processing means for equalizing these.
The imaging apparatus according to a second aspect of the present invention is configured to increase imaging sensitivity when performing imaging in the second illumination mode in the first aspect.

An image pickup apparatus according to a third aspect of the present invention is the image pickup apparatus comprising: an image pickup unit capable of shooting a moving image by continuously taking an image; and an illumination unit that compensates for the amount of light at the time of image pickup in conjunction with the image pickup unit. The means controls the amount of light at the time of shooting in the first illumination mode in which illumination is performed by flash emission, or in the second illumination mode in which the amount of light per frame is less than that of the flash emission and the plurality of frames are continuously illuminated. The imaging apparatus is configured so that the contour information of the image captured in the first illumination mode is equivalent to the contour movement information of the image of each frame captured in the second illumination mode. Image processing means for deforming an image taken in the first illumination mode is provided.
An imaging apparatus according to a fourth aspect of the present invention increases the imaging sensitivity when performing imaging in the second illumination mode in the third aspect.

  An image pickup apparatus according to a fifth aspect of the invention is an image pickup means capable of taking a moving image by continuously taking an image, and interlocking with the shooting of the moving image by the image pickup means, and flashing once every a plurality of frames. A first illumination unit that compensates for the amount of light at the time of imaging, and a frame that does not perform the flash emission by the first illumination unit, the amount of light per frame is less than the flash emission and is applied to a plurality of frames. Second illumination means for continuously illuminating to supplement the amount of light at the time of photographing, and image processing means for correcting the image photographed by the continuous illumination based on the image photographed by the flash emission.

In the imaging apparatus according to a sixth aspect based on the fifth aspect, the image processing means corrects noise and color of the image captured with the continuous illumination based on the image captured with the flash emission.
An image pickup apparatus according to a seventh invention is the imaging device according to the fifth invention, wherein the image processing means detects a motion vector of a contour of an image photographed by the flash light emission and the continuous illumination, and an image photographed by the flash light emission. Is used to correct the contour of the image captured by the continuous illumination.

In the imaging device according to an eighth invention, in the fifth invention, the imaging means increases imaging sensitivity when shooting with the continuous illumination as compared to shooting with flash emission.
An image pickup apparatus according to a ninth invention is the imaging device according to the fifth invention, wherein the first illumination means is supplied with power from within the flash unit, and the second illumination means is supplied with power from within the camera body. receive.

An image pickup apparatus according to a tenth aspect of the present invention is the imaging apparatus according to the fifth aspect, wherein the first illuminating means has a charging circuit for performing the flash emission, and the charging circuit in a frame that does not perform the flash emission. Charge the battery.
In an imaging apparatus according to an eleventh aspect of the present invention, in the fifth aspect, the second illumination unit performs the continuous illumination only during an imaging period of the imaging unit.

  In the imaging device according to a twelfth aspect of the present invention, in the fifth aspect of the invention, the first illuminating means causes the light-emitting diode to pass a current stored in a capacitor in the charging circuit in a short time to emit high-intensity flash light. The second illumination means performs continuous illumination by continuously energizing the light emitting diode.

  In the imaging device according to a thirteenth aspect of the present invention, in the fifth aspect, the first illuminating unit discharges the current stored in the flash capacitor in the charging circuit in the flash light emitting tube in a short time to emit flash light. The second illuminating means performs flat light emission by repeating minute light emission by turning on and off the current stored in the flash capacitor in the charging circuit in the flash light emitting tube.

  An image pickup apparatus according to a fourteenth aspect of the invention is an image pickup means capable of taking a moving image by continuously taking an image, and interlocking with the shooting of the moving image by the image pickup means, and flashing once for each of a plurality of frames. The first illumination unit that compensates for the amount of light at the time of imaging, and the frame that does not perform the flash emission by the first illumination unit, the amount of light per frame is less than the flash emission, and for a plurality of frames Second illumination means for supplementing the amount of light at the time of photographing with continuous illumination, and the first illumination means further includes a charging circuit for performing the flash emission, and does not perform the flash emission. In the frame, the charging circuit is charged.

  An imaging method according to a fifteenth aspect of the invention is an imaging method in which the amount of light when capturing a moving image is supplemented by illumination means, and the amount of light per frame is determined by an image captured in the first illumination mode illuminated by flash emission. The image quality of all frames is made equal by correcting the color tone and noise of an image shot in the second illumination mode in which a plurality of frames are continuously illuminated with a light amount smaller than that of light emission.

  An imaging method according to a sixteenth aspect of the invention is an imaging method in which the amount of light when capturing a moving image is supplemented by illumination means, and the contour information of the image captured in the first illumination mode illuminated by flash emission is the amount of light per frame. In the first illumination mode so that it is equivalent to the contour movement information of the image of each frame shot in the second illumination mode that continuously illuminates a plurality of frames with less light than the flash emission. Deform a captured image.

  An image pickup method according to a seventeenth aspect of the invention is an image pickup method in which the amount of light when a moving image is picked up is supplemented by illumination means. Once each time, a step of capturing a moving image by supplementing the amount of light at the time of imaging by flashing light and continuously illuminating a frame that does not emit the flash light to compensate for the amount of light at the time of shooting; And correcting the image photographed by the continuous illumination.

  According to the first aspect of the invention, it is possible to adjust the image quality of a low-quality frame imaged by continuous light emission that is insufficient in light quantity with reference to the image of the frame imaged by flash light emission. For this reason, it is possible to provide an imaging apparatus including an illumination unit that can shoot with good image quality even in a dark place and that has less power required for illumination and does not worry about overheating of the illumination unit.

  According to the second invention, since the imaging sensitivity is increased in a frame where the light quantity is insufficient due to continuous light emission, the brightness of the image of the captured frame is close to the brightness of the image of the frame captured by flash light emission. Thus, the process of matching with the flashed frame after imaging is facilitated.

