JP2014041300A - Signal processing device, imaging device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy of a noise estimation in noise reduction processing.SOLUTION: A signal processing device comprises: a conversion part that converts a sound signal to be input into a frequency spectrum in a frequency domain; a processing part that performs signal processing to the frequency spectrum converted by the conversion part; an inverse conversion part that converts the frequency spectrum subjected to the signal processing by the processing part into a sound time signal in a time domain; and a coupling adjustment part that multiplies the sound time signal to be output from the inverse conversion part with a window function in which values at both ends in a unit section in a time axis direction are smaller than a value at a center therein.

Description

  The present invention relates to a signal processing device, an imaging device, and a program that perform signal processing on a sound signal.

When signal processing such as noise reduction processing is performed on the microphone sound signal collected by the microphone, for example, the microphone sound signal is divided into frames, and the sound time signal corresponding to each frame is converted into a frequency spectrum. Then, a noise reduction process is performed on the frequency spectrum, and a process of returning the frequency spectrum after the noise reduction process to the time domain is performed.
For example, the microphone sound signal is divided into frames, multiplied by a window function, and the sound time signal multiplied by the window function is Fourier transformed to convert the sound time signal in the time domain into a frequency spectrum in the frequency domain. There is a method of subtracting a frequency spectrum estimated as noise from this frequency spectrum and performing an inverse Fourier transform on the frequency spectrum as a subtraction result to return to a time-domain sound time signal (see, for example, Patent Document 1).

JP 2011-095567 A

  As described above, when signal processing is performed after the sound time signal is converted into the frequency spectrum, and the frequency spectrum after the signal processing is returned to the sound time signal, the amplitude value of the sound time signal shifts at the joint between frames, thereby causing noise. May occur. That is, when the frequency spectrum is returned to the time domain, the joint between frames becomes discontinuous, so that the sound skips and noise may occur at the joint.

  The present invention has been made in view of the above points. When the sound time signal is converted into the frequency domain, signal processing is performed, and the frequency spectrum of the signal-processed frequency domain is returned to the sound time signal. An object of the present invention is to provide a signal processing device, an imaging device, and a program for reducing noise that may occur at a joint.

  The present invention has been made to solve the above-described problem, and the signal processing device converts the input sound signal into a frequency spectrum in the frequency domain, and the frequency spectrum converted by the conversion unit. A signal processing unit, an inverse conversion unit for converting the frequency spectrum signal-processed by the processing unit into a sound time signal in a time domain, and a window function in which values at both ends in a unit section are smaller than a central value, A connection adjustment unit that multiplies the sound time signal converted by the inverse conversion unit.

  According to the present invention, when signal processing is performed after a sound time signal in the time domain is converted to the frequency domain, and the frequency spectrum of the signal processed frequency domain is returned to the sound time signal in the time domain, a joint is generated. Possible noise can be reduced.

1 is a block diagram illustrating an example of a configuration of an imaging apparatus according to a first embodiment of the present invention. It is a reference figure for explaining an example of the relation between the operation timing signal of the operation part concerning the 1st embodiment of the present invention, and the microphone sound signal. It is a reference diagram for demonstrating the microphone sound signal shown in FIG. It is a block diagram which shows an example of a function structure of the reduction process part which concerns on 1st Embodiment of this invention. It is a figure for demonstrating an example of an impact sound process frequency spectrum and an impact sound flooring spectrum. It is a figure for demonstrating an example of the frequency component of a frequency spectrum. It is a figure for demonstrating an example of the impact sound noise reduction process which concerns on 1st Embodiment of this invention. It is a diagram illustrating an example of a Hamming window function W _1. Is a diagram illustrating an example of a Hanning window function W _2. Is a diagram illustrating an example of a coupling adjustment window function W _3. It is a figure which shows an example of the microphone sound signal input into a reduction process part. It is a figure which shows an example of the sound time signal cut out by the sound signal cutout part. Is a diagram illustrating an example of the sound time information obtained by multiplying the Hamming window function W ₁ to the sound time signal by a Hamming windowing unit. It is a figure which shows an example of the sound time information after a noise reduction process was made | formed by the noise reduction process part. It is an enlarged view which expands and shows the part corresponding to the edge part of the window of the sound time signal shown in FIG. It is a figure which shows the sound information connected by the signal superimposition part. It is the enlarged view to which the joint shown in FIG. 16 was expanded. It is a figure for demonstrating an example when not depending on this embodiment. It is a figure for demonstrating an example when not depending on this embodiment. It is a figure for demonstrating an example when not depending on this embodiment. It is a figure for demonstrating an example when not depending on this embodiment. It is a figure for demonstrating an example when not depending on this embodiment. It is a flowchart for demonstrating an example of the noise reduction processing method which concerns on 1st Embodiment of this invention. It is a diagram illustrating an example of a window function of a molecule of the coupling adjustment window function W _5. Is a diagram illustrating an example of a coupling adjustment window function W _5. It is a figure for demonstrating an example of the window function which can be utilized for this embodiment. It is a figure for demonstrating an example of the window function which can be utilized for this embodiment. It is a figure for demonstrating an example of the window function which can be utilized for this embodiment. It is a figure which shows the structural example which concerns on 2nd Embodiment of this invention.

[First Embodiment]
Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating the configuration of the imaging apparatus according to the present embodiment. In the present embodiment, an example in which the signal processing device according to the present invention is mounted on an imaging device will be described below, but the present invention is not limited to this.
As shown in FIG. 1, the imaging device 100 captures an image by an optical system, stores the obtained image data in the storage medium 200, and performs noise reduction processing on the microphone sound signal collected by the microphone. The sound information after the noise reduction processing is stored in the storage medium 200.
The imaging apparatus 100 includes a reduction processing unit 250. The reduction processing unit 250 acquires estimated noise included in the microphone sound signal and performs noise reduction processing for reducing noise from the microphone sound based on the estimated noise.

  The reduction processing unit 250 according to the present embodiment performs noise reduction processing for reducing noise (hereinafter referred to as operation sound) generated when the operation unit operates. For example, in the imaging apparatus 100, when the optical system is driven in processing such as AF (Auto Focus) and VR (Vibration Reduction), an operation sound is generated by the movement of the motor and the optical system. In addition, a loud operating sound is temporarily generated at the start of driving the motor, at the end of driving, and at the time of switching the rotation direction. In this way, a loud sound that is temporarily generated when the operating state of the operating unit changes is referred to as an impact sound. On the other hand, a sound that is smaller than the impact sound and is generated when the optical system or the motor is moving is called a drive sound. That is, the drive sound is an operation sound (noise) other than the impact sound. The noise to be reduced by the reduction processing unit 250 according to the present embodiment is an operation sound including a driving sound and an impact sound. That is, the reduction processing unit 250 performs impact sound noise reduction processing for reducing noise due to impact sound from the microphone sound signal, and performs drive sound noise reduction processing for reducing noise due to drive sound from the microphone sound signal.

  Hereinafter, an exemplary configuration of the imaging apparatus 100 and the reduction processing unit 250 will be described in detail. In the present embodiment, an example in which the reduction processing unit 250 is built in the imaging apparatus 100 will be described, but the present invention is not limited to this. For example, the reduction processing unit 250 may be an external device of the imaging device 100.

  The imaging apparatus 100 includes an imaging unit 110, a lens CPU 120, a buffer memory unit 130, an image processing unit 140, a display unit 150, a storage unit 160, a communication unit 170, an operation unit 180, a body CPU 190, The timer unit 220, the microphone 230, the A / D converter 240, the reduction processing unit 250, and the battery 260 are provided.

  The imaging unit 110 includes an optical system 111, an imaging element 119, and an A / D (Analog / Digital) conversion unit 121, and is determined in advance according to imaging conditions (for example, an aperture value, an exposure value, and the like) that are set. The lens CPU 120 is controlled according to the operation pattern. The imaging unit 110 forms an optical image by the optical system 111 on the imaging device 119 and generates image data based on the optical image converted into a digital signal by the A / D conversion unit 121.

The optical system 111 includes a focus adjustment lens (hereinafter referred to as “AF lens”) 112, a camera shake correction lens (hereinafter referred to as “VR lens”) 113, a zoom lens 114, a zoom encoder 115, and a lens driving unit 116. And an AF encoder 117 and a camera shake correction unit 118.
Each component of the optical system 111 is driven in accordance with an operation pattern determined in advance according to processing of each function in focus adjustment processing, camera shake correction processing, and zoom processing by the lens CPU 120. That is, the optical system 111 is an operation unit in the imaging apparatus 100.

The optical system 111 guides an optical image incident from the zoom lens 114 and passed through the zoom lens 114, the VR lens 113, and the AF lens 112 in this order to the light receiving surface of the image sensor 119.
The lens driving unit 116 inputs drive control signals (commands) for controlling the positions of the AF lens 112 and the zoom lens 114 from the lens CPU 120. The lens driving unit 116 controls the positions of the AF lens 112 and the zoom lens 114 in accordance with an input command.
That is, when this command is input from the lens CPU 120 to the lens driving unit 116 and the lens driving unit 116 is driven, the AF lens 112 and the zoom lens 114 move (operate). In the present embodiment, the timing at which the lens CPU 120 outputs a command is referred to as an operation start timing at which the operations of the AF lens 112 and the zoom lens 114 are started.

  The zoom encoder 115 detects a zoom position representing the position of the zoom lens 114 and outputs it to the lens CPU 120. The zoom encoder 115 detects the movement of the zoom lens 114, and outputs a pulse signal to the lens CPU 120 when the zoom lens 114 is moving in the optical system 111, for example. On the other hand, when stopped, the zoom encoder 115 stops outputting the pulse signal.

