JP2012249127A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a captured image from being blurred.SOLUTION: An imaging apparatus includes a microphone section 18, a sound processing section 20, a wind noise determination section 22 and a CPU 28. When a self-timer is turned on and a shutter button 30s is fully pressed, the apparatus starts to count a timer time and collect sound from the microphone section 18. The sound processing section 20 extracts a high-pass frequency component and a low-pass frequency component from the collected sound to output the components to the wind noise determination section 22. The wind noise determination section 22 detects levels of the high-pass frequency component and the low-pass frequency component, determines whether wind blows or not on the basis of the relative magnitude of the low-pass frequency component to the level of the high-pass frequency component, to set a wind determination flag. When the timer time has passed, the CPU 28 refers to the wind determination flag, delays imaging when it is determined that wind blows, and executes imaging when it is determined that wind does not blow.

Description

  The present invention relates to an imaging apparatus having a self-timer function.

  In recent years, imaging apparatuses having a camera shake correction function for reducing image blur due to camera shake have become widespread. However, even if the camera shake correction function is used, camera shake cannot be completely corrected.

  In order to avoid image blurring, it is ideal to shoot in a state where there is no camera shake. Therefore, as a method of performing photographing without causing camera shake, there is a method of performing photographing using a self-timer function with an imaging device fixed to a support such as a tripod.

  Normally, when taking a picture by this method, camera shake does not occur, so the camera shake correction function is often set to off. For example, Patent Document 1 discloses a camera that switches on / off the camera shake correction function between a state in which the camera body is gripped and a state in which the camera body is supported by a support such as a tripod.

JP 2011-39240 A

  However, even when the imaging device is fixed to a support such as a tripod and the self-timer function is used for shooting, for example, the imaging device cannot be prevented from shaking due to the influence of the wind, and an image blur image is taken. There is a risk that.

  The present invention has been made in view of the above-described problems, and an imaging apparatus according to the present invention performs imaging on an imaging unit that acquires a subject image by imaging, and on an imaging unit after a predetermined time has elapsed since the imaging instruction was issued. The wind is generated based on the sound acquired by the sound capturing means, the sound collecting means for acquiring the sound around the own device and generating the sound signal in response to the shooting instruction being issued, The timer photographing means delays the execution of photographing by the photographing means when it is determined that the wind is generated by the judging means after a predetermined time has elapsed, When it is determined that no wind is generated, photographing by the photographing unit is executed.

  According to the present invention, it is possible to suppress shooting of an image blur image.

It is a block diagram which shows the outline of a structure of the imaging device 1 concerning this invention. 4 is a flowchart illustrating processing operations of the imaging apparatus 1 in a normal shooting mode. It is a flowchart which shows the processing operation of the imaging device 1 at the time of self-timer mode. 3 is a block diagram showing an outline of the internal configuration of an audio processing unit 20 and a wind sound determination unit 22. FIG. It is a spectrum distribution map of a wind sound and an audio | voice. It is a flowchart which shows the processing operation of a wind noise determination.

(Configuration of the imaging device 1)
An embodiment of the present invention will be described with reference to the drawings. In this embodiment, the imaging device is assumed to be fixed to a support such as a tripod.

  FIG. 1 is a block diagram showing an outline of the configuration of an imaging apparatus 1 according to the present invention. The image pickup apparatus 1 includes an image pickup device (image sensor) 2, a zoom lens 4 for forming an optical image of the subject on the image pickup device 2, a focus lens 6 for focusing on the subject, and a diaphragm 8 for adjusting the exposure amount. And an imaging unit 10 including a zoom lens 4 and the like.

  In addition, the imaging apparatus 1 includes a memory 12 that temporarily records an image corresponding to a subject captured by the imaging unit (hereinafter referred to as a subject image) and the like, a color interpolation process on a subject image temporarily recorded in the memory 12, and white A signal processing unit 14 that performs various signal processing such as balance adjustment and noise reduction processing. If the subject image processed by the signal processing unit 14 is a still image, JPEG (Joint Photographic Experts Group) method, In the case of a photographed image, an image codec unit 16 that performs compression coding processing on the subject image by the MPEG (Moving Picture Experts Group) method or the like to generate a compressed image signal is provided.

  In addition, the imaging device 1 collects sound around the own device, and the sound processing that extracts the high frequency component and the low frequency component from the sound signal based on the sound collected from the microphone unit 18. Unit 20 and a wind sound determination unit 22 that determines whether or not wind is generated around the imaging apparatus 1 from the audio signal processed by the audio processing unit 20.

  In addition, the imaging device 1 includes a display unit 24 that displays a frame image, a recording medium 26 that records the captured frame image, a CPU (Central Processing Unit) 28 that controls the operation of the imaging device 1, and a user for the imaging device 1. And an operation unit 30 that gives an instruction corresponding to the operation to the CPU.