  According to the third invention, a change in the contour of an image captured by continuous light emission is detected on the basis of an image of the frame captured by flash light emission, and the continuous light emission is performed by deforming the image of the frame imaged by flash light emission. The image data picked up by is generated. For this reason, it is possible to provide an imaging apparatus including an illumination unit that can shoot with good image quality even in a dark place, has less power required for illumination, and does not worry about overheating of the illumination unit.

  According to the fourth aspect of the invention, since the imaging sensitivity is increased in a frame in which the amount of light is insufficient due to continuous light emission, the contour detection of the captured frame is facilitated, and the image of the frame captured by flash emission is captured. As a reference, it is possible to easily detect a change in the contour of an image captured by continuous light emission and to transform a frame image captured by flash light emission.

  According to the fifth aspect of the invention, an image captured by continuous light emission with insufficient light quantity is corrected with reference to an image of a frame captured by flash light emission. For this reason, it is possible to provide an imaging apparatus including an illumination unit that can shoot with good image quality even in a dark place, has less power required for illumination, and does not worry about overheating of the illumination unit.

  According to the sixth aspect of the invention, it is possible to perform image quality adjustment of a low-quality frame imaged by continuous light emission that is insufficient in light quantity with reference to an image of a frame imaged by flash light emission. For this reason, it is possible to provide an imaging apparatus including an illumination unit that can shoot with good image quality even in a dark place and that has less power required for illumination and does not worry about overheating of the illumination unit.

  According to the seventh aspect, by detecting a change in the contour of an image captured by continuous light emission based on an image of a frame captured by flash light emission, and correcting the contour of the frame image captured by flash light emission. Image data captured with continuous light emission is generated. For this reason, it is possible to provide an imaging apparatus including an illumination unit that can shoot with good image quality even in a dark place and that has less power required for illumination and does not worry about overheating of the illumination unit.

  According to the eighth aspect of the invention, the imaging sensitivity is increased in a frame where the amount of light is insufficient due to continuous light emission. For this reason, the imaging sensitivity is increased in a frame where the amount of light is insufficient due to continuous light emission, so the brightness of the image of the captured frame is close to the brightness of the image of the frame captured by flash emission, and the flash is flashed after imaging. Processing to match the emitted frame becomes easy.

  According to the ninth aspect, the first illumination means is supplied with power from within the flash unit, and the second illumination means is supplied with power from within the camera body. For this reason, even when the load of the power supply of the flash unit is large, the second illumination unit can obtain sufficient power.

  According to the tenth and fourteenth aspects, the first illumination means has a charging circuit for performing flash emission, and charges the charging circuit in a frame that does not perform flash emission. Therefore, the charging circuit can be charged in a frame that does not emit flash light, and light emission can be continued even for a long-time moving image.

  According to the eleventh aspect, the second illumination means performs continuous illumination only during the imaging period of the imaging means. For this reason, the light emission power of the second illumination means can be reduced.

  According to the twelfth aspect, the light emitting diode can be used as both the first and second illumination means. For this reason, since control is simple, energy efficiency is good, and there is little heat_generation | fever, it is suitable for long-time video recording.

  According to the thirteenth aspect of the invention, continuous illumination with a large amount of light can be obtained, and this is effective for a long-distance subject that requires a large amount of continuous light emission for a relatively short time.

  According to the fourteenth aspect of the invention, flash light is emitted once every plural frames, and the charging circuit is charged in a frame in which no flash light is emitted, so that light emission can be continued even for a long movie. it can.

  According to the fifteenth aspect, it is possible to adjust the image quality of a low-quality frame imaged by continuous light emission with insufficient light quantity, with reference to an image of a frame imaged by flash light emission. For this reason, it is possible to provide an imaging method including an illuminating unit that can capture an image with good image quality even in a dark place, and that requires less power for illumination and does not worry about overheating of the illuminating unit.

  According to the sixteenth aspect, by detecting a change in the contour of the image captured by the continuous illumination on the basis of the image of the frame captured by the flash emission, and deforming the image of the frame captured by the flash emission. Image data captured with continuous illumination is generated. For this reason, it is possible to provide an imaging method that can capture images with good image quality even in a dark place, and that requires less power for illumination and does not worry about overheating of the illumination unit.

  According to the seventeenth aspect, an image captured by continuous light emission that is insufficient in light quantity is corrected with reference to an image of a frame captured by flash light emission. For this reason, it is possible to provide an imaging method that can capture images with good image quality even in a dark place, and that requires less power for illumination and does not worry about overheating of the illumination unit.

It is the external appearance perspective view seen from the front side of the imaging device concerning a 1st embodiment of the present invention. It is the external appearance perspective view seen from the back side of the imaging device concerning a 1st embodiment of the present invention. It is an external appearance perspective view which shows the hot shoe of the camera body in the imaging device concerning 1st Embodiment of this invention. It is the external appearance perspective view which looked at the flash unit of the imaging device concerning 1st Embodiment of this invention from the downward side. 1 is a block diagram illustrating an electrical configuration of an imaging apparatus according to a first embodiment of the present invention. 4 is a time chart showing the operation timing at the time of moving image shooting in the imaging apparatus according to the first embodiment of the present invention. It is a figure explaining the method of an image process in the imaging device concerning 1st Embodiment of this invention. It is a figure explaining the method of an image process in the imaging device concerning 1st Embodiment of this invention. 4 is a flowchart illustrating image noise and color correction processing in the imaging apparatus according to the first embodiment of the present invention. It is a time chart which shows the operation timing at the time of video recording in the imaging device concerning a 2nd embodiment of the present invention. 12 is a flowchart illustrating processing for generating a high-quality image corresponding to frame 2 in the imaging apparatus according to the second embodiment of the present invention. It is a time chart which shows the operation timing at the time of video recording in the imaging device concerning a 3rd embodiment of the present invention. It is a time chart which shows the operation timing at the time of video recording in the imaging device concerning a 4th embodiment of the present invention.