  The AF encoder 117 detects a focus position representing the position of the AF lens 112 and outputs it to the lens CPU 120 and the body CPU 190. The AF encoder 117 detects the movement of the AF lens 112. The AF encoder 117 detects the movement of the AF lens 112, and outputs a pulse signal to the lens CPU 120 when the AF lens 112 is moving in the optical system 111, for example. On the other hand, when stopped, the AF encoder 117 stops outputting the pulse signal.

The zoom encoder 115 may detect the driving direction of the zoom lens 114 in order to detect the zoom position. Further, the AF encoder 117 may detect the driving direction of the AF lens 112 in order to detect the focus position.
For example, the zoom lens 114 and the AF lens 112 are moved in the direction of the optical axis when a driving mechanism (for example, a motor or a cam) driven by the lens driving unit 116 rotates clockwise (CW) or counterclockwise (CCW). Moving. The zoom encoder 115 and the AF encoder 117 respectively detect that the zoom lens 114 and the AF lens 112 are moving by detecting the rotation direction (here, clockwise or counterclockwise) of the drive mechanism. It may be.

  The camera shake correction unit 118 includes, for example, a vibration gyro mechanism, detects an optical axis shake of an image by the optical system 111, and moves the VR lens 113 in a direction to cancel the optical axis shake. The camera shake correction unit 118 outputs a high level signal to the lens CPU 120 in a state where the VR lens 113 is moved, for example. On the other hand, in a state where the VR lens 113 is stopped, the camera shake correction unit 118 outputs a low level signal to the lens CPU 120.

The image sensor 119 includes, for example, a photoelectric conversion surface, converts an optical image formed on the light receiving surface into an electric signal, and outputs the converted electric signal to the A / D conversion unit 121.
The image sensor 119 stores image data obtained when a shooting instruction is received via the operation unit 180 in the storage medium 200 via the A / D conversion unit 121 as still image data or moving image data. On the other hand, the image sensor 119 uses the continuously obtained image data as through image data (preview image data) in the state where the imaging instruction is not received via the operation unit 180, and the body via the A / D conversion unit 121. The data is output to the CPU 190 and the display unit 150.

  The A / D converter 121 digitizes the electrical signal converted by the image sensor 119 and outputs image data that is a digital signal to the buffer memory unit 130.

  The buffer memory unit 130 temporarily stores image data captured by the imaging unit 110. The buffer memory unit 130 temporarily stores a microphone sound signal corresponding to the microphone detection sound collected by the microphone 230.

  The image processing unit 140 refers to the information indicating the image processing conditions stored in the storage unit 160 and performs image processing on the image data temporarily stored in the buffer memory unit 130. The image data subjected to the image processing is stored in the storage medium 200 via the communication unit 170. Note that the image processing unit 140 may perform image processing on the image data stored in the storage medium 200.

  The display unit 150 is, for example, a liquid crystal display, and displays image data, an operation screen, and the like obtained by the imaging unit 110.

  The storage unit 160 stores information indicating determination conditions referred to when the lens CPU 120 performs scene determination, information indicating imaging conditions associated with each scene determined by scene determination, and the like.

  The communication unit 170 is connected to a removable storage medium 200 such as a card memory, and writes, reads, or erases information (image data, sound data, etc.) to the storage medium 200.

  The operation unit 180 includes, for example, a power switch, a shutter button, a multi-selector (cross key), or other operation keys. The operation unit 180 receives an operation input from the user when operated by the user, and an operation content corresponding to the operation input. Is output to the lens CPU 120 and the body CPU 190. The operation unit 180 may generate a physical operation sound when pressed by the user. In the present embodiment, the timing at which operation information indicating the operation content corresponding to the user's operation input is input from the operation unit 180 to the lens CPU 120 or the body CPU 190 is referred to as an operation start timing at which the operation of the operation unit 180 is started.

  The storage medium 200 is a storage unit that is detachably connected to the image capturing apparatus 100. For example, the storage medium 200 is image data generated (captured) by the image capturing unit 110 or subjected to signal processing by the reduction processing unit 250. Stores sound information.

  The bus 210 includes an imaging unit 110, a lens CPU 120, a buffer memory unit 130, an image processing unit 140, a display unit 150, a storage unit 160, a communication unit 170, an operation unit 180, a body CPU 190, and a clock. The unit 220, the A / D conversion unit 240, and the reduction processing unit 250 are connected to transfer data output from each component.

  The timekeeping unit 220 measures the date and time and outputs date / time information indicating the time / date.

  The microphone 230 picks up surrounding sounds and outputs a microphone sound signal of this sound to the A / D converter 240. The microphone sound signal collected by the microphone 230 mainly includes a target sound to be collected and an operation sound (noise) by the operation unit.

Here, the microphone sound signal acquired by the microphone 230 will be described with reference to FIGS. 2 and 3 by taking, for example, a microphone sound signal obtained when the AF lens 112 is operating.
FIG. 2A shows an example of the relationship between the output of the AF encoder 117 and time. FIG. 2B shows an example of the relationship between the microphone sound signal and time. The time axes in FIGS. 2A and 2B indicate the same time. For convenience of explanation, FIG. 2B shows only the microphone sound signal of the operation sound among the microphone sound signals, and the illustration of the microphone sound signal of the target sound is omitted. The operation pattern of the AF lens 112 shown in FIGS. 2A and 2B is, for example, an operation pattern when performing AF processing for focusing at a distance P.

In FIG. 2A, the vertical axis indicates the rotation direction (CW, CWW) of the drive mechanism that drives the AF lens 112 based on the output of the AF encoder 117.
In the operation pattern for performing AF processing for focusing at this distance P, as shown in FIG. 2A, the driving mechanism for driving the AF lens 112 rotates clockwise CW from time t10 to t20, and then Quiesce.
That is, time t10 represents the operation start timing of the AF lens 112, and time t20 represents the operation stop timing of the AF lens 112. In the present embodiment, the time t10 of the operation start timing is the timing (time) at which the lens CPU 120 outputs a command for controlling the position of the AF lens 112 to the lens driving unit 116. The operation stop timing time t20 is a timing at which the output of the pulse signal from the AF encoder 117 is stopped.

Therefore, as shown in FIG. 2B, the operation sound by the AF lens 112 is superimposed on the target sound or the operation sound is superimposed on the target sound during the period from time t10 to t20. Probability is high. In the present embodiment, the following description will be given by taking as an example a case where noise, which is an operation sound generated by the AF lens 112, is generated during the period from time t10 to t20.
Further, as shown in FIG. 2B, there is a high possibility that impact sounds are generated at times t10 and t20. In the present embodiment, the following description will be given by taking as an example a case where an impact sound is generated by the AF lens 112 at times t10 and t20.

In addition, when an impact sound is generated, a time length (period) during which the impact sound is highly likely to be generated is determined in advance according to each operation pattern. In the operation pattern in which the AF process for focusing at the distance P is performed, time lengths L1 and L2 at which impact sounds are generated as shown in FIG. 3 are determined.
FIG. 3 is a diagram illustrating an example of a microphone sound signal picked up by the microphone 230 when the AF lens 112 is driven with an operation pattern in which an AF process for focusing at a distance P is performed. The graph shown in FIG. 3 shows the amplitude of the microphone sound signal collected by the microphone 230 on the vertical axis, and the time on the horizontal axis. For convenience of explanation, FIG. 3 shows only the microphone sound signal of the operation sound among the microphone sound signals, and the illustration of the microphone sound signal of the target sound is omitted. 3 are the same as the times t10 and t20 shown in FIGS. 2 (A) and 2 (B).

In the operation pattern in which the AF process for focusing at the distance P is performed, the period from the operation start timing to the time length L1 and the period from the operation stop timing to the time length L2 are preliminarily set to be the time length at which the impact sound is generated. It has been decided. Therefore, in this embodiment, the period from time t10 to time length L1 (t10 to t11) and the period from time t20 to time length L2 (t20 to t21) are periods in which impact sounds are generated. Here, a period of time length L1 from the operation start timing is referred to as an operation start timing period. Further, a period of time length L2 from the operation stop timing is referred to as an operation stop timing period.
Here, a period during which the operating unit is highly unlikely to operate is defined as a non-operation period Ta. Further, a period during which an impact sound is highly likely to be generated by the operation of the operation unit is referred to as an impact sound generation period Tb. Furthermore, a period during which a driving sound is likely to be generated by the operation of the operating unit is defined as a driving sound generation period Tc. In the present embodiment, the period from time t0 to time t10 and the period from t21 to t is the non-operation period Ta. The period from time t10 to t11 and the period from time t20 to t21 are the impact sound generation period Tb. The period from time t11 to t20 is the drive sound generation period Tc.

Returning to FIG. 1, the description of each configuration of the imaging apparatus 100 is continued.
The lens CPU 120 controls the imaging unit 110 according to an operation pattern according to the set imaging conditions (for example, aperture value, exposure value, etc.). The lens CPU 120 generates a command for driving the lens driving unit 116 based on the zoom position output from the zoom encoder 115 and the focus position output from the AF encoder 117, and outputs the command to the lens driving unit 116. As the generation algorithm, an existing algorithm may be appropriately used as necessary.

The body CPU 190 comprehensively controls the imaging device 100. The body CPU 190 includes an operation timing detection unit 191.
The operation timing detection unit 191 detects timing at which the operation state of the operation unit included in the imaging apparatus 100 changes. The timing at which the operation state changes includes, for example, an operation start timing at which the operation unit starts operation and an operation stop timing at which the operation of the operation unit stops.
The operation unit referred to here is, for example, the optical system 111 or the operation unit 180 described above. By operating or operating among the configurations of the imaging apparatus 100, This is a configuration that generates an operation sound (or that may generate an operation sound).
In other words, the operation unit refers to the operation sound generated by the operation of the operation unit or the operation sound generated by the operation of the operation unit being included in the imaging apparatus 100 by the microphone 230. The sound is collected (or possibly picked up).