  The operation unit 30 includes a zoom switch 30z that drives the zoom lens 4 to adjust the zoom magnification of the subject, a timer switch 30t that sets a self-timer, a shutter button 30s that executes a shooting process, and the like.

  In addition, the imaging device 1 includes a support attachment portion 32 for attaching a support 34 for supporting and / or fixing the imaging device 1 such as a tripod. The support 34 can be attached to and detached from the imaging device 1 via the support mounting portion 32.

  As the imaging device 2, for example, a solid-state imaging device such as a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor is used.

  As the memory 12, for example, a commonly used memory such as a video random access memory (VRAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), or a synchronous DRAM (SDRAM) is used. .

  As the display unit 24, for example, an LCD (Liquid Crystal Display) monitor or an organic EL (Electro-Luminescence) monitor is used. The display unit 24 may be a touch panel type that senses the contact of a person's finger.

  The recording medium 26 is, for example, an internal recording medium built in the imaging apparatus 1 such as a flash memory or a built-in HDD (Hard Disk Drive), or an imaging apparatus 1 such as an SD memory card or a Memory Stick (registered trademark) external HDD. A removable external recording medium is used.

(Processing in normal shooting mode)
Next, with reference to FIG. 2, the basic operation of the imaging apparatus 1 during still image shooting will be described using a flowchart. When the power of the imaging apparatus 1 is turned on by the user, the driving mode of the imaging apparatus 1, that is, the driving mode of the imaging element 2 is set to the preview mode (S201).

  The preview mode is a mode in which an image to be photographed is displayed on the display unit 24 without being recorded, and can be used to determine a photographing object and determine a composition.

  Next, the camera enters a shooting mode input waiting state, and selects a mode suitable for the function of the imaging apparatus 1 and a shooting scene, such as a mode suitable for shooting a person, a mode suitable for shooting a moving object, and a mode suitable for shooting in backlight. Is done.

  At this time, the self-timer on / off setting can also be selected. When the shooting mode is not input, it is assumed that the normal shooting mode is selected.

In the preview mode, an analog image signal obtained by the photoelectric conversion operation of the image sensor 2 is converted into a digital image signal by an AFE (not shown), and the signal processing unit 14 performs color separation, white balance adjustment, and YUV. Image processing such as conversion is performed and written in the memory 12. The image signal written in the memory 12 is sequentially displayed on the display unit 24.
As a result, a real-time moving image (preview image) representing the imaging region is sequentially displayed on the display unit 24 every predetermined period (for example, every 1/30 seconds or 1/60 seconds).
Subsequently, the user sets the zoom magnification with the optical zoom so that the desired angle of view is obtained with respect to the subject to be imaged (S203). At that time, the image pickup unit 10 is controlled by the CPU 28 based on the image signal input to the signal processing unit 14, and optimal exposure control (Automatic Exposure; AE) and focus control (Automatic Focus; AF) are performed (S205). .
The focusing control is performed by, for example, hill-climbing AF control. In the hill-climbing AF control, a high frequency component of a luminance signal included in an image signal of a subject image received by the image sensor 2 is detected, and an integrated value (hereinafter referred to as AF evaluation value) of the high frequency component of the luminance signal. The focus lens position where the AF evaluation value is maximum, that is, the peak position is searched, and control is performed so that the focus lens 6 is disposed at this position.
The acquisition of the AF evaluation value is not normally performed on the entire image signal of the shooting area captured by the imaging apparatus 1, but a focus area is set in the image signal, and the AF evaluation value is set in the focus area. It is often acquired.
When the user determines the shooting angle of view and composition and half-presses the shutter button 30s of the operation unit 30 (Yes in S207), AE adjustment processing and AF optimization processing are performed (S209).

After that, when the shutter button is fully pressed (Yes in S211), the timing of each of the image sensor 2, the AFE, the signal processing unit 14, and the image codec unit 16 is transmitted from TG (Timing Genelator: not shown). A control signal is given, the operation timing of each part is synchronized, the drive mode of the image sensor 2 is set to the still image shooting mode, and the analog image signal output from the image sensor 2 is converted into a digital image signal by the AFE. The data is written into the frame memory in the processing unit 14 (S213).
The digital image signal is read from the frame memory, and various signal processes such as a signal conversion process for generating a luminance signal and a color difference signal are performed in the signal processing unit 14.

  The digital image signal that has been subjected to signal processing is compressed into a JPEG (Joint Photographic Experts Group) format by the image codec unit 16 (S215), and then the compressed image is written to the recording medium 26 (S217), thereby completing the photographing. To do. Then, it returns to preview mode.

