JP2010074725A - Imaging apparatus and control method of same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus easily preventing specular reflection from being reflected even when a subject that performs specular reflection, is photographed using an illuminator including a plurality of light-emitting sections. <P>SOLUTION: The imaging apparatus includes the illuminator 27 having a plurality of lighting patterns for lighting predetermined LEDs among the plurality of LEDs. In a state where LEDs are lighted in the respective lighting patterns, a microcomputer 16 obtains images corresponding to the lighting patterns and composites each of the obtained images. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging device that performs strobe shooting using an illumination device having a plurality of light emitting units, and a method for controlling the imaging device.

  In an imaging device, a ring strobe or the like is currently used when taking a strobe with close-up photography.However, if the subject is specularly reflected, the specular reflection of the light emitting part of the ring strobe may appear round and unnatural. It was.

  In particular, in the case of insect photography, the reflection of the round specular reflection does not seem to be very preferable because the insect appears to have scratches (dents).

  FIG. 6 is a conceptual diagram of the reflection of the regular reflection of the ring strobe, and the reflection of the regular reflection of the ring strobe 61 shown in (b) appears as shown in (a).

  In addition, as an illumination device for close-up photography, there is a device using an LED, but an illumination device using a plurality of LEDs has been proposed because a single LED cannot obtain a sufficient amount of light.

  FIG. 7 is a conceptual diagram of reflection of regular reflection of a plurality of LEDs.

  When a lighting device using a plurality of LEDs is used, the reflection of the regular reflection of the LED illumination unit 71 shown in (b) is reflected as a point corresponding to the plurality of LEDs as shown in (a), which is unnatural. It becomes a photographed image.

  Therefore, Patent Document 1 discloses a technique aimed at solving the problem that the above-described illumination is reflected on the surface of the subject.

In Patent Document 1, regular reflection on the surface of a subject is prevented by using a linearly polarized light source and taking a picture while changing the polarization plane of the linearly polarized light element mounted in front of the lens or in front of the imaging element.
Japanese Patent Laid-Open No. 11-41514

  However, since the technique disclosed in Patent Document 1 needs to perform imaging while using a linearly polarized light source and changing the polarization plane of the linearly polarizing element, a captured image that does not reflect illumination is easily acquired. I can't.

An object of the present invention is to provide an imaging device and a control method for the imaging device that can easily prevent reflection of regular reflection when shooting a subject that is regularly reflected using an illumination device having a plurality of light emitting units. There is to do.

  In order to achieve the above object, an imaging apparatus of the present invention is an imaging apparatus that performs stroboscopic imaging using an illumination device having a plurality of light emitting units, and is configured to perform a plurality of times with different combinations of the light emitting units during stroboscopic imaging. A light emission control unit that emits light, an image acquisition unit that acquires a plurality of images with different combinations of the light emitting units that emit light when the light emitting unit emits light a plurality of times, and the plurality of images acquired by the image acquisition unit Synthesizing means for synthesizing.

  According to the imaging apparatus of the present invention, it is possible to easily prevent reflection of specular reflection when photographing a subject that is specularly reflected using an illumination device having a plurality of light emitting units.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram of an imaging apparatus according to an embodiment of the present invention.

  The imaging device of the present invention includes an illuminating device 27 having a plurality of lighting patterns for lighting predetermined LEDs among a plurality of LEDs. The following units are provided.

  The interchangeable photographic lens 1 may be a zoom lens. The taking lens 1 communicates with the microcomputer 16. An internal AF (autofocus) lens drive circuit unit is constituted by a stepping motor, for example, and adjusts the focus by changing the focus lens position in the photographing lens 1 under the control of the microcomputer 16.

  The defocus amount used for the focus calculation is calculated using the output of the AF sensor 24. The photographing lens 1 has an aperture drive circuit unit that changes the optical aperture value under the control of the microcomputer 16.

  Further, the microcomputer 16 can communicate with the photographing lens 1 and acquire information on the current zoom position (focal length information) and the current distance position (subject distance). The microcomputer 16 can determine whether the photographic lens 1 is attached or not, depending on whether communication with the photographic lens 1 is possible.

  The quick return mirror 2 is moved up and down by an actuator (not shown) according to an instruction from the microcomputer 16 during exposure. The quick return mirror 2 is a half mirror for guiding light to the AF optical system, and the sub mirror is also interlocked.

  The photographer can confirm the focus and composition of the image obtained through the photographing lens 1 by observing the focusing screen 3 through the pentaprism 4 and the finder optical system.

  The focal plane shutter 5 can freely control the exposure time of the CCD under the control of the microcomputer 16. The focal plane shutter 5 is generally composed of a front curtain and a rear curtain, and a free exposure time is controlled by an interval between the two curtains.