  For example, the operation timing detection unit 191 may detect the timing at which the operation state of the operation unit changes based on a command for operating the operation unit. This command is a drive control signal that causes the operating unit to operate with respect to the drive unit that operates the operating unit, or a drive control signal that drives the drive unit.

For example, in order to drive the zoom lens 114, the VR lens 113, or the AF lens 112, the operation timing detection unit 191 is based on a command input to the lens driving unit 116 or the camera shake correction unit 118, and the zoom lens 114, The operation start timing when the operation of the VR lens 113 or the AF lens 112 is started is detected. In this case, when the lens CPU 120 generates a command, the operation timing detection unit 191 may detect the operation start timing based on a process or command executed in the lens CPU 120.
Further, the operation timing detection unit 191 may detect the operation start timing based on an operation signal indicating that the zoom lens 114 or the AF lens 112 is input from the operation unit 180.

Further, the operation timing detection unit 191 may detect the timing at which the operation state of the operation unit changes based on a signal indicating that the operation unit has operated.
For example, the operation timing detector 191 starts the operation of the zoom lens 114 or the AF lens 112 by detecting that the zoom lens 114 or the AF lens 112 is driven based on the output of the zoom encoder 115 or the AF encoder 117. Timing may be detected. Further, the operation timing detection unit 191 detects that the zoom lens 114 or the AF lens 112 has been stopped based on the output of the zoom encoder 115 or the AF encoder 117, thereby stopping the operation of the zoom lens 114 or the AF lens 112. Timing may be detected.
Further, the operation timing detection unit 191 may detect the operation start timing of the VR lens 113 by detecting that the VR lens 113 is driven based on the output from the camera shake correction unit 118. The operation timing detection unit 191 may detect the operation stop timing of the VR lens 113 by detecting that the VR lens 113 is stopped based on the output from the camera shake correction unit 118.
Furthermore, the operation timing detection unit 191 may detect the timing at which the operation unit operates by detecting that the operation unit 180 has been operated based on an input from the operation unit 180.

The operation timing detection unit 191 detects the operation start timing of the operation unit included in the imaging apparatus 100 and outputs an operation timing signal indicating the detected operation start timing to the reduction processing unit 250. Further, the operation timing detection unit 191 detects the operation stop timing of the operation unit provided in the imaging apparatus 100 and outputs an operation timing signal indicating the detected operation stop timing to the reduction processing unit 250.
In the present embodiment, the operation timing detection unit 191 determines the timing at which a command for moving the AF lens 112 is output from the lens CPU 120 to the lens driving unit 116 based on the command input from the lens CPU 120, and the operation start timing of the AF lens 112. Is determined. The operation timing detection unit 191 refers to the generation time length L1 of the impact sound, for example, information indicating the times t10 to t11 at which the impact sound is generated in the example using FIG. Is output as a signal (operation timing signal).

  The operation timing detection unit 191 determines, based on the pulse signal input from the AF encoder 117, the operation stop timing at which the operation of the AF lens 112 is stopped when the output of the pulse signal is stopped. In addition, the operation timing detection unit 191 refers to the generation time length L2 of the impact sound, for example, information indicating the times t20 to t21 when the impact sound is generated in the example illustrated in FIG. A signal indicating the period (operation timing signal) is output.

  The A / D converter 240 converts the microphone sound signal that is an analog signal input from the microphone 230 into a microphone sound signal that is a digital signal. The A / D converter 240 outputs a microphone sound signal, which is a digital signal, to the reduction processing unit 250. The A / D conversion unit 240 may be configured to store a microphone sound signal that is a digital signal in the buffer memory unit 130 or the storage medium 200. In this case, the A / D conversion unit 240 associates the information indicating the time when the microphone sound signal is acquired based on the date and time information measured by the time measuring unit 220 with the buffer sound unit 130 or the storage medium. 200.

  The reduction processing unit 250 reduces noise, which is an operation sound generated by the operation unit such as the AF lens 112, the VR lens 113, and the zoom lens 114, with respect to the microphone sound signal converted into a digital signal by the A / D conversion unit 240. The noise reduction process such as performing the noise reduction process is executed, and the sound information subjected to the noise reduction process is stored in the storage medium 200.

Next, the reduction processing unit 250 will be described in detail with reference to FIG. FIG. 4 is a block diagram illustrating an example of a functional configuration of the reduction processing unit 250 according to the present embodiment.
The reduction processing unit 250 includes a sound signal cutout unit 251, a Hamming window processing unit 252, a Fourier transform unit 253, a noise reduction processing unit 254, an inverse Fourier transform unit 255, a connection adjustment unit 256, and a signal superposition unit. 257.

The sound signal cutout unit 251 cuts out the sound time signal in units of frames by dividing the microphone sound signal output from the A / D conversion unit 240 into frames having a predetermined time length. Here, for the convenience of explanation, odd-numbered numbers (S101, S103, S105...) Are attached to the sound time signals in frame units cut out by the sound signal cutout unit 251. Further, the sound signal cutout unit 251 cuts out the sound time signal in units of frames from the microphone sound signal so as to overlap with the sound time signals S101, S103, S105,. . Here, for the convenience of explanation, an even number (S102, S102, S102, S105,...) Is included in the sound time signal in frame units cut out by the sound signal cutout unit 251 so as to overlap the sound time signals S101, S103, S105. S104, S106...
Also, frames corresponding to the sound time signals S101, S102, S103, S104, S105, S106,... Are denoted as frames F101, F102, F103, F104, F105, F106,.

The sound time signals S101, S103, S105... And the sound time signals S102, S104, S106. Further, as shown in FIG. 3, the frames F101, F102, F103, F104, F105, F106,...
In this embodiment, the sound signal cutout unit 251 cuts out the sound time signals S101, S102, S103, S104, S105, S106... So that the sampling frequency is 48 kHz and the frame length is 1024 points. Therefore, the sound time signal S102 includes information common to the second half 512 points of the sound time signal S101 and the first half 512 points of the sound time signal S103.

Hamming window processing unit 252, the sound signal clipping section sound time signal S101 that has been cut out by 251, S102, S103, S104, S105, S106 multiplies the Hamming window function _{W 1} to each .... Note that the sound time signals weighted by the Hamming window function W ₁ by the Hamming window processing unit 252 are hereinafter referred to as S201, S202, S203, S204, S205, S206.
Further, the Hamming window function _{W 1} is expressed by the following equation (1). In Equation (1), the window range is 0 to T, and the variable is indicated by time t (0 ≦ t ≦ T).

Fourier transform unit 253 converts Hamming window processing unit 252 Hamming window function _{W 1} weighted sound time signal S201 by, S202, S203, and S204, S205, S206 · · · to the spectrum represented in the frequency domain, The spectrum (frequency spectrum) represented in this frequency domain is output to the noise reduction processing unit 254.
The Fourier transform unit 253 transforms the sound time signal into the frequency domain, for example, by performing Fourier transform or fast Fourier transform (FFT) on the sound time signal. In the present embodiment, the Fourier transform unit 253 performs, for example, Fourier transform on the sound time signals S201, S202, S203, S204, S205, S206, and so on, so that the frequency spectrum corresponding to each specified period of the window function is obtained. calculate. The means for the Fourier transform unit 253 to convert the sound time signal into a frequency spectrum is not limited to Fourier transform.
The frequency spectrum converted into the frequency domain by the Fourier transform unit 253 is hereinafter referred to as S301, S302, S303, S304, S305, S306. That is, the Fourier transform unit 253 converts the input sound time signals S201, S202, S203, S204, S205, S206... Into frequency spectra S301, S302, S303, S304, S305, S306. Output to the noise reduction processing unit 254.

As shown in FIG. 3, in the operation pattern when performing AF processing for focusing at a distance P, an impact sound is generated in the operation start timing period and the operation stop timing period.
As described above, the period from the time t0 to the time t10 and the period from the time t21 to the non-operation period Ta (a period during which the operation unit is unlikely to operate). The period from time t10 to t11 (operation start timing period) and the period from time t20 to t21 (operation stop timing period) are the impact sound generation period Tb (a period during which an impact sound is highly likely to be generated by the operation of the operation unit). is there. A period from time t11 to t20 is a drive sound generation period Tc (a period during which drive sound is highly likely to be generated by the operation of the operation unit).
That is, the frequency spectra S301, S313, and S314 corresponding to the frames F101, F113, and F114 are the frequency spectra of the microphone sound signal acquired during the non-operation period Ta. Frequency spectra S305 to S308 corresponding to the frames F105 to F108 are frequency spectra of the microphone sound signal acquired in the drive sound generation period Tc in the period in which the operation unit is highly likely to operate.
In addition, the frequency spectrums S302 to S304 corresponding to the frames F102 to F104 and the frequency spectra S309 to S312 corresponding to the frames F109 to F112 are acquired in the impact sound generation period Tb in the period during which the operation unit is likely to operate. It is a frequency spectrum of the made microphone sound signal.

  The noise reduction processing unit 254 includes an impact sound noise reduction processing unit 2541 and a driving sound noise reduction processing unit 2542. The noise reduction processing unit 254 is a processing unit that performs signal processing on the frequency spectrums S301, S302, S303, S304, S305, S306,... Converted into the frequency domain by the Fourier transform unit 253. In the present embodiment, the noise reduction processing unit 254 is a processing unit that executes a noise reduction process that reduces drive sound and impact sound generated by the operation of the operation unit.