(Processing during self-timer shooting)
Next, the processing operation of the imaging apparatus 1 during self-timer shooting will be described with reference to FIG. Note that the steps denoted by the same reference numerals as those in FIG.

  When shooting using the self-timer, after shifting to the preview mode, the timer switch 30t is operated while waiting for input of the shooting mode, and the self-timer is set to ON.

  When the self-timer is set to ON (Yes in S301), a predetermined timer time (for example, 10 seconds) is set (S303). At this time, the user may arbitrarily change the timer time.

  Next, the CPU 28 sets the shooting determination flag L to 0 and stores it in the memory 12 (S305). This shooting determination flag L is set to 0 before shooting processing, that is, capturing of a subject image by the imaging unit 10, and is set to 1 when capturing of the subject image is completed.

  When the shutter button is fully pressed, the self-timer starts counting (S307). At this time, in parallel with the count of the self-timer, a wind sound determination process described later is started.

  The wind sound determination process determines whether or not wind is blowing around the imaging device 1 based on the sound collected from the microphone unit 18. If it is determined that the wind is blowing, the wind determination flag K is set. 1 is set; otherwise, the wind determination flag K is set to 0 and stored in the memory 12.

  When the count time of the self-timer has passed a set timer time (for example, 10 seconds) (Yes in S309), the CPU 28 refers to the value of the wind determination flag K stored in the memory 12.

  When K = 0 (Yes in S311), the imaging unit 10 is instructed to capture the subject image, and when the capture of the subject image is completed, the shooting determination L is set to 1 (S313). When the recording of the subject image is completed, the preview mode is restored.

  When K = 1 (No in S311), the reference of the value of the wind determination flag K is repeated at a predetermined cycle (for example, every second), and the capturing of the subject image is delayed until K = 0.

  By doing in this way, it is possible to prevent the tripod and the imaging device 1 from shaking due to the influence of wind during the self-timer shooting and shooting a blurred image.

(Wind sound judgment processing)
Next, with reference to FIGS. 4 and 5, the processing operation of the wind noise determination process will be described. FIG. 4 is a block diagram showing an outline of the internal configuration of the sound processing unit 20 and the wind sound determination unit 22.

  The audio processing unit 20 extracts an HPF (High-Pass Filter) 201H that extracts a high frequency component from the analog audio signal collected by the microphone 18, and extracts a low frequency component from the analog audio signal collected by the microphone 18. An A / D conversion unit 202 that converts frequency components extracted from an LPF (Low-Pass Filter) 201L, HPF 201H, and LPF 201L into digital audio signals, and an adder 203, respectively.

  The wind sound determination unit 22 is a high frequency level detection unit 221H that detects a high frequency component level AH from an A / D converted digital audio signal of a high frequency component. A / D converted low frequency component digital The low frequency level detection unit 221L that detects the low frequency component level AL from the audio signal, the high frequency component level AH and the low frequency level detection unit 221L detected by the high frequency level detection unit 221H and the low frequency level detection unit 221L. A determination unit 222 that determines whether wind is blowing around the imaging device 1 from the detected low frequency level AL.

  When the shooting mode is set to the self-timer mode and the shutter button 30 s is fully pressed, the CPU 28 outputs a sound collection instruction to the microphone unit 18. In response to the sound collection instruction output from the CPU 28, the microphone unit 18 starts collecting sound.

  The collected sound is separated into a high frequency component and a low frequency component by the HPF 201H and the LPF 201L, and converted into a digital audio signal by the A / D converter 202, respectively.

  Further, these frequency components are input to the high frequency level detection unit 221H and the low frequency level detection unit 221L, respectively, and the high frequency component level AH and the low frequency component level AL are detected and input to the determination unit 222, respectively. .

  The determination unit 222 compares the value AL / AH obtained by dividing the low frequency component level AL by the high frequency component level AH with a preset threshold value Sth. As a result, when AL / AH is smaller than Sth (in other words, AL / AH <Sth), it is determined that the wind is not blowing, and AL / AH is equal to or greater than Sth (in other words, AL / AH ≧ Sth). If there is, it is determined that the wind is blowing. The basis for this will be described below.

  FIG. 5 is a distribution diagram showing the spectrum of the output signal of the microphone unit 18 when a human voice is input and the spectrum of the output signal of the microphone unit 18 when a wind sound is input. The vertical axis represents the audio signal level, and the horizontal axis represents the audio frequency.

  From the comparison of these two spectra, it can be seen that the lower the frequency of the wind noise, the higher the sound signal level. In contrast, human speech has the highest audio signal level in the frequency band around 1 kHz.

  Therefore, for example, the high frequency component level AH is detected from the high frequency band near 800 Hz to 1.2 kHz, and the low frequency component level AL in the low frequency band near 20 Hz to 100 Hz is detected, respectively. It is determined whether or not the wind is blowing by determining whether or not the relative magnitude of the low frequency component level AL with respect to the component level AH (ie, AL / AH) exceeds a predetermined level (Sth). I can do it.