  A CCD or the like is used as the image sensor 6, and a film image (image data) imaged on the image sensor 6 by the photographing lens 1 is photoelectrically converted and taken out as an electric signal.

  The clamp / CDS circuit 7 and the AGC circuit 8 perform basic analog processing before image data (video signal) is A / D converted. The microcomputer 16 can change the clamp level and the AGC reference level.

  The A / D converter 9 converts analog image data into a digital signal (digital image data). At this time, conversion is performed according to the set ISO sensitivity.

  The video signal processing circuit 10 performs filter processing, color conversion processing, and gamma / knee processing on the digitized image data, and outputs the result to the memory controller 13.

  The video signal processing circuit 10 also includes a D / A converter, which converts the video signal input from the image sensor 6 or the image data input reversely from the memory controller 13 into an analog signal, and drives the liquid crystal It is also possible to output to the liquid crystal display unit 12 through the circuit 11.

  The function switching of the video signal processing circuit 10 is performed by exchanging data with the microcomputer 16, and white balance information can be output to the microcomputer 16. Based on the information, the microcomputer 16 performs white balance adjustment.

  It is also possible to store image data in the buffer memory 19 through the memory controller 13 without performing video signal processing according to instructions from the microcomputer 16. The video signal processing circuit 10 also has a compression processing function such as JPEG.

  In the continuous shooting mode, image data is temporarily stored in the buffer memory 19, and when there is processing time, unprocessed image data is read through the memory controller 13, and image processing or compression processing is performed by the video signal processing circuit 10. To improve the continuous shooting speed.

  The number of continuous shots greatly depends on the capacity of the buffer memory 19. In the present embodiment, a plurality of image data can be stored in the buffer memory 19 and synthesized by the video signal processing circuit 10 into one image data. The image synthesizing unit here uses a unit that compares luminance components at the same position of a plurality of images and synthesizes them using image data having a smaller value.

  Further, the microcomputer 16 can check the capacity of the memory 14 through the memory controller 13 based on the predicted value data of the image size corresponding to the ISO sensitivity, the image size, and the image quality set before the shooting, and the shooting can be performed. The remaining number is calculated and displayed on the display member.

  The memory controller 13 stores unprocessed image data input from the video signal processing circuit 10 in the buffer memory 19 and stores processed image data in the memory 14. Conversely, the memory controller 13 outputs image data from the buffer memory 19 and the memory 14 to the video signal processing circuit unit 10.

  The memory controller 13 can store the image data sent from the interface 15 in the memory 14 and output the image data stored in the memory 14 from the interface 15. The memory 14 may be removable.

  The power supply 17 supplies power necessary for each IC and drive system. The operation member 18 informs the microcomputer 16 of the state (instructed by the photographer), and the microcomputer 16 controls each part in accordance with the change of the operation member 18.

  The release button 20 is an input switch of the operation member 18. When only SW1 is on, the release button is half-pressed, and when both SW1 and SW2 are on, the release button is fully pressed and photographing is performed.

  In addition to the release button 20, the operation member 18 includes an ISO setting button, an image size setting button, an image quality setting button, an information display button, an AF distance point selection button (automatic selection or any distance point can be selected). The buttons (not shown) are connected, and the state of the button is detected.

  With this operation member 18, a combination pattern of light emitting LEDs can be selected and set for each exposure, and when the synthesized image data is recorded on a recording medium, only the synthesized image data is recorded or becomes a basis for synthesis. It is possible to select and set whether to record recorded image data.

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

  The AF sensor 24 is a sensor capable of measuring a distance at a plurality of portions on the screen, outputs defocus information to the microcomputer 16, communicates with the photographing lens 1 based on the defocus information, and uses an internal AF lens driving circuit. Adjust the focus.

  The AE sensor 25 measures a plurality of areas of the screen on the finder screen, and measures the luminance of the subject through the photographing lens 1. The low-pass filter 26 also has an infrared cut function.

  The illuminating device 27 including a plurality of light emitting units (LEDs) incorporates a light emission control unit capable of individually controlling light emission of each LED in accordance with a command from the microcomputer 16. The LED that emits light at each exposure is determined by the pattern set by the operation member 18.

  FIG. 2 is a flowchart showing a procedure of photographing (imaging) processing at the time of strobe photographing performed by the imaging device of FIG.

  This process is executed under the control of the microcomputer 16 in FIG.

  In step S201, the microcomputer 16 determines whether or not the power-off timer has timed out. If it is determined that time-out has occurred, the microcomputer 16 proceeds to step S220 for power-off processing. If not timed out, the process proceeds to step S202.