The noise reduction processing unit 254 acquires the frequency spectrum of the sound time signal acquired during a period when the operation unit is likely to operate based on the operation timing signal input from the operation timing detection unit 191. The noise reduction processing unit 254, for example, based on the operation timing signal input from the operation timing detection unit 191, all the frequency spectrums S302 to S302 corresponding to the impact sound period Tb and the drive sound period Tc output from the Fourier transform unit 253. S312 is acquired.
In the present embodiment, the noise reduction processing unit 254 is based on the operation timing signal. For example, there is a possibility that both the impact sound and the drive sound are generated from the period when the operation sound is highly likely to be generated. It is preferable to obtain a frequency spectrum by distinguishing between a high period (impact sound period Tb) and a period (drive sound period Tc) in which only drive sound is likely to be generated. Although details will be described later, the noise reduction processing unit 254 performs both the impact sound noise reduction process and the driving sound noise reduction process.
Specifically, the noise reduction processing unit 254 is based on the operation timing signal input from the operation timing detection unit 191, for example, the frequency spectrum S301, S302, S303, S304, S305, S306 output from the Fourier transform unit 253. ..., it is highly likely that both the frequency spectrum S305 to S308 corresponding to the period during which only the driving sound is likely to occur (impact sound period Tb) and both the impact sound and the driving sound are occurring. Frequency spectra S302 to S304 and S309 to S312 corresponding to the period (impact sound period Tc) are acquired.

That is, based on the operation timing signal, the noise reduction processing unit 254 determines a period in which there is a high possibility that an impact sound is occurring as the operation start timing period. And the noise reduction process part 254 acquires the frequency spectrum S302-S304 of the microphone sound signal acquired in this period as a frequency spectrum of the microphone sound signal containing both an impact sound and a drive sound.
In addition, the noise reduction processing unit 254 determines a period during which the impact sound is highly likely to be generated as the operation stop timing period based on the operation timing signal. And the noise reduction process part 254 acquires the frequency spectrum S309-S312 of the microphone sound signal acquired in this period as a frequency spectrum of the microphone sound signal containing both an impact sound and a drive sound.
Further, the noise reduction processing unit 254 determines, based on the operation timing signal, a period in which driving sound is likely to be generated as a period from the end point of the operation start timing period to the start point of the operation stop timing period. . And the noise reduction process part 254 acquires the frequency spectrum S305-S308 of the microphone sound signal acquired in this period as a frequency spectrum of the microphone sound signal containing a drive sound.

The noise reduction processing unit 254 performs noise reduction processing for reducing noise determined in advance according to the operation pattern for the acquired frequency spectra S302 to S312.
For example, the impact sound noise reduction processing unit 2541 of the noise reduction processing unit 254 has a frequency spectrum corresponding to the impact sound with respect to the frequency spectra S302 to S304 and S309 to S312 of the microphone sound signal including both the impact sound and the driving sound. The impact noise reduction process for reducing the noise is executed.
In addition, the driving sound noise reduction processing unit 2542 of the noise reduction processing unit 254 executes a driving sound reduction process for reducing the frequency spectrum corresponding to the driving sound with respect to the frequency spectrum S302 to S312 of the microphone sound signal including the operation sound. To do. The drive sound noise reduction processing unit 2542 generates drive sound for both the frequency spectrums S302 to S304 and S309 to S312 that have been subjected to the impact sound reduction process, and the frequency spectrum S305 to S308 of the microphone sound signal that includes only the drive sound. It is preferable to perform a reduction process. In the present embodiment, an example in which the drive sound noise reduction processing unit 2542 executes the drive sound reduction process on all frequency spectra S302 to S312 during operation including the frequency spectrum on which the impact sound reduction process has been performed will be described.

  The shock noise reduction processing unit 2541 is based on the timing signal input from the operation timing detection unit 191, for example, from the frequency spectrum S301, S302, S303, S304, S305, S306... Output from the Fourier transform unit 253. A frequency spectrum (hereinafter referred to as an impact sound processing frequency spectrum SS) corresponding to a period during which the impact sound is likely to be generated is acquired. For example, the impact sound noise reduction processing unit 2541 generates a frequency spectrum corresponding to a period in which an impact sound may be generated based on an operation timing signal indicating an impact sound generation period t10 to t11 corresponding to the operation start timing t10. S302 to S304 are acquired as the impact sound processing frequency spectrum SS. The impact sound noise reduction processing unit 2541 is based on the operation timing signal indicating the impact sound generation period t20 to t21 corresponding to the operation stop timing t20, and the frequency spectrum S309 to the frequency spectrum S309 to correspond to the period in which the impact sound may be generated. S312 is acquired as the impact sound processing frequency spectrum SS.

Further, the shock noise reduction processing unit 2541 is based on the frequency spectrum S301, S302, S303, S304, S305, S306... Output from the Fourier transform unit 253 based on the timing signal input from the operation timing detection unit 191. A frequency spectrum (hereinafter referred to as an impact sound flooring spectrum FS) corresponding to a period during which there is a high possibility that no impact sound is generated is acquired. The impact sound noise reduction processing unit 2541 obtains an impact sound flooring spectrum FS that is unlikely to include the impact sound for each impact sound processing frequency spectrum SS that is likely to include the impact sound. In the present embodiment, the impact sound noise reduction processing unit 2541 acquires a frequency spectrum other than the impact sound processing frequency spectrum SS closest to the impact sound processing frequency spectrum SS in the time axis direction as the impact sound flooring spectrum FS. That is, the impact sound noise reduction processing unit 2541 acquires a frequency spectrum other than the impact sound processing frequency spectrum SS adjacent to or overlapping the impact sound processing frequency spectrum SS in the time axis direction as the impact sound flooring spectrum FS.
In the present embodiment, the impact sound flooring spectrum FS is a frequency spectrum corresponding to a period in which there is a high possibility that no impact sound is generated. However, the present invention is not limited to this, and the impact sound flooring spectrum FS may be a frequency spectrum corresponding to a period during which an operation sound other than the impact sound (that is, a drive sound) is likely to be generated. . In addition, it is preferable that the impact sound flooring spectrum FS is a frequency spectrum corresponding to a period during which noise noise generated by the operation of the operation unit is highly unlikely to occur.

Here, an example of the relationship between the impact sound processing frequency spectrum SS and the impact sound flooring spectrum FS acquired by the impact sound noise reduction processing unit 2541 will be described with reference to FIG. FIG. 5 is a diagram for explaining an example of the impact sound processing frequency spectrum SS and the impact sound flooring spectrum FS acquired by the impact sound noise reduction processing unit 2541.
For example, the impact sound noise reduction processing unit 2541 converts the frequency spectrum S302 to S304 corresponding to the period during which the impact sound may be generated into the impact sound based on the operation timing signal indicating the impact sound generation period t10 to t11. Obtained as the processing frequency spectrum SS.
Then, the shock noise reduction processing unit 2541 is based on the operation timing signal indicating the shock sound generation periods t10 to t11, and the frequency corresponding to the non-operation period Ta closest to the frequency spectrums S302 and S303 which are the shock sound processing frequency spectrum SS. The spectrum S301 is determined as the impact sound flooring spectrum FS corresponding to the frequency spectra S302 and S303 which are the impact sound processing frequency spectrum SS.
Further, the impact sound noise reduction processing unit 2541 is based on the operation timing signal indicating the impact sound generation periods t10 to t11, and the frequency spectrum corresponding to the drive sound generation period Tc closest to the frequency spectrum S304 that is the impact sound processing frequency spectrum SS. S305 is determined as the impact sound flooring spectrum FS corresponding to the frequency spectrum S304 which is the impact sound processing frequency spectrum SS.

Further, the impact sound noise reduction processing unit 2541 converts the frequency spectrum S309 to S312 corresponding to the period during which the impact sound may be generated into the impact sound based on the operation timing signal indicating the impact sound generation period t20 to t21. Obtained as the processing frequency spectrum SS.
The impact sound noise reduction processing unit 2541 corresponds to the drive sound generation period Tc that is closest to the frequency spectrums S309 and S310, which are the impact sound processing frequency spectrum SS, based on the operation timing signal indicating the impact sound generation periods t20 to t21. The frequency spectrum S308 is determined as the impact sound flooring spectrum FS corresponding to the frequency spectra S309 and S310 which are the impact sound processing frequency spectrum SS.
Further, the impact sound noise reduction processing unit 2541 has a frequency corresponding to the non-operation period Ta closest to the frequency spectrums S311 and S312 which are the impact sound processing frequency spectrum SS, based on the operation timing signal indicating the impact sound generation period t20 to t21. The spectrum S313 is determined as the impact sound flooring spectrum FS corresponding to the frequency spectra S311 and S312 which are the impact sound processing frequency spectrum SS.

Furthermore, the impact sound noise reduction processing unit 2541 replaces at least a part of the impact sound processing frequency spectrum SS with a corresponding part of the impact sound flooring spectrum FS.
For example, the impact sound noise reduction processing unit 2541 includes a frequency spectrum that is greater than or equal to a predetermined threshold frequency in the impact sound processing frequency spectrum SS, and a frequency spectrum that is greater than or equal to a predetermined threshold frequency in the impact sound flooring spectrum FS. Are compared for each frequency component. When it is determined that the impact sound flooring spectrum FS is smaller than the impact sound processing frequency spectrum SS, the impact sound noise reduction processing unit 2541 converts the frequency component in the impact sound processing frequency spectrum SS to the impact sound floor. Replace with the frequency component of the ring spectrum FS.

This will be described in detail with reference to FIG. FIG. 6 is a diagram for explaining an example of frequency components of a part of the frequency spectrum. In the present embodiment, for convenience of explanation, among the microphone sound signals shown in FIG. S313 will be described.
As shown in FIG. 6, the frequency spectrums S301, S303, S305, S307, S311, and S313 each include frequency components f1 to f9.
For example, the impact sound noise reduction processing unit 2541 compares the impact sound processing frequency spectrum SS and the impact sound flooring spectrum FS in advance for the frequency components f3 to f9 as frequency components equal to or higher than the threshold frequency of each frequency spectrum. It has been decided. Therefore, the impact sound noise reduction processing unit 2541 does not compare the impact sound processing frequency spectrum SS and the impact sound flooring spectrum FS for the frequency components f1 and f2.