  A preferred embodiment will be described below using an imaging apparatus to which the present invention is applied according to the drawings. As shown in FIG. 1, the imaging apparatus according to the first embodiment of the present invention includes a lens body 100 with interchangeable lenses, a lens unit 200 detachably attached to the camera body 100, and a flash unit 300 detachably attached to the camera body 100. It consists of.

  The camera body 100 and the lens unit 200 constitute a camera, and the camera in the present embodiment is a digital camera. As shown in FIG. 1, the lens body 100 can be detachably mounted on the front side of the camera body 100. On the upper surface of the camera body 100, a release button 101, a power switch 102, and a hot shoe 103 are arranged. The release button 101 is an operation member for instructing to shoot a still image and to start and end the shooting of a moving image. The power switch 102 is an operation member for instructing on / off of the power supply of the camera. The hot shoe 103 is a holding member for attaching the flash unit 300 to the camera body 100 and has an electrical contact with the flash unit 300.

  On the back side of the camera body 100, as shown in FIG. 2, a back LCD panel 104, a control button 105, and a menu button 106 are arranged. On the rear LCD panel 104, the subject image is displayed in live view as a moving image based on the image data acquired by the image sensor 155 (see FIG. 5) during live view display. The photographer determines the composition and the photo opportunity by observing the live view image. Further, the rear LCD panel 104 displays a menu screen for the photographer to make various settings, and also displays a reproduction display of recorded image data. The rear LCD panel 104 is not limited to the LCD as long as there is a display panel that can display an image, and may be a display panel such as an organic EL.

  The control button 105 includes a center button and four cross buttons around the center button. When a menu screen or the like is displayed on the rear LCD panel 104, an operation input can be confirmed by moving the cursor with the cross button in the control button 105 and operating the center button. Menu button 106 is an operation button for displaying a menu screen on rear LCD 104.

  On the front side of the flash unit 300, as shown in FIG. 1, a light emission window 301 for flash emission by a xenon tube and an irradiation window 302 for continuous illumination by an LED 320 are arranged. On the back side of the flash unit 300, as shown in FIG. 2, a charge lamp 303 for displaying a charging state, a power button 304 for instructing on / off of the power supply of the flash unit 300, and a camera body 100 are attached. The shoe foot 305 is disposed.

  The hot shoe 103 of the camera body 100 and the shoe foot 305 of the flash unit 300 will be described with reference to FIGS. FIG. 3 is an external perspective view in which the flash unit 300 is removed from the camera body 100 and the camera body 100 is viewed obliquely from the rear. FIG. 4 is a perspective view of the flash unit 300 removed from the camera body 100 and the flash unit 300 is viewed from below. FIG.

  The hot shoe 103 is disposed on the upper surface of the camera body 100 and fixes the flash unit 300 to the camera body 100 by a fitting groove that fits into the groove of the shoe foot 305. A plurality of hot shoe contacts 107 are provided inside the hot shoe 103. The hot shoe contact 107 can transmit and receive data between the camera body 100 and the flash unit 300 by serial communication in addition to the light emission signal. When the flash unit 300 is attached to the camera body 100, the shoe foot contact 307 (see FIG. 4) of the flash unit 300 contacts the hot shoe contact 107, and electrical connection is established.

  A back connector 108 is provided on the back side of the camera body 100 and in the vicinity of the hot shoe 103. A connector 308 is provided below the shoe foot 305 of the flash unit 300. When the groove of the shoe foot 305 of the flash unit 300 is fitted and slid into the fitting groove of the hot shoe 103, the back connector 108 and the connector 308 are engaged, and the plurality of built-in contact pins contact each other. Electrical connection can be made.

  Next, the electrical configuration of the imaging apparatus according to the present embodiment will be described with reference to the block diagram shown in FIG. In the camera body 100, a camera calculation control circuit 151 is provided. The camera calculation control circuit 151 performs overall control within the camera body 100, and also performs communication with the lens unit 200, communication with the flash unit 300, and image processing and recording of image data and the like on the recording medium 154. Various controls are performed. Further, as will be described later, based on the captured image acquired at the time of flash emission, image correction of the captured image acquired for continuous illumination is also performed.

  In addition, a battery 152 is provided in the camera body 100. A power supply circuit 153 is connected to the battery 152, and the power supply circuit 153 generates power to be supplied to each unit such as the camera arithmetic control circuit 151 in the camera body 100. A recording medium 154 is connected to the camera calculation control circuit 151. The recording medium 154 is a rewritable non-volatile memory such as a flash memory, and is arranged in the camera body 100 so as to be fixed or attachable. The recording medium 154 records captured still image and moving image data. An image sensor 155 is connected to the camera calculation control circuit 151. The image sensor 155 is a solid-state image sensor such as a CCD or a CMOS, and takes in a subject image formed by the lens 201 in the lens unit 200 and outputs image data.

  A flash control circuit 311 is provided in the flash unit 300. The flash control circuit 311 performs various controls in the flash unit 300 and charges the flash capacitor, and responds to instructions from the camera body 100 side. Control the flash.

  The memory 312 connected to the flash control circuit 311 is an electrically rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable ROM). The memory 312 stores fixed values used for light emission and charging control, adjustment constants, and the like. A battery 313 is disposed in the flash unit 300 and is connected to each unit such as the flash control circuit 311, the charging circuit 314, and the light emitting circuit 315, and supplies power for performing various operations.