  In step S202, the microcomputer 16 performs various settings. Specifically, the microcomputer 16 performs various settings such as a shooting mode in response to an input from the operation member 18. In addition, when the microcomputer 16 selects and sets a combination pattern of light emitting LEDs for each exposure or records the synthesized image data on a recording medium, the microcomputer 16 records only the synthesized image data or becomes a basis for synthesis. Select whether to record the recorded image data.

  In step S203, the microcomputer 16 uses the AF sensor 24 to detect the defocus of the subject and adjust the focus.

  In step S204, the microcomputer 16 measures the luminance of the subject using the AE sensor 25, and calculates the shutter time and aperture value for obtaining a proper exposure.

  In step S205, the microcomputer 16 displays various setting states set in step S202 on the display member (external liquid crystal display member 22). Further, the microcomputer 16 confirms the memory capacity through the memory controller 13 based on the predicted value data of the image size corresponding to the ISO sensitivity, the image size, and the image quality set in step S202, and determines the remaining number of shootable images. Calculate and display on the display member. Further, the microcomputer 16 displays on the display member the focus state detected in step S203 and the shutter time and aperture value calculated in step S204.

  In step S206, the microcomputer 16 determines whether the release button 20 is half-pressed (whether SW1 is ON). If the release button 20 is half-pressed, the microcomputer 16 proceeds to step S207 to update the timer. . If the release button 20 is not pressed at all, the process returns to step S201.

  In step S207, the microcomputer 16 updates the power OFF timer.

  In step S208, the microcomputer 16 determines whether or not the release button 20 is fully pressed (whether SW2 is ON). If the release button 20 is fully pressed, the microcomputer 16 proceeds to step S209 to capture the image. If not, the process returns to step S201.

  In step S209, the microcomputer 16 pre-lights the LED of the illumination device 27, measures the light with the AE sensor 25, and determines the light emission amount.

  In step S210, the microcomputer 16 controls the quick return mirror 2 to bring the quick return mirror 2 into an up state and communicates with the photographing lens 1 to control the aperture to the aperture value calculated in step S204.

  In step S211, the microcomputer 16 emits only the combination of LEDs determined in advance with the light emission amount determined in step S209 (FIG. 3), and controls the shutter time calculated in step S204 by the focal plane shutter 5. . The microcomputer 16 takes in the image data of the image sensor 6 by the clamp / CDS circuit 7, the AGC circuit 8, and the A / D converter 9.

  In step S211, an image corresponding to the first lighting pattern is acquired in a state where the LEDs are lit with the first lighting pattern.

  In step S212, the microcomputer 16 stores the image captured in step S211 in the buffer memory 19.

  In step S213, the microcomputer 16 emits only another combination of LEDs determined in advance with the light emission amount determined in step S209 (FIG. 4). The microcomputer 16 controls the shutter time calculated in step S <b> 204 with the focal plane shutter 5, and the image data of the image sensor 6 is transferred to the clamp / CDS circuit 7, AGC circuit 8, and A / D converter 9. take in.

  In step S213, an image corresponding to the second lighting pattern is acquired in a state where the LED is lit with the second lighting pattern.

  In step S214, the microcomputer 16 stores the image captured in step S213 in the buffer memory 19.

  In step S215, the microcomputer 16 controls the quick return mirror 2, returns the quick return mirror 2 to the down state, communicates with the photographing lens 1, and controls the aperture to the open state.

  In step S216, the microcomputer 16 combines the two image data saved in the buffer memory 19 in steps S212 and S214. In this image composition, a means for comparing the luminance components at the same position of a plurality of image data and using the image data having a smaller value is used. The synthesized image data is compressed and written in the memory 14. Depending on the setting of the imaging device, it is possible to switch between a mode in which both the pre-combination image data and the composited image data are stored in the memory 14 and a mode in which only the combined image data is stored.

  In step S 217, the microcomputer 16 sends the image data processed in step S 216 to the liquid crystal drive circuit 11 and displays it on the liquid crystal display unit 12. Further, the microcomputer 16 sends the photographing information determined in steps S203 and S204 to the liquid crystal driving circuit 121 and displays it on the external liquid crystal display member 22. Similarly, the image is displayed on the in-finder liquid crystal display member 23.

  In step S 218, the microcomputer 16 determines whether there are areas that can be stored in the memory 14 and the buffer memory 19, and determines whether photographing is possible based on the determination result. If it is possible to shoot, the process returns to step S201. If it is not possible to shoot, the process proceeds to step S219 to display a warning.

  In step S219, the microcomputer 16 displays the information determined in step S218 as being in a shooting impossible state.