Next, with reference to FIG. 7, an example of impact sound noise reduction processing by the impact sound noise reduction processing unit 2541 will be described for the frequency spectra S301 and S303.
FIG. 7 is a diagram for explaining comparison of amplitude for each frequency component of the frequency spectra S301 and S303.
For example, the impact noise reduction processing unit 2541 compares the amplitude of the frequency component f3 of the frequency spectrum S301 with the amplitude of the frequency component f3 of the frequency spectrum S303. In this case, the amplitude of the frequency component f3 of the frequency spectrum S301 is smaller than the amplitude of the frequency component f3 of the frequency spectrum S303. Therefore, the impact sound noise reduction processing unit 2541 replaces the frequency component f3 of the frequency spectrum S303 with the frequency component f3 of the frequency spectrum S301.

Further, the impact sound noise reduction processing unit 2541 compares the amplitude of the frequency component f4 of the frequency spectrum S301 with the amplitude of the frequency component f4 of the frequency spectrum S303. In this case, the amplitude of the frequency component f4 of the frequency spectrum S301 is larger than the amplitude of the frequency component f4 of the frequency spectrum S303. Therefore, the impact sound noise reduction processing unit 2541 does not replace the frequency component f3 of the frequency spectrum S303 with the frequency component f3 of the frequency spectrum S301.
In this way, the impact sound noise reduction processing unit 2541 converts the frequency component of the frequency spectrum S303 into the frequency spectrum only when the amplitude of the frequency component of the frequency spectrum S301 is smaller than the amplitude of the frequency component of the frequency spectrum S303. Replace with the frequency component of S301.
In the case illustrated in FIG. 7, the impact noise reduction processing unit 2541 replaces the frequency components f3 and f6 to f9 of the frequency spectrum S303 with the frequency components f3 and f6 to f9 of the frequency spectrum S301.

  The drive sound noise reduction processing unit 2542 is based on the timing signal input from the operation timing detection unit 191, for example, from the frequency spectrum S301, S302, S303, S304, S305, S306... Output from the Fourier transform unit 253. A frequency spectrum (hereinafter referred to as a driving sound processing frequency spectrum KS) corresponding to a period during which driving sound is likely to be generated is acquired. For example, the drive sound noise reduction processing unit 2542 includes an operation timing signal indicating an impact sound generation period t10 to t11 corresponding to the operation start timing t10 and an operation timing signal indicating an impact sound generation period t20 to t21 corresponding to the operation stop timing t20. Based on the above, the frequency spectrums S302 to S312 corresponding to the period in which the driving sound may be generated are acquired as the driving sound processing frequency spectrum KS.

  The drive sound noise reduction processing unit 2542 performs drive sound noise reduction processing for reducing noise determined in advance according to the drive pattern, on the acquired drive sound processing frequency spectrum KS. For example, the drive sound noise reduction processing unit 2542 uses a frequency spectrum subtraction method in which a frequency component of a frequency spectrum representing noise determined in advance according to a drive pattern is subtracted from the frequency component of the drive sound processing frequency spectrum KS. Note that the frequency spectrum of noise determined in advance according to the drive pattern is preset in the drive sound noise reduction processing unit 2542 as a set value. However, the present invention is not limited to this, and the drive sound noise reduction processing unit 2542 calculates a frequency spectrum of a frame where no drive sound is generated from a frequency spectrum of a frame where the drive sound is generated based on the past microphone sound signal. By subtracting, the frequency spectrum of the noise of the estimated driving sound (hereinafter referred to as the estimated noise spectrum) may be calculated for each driving pattern.

  Hereinafter, the frequency spectrum after the signal processing by the noise reduction processing unit 254 is referred to as S401, S402, S403, S404, S405, S406. That is, the noise reduction processing unit 254 performs the frequency spectrum S401, S402, S403, S404, S405, S406,..., Which is a processing result obtained by performing signal processing on the input frequency spectrum S301, S302, S303, S304, S305, S306. Is output to the inverse Fourier transform unit 255.

The inverse Fourier transform unit 255 performs, for example, an inverse Fourier transform or an inverse fast Fourier transform (IFFT :) on the frequency spectrums S401, S402, S403, S404, S405, S406... Processed by the noise reduction processing unit 254. Inverse Fast Fourier Transform) is performed to convert to the time domain.
Note that the sound time signals converted into the time domain by the inverse Fourier transform unit 255 are hereinafter referred to as S501, S502, S503, S504, S505, S506,. That is, the inverse Fourier transform unit 255 converts the input frequency spectrum S401, S402, S403, S404, S405, S406... Into sound time signals S501, S502, S503, S504, S505, S506. And output to the connection adjustment unit 256.

Coupling adjusting unit 256 multiplies the inverse Fourier transform unit sound time signal S501 input from 255, S502, S503, S504, S505, S506 coupling adjustment window function _{W 3} each of .... Incidentally, the sound time signal weighted with coupling adjusting window function _{W 3} by connecting adjuster 256, hereinafter referred to as S601, S602, S603, S604, S605, S606 ···.
In the present embodiment, the connection adjusting unit 256 uses the connection adjustment window function W ₃ = Hanning window function W ₂ / Humming window function W ₁ shown in the following formula (2) as the sound time signals S501, S502, S503, S504. Multiply each of S505, S506. In Equation (2), the window range is 0 to T, and the variable is indicated by time t (0 ≦ t ≦ T).

Incidentally, Hanning window function _{W 2} is shown in the following equation (3). In Expression (3), the window range is 0 to T, and the variable is indicated by time t (0 ≦ t ≦ T).

  Based on the sound time signals S601, S602, S603, S604, S605, S606,... Input from the connection adjusting unit 256, the signal superimposing unit 257 is connected in accordance with the arrangement of the original microphone sound signals. In the present embodiment, the microphone sound signal is cut out in units of frames by the sound signal cutout unit 251 so that the odd-numbered and even-numbered sound time signals overlap each other in half. Therefore, the signal superimposing unit 257 superimposes the sound time signals S601, S602, S603, S604, S605, S606... So that the sound time signals with odd numbers and even numbers are overlapped by half. Connect.

  The signal superimposing unit 257 causes the storage medium 200 to store sound information obtained by connecting the sound time signals S601, S602, S603, S604, S605, S606. Note that the signal superimposing unit 257 may store the connected sound information and the image data captured by the image sensor 119 in the storage medium 200 in association with each other having corresponding date and time information. You may memorize | store as a moving image containing sound information.

Next, an example of a sound time signal processed by the reduction processing unit 250 according to the present embodiment will be described with reference to FIGS.
Figure 8 is a diagram showing an example of a Hamming window function W _1. 9 is a diagram showing an example of a Hanning window function W _2. Further, FIG. 10 is a diagram showing an example of the connection adjustment window function W _3.
As shown in FIG. 8, Hamming window function W ₁ is smaller values at both ends of the window than the center value, and the ends of the window is larger window function than 0 (zero).
On the other hand, Hanning window function W _2, as shown in FIG. 9, the values at both ends of the window is smaller than the center value, and a window function both ends of the window is 0 (zero).
The coupling adjustment window function W ₃ being as shown in FIG. 10, the values of both ends of the window is smaller than the center value, and a window function both ends of the window is 0 (zero). Note that near the center of the coupling adjustment window function W ₃ being compared to Hamming window function W ₁ or Hanning window function W _2, a value close to 1.

FIG. 11 is a diagram illustrating an example of a microphone sound signal input to the reduction processing unit 250. FIG. 11 shows only portions corresponding to the frames F101 to F103.
FIG. 12 shows an example of the sound time signal S103 corresponding to the frame F103 cut out by the sound signal cutout unit 251. As shown in FIG. 12, the sound time signal corresponding to the frame F103 includes an impact sound.
Figure 13 shows an example of the sound time signal S203 obtained by multiplying the Hamming window function _{W 1} to the sound time signal S103 by a Hamming windowing unit 252. As shown in FIG. 13, both ends of the sound time signal S203 are smaller than both ends of the sound time signal S103 shown in FIG. 12, but the values at both ends are not 0 (zero).
FIG. 14 shows an example of the sound time signal S603 after the noise reduction processing is performed by the noise reduction processing unit 254. That is, FIG. 14 shows an example of the sound time signal S603 obtained by multiplying the consolidation adjustment window function W ₃ in the sound time signal S503 obtained by converting the frequency spectrum S403 that the noise reduction processing has been performed in the time domain. FIG. 15 is an enlarged view showing a portion corresponding to the end of the window of the sound time signal S603 shown in FIG.
As shown in FIGS. 14 and 15, the sound time signal S603 has a reduced impact sound (or drive sound), and both ends of the window of the sound time signal S603 are 0 (zero).

FIG. 16 is a diagram illustrating sound information obtained by connecting the sound time signals S601, S602, and S603 by the signal superimposing unit 257. FIG. 17 is an enlarged view in which the joint between the sound time signals S601 and S603 is enlarged. As shown in FIGS. 16 and 17, the joint between the sound time signals S601 and S603 is in a continuous state. As shown in FIGS. 14 and 15, the frequency spectrum subjected to the noise reduction processing by the noise reduction processing unit 254 is converted into the time domain and then multiplied by the connection adjustment window function W _3. This is because the values at both ends of the sound time signal window become 0 (zero).
In this way, by multiplying the sound time signal subjected to noise reduction by the window function having both ends of 0 (zero), the values at both ends of the sound time signal window can be set to 0 (zero). . Therefore, since the joint value of the sound time signals matches with 0 (zero), noise that may occur due to the sound skipping due to the different joint value can be reduced.