  A charging circuit 314 connected to the flash control circuit 311 and the battery 313 is a charging circuit for a flash capacitor. The power supply voltage of the battery 313 is boosted to a high voltage for flash emission, and the flash capacitor is charged with the boosted voltage. To do. The light emitting circuit 315 connected to the charging circuit 314 and the battery 313 applies a high voltage to the xenon tube 317 according to an instruction from the flash control circuit 311 to start light emission, and stops light emission according to an instruction from the flash control circuit 311. The xenon tube 317 is connected to the light emitting circuit 315, and a reflector 316 for collecting the flash light of the xenon tube 317 is disposed around the xenon tube 317.

  A drive circuit 318 connected to the flash control circuit 311 is a drive circuit for the LED 320 and causes the LED 320 to emit light continuously. Around the LED 320, an LED reflector 319 for condensing the continuous light emission of the LED 320 is disposed. In the present embodiment, the power source of the LED 320 as a continuous light source is supplied from a battery 152 and a power circuit 153 in the camera body 100 as shown in FIG.

  By connecting the shoe foot contact 307 in the flash unit 300 and the hot shoe contact 107 in the camera body 100, the camera arithmetic control circuit 151 and the flash control circuit 311 can perform digital data communication. As this digital data communication, for example, the state of the flash unit 300 is transmitted to the camera calculation control circuit 151, and the camera calculation control circuit 151 flashes based on the received data and the data in the camera body 100 and the lens unit 200. Various instructions including a flash emission instruction can be transmitted to the control circuit 311. Further, when the rear connector 108 in the camera body 100 and the connector 308 disposed on the shoe foot 305 of the flash unit 300 are connected, driving power is supplied to the LED 320 from the camera body 100.

  Next, an illumination method when shooting a moving image in the imaging apparatus according to the present embodiment will be described with reference to FIG. FIG. 6 is a time chart showing light emission by the illumination means during moving image shooting. In this embodiment, as shown in FIG. 6, illumination by flash light emission (Xe light emission) by the xenon tube 317 is performed for every fourth frame (frames 1 and 5 in the figure). In the other three frames (frames 2 to 4 in the figure), illumination by continuous illumination (LED emission) by the LED 320 is performed.

  In the present embodiment, the imaging sensitivity of the imaging device 155 is set to a base sensitivity of, for example, about ISO 100 for frames 1 and 5 that perform flash emission. In frames 2 to 4 and the like that perform continuous illumination by the LED 320, the sensitivity is set to appropriate exposure depending on the brightness of the subject obtained by the illumination. However, when the sensitivity is not increased and the appropriate level is not reached, the highest sensitivity is obtained. For example, ISO 3200 is set.

  Flash light emission by the xenon tube 317 is performed at a timing when all pixels of the image sensor 155 are functioning during the frame exposure time. On the other hand, continuous illumination by the LED 320 is performed from the start of exposure to the end of exposure of a frame to be imaged by irradiating the LED 320. The charging of the flash capacitor in the charging circuit 314 is stopped at the start of exposure of the flashing frame and restarted at the end of exposure of the flashing frame. Reading of the image signal from the image sensor 155 is performed by the camera calculation control circuit 151 at a timing between frame exposures, and image data based on the read image signal is built in the camera calculation control circuit 151. Temporarily stored in the memory.

  Moving image shooting is performed while illuminating according to the above concept. The procedure at this time will be described with reference to a time chart shown in FIG. First, an image of frame 1 is acquired while illuminating the subject with flash light emission. For this reason, at time t11, the image sensor 155 starts imaging (exposure) and stops charging the flash capacitor of the charging circuit 314. At time t12 when all the pixels of the image sensor 155 are functioning, the camera calculation control circuit 151 outputs a flash emission start instruction to the flash control circuit 311 and the xenon tube 317 performs flash emission. At time t14, the imaging of the image sensor 155 is terminated, and the charging of the flash capacitor is resumed. Then, between time t15 and time t16, an image signal is read from the image sensor 155 and temporarily stored. In the period of frame 1 from time t11 to t21, the LED 320 remains off, and the imaging sensitivity is set to ISO 100 in the illustrated example.

  When flash data is emitted in frame 1 and image data is acquired, image data is acquired in frame 2 while performing continuous illumination by the LED 320. First, at time t <b> 21, continuous illumination by the LED 320 is started, and imaging of the image sensor 155 is started. At time t22, the imaging is stopped, and the image signal is read and the image data is acquired between time t25 and time t26. In frame 3 and frame 4, as in frame 2, imaging and image reading are performed. During this time, the LED 320 maintains continuous illumination, and in the illustrated example, the imaging sensitivity is set to a high sensitivity of ISO 3200. Further, the charging of the flash capacitor in the charging circuit 314 continues.

  When image data is acquired in frame 4, the process moves from time t51 to frame 5, but the operation here is the same as that of frame 1, and flashing is performed to acquire image data. Thereafter, moving image shooting is performed while alternately repeating three frames with continuous illumination and one frame with flash emission.

  Next, image processing in the imaging apparatus according to the present embodiment will be described with reference to FIGS. As described above, in the frames 1, 5, etc., the subject is irradiated with a large amount of flash light, so that a high-quality image can be acquired. Since the subject is irradiated with continuous illumination, only low-quality images can be acquired. Therefore, in this embodiment, an image acquired during continuous illumination is corrected using a high-quality image acquired during flash emission.

  FIGS. 7A, 7B1, 7C1, 7D, and 7E1 show captured images in frame 1, frame 2, frame 3, frame 5, and frame 6, respectively. Show. The captured image at frame 4 is omitted because it is the same as the captured image at frame 3, and frame 6 performs the same operation as frame 2.

  The photographed image shown in FIG. 7A photographed in the frame 1 and the photographed image depicted in FIG. 7D photographed in the frame 5 are illuminated by flash emission by the xenon tube 317, and the ISO 100 has low noise and low noise. Since the images are taken with, the final image is basically made without any major correction. On the other hand, the captured images shown in FIGS. 7 (b1), 7 (c1), and 7 (e1) captured in the frames 2, 3, and 6 are captured images with continuous illumination by the LED 320, and the amount of light is insufficient. Therefore, shooting is performed with high sensitivity ISO3200. For this reason, the color reproducibility is poor and the image is noisy.