  As a result of the comparison, if it is determined that the wind is blowing, the wind determination flag K is set to 1 and stored in the memory 12. Otherwise, the wind determination flag K is set to 0 and stored in the memory 12.

  This wind noise determination process is repeated at a predetermined cycle (for example, every second) until the self-timer shooting is completed, that is, the shooting determination flag L becomes 1, and the wind determination flag K indicates the determination result in each cycle. Will be updated accordingly.

  FIG. 6 is a flowchart showing the processing operation of the wind determination process. In step S601, it is determined whether the shooting mode is set to the self-timer mode. If the self-timer mode is set, the process proceeds to step S603, and if not, step S601 is repeated.

  In step S603, it is determined whether or not the shutter button 30s has been fully pressed. If the shutter button 30s is fully pressed, the process proceeds to step S605. If not, step S603 is repeated.

  In step S605, sound collection from the microphone unit 18 is started. In step S607, high frequency components and low frequency components are extracted from the sound collected from the microphone unit 18, and the respective frequency components are converted into A / D. Convert.

  In step S609, the high frequency component level AH is detected from the A / D converted high frequency component, and the low frequency component level AL is detected from the A / D converted low frequency component.

  In step 611, a value AL / AH obtained by dividing the low frequency component level AL by the high frequency component level AH is compared with a predetermined threshold value Sth. If AL / AH is smaller than Sth, the process proceeds to step S613; otherwise, the process proceeds to step S615.

  In step S613, the wind determination flag K is set to 0 and stored in the memory 12. In step S615, the wind determination flag K is set to 1 and stored in the memory 12.

  In step S617, it is determined whether or not the shooting determination flag L is set to 1. If the shooting determination flag L is set to 1, the wind noise determination process is terminated, otherwise the process returns to step S605.

  In the above embodiment, the wind sound determination process is always performed when the self-timer mode is set. For example, the wind sound determination process is performed only when the zoom magnification is set to a predetermined magnification or higher. May be.

  This is because the larger the zoom magnification, the greater the influence of the shaking of the imaging device 1, and the higher the possibility of taking a blurred image.

  Further, in the above embodiment, when the wind determination flag K is set to 1, shooting is delayed until the wind determination flag K becomes 0. If K remains 1, shooting may be stopped.

  In the above embodiment, the microphone unit 18 is a monaural microphone, but a pair of stereo microphones may be used. In this case, either one of the microphones may be used to perform the wind sound determination described above, or the wind sound determination may be performed using the fact that a phase difference occurs in the wind sound input to each microphone. Also good.

  As mentioned above, although one Example of this invention was described, this invention is not limited to these Examples, A deformation | transformation and change are possible within the range of the summary.

2 Image sensor 4 Zoom lens 6 Focus lens 8 Aperture 12 Memory 14 Signal processing unit 16 Image codec unit 18 Microphone unit 20 Audio processing unit 201H HPF
201L LPF
202 A / D conversion unit 203 Adder 22 Wind sound determination unit 221H High frequency level detection unit 221L Low frequency level detection unit 222 Determination unit 24 Display unit 26 Recording medium 28 CPU
30 Operation unit 30s Shutter button 30t Timer switch 30z Zoom switch

Claims (4)

Photographing means for acquiring a subject image by photographing;
Timer photographing means for causing the photographing means to perform photographing after a predetermined time has elapsed since the photographing instruction was issued;
In response to the shooting instruction being issued, sound is collected around the device to generate sound signals, and wind is generated based on the sound signals generated by the sound collecting means. Determination means for repeatedly determining whether or not
The timer photographing means postpones execution of photographing by the photographing means when it is determined that the wind is generated by the determining means after the predetermined time has elapsed, and it is determined that no wind is generated. The imaging apparatus characterized in that imaging by the imaging unit is executed. A high-pass filter that extracts a high-frequency component from the audio signal generated by the sound collecting means, and a low-pass filter that extracts a low-frequency component from the audio signal generated by the sound collecting means,
2. The imaging apparatus according to claim 1, wherein the determination unit determines that a wind is generated when a relative magnitude of the low frequency component with respect to the high frequency component exceeds a predetermined threshold. .   3. The imaging apparatus according to claim 1, wherein the determination unit repeatedly executes the determination at a predetermined period from when the shooting instruction is issued until shooting by the shooting unit is executed. A zoom lens, and drive means for driving the zoom lens along the optical axis direction,
4. The image pickup apparatus according to claim 1, wherein the determination unit is executed when the photographing instruction is issued in a state where the zoom lens is driven to a telephoto side from a predetermined position.

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