Further, the reduction processing unit 250 according to the present embodiment performs a Hamming window function W _{1 on} the sound time signals S101, S102, S103, S104, S105, S106,... Before being converted into a frequency spectrum by the Fourier transform unit 253. Is multiplied. The Hamming window function W ₁ has a feature that the side lobe is smaller than the Hanning window function W ₂ . More specifically, the side lobes of the Hamming window function _{W 1} whereas a -43 dB, the side lobes of the Hanning window function _{W 2} is -32 dB. Therefore, by signal processing in the frequency domain after weighted Hamming window function W _1, the noise reduction processing section 254, it becomes easy to separate the frequency components approaching included in the processing target sound. Therefore, there is an advantage that the processing effect of the noise reduction processing unit 254 can be improved.

Next, an example not according to the present embodiment will be described with reference to FIGS.
Figure 18 shows an example of a Hanning window function _W sound ₂ is multiplied times the signal S1203 to the sound time signal S103. As shown in FIG. 18, the values at both ends of the window of the sound time signal S1203 are smaller than both ends of the window of the sound time signal S103 and become 0 (zero).
FIG. 19 shows an example of a sound time signal subjected to noise reduction processing. That is, FIG. 19 shows an example of a sound time signal S1503 obtained by converting the frequency spectrum S1403 subjected to noise reduction processing into the time domain. The frequency spectrum S1403 is a frequency spectrum obtained by performing noise reduction processing on the frequency spectrum S1303 obtained by converting the sound time signal S1203 into the frequency domain.
FIG. 20 is an enlarged view showing a portion corresponding to the end of the window of the sound time signal S1503 shown in FIG.
As shown in FIGS. 19 and 20, the sound time signal S1503 has reduced impact sound (or drive sound), but the values at both ends of the window of the sound time signal S1503 are not 0 (zero). In the examples shown in FIGS. 19 and 20, the value at the left end of the sound time signal S1503 is 0.01.

Here, the reason why the values at both ends of the sound time signal S1503 are not 0 (zero) will be described.
The main frequency spectrum included in the sound time signal S103 before the reduction process is a cosine component of 8 periods in the frame F103. In addition, the sound time signal S103 includes the frequency spectrum of the impact sound.
That is, the frequency spectrum of the sound time signal S103 to the Hanning window function W ₂ sound time signal S1203 multiplied by the plus the effect of the Hanning window function W ₂ into a frequency spectrum including the cos component and the impact sound of the 8 cycles is there. In this state, the values at both ends of the sound time signal S1203 are 0 (zero). This is because the sound time signal S1203 includes a plurality of frequency components whose values at both ends of the cos component, which is the main frequency spectrum, are 0 (zero), and cancels out with the cos component.
However, when the impact sound is removed by the noise reduction processing, the frequency spectrum derived from the impact sound is removed, the balance cancelled with the cos component is lost, and the values at both ends are not 0 (zero).
For this reason, the values at both ends of the window of the sound time signal S1503 after the noise reduction processing are not 0 (zero).

FIG. 21 is a diagram showing sound information obtained by connecting sound time signals obtained by converting the frequency spectrum after noise reduction processing into the time domain. More specifically, FIG. 21 shows sound information in which the sound time signal S1503 shown in FIGS. 19 and 20 is connected to the sound time signal S1501 adjacent to the sound time signal S1503 and the sound time signal S1502 is superimposed. .
FIG. 22 is an enlarged view in which the joint between the sound time signals S1501 and S1503 is enlarged. As shown in FIGS. 21 and 22, the joint between the sound time signals S1501 and S1503 is not continuous. This is because, as shown in FIGS. 19 and 20, when not according to the present invention, the frequency spectrum S1401 after the noise reduction process, S1402, with respect to S1403 · · ·, without consolidation adjustment window function _{W 3} is multiplied This is because the frequency spectra S1401, S1402, S1403,... Are converted into sound time signals S1501, S1502, S1503,.
Thus, when the values at both ends of the window of the sound time signal after the noise reduction processing are not 0 (zero), the joints of the sound time signals do not match. Therefore, the sound skips due to the different values of the joints, and noise may occur. The present invention solves this problem.

Next, an example of the noise reduction processing method according to the present embodiment will be described with reference to FIG. FIG. 23 is a flowchart illustrating an example of the noise reduction processing method according to the present embodiment.
For example, when the power switch of the operation unit 180 is turned on, the imaging apparatus 100 is powered on, and power is supplied from the battery 260 to each component. In the present embodiment, it is set in advance for the image capturing apparatus 100 to store image data and sound data at the time of image capturing in association with each other in the storage medium 200.

(Step ST1)
For example, when the moving image shooting button is turned on, the microphone 230 outputs the collected microphone sound signal to the A / D conversion unit 240. The A / D converter 240 outputs the microphone sound signal obtained by digitally converting the microphone sound signal, which is an analog signal, to the reduction processing unit 250.
The reduction processing unit 250 inputs the microphone sound signal from the A / D conversion unit 240.

Here, it is assumed that the release button of the operation unit 180 is pressed by the user, for example. In this case, the lens CPU 120 outputs, to the lens driving unit 116 and the operation timing detection unit 191, a command for executing an AF process for focusing at a distance P in the AF process, for example.
The lens driving unit 116 moves the AF lens 112 according to a driving pattern for focusing at a distance P based on an input command. For example, the lens driving unit 116 rotates the driving mechanism of the AF lens 112 by a predetermined amount clockwise to move the AF lens 112 along the optical axis. Note that the rotation amount and speed for rotating the drive mechanism are determined in advance as a drive pattern for focusing at the distance P.
When the AF lens 112 moves, the AF encoder 117 outputs a pulse signal to the body CPU 190. The body CPU 190 outputs information indicating that the pulse signal is input from the AF encoder 117 to the operation timing detection unit 191. When the AF lens 112 that has moved stops, the AF encoder 117 stops outputting the pulse signal to the body CPU 190. The body CPU 190 outputs information indicating that the output of the pulse signal from the AF encoder 117 is stopped to the operation timing detection unit 191.

The operation timing detection unit 191 generates an operation timing signal according to a driving pattern for focusing at a distance P based on an input command and an output of the AF encoder 117, and outputs the operation timing signal to the reduction processing unit 250.
For example, when a command for executing an AF process for focusing at a distance P is input from the lens CPU 120, the operation timing detection unit 191 has an impact sound generation period (operation start timing) corresponding to the operation start timing t 10 of the AF lens 112. Period) An operation start timing signal indicating t10 to t11 is generated and output to the reduction processing unit 250.
When the pulse signal input from the AF encoder 117 is stopped, the operation timing detection unit 191 performs an operation indicating an impact sound generation period (operation start timing period) t20 to t21 corresponding to the operation stop timing t20 of the AF lens 112. A stop timing signal is generated and output to the reduction processing unit 250.

(Step ST2)
The reduction processing unit 250 determines whether or not an operation timing signal is input from the operation timing detection unit 191.
(Step ST3)
When the operation timing signal is input, the reduction processing unit 250 performs noise reduction processing based on the frequency spectrum obtained by converting the input microphone sound signal into the frequency domain.
More specifically, the sound signal cutout unit 251 of the reduction processing unit 250 divides the microphone sound signal into frames having a predetermined time length, and the sound time signals S101, S102, S103, S104, S105, in units of frames. S106... Are output to the Hamming window processing unit 252.
Hamming window processing unit 252, a sound inputting time signal S101, S102, S103, S104, S105, S106 multiplies the Hamming window function _{W 1} to each .... The Hamming window processing unit 252, a Hamming window function _{W 1} sound time signal weighted in S201, S202, S203, S204, S205, S206 and ..., and outputs the Fourier transform unit 253.
The Fourier transform unit 253 then converts the input sound time signals S201, S202, S203, S204, S205, S206... Into frequency spectra S301, S302, S303, S304, S305, S306. The data is converted and output to the noise reduction processing unit 254.

(Step ST4)
Next, the impact sound noise reduction processing unit 2541 performs impact sound noise reduction processing on the frequency spectra S301, S302, S303, S304, S305, S306,... Input from the Fourier transform unit 253.
For example, the impact sound noise reduction processing unit 2541 generates a frequency spectrum corresponding to a period in which an impact sound may be generated based on an operation timing signal indicating an impact sound generation period t10 to t11 corresponding to the operation start timing t10. S302 to S304 are acquired as the impact sound processing frequency spectrum SS.
The impact sound noise reduction processing unit 2541 then performs impact corresponding to the frequency spectrums S302 and S303, which are the impact sound processing frequency spectrum SS, based on the operation timing signal indicating the impact sound generation period t10 to t11 corresponding to the operation start timing t10. As the sound flooring spectrum FS, the frequency spectrum S301 immediately before the frequency spectra S302 and 303 is acquired. Moreover, the impact sound noise reduction processing unit 2541 is based on the operation timing signal indicating the impact sound generation period t10 to t11 corresponding to the operation start timing t10, and the impact sound floor corresponding to the frequency spectrum S304 which is the impact sound processing frequency spectrum SS. A frequency spectrum S305 immediately after the frequency spectrum S304 is acquired as the ring spectrum FS.

Also, the impact sound noise reduction processing unit 2541 has a frequency spectrum corresponding to a period in which the impact sound may be generated based on the operation timing signal indicating the impact sound generation period t20 to t21 corresponding to the operation stop timing t20. S309 to S312 are acquired as the impact sound processing frequency spectrum SS.
The shock noise reduction processing unit 2541 then performs shocks corresponding to the frequency spectra S309 and S310 that are the shock sound processing frequency spectrum SS based on the operation timing signal indicating the shock sound generation period t20 to t21 corresponding to the operation stop timing t20. As the sound flooring spectrum FS, the frequency spectrum S308 immediately before the frequency spectra S309 and S310 is acquired. Further, the impact sound noise reduction processing unit 2541 performs the impact corresponding to the frequency spectrums S311 and S312 which are the impact sound processing frequency spectrum SS based on the operation timing signal indicating the impact sound generation period t20 to t21 corresponding to the operation start timing t20. As the sound flooring spectrum FS, the frequency spectrum S313 immediately after the frequency spectra S311 and S312 is acquired.