  In step S220, the microcomputer 16 causes the liquid crystal drive circuit 11 to turn off the liquid crystal display unit 12, and the backlight of the in-finder liquid crystal display member 23 is also turned off.

  In step S221, the microcomputer 16 waits for the completion of the image processing, compression, and memory storage started in step S216, and for the captured image area of the buffer memory 19 to be empty.

  In step S222, the microcomputer 16 gives an instruction to the power supply 17 and turns off unnecessary power. Then, this process ends.

  FIG. 3 is a conceptual diagram showing the state of regular reflection of the image taken in step S211 in FIG. FIG. 4 is a conceptual diagram showing the state of regular reflection of the image taken in step S213 in FIG.

  As shown in FIG. 3B, when the subject is illuminated with the first lighting pattern in which the LEDs in the first and third rows from the left of the lighting device 27 are lit, as shown in FIG. Is reflected in the specular reflection corresponding to the lit LED.

  When the subject is illuminated with the second lighting pattern in which the LEDs in the second and fourth rows from the left of the lighting device 27 are lit as shown in FIG. 4B, the subject is turned on as shown in FIG. Reflected reflections occur corresponding to the LEDs.

  That is, since the subject is illuminated by changing the lighting pattern of the LED, the reflection position of the regular reflection differs between FIG. 3 (a) and FIG. 4 (a).

  Further, when the lighting device 27 is caused to emit light a plurality of times with different lighting patterns, the LED once emitted as shown in FIGS. 3B and 4B is not lit with other lighting patterns.

  FIG. 5 is a conceptual diagram of the image synthesized in step S216 in FIG.

  Since the two images shown in FIGS. 3A and 4A have different reflection positions for specular reflection, the luminance component values at the specular reflection positions in FIG. 3A correspond to each other. It becomes larger than the value of the luminance component at the position shown in FIG. For this reason, the image is divided into a plurality of regions, the luminance component values of the two image data are compared in each region, and the image data with the smaller luminance component value is combined and combined to produce a regular reflection image. It is possible to synthesize an image that is not complicated. That is, an image without specular reflection can be synthesized by combining the two image data using portions where the specular reflection is not reflected.

  As described above, according to the present invention, even when a subject that is regularly reflected is photographed using an illumination device having a plurality of light emitting units, it is possible to easily obtain a photographed image without reflection of regular reflection.

  In the present embodiment, the illumination device 27 is provided in the imaging device, but the illumination device 27 may be detachable from the imaging device.

    In addition, the images were synthesized using images obtained by lighting the LEDs with two different lighting patterns, but the lighting patterns are not limited to two. For example, the LEDs of the lighting device 27 are sequentially arranged from the left. There may be four lighting patterns so that each row is lit.

It is a block diagram of the imaging device concerning an embodiment of the invention. 3 is a flowchart illustrating a procedure of imaging (imaging) processing executed by the imaging apparatus of FIG. 1. It is a conceptual diagram which shows the condition of the regular reflection of the image image | photographed by step S211 in FIG. It is a conceptual diagram which shows the condition of the regular reflection of the image image | photographed by step S213 in FIG. It is a conceptual diagram of the image synthesize | combined by step S216 in FIG. It is a conceptual diagram of the reflection of a regular reflection of a ring strobe. It is a conceptual diagram of the reflection of the regular reflection of several LED.

Explanation of symbols

1 photographing lens 10 video signal processing circuit 16 microcomputer 27 lighting device

Claims (4)

An imaging device that performs flash photography using an illumination device having a plurality of light emitting units,
Light emission control means for emitting light a plurality of times with different combinations of the light emitting parts during flash photography,
An image acquisition means for acquiring a plurality of images with different combinations of the emitted light emitting units when the light emitting unit emits light a plurality of times;
Combining means for combining the plurality of images acquired by the image acquiring means;
An imaging device comprising:   The synthesizing unit divides the image acquired by the image acquiring unit into a plurality of regions, compares the luminance component value for each region with the plurality of images, and the luminance component value is the highest in each region. The imaging apparatus according to claim 1, wherein a small image is used as an image in the region.   3. The imaging apparatus according to claim 1, wherein the light emission control unit does not cause the light emitting unit that has once emitted light to emit light again while the light emitting unit emits light a plurality of times with different combinations of the light emitting units. A method for controlling an imaging apparatus that performs flash photography using an illumination device having a plurality of light emitting units,
A light emission control step of emitting light a plurality of times with different combinations of the light emitting parts during flash photography,
An image acquisition step of acquiring a plurality of images with different combinations of the emitted light emitting units when the light emitting unit emits light a plurality of times;
A combining step of combining the plurality of images acquired in the image acquiring step;
A method for controlling an imaging apparatus, comprising:

Images