  Therefore, with respect to the captured images shown in FIGS. 7 (b1) and 7 (c1), with reference to the captured image shown in FIG. Color reproduction and color and gradation when noise is reduced are corrected to be the same. Accordingly, the photographed image shown in FIG. 7 (b1) is as shown in FIG. 7 (b2) after correction, and the photographed image shown in FIG. 7 (c1) is as shown in FIG. 7 (c2) after modification. Thus, the color reproducibility is improved, noise is reduced, and the photographed image is corrected in color gradation.

  Similarly, with respect to the photographed image shown in FIG. 7 (e1), the photographed image shown in FIG. 7 (d) in the frame 5 photographed immediately before that is referred to, and the portion assumed to be the same is corrected. After correction, the photographed image shown in (e1) becomes a photographed image with improved color reproducibility, noise reduction, and color tone correction as shown in FIG. 7 (e2). Eventually, the frame image of the moving image becomes FIG. 7 (a), FIG. 7 (b2), FIG. 7 (c2), FIG. 7 (d), FIG. Is done.

  When correcting an image as shown in FIG. 7, the captured image of each frame often moves little by little. Therefore, in this embodiment, the movement vector of the captured image between two frames is detected, and the corresponding position is determined in consideration of this movement vector. FIG. 8 is a diagram showing movement vector detection values of the images of the frames 1 and 2 from the contour. 8A is a captured image of frame 1, FIG. 8B is a captured image of frame 2, and FIG. 8C is a diagram in which both captured images are superimposed. The arrow in FIG.8 (c) has shown the direction and magnitude | size detected from the outline movement of each place. For example, the area A1 in the frame 1 image has moved to the area A2 in the frame 2 image.

  Next, image noise and color correction processing in the imaging apparatus according to the present embodiment will be described with reference to the flowchart shown in FIG. Here, as an example, a flow for correcting the image of frame 2 will be described. This flow is executed by the camera calculation control circuit 151 in accordance with a program written in the nonvolatile memory.

  When the imaging of the image of frame 2 is completed, first, it is determined whether or not the noise of frame 2 is large (S1). Here, the amount of noise is detected based on the image data of the entire captured image of frame 2, and it is determined whether or not the amount of noise is greater than a predetermined value. The predetermined value is such that the image quality is poor and cannot be appreciated.

  If the result of determination in step S1 is that the noise in frame 2 is not large, it is next determined whether or not the color shift in frame 2 is large (S2). Here, the image data of frame 1 subjected to flash photography is compared with the image data of frame 2, and it is determined whether or not the color shift is large. Even if the noise is small as a result of the determination in step S1, the color misregistration may be large.

  Here, the determination of the magnitude of the noise is made, for example, by looking at the output level variation for each pixel in a predetermined area in the frame 2 and comparing it with a variation value determined in a sensory manner. As for color misregistration, for example, the chromaticity of a predetermined area in the frame 2 is compared with the chromaticity value of the predetermined area in the frame 1, and if there is a difference equal to or greater than the predetermined chromaticity value, the color misregistration is determined to be large.

  If the noise in frame 2 is large as a result of the determination in step S1, or if the color misregistration in frame 2 is large as a result of the determination in step S2, then image correction is performed in step S3 and subsequent steps. I do. First, for image correction, the contour information of frame 1 is detected (S3), and then the contour information of frame 2 is detected (S4). When detecting the contour information, the image data is used to search for a place where the brightness or color changes greatly, and that portion is used as the contour.

  When the contour information of the frame 1 and the frame 2 is detected, a movement vector for each area is detected (S5), and a reference area of the frame 1 is set for each fine area of the frame 2 (S6). Here, the contours of the captured images of the frames 1 and 2 are compared and correlated, and the movement vector of the contours of the frames 1 and 2 is detected for each fine area as described with reference to FIG. In calculating the movement vector, the area far from the contour is calculated by interpolation from the movement vector of the surrounding contour. When the movement vector is determined, the reference area of frame 1 corresponding to the fine area of frame 2 is determined and set using this movement vector. Since the fine area is a unit for image correction, it may be an area size that provides a natural feeling when viewed with the naked eye.

  When the movement vector is detected and the reference area is set, the image of frame 2 is then corrected (S7). Here, based on the movement vector for each area set in step S106, color matching and noise removal for each fine area of frame 2 are performed in accordance with the corresponding fine area of frame 1. In the example shown in FIG. 8, the area A <b> 2 of the frame 2 reduces noise in accordance with the color of the area A <b> 1 of the frame 1. When the corrected image is generated in step S7, the correction flow for frame 2 is terminated.

  When the correction for the frame 2 is performed, the imaging and the image reading for the frame 3 are performed, and the flow similar to the flow illustrated in FIG. 9 is executed using the read image data and the captured image for the frame 1. Then, a corrected image for frame 3 is generated. Thereafter, the captured image acquired under the continuous illumination of the LED 320 is corrected, and a corrected moving image is generated. The corrected moving image is recorded as a recording medium 154 as a final moving image file.

  As described above, in the imaging device according to the first embodiment of the present invention, flash light is emitted at a rate of once per a plurality of frames, and supplementary charging of the charging circuit 314 is performed in a frame where no flash light is emitted. And can continue to emit light even for a long-time video.

  In the present embodiment, in a frame where no flash emission is performed, since continuous illumination is performed by the LED 320, an image of a certain level can be acquired. Further, since the imaging sensitivity is set high in a frame that does not emit flash light, an image of a certain level can be obtained even under continuous illumination with a small amount of light.

  Furthermore, in the present embodiment, noise and color of an image that is not flashing is corrected based on an image captured by flashing. For this reason, even in a frame that does not emit flash light, an image quality substantially equivalent to a captured image by flash light emission can be obtained.