(Step ST5)
Next, the impact sound noise reduction processing unit 2541 compares the impact sound processing frequency spectrum SS and the impact sound flooring spectrum FS for the frequency components f3 to f9 as frequency components equal to or higher than the threshold frequency of each frequency spectrum.
For example, the impact noise reduction processing unit 2541 compares the amplitude of the frequency component f3 of the frequency spectrum S301 with the amplitude of the frequency component f3 of the frequency spectrum S302. In this case, the amplitude of the frequency component f3 of the frequency spectrum S301 is smaller than the amplitude of the frequency component f3 of the frequency spectrum S302. Therefore, the impact sound noise reduction processing unit 2541 replaces the frequency component f3 of the frequency spectrum S303 with the frequency component f3 of the frequency spectrum S301.
Further, the impact sound noise reduction processing unit 2541 compares the amplitude of the frequency component f4 of the frequency spectrum S301 with the amplitude of the frequency component f4 of the frequency spectrum S303. In this case, the amplitude of the frequency component f4 of the frequency spectrum S301 is larger than the amplitude of the frequency component f4 of the frequency spectrum S303. Therefore, the impact sound noise reduction processing unit 2541 does not replace the frequency component f4 of the frequency spectrum S303 with the frequency component f4 of the frequency spectrum S301.
In this way, the impact sound noise reduction processing unit 2541 converts the frequency component of the frequency spectrum S303 into the frequency spectrum only when the amplitude of the frequency component of the frequency spectrum S301 is smaller than the amplitude of the frequency component of the frequency spectrum S303. Replace with the frequency component of S301.
Then, the shock noise reduction processing unit 2541 replaces the frequency components f3 and f6 to f9 of the frequency spectrum S303 with the frequency components f3 and f6 to f9 of the frequency spectrum S301, and the frequency after the shock noise reduction processing. The spectrum S ′ 303 is output to the drive sound noise reduction processing unit 2542.

  Similarly, the impact sound noise reduction processing unit 2541 compares the frequency spectrum S2 that is the impact sound processing frequency spectrum SS with the frequency spectrum S1 that is the impact sound flooring spectrum FS, and the frequency that is the impact sound processing frequency spectrum SS. The spectrum S304 is compared with the frequency spectrum S305 which is the impact sound flooring spectrum FS. Only when the amplitude of the frequency component of the second frequency spectrum S301, S305 is smaller than the amplitude of the frequency component of the frequency spectrum S302, S304, respectively, the frequency component of the frequency spectrum S302, S304 is set to the frequency spectrum S301, respectively. The frequency spectrums S ′ 302 and S ′ 304 after the impact noise reduction processing are output to the drive sound noise reduction processing unit 2542 instead of the frequency components of S 305.

  Similarly, the impact sound noise reduction processing unit 2541 compares the frequency spectrums S309 and S310 which are the impact sound processing frequency spectrum SS with the frequency spectrum S308 which is the impact sound flooring spectrum FS, and the impact sound processing frequency spectrum. A comparison is made between the frequency spectrums S311 and S312 which are SS and the frequency spectrum S313 which is the impact sound flooring spectrum FS. And only when the amplitude of the frequency component of the frequency spectrum S308 which is the impact sound flooring spectrum FS is smaller than the amplitude of the frequency component of the frequency spectrum S309, S310, the frequency component of the frequency spectrum S309, S310 is obtained. The frequency spectra S ′ 309 and S ′ 310 after the impact sound noise reduction processing are output to the drive sound noise reduction processing unit 2542 by replacing each with the frequency component of the frequency spectrum S 308. Similarly, only when the amplitude of the frequency component of the frequency spectrum S313 which is the impact sound flooring spectrum FS is smaller than the amplitude of the frequency component of the frequency spectrum S311 and S312 respectively, the frequency of the frequency spectrum S311 and S312. The components are replaced with the frequency components of the frequency spectrum S313, respectively, and the frequency spectra S′311 and S′312 after the impact noise reduction processing are output to the drive noise reduction processing unit 2542.

(Step ST6)
Next, the driving sound noise reduction processing unit 2542 is based on the frequency spectrum of the microphone sound signal input from the Fourier transform unit 253 and the frequency spectrum after the impact sound noise reduction processing input from the impact sound noise reduction processing unit 2541. Perform noise reduction processing. For example, the drive sound noise reduction processing unit 2542 includes an operation timing signal indicating an impact sound generation period t10 to t11 corresponding to the operation start timing t10 and an operation timing signal indicating an impact sound generation period t20 to t21 corresponding to the operation stop timing t20. Based on the above, the frequency spectrums S302 to S312 corresponding to the period in which the driving sound may be generated are acquired as the driving sound processing frequency spectrum KS.
The drive sound noise reduction processing unit 2542 selects a frequency spectrum corresponding to the frequency spectrum after the impact sound noise reduction process from among the frequency spectra S302 to S312 which are the acquired drive sound processing frequency spectrum KS as S302 to S304 and S309 to S312. Is replaced with the frequency spectrum S′302, S′303, S′304, S′309, S′310, S′311 and S′312 after the impact noise reduction processing.
Then, the drive sound noise reduction processing unit 2542 has frequency frequencies S′302, S′303, S′304, S′309, S′310, S′311 and S′312 after the impact sound noise reduction processing, and the frequency Drive noise reduction processing is executed for the spectra S305 to S307. In other words, the drive sound noise reduction processing unit 2542 uses the frequency spectrum of the frequency spectrum representing noise determined in advance according to the drive pattern as the frequency spectrum S ′ that is the drive sound processing frequency spectrum KS after the impact sound noise reduction process. Subtraction is performed from the frequency components of 302 to S′304, S305 to 307, and S′309 to S′312. The drive sound noise reduction processing unit 2542 outputs the frequency spectrums S401, S402, S403, S404, S405, S406... After the drive sound noise reduction processing to the inverse Fourier transform unit 255.

(Step ST7)
The inverse Fourier transform unit 255 performs, for example, an inverse Fourier transform on the frequency spectrums S401, S402, S403, S404, S405, S406... After the drive sound noise reduction processing that has been signal-processed by the noise reduction processing unit 254. In this way, the time domain is converted. The inverse Fourier transform unit 255 outputs the sound time signals S501, S502, S503, S504, S505, S506,... Converted to the time domain to the connection adjustment unit 256.

(Step ST8)
Coupling adjusting unit 256 multiplies the inverse Fourier transform unit sound time signal S501 input from 255, S502, S503, S504, S505, S506 coupling adjustment window function _{W 3} each of .... The connection adjustment unit 256 coupled adjustment window function _{W 3} sound time signal weighted in S601, S602, S603, S604, S605, S606 and outputs a ... a signal superposition section 257.

  Based on the sound time signals S601, S602, S603, S604, S605, S606,... Input from the connection adjusting unit 256, the signal superimposing unit 257 is connected in accordance with the arrangement of the original microphone sound signals. Then, the signal superposition unit 257 causes the storage medium 200 to store sound information obtained by connecting the sound time signals S601, S602, S603, S604, S605, S606.

  As described above, the imaging apparatus 100 according to the present embodiment can detect the timing at which the operation state of the operation unit changes by the operation timing detection unit 191 and can superimpose an impact sound based on this timing signal. The impact sound noise reduction processing is performed in which a part of the frequency spectrum of the characteristic microphone sound signal is replaced with a part of the frequency spectrum of the microphone sound signal that may not have the impact sound superimposed thereon. Thereby, even if the impact sound has a wide frequency spectrum band, the discontinuity of the target sound is not noticeable, and sound information with reduced impact sound can be acquired.

[Other examples of window functions]
In addition, the reduction process part 250 which concerns on this invention is not restricted to the above-mentioned embodiment, For example, a window function as demonstrated below can be used.
For example, when the Hamming window processing unit 252 uses the Hamming window function W ₁ as a window function, the connection adjustment unit 256 converts the connection adjustment window function W ₃ = Hanning window function W ₂ / Humming window function W ₁ to a sound time signal. Although the example of multiplying each of S501, S502, S503, S504, S505, S506... Has been described, a window function other than this may be multiplied. For example, the connection adjustment unit 256 generates a connection adjustment window function W ₅ = window function W ₄ / Humming window function W ₁ with a window function W ₄ as a numerator as shown in FIG. 24, and the sound time signals S501, S502, S503. , S504, S505, S506,...
Note that the window function _{W 4} are shown in the following equation (4). The coupling adjustment window function _{W 5} are shown in the following equation (5). In Expressions (4) and (5), the window range is 0 to T, and the variable is indicated by time t (0 ≦ t ≦ T).

As in the present embodiment, a Hamming window processing unit 252, the sound time signal S101 to be input, S102, S103, S104, S105, S106 when multiplying the Hamming window function _{W 1} in., Coupling of the coupling adjusting unit 256 the adjustment window function, the value of both ends of the window can be utilized Hamming window function W ₁ across the value smaller than the window function W _{4 (Hamming} window function W _1> window function W _4). Thus, coupling adjuster 256 sound time signal S501, S502, S503, S504, S505, S506 the value of the both ends of the connection adjustment window function _{W 5} for multiplying each ... may be less than 1. The coupling adjusting unit 256 may multiply the coupling adjustment window function _{W 5} values at both ends is less than the center sound time signal S501, S502, S503, S504, S505, S506 to each .... Accordingly, by coupling adjusting unit 256 multiplies the coupling adjustment window function _{W 5,} the sound time signal S601, S602, is S603, S604, S605, S606 joint between ... it is reduced to be a discontinuous it can. As shown in FIG. 25, the connection adjustment window function W ₅ = window function W ₄ / Humming window function W ₁ is 0.5, which is smaller than 1 at both ends of the window.