  Furthermore, in the present embodiment, the motion vector of the contour of the captured image is detected, and an area to be associated between frames is determined. For this reason, the image at the time of continuous illumination can be correct | amended correctly for every area using the image acquired by flash light emission.

  Further, in the present embodiment, the power source of the LED 320 for performing continuous illumination is configured to be supplied from the camera body 100 side. Therefore, sufficient power can be obtained even when the flash unit 300 is being charged with the flash capacitor and the battery is heavily loaded. In addition, since the charging time of the flash capacitor is not affected, even if the still image is switched from the moving image, the flash can be emitted immediately.

  In the present embodiment, the camera body 100 and the lens unit 200 are detachable, and the flash unit 300 and the camera body 100 are detachable. However, the present invention is not limited to this, and at least one of the lens unit 200 and the flash unit 300 may be fixed to the camera body 100 and not removable.

  In the present embodiment, the flash emission interval is set to once every four frames. However, the present invention is not limited to this, and the number of frames may be larger or smaller than four frames. In particular, when there is little movement, there is no problem even if more intervals are provided. Alternatively, the movement of the subject may be detected, and the flash emission interval may be varied based on the detected movement.

  Furthermore, in this embodiment, the power source of the LED 320 that performs continuous illumination is supplied from the battery 152 in the camera body 100. However, the present invention is not limited to this, and the battery 313 in the flash unit 300 may be used. In this case, since the flash capacitor of the charging circuit 314 is charged from the battery 313, it is desirable to use a large capacity battery.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 10 and 11. In the first embodiment, during continuous illumination by the LED 320, light was continuously emitted from time t21 to time t44 in the frame 2 to the frame 4. In contrast, in the second embodiment, continuous light emission is performed between frames 2 and 4 only during imaging (exposure) by the imaging device 155. The configuration in this embodiment is the same as the configuration shown in FIGS. 1 to 5, but is different from the operation shown in the time chart shown in FIG. 6 and the flowchart shown in FIG. 9. Explained.

  FIG. 10 shows a time chart in the present embodiment. The difference from the first embodiment is that the light emission pattern of the LED 320 is turned on in response to the start of exposure for imaging for each frame and turned off in response to the stop of exposure. That is, in frame 2, the image sensor 155 starts imaging at time t21, and the LED 320 starts continuous light emission. At time t24, the image sensor 155 stops imaging, and the LED 320 stops continuous light emission.

  FIG. 11 shows a flowchart in the present embodiment. Similarly to the case of the first embodiment, this flowchart is also executed by the camera arithmetic control circuit 151 according to the program stored in the nonvolatile memory, and the image corresponding to the frame 2 is corrected to a high quality image. Will be described.

  In FIG. 11, when the imaging of the frame 2 is completed, first, the contour information of the frame 1 is detected (S11), and then the contour information of the frame 2 is detected (S12). Here, as in steps S3 and S4 in the case of the first embodiment, when detecting the contour information, the image data is used to search for a place where the change in brightness or color is large, and that portion is set as the contour.

  Next, a movement vector for each area is detected (S13). Here, as in step S5 of the first embodiment, here, the contours of the captured images of frame 1 and frame 2 are compared and correlated, and the movement vector of the contours of frame 1 and frame 2 is determined for each fine area. calculate. If no contour is detected in the vicinity, the contour is calculated by interpolation from the movement of the surrounding contour.

  Once the movement vector is calculated, next, based on the movement vector amount, the image of the frame 1 is transformed so as to match the contour of the frame 2 (S14). Here, for example, in FIG. 8C, the area A1 of the image of frame 1 is moved to the area A2 of the image of frame 2, and each area is moved over the entire screen to obtain a deformed image. By this image deformation, an image having the same image quality as that of the frame 1 and matching the frame 2 is generated.

  Once the image has been transformed, the luminance change from frame 1 to frame 2 is then reflected in the transformed image (S15). Here, if there is a portion where the brightness has changed in frame 2 with respect to frame 1, the brightness of the corresponding area is adjusted. When the corrected image is generated in step S15, the correction flow for frame 2 ends.

  When the correction for frame 2 is performed, next, imaging and image reading for frame 3 are performed, and the flow similar to the flow shown in FIG. 11 is executed using the read image data and the captured image for frame 1. Then, a corrected image for frame 3 is generated. Thereafter, the captured image acquired under the continuous illumination of the LED 320 is corrected, and a corrected moving image is generated. The corrected moving image is recorded on the recording medium 154 as a final moving image file.

  As described above, in the imaging apparatus according to the second embodiment of the present invention, the light emission pattern of the LED 320 continuously emits light only during imaging of the imaging element 155, so that it is compared with the case of the first embodiment. In addition, the light emission power of the LED 320 can be reduced.

  In the present embodiment, the modified image of the frame that is not illuminated by the flash emission is deformed based on the image of the frame that is emitted by the flash emission, and therefore noise for the frame that is not illuminated by the flash emission. Reduction processing is not necessary, and even a processing circuit with low noise processing capability can be handled. In addition, the degree of coincidence of the color tone and the frame when flashing is performed can be increased. In addition, the effect accompanying the structure similar to 1st Embodiment can also be achieved.

  In the present embodiment, the contour information of the frame 1 is detected in step S11 performed after the image data of the frame 2 is acquired. However, the present invention is not limited to this, and it is of course possible to detect the contour information after acquiring the image data of frame 1 and before acquiring the image data of frame 2.

  Next, a third embodiment of the present invention will be described with reference to FIG. In the first and second embodiments, the flash emission is performed by the xenon tube 317, but in the third embodiment, the flash emission is also performed by the LED 320 that performs continuous illumination. The configuration in the present embodiment is the same as the configuration shown in FIGS. 1 to 5, and the time chart shown in FIG. 6 is different, so this difference will be mainly described.

  FIG. 12 is a time chart in the present embodiment. In this embodiment as well, flash light is emitted in the frame 1 and continuous illumination by the LEDs 320 is performed in the frames 2 to 4. However, the flash emission in the frame 1 is performed at a high brightness for a short time by the LED 320 from the time t11 to the time t13. In the frame 5 as well, flash light is emitted with high brightness by the LED 320 during a short period from time t51 to time t53. Note that time t13 and time t53 may be earlier or later than time t12 and time t52 in FIG.

  Flash light emission by the LED 320 is obtained by injecting the charge of the flash capacitor of the charging circuit 314 for the xenon tube 317 into the LED 320 to emit light with high brightness for a short time. In addition, for flash emission by the LED 320, another capacitor may be disposed in addition to the flash capacitor, and this capacitor may be used. In addition, when there is a margin in the power supply, a large current may be directly supplied from the power supply without using the capacitor charging current.

  According to the third embodiment of the present invention, when a light amount as high as the flash emission by the xenon tube 317 is not required, the control is simple, the energy efficiency is high, and the heat generation is small. It is suitable for. In addition, the effects associated with the same configuration as in the first and second embodiments can also be achieved.

  In the present embodiment, in the frames 2 to 4, the LED 320 performs continuous illumination only during the imaging period as in the second embodiment. However, as in the first embodiment, the LEDs 320 During this time, continuous illumination may be performed. Further, since the present embodiment is a modification of the illumination method in the first embodiment, the image processing executes the flowchart shown in FIG. 9 as in the first embodiment, but is shown in FIG. A flowchart may be executed.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. In the first to third embodiments, continuous illumination is performed by the LED 320, but in the fourth embodiment, continuous illumination is also performed by the xenon tube 317 that performs flash emission. The configuration in the present embodiment is the same as the configuration shown in FIGS. 1 to 5, and the time chart shown in FIG. 6 is different, so this difference will be mainly described.

  FIG. 13 is a time chart in the present embodiment. In this embodiment as well, flash light is emitted from the xenon tube 317 in the frame 1 and continuous illumination is performed in the frames 2 to 4. However, continuous illumination (time t21 to t24, time t31 to t34, time t41 to t44) in the frames 2 to 4 is performed by the so-called flat light emission of the flash by the xenon tube 317.

  Flat light emission is a light emission method in which the xenon tube 317 starts light emission, and after the start, the current flowing through the xenon tube 317 is repeatedly turned on and off in a very short cycle, thereby making minute light emission continuous and substantially continuous light emission. is there.

  According to the fourth embodiment of the present invention, since continuous illumination is performed by flat light emission by the xenon tube 317, continuous illumination with a large amount of light can be obtained. Therefore, although it is a relatively short time, it is effective for a long-distance subject that requires a large amount of continuous light emission. Moreover, in this embodiment, LED320 is not required. For this reason, the flash unit 320 can be reduced in size. In addition, the effects associated with the same configuration as in the first to third embodiments can be achieved. Since this embodiment is a modification of the illumination method in the first embodiment, the image processing executes the flowchart shown in FIG. 9 as in the first embodiment, but is shown in FIG. A flowchart may be executed.

  As described above, in each embodiment of the present invention, flashing is performed once for each of a plurality of frames (for example, frames 1 and 6) in conjunction with moving image shooting by an imaging unit including the imaging device 155 and the like. First illumination means (for example, a xenon tube 317, a charging circuit 314, a light emission circuit 315, etc.) that compensates for the amount of light at the time of imaging, and a frame that does not perform flash emission by the first illumination means (for example, frames 2 to 5) On the other hand, there is a second illumination means (for example, LED 320, drive circuit 318, etc.) that supplements the amount of light at the time of photographing by continuous illumination with a light amount per time smaller than that of flash light emission, and an image of a frame imaged by flash light emission. Based on the above, the image captured by continuous light emission with insufficient light quantity is corrected. For this reason, it is possible to shoot with good image quality even in a dark place, and there is little power required for illumination, and there is no concern about overheating of the illumination unit.

  In each embodiment of the present invention, the photographing apparatus has a configuration in which the lens unit 200 is detachable from the camera body 100. However, the present invention is not limited thereto, and the lens unit is fixed to the camera body 100 and cannot be detached. It does not matter as a configuration. Further, although the flash emission interval is set to once every four frames, the interval is not limited to this. If there is little movement, there is no problem even if the interval is widened. The movement of the subject may be detected, and the flash emission interval may be varied based on the detection result.

  In each embodiment of the present invention, the power source of the flash unit 300 is disposed inside, but another power source disposed outside the flash unit 300 may be used. Alternatively, it may be operated only by supply from the camera body 100. Further, the LED may be operated by the power source of the flash unit 300.

  Furthermore, in each embodiment of the present invention, the xenon tube 317 and the LED 320 are disposed. However, the xenon tube 317 may be another flash discharge tube, and the LED 320 can continuously emit light from other semiconductor light emitting elements. An element may be sufficient.