  As described above, the connection adjustment window function preferably has a value at both ends of the window of 0 (zero), but at least if the window function has a value at both ends of the window that is smaller than the central value. Good. Thereby, it can reduce that a joint becomes discontinuous and can reduce the noise which may arise in a joint.

The Hamming window processing unit 252 is not limited to the Hamming window function W _1, and the sound time signals S 101, S 102, S 103, S 104, S 105, which are input with window functions whose values at both ends of the window are smaller than the center values. S106... Can be multiplied. For example, the Hamming window processing unit 252 is a sound that inputs a Blackman-Harris window function, a Black-Natole window function, a flat-top window function, a Tukey window function, a Ranchos window function, a triangular window function, a Gauss window function, and the like. The time signal can be multiplied.
In this case, the window function of the denominator of the connection adjustment window function that the connection adjustment unit 256 multiplies to the sound time signals S501, S502, S503, S504, S505, S506. Preferably, 252 matches the window function to multiply. Further, the window function of the numerator of the connection adjustment window function that the connection adjustment unit 256 multiplies each of the sound time signals S501, S502, S503, S504, S505, S506,. It is preferable that the window function is smaller than the values at both ends. Thereby, the value of the both ends of a connection adjustment window function can be made smaller than one. Further, the connection adjustment unit 256 can multiply the sound time signals S501, S502, S503, S504, S505, S506,... By a connection adjustment window function whose values at both ends are smaller than those at the center. Thereby, it can reduce that a joint becomes discontinuous and can reduce the noise which may arise in a joint.

[An example of a window function where the overlapping range is 1/4 of the window]
Further, Hamming window processing unit 252, a window function _{W 7} as shown in FIG. 27, a sound inputting time signal S101, S102, S103, S104, S105, S106 may be configured to multiply the .... The window function _{W 7} is represented by the following formula (7-1) to (7-3). In Expressions (7-1) to (7-3), the window range is 0 to T, and the variable is indicated by time t (0 ≦ t ≦ T).

Formula (7-1) as shown to (7-3), the window function _{W 7} is in the range of both ends of the window (0 ≦ t ≦ T / 4,3T / 4 ≦ t ≦ T) Hamming window _{W 1} And a function in which the central range of the window (T / 4 ≦ t ≦ 3T / 4) becomes flat.

In this case, the connection adjustment unit 256 multiplies the sound time signals S501, S502, S503, S504, S505, S506,... By the connection adjustment window function W ₈ = window function W ₆ / window function W ₇ . An example of the window function _{W 6,} shown in Figure 26. An example of a coupling adjustment window function W _8, shown in Figure 28.
Further, the window function _{W 6} being represented by formula (6-1) to (6-3). Coupling adjustment window function W ₈ is expressed by the following equation (8). In Expressions (6-1) to (6-3) and Expression (8), the window range is 0 to T, and the variable is indicated by time t (0 ≦ t ≦ T).

As shown in the equations (6-1) to (6-3), the window function W ₆ has a range of both ends of the window (0 ≦ t ≦ T / 4, 3T / 4 ≦ t ≦ T). ₂ is a function in which the central range (T / 4 ≦ t ≦ 3T / 4) of the window is flat.
In the present embodiment, by using the window function W ₆ and the window function W ₇ , the overlapping range of the sound time signals can be ¼ of the window. In this way, by using a window function in which the central range of the window is flat (= 1), it is possible to reduce the overlapping region and reduce the Fourier transform calculation frame.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. FIG. 29 is a diagram for explaining an example of the signal processing device 500 including the reduction processing unit 250 according to the first embodiment.
The signal processing device 500 includes a reduction processing unit 250. As the signal processing device 500, for example, a personal computer, a smartphone, a tablet terminal, or the like can be used.

In this case, the imaging apparatus 100 stores the microphone sound signal collected by the microphone 230 and the operation timing signal output from the operation timing detection unit 191 in the storage unit 160 or the storage medium 200 in association with each other. Note that the imaging apparatus 100 includes an operation timing signal indicating an operation timing generated during a period in which the microphone sound signal is picked up according to the time at which the microphone sound signal is picked up based on the date and time information timed by the time measuring unit 220. The microphone sound signal can be associated with each other.
More specifically, the A / D conversion unit 240 is a microphone sound signal picked up by the microphone 230 and information indicating the timing at which the operation unit provided in the device that recorded the microphone sound signal operates (for example, Are stored in the storage unit 160 or the storage medium 200 in association with each other. In this case, the microphone sound signal and the timing information (operation timing signal) stored in association with each other may be written in the same file, or the files are written in separate files. May be associated according to the time of the information collected and the time of the information indicating the timing.

When the imaging device 100 and the signal processing device 500 are connected via the communication unit 170 and the communication unit 570, the microphone sound signals stored in the storage unit 160 and the storage medium 200 are stored in association with each other. Information indicating the timing (operation timing signal) is output to the reduction processing unit 250 mounted on the signal processing device 500.
Thereby, the reduction processing unit 250 can perform noise reduction processing outside the imaging apparatus 100.

As described above, in the first embodiment, the example in which the reduction processing unit 250 performs signal processing on the microphone sound signal collected by the microphone 230 has been described. However, the reduction processing unit 250 according to the present embodiment is The present invention is not applied only to such microphone sound signals collected in real time.
By executing the noise reduction processing also outside the imaging apparatus 100, it is possible to reduce processing load such as imaging processing of the imaging apparatus. In addition, since the noise reduction process can be executed at an arbitrary time desired by the user, the power consumption of the imaging apparatus 100 due to the imaging apparatus 100 executing the noise reduction process can be suppressed. Therefore, it is possible to reduce power consumption of the imaging apparatus 100 when away from home.

  A program for realizing the procedure by the imaging device 100, the reduction processing unit 250, etc. is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. Execution processing may be performed. Here, the “computer system” may include hardware such as an OS (Operating System) and peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic) in a computer system which becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above.
Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 100 ... Imaging device, 110 ... Imaging part, 120 ... Lens CPU, 130 ... Buffer memory, 140 ... Image processing part, 150 ... Display part, 160 ... Memory | storage part, 170 ... Communication part, 180 ... Operation part, 190 ... Body CPU , 220 ... Timekeeping section, 230 ... Microphone, 240 ... A / D conversion section, 250 ... Reduction processing section, 251 ... Sound signal cutout section, 252 ... Hamming window processing section (window processing section), 253 ... Fourier transform section, 254 ... Noise reduction processing unit, 255 ... Inverse Fourier transform unit, 256 ... Connection adjustment unit, 257 ... Sound signal superposition unit, 260 ... Battery, 191 ... Operation timing detection unit, 2541 ... Impact noise reduction processing unit, 2542 ... Drive Sound noise reduction processing section

Claims (10)

A conversion unit that converts an input sound signal into a frequency spectrum in the frequency domain;
A processing unit that performs signal processing on the frequency spectrum converted by the conversion unit;
An inverse conversion unit that converts the frequency spectrum signal-processed by the processing unit into a sound time signal in a time domain;
A connection adjustment unit that multiplies the sound time signal converted by the inverse conversion unit with a window function in which values at both ends in the unit interval are smaller than a central value;
A signal processing apparatus comprising: The connection adjusting unit is
The signal processing apparatus according to claim 1, wherein the sound time signal converted by the inverse conversion unit is multiplied by a window function whose values at both ends in the unit interval are zero. The connection adjusting unit is
The signal processing apparatus according to claim 1, wherein the sound time signal converted by the inverse conversion unit is multiplied by a Hanning window function.   4. The window processing unit according to claim 1, further comprising a window processing unit that multiplies the sound signal input to the conversion unit by a window function in which values at both ends in a unit interval are smaller than a center value. The signal processing device according to item. The window processing unit
Multiplying the sound time signal input to the converter by a Hamming window function,
The connection adjusting unit is
The signal processing apparatus according to claim 4, wherein the sound time signal converted by the inverse conversion unit is multiplied by a Hanning window function / Hamming window function. The window processing unit
Multiplying the sound time signal input to the converter by a window function W _{7 represented} by the following equation:

The connection adjusting unit is
A window function W _{8 represented} by the following expression is applied to the sound time signal converted by the inverse conversion unit.

The signal processing device according to claim 4, wherein A sound signal cutout unit that cuts out a sound time signal in units of frames by dividing a sound signal to be input into frames of a predetermined time length;
A window processing unit that multiplies the sound time signal cut out by the sound signal cut-out unit by a first window function in which values at both ends in a unit interval are smaller than a central value;
A conversion unit that converts a sound time signal multiplied by the first window function by the window processing unit into a frequency spectrum in a frequency domain;
A processing unit that performs signal processing on the frequency spectrum converted by the conversion unit;
An inverse conversion unit that converts the frequency spectrum signal-processed by the processing unit into a sound time signal in a time domain;
A connection adjustment unit that multiplies the sound time signal converted by the inverse conversion unit with a window function in which values at both ends in the unit interval are smaller than a central value;
A signal processing apparatus comprising:   An image pickup apparatus comprising the signal processing apparatus according to any one of claims 1 to 7. Computer
Conversion means for converting an input sound signal into a frequency spectrum in the frequency domain;
Processing means for performing signal processing on the frequency spectrum converted by the conversion means;
Inverse conversion means for converting the frequency spectrum signal-processed by the processing means into a sound time signal in a time domain,
A connection adjustment unit that multiplies the sound time signal converted by the inverse conversion unit with a window function in which values at both ends in a unit interval are smaller than a center value;
Program to function as. Sound signal cutout means for cutting out the sound time signal in frame units by dividing the sound signal to be input into frames of a predetermined time length;
Window processing means for multiplying the sound time signal cut out by the sound signal cut-out means by a window function in which values at both ends in a unit interval are smaller than a central value;
The program according to claim 9, further comprising:

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