  In the present embodiment, the digital camera is used as the photographing device. However, the camera may be a digital single-lens reflex camera or a compact digital camera, and may be a mobile phone or a personal digital assistant (PDA). Personal Digital Assist) or a camera built in a game machine or the like may be used. In any case, the present invention can be applied to any imaging device capable of shooting a moving image.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, you may delete some components of all the components shown by embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 100 ... Camera body, 101 ... Release button, 102 ... Power switch, 103 ... Hot shoe, 104 ... Rear LCD panel, 105 ... Control button, 106 ... Menu button, DESCRIPTION OF SYMBOLS 107 ... Hot shoe contact, 108 ... Back connector, 151 ... Camera arithmetic control circuit, 152 ... Battery, 153 ... Power supply circuit, 154 ... Recording medium, 155 ... Imaging element , 200 ... lens unit, 201 ... lens, 300 ... flash unit, 301 ... light emission window, 302 ... irradiation window, 303 ... charge lamp, 304 ... power button, 305 ... Shoe foot, 307 ... Shoe foot contact, 308 ... Connector, 311 ... Flash control circuit, 312 ... Memory, 313 - battery, 314 ... charging circuit, 315 ... light-emitting circuit, 316 ... reflector, 317 ... xenon tube, 318 ... driving circuit, 319 ... reflector, 320 ... LED

Claims (17)

In an imaging apparatus having an imaging unit capable of capturing a moving image by continuously capturing an image, and an illumination unit that supplements the amount of light at the time of imaging in conjunction with the imaging unit,
The illuminating means may be used in a first illumination mode for illuminating with flash light emission, or in a second illumination mode for continuously illuminating a plurality of frames with a light amount per frame smaller than that for the flash light emission. It supplements the amount of light,
The imaging apparatus includes an image processing unit that corrects the color tone and noise of an image shot in the second illumination mode with an image shot in the first illumination mode, and equalizes the image quality of all frames. An imaging apparatus characterized by the above.   The imaging apparatus according to claim 1, wherein the imaging sensitivity is increased when imaging is performed in the second illumination mode. In an imaging apparatus having an imaging unit capable of capturing a moving image by continuously capturing an image, and an illumination unit that supplements the amount of light at the time of imaging in conjunction with the imaging unit,
The illuminating means may be used in a first illumination mode for illuminating with flash light emission, or in a second illumination mode for continuously illuminating a plurality of frames with a light amount per frame smaller than that for the flash light emission. It supplements the amount of light,
The imaging apparatus includes the first illumination so that the contour information of the image captured in the first illumination mode is equivalent to the contour movement information of the image of each frame captured in the second illumination mode. An image pickup apparatus comprising image processing means for deforming an image shot in a mode.   The imaging apparatus according to claim 3, wherein the imaging sensitivity is set high when imaging is performed in the second illumination mode. An imaging means capable of capturing a moving image by continuously capturing images;
In conjunction with the shooting of the moving image by the imaging means, a first illuminating means for supplementing the amount of light at the time of imaging by flashing once every a plurality of frames;
A second light source that compensates for a light amount at the time of photographing by continuously illuminating a plurality of frames with a light amount per frame smaller than that of the flash light emission for a frame that does not perform the flash light emission by the first illumination means. Lighting means;
Image processing means for correcting the image captured by the continuous illumination based on the image captured by the flash emission;
An imaging apparatus comprising:   The imaging apparatus according to claim 5, wherein the image processing unit corrects noise and color of the image captured by the continuous illumination based on the image captured by the flash emission.   The image processing means detects the motion vector of the contour of the image captured with the flashlight and the continuous illumination, and corrects the contour of the image captured with the continuous illumination using the image captured with the flashlight. The imaging apparatus according to claim 5.   The imaging apparatus according to claim 5, wherein the imaging unit increases imaging sensitivity when shooting with the continuous illumination as compared to shooting with the flash emission. The first illumination means is supplied with power from within the flash unit,
The second illumination means is supplied with power from within the camera body.
The imaging apparatus according to claim 5.   The imaging apparatus according to claim 5, wherein the first illumination unit includes a charging circuit for performing the flash emission, and charges the charging circuit in a frame that does not perform the flash emission. .   The imaging apparatus according to claim 5, wherein the second illumination unit performs the continuous illumination only during an imaging period of the imaging unit. The first illuminating means performs high-intensity flash emission by energizing a light-emitting diode with a current stored in a capacitor in a charging circuit in a short time,
The second illumination unit performs continuous illumination by continuously energizing the light emitting diode.
The imaging apparatus according to claim 5. The first illumination means performs flash emission by discharging the flash arc tube in a short time with the current stored in the flash capacitor in the charging circuit,
The second illumination means performs flat light emission by repeating minute light emission by turning on and off the current stored in the flash capacitor in the charging circuit in the flash light emission tube.
The imaging apparatus according to claim 5. An imaging means capable of capturing a moving image by continuously capturing images;
In conjunction with the shooting of the moving image by the imaging means, a first illuminating means for supplementing the amount of light at the time of imaging by flashing once every a plurality of frames;
A second light source that compensates the light amount at the time of photographing by continuous illumination for a plurality of frames with a light amount per frame smaller than that of the flash light emission for a frame that does not perform the flash light emission by the first illumination means. Lighting means;
Comprising
The imaging apparatus according to claim 1, wherein the first illuminating unit further includes a charging circuit for performing the flash emission, and the charging circuit is charged in a frame in which the flash emission is not performed. In an imaging method in which the amount of light when capturing a moving image is supplemented by illumination means,
An image shot in the second illumination mode in which a plurality of frames are continuously illuminated with an amount of light per frame smaller than that of the flash emission by an image taken in the first illumination mode illuminated by flash emission. An imaging method, wherein color tone and noise are corrected to equalize the image quality of all frames. In an imaging method in which the amount of light when capturing a moving image is supplemented by illumination means,
The contour information of the image taken in the first illumination mode that illuminates by flash emission is taken in the second illumination mode in which the amount of light per frame is less than that of the flash emission and the plurality of frames are continuously illuminated. An image capturing method, comprising: transforming an image captured in the first illumination mode so as to be equivalent to the outline movement information of each frame image. In an imaging method in which the amount of light when capturing a moving image is supplemented by illumination means,
Capturing a video by continuously capturing images;
A step of supplementing the amount of light at the time of imaging by flashing light once every plural frames in conjunction with shooting of the moving image, and capturing a moving image by supplementing the amount of light at the time of shooting by continuously illuminating a frame that does not emit the flashing light. When,
Correcting the image taken with the continuous illumination based on the image taken with the flash;
An imaging method characterized by comprising: