JP2017022596A - Image processing apparatus, control method of the same, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus that prevents reduction in dynamic resolution at low illuminance and noise increase in a still area, while improving resolution (dynamic resolution) of an area where a subject is a moving body.SOLUTION: An imaging system control circuit 104 divides an imaging element for control so as to capture a subject image in parallel in different accumulation times. A move detection circuit 112 acquires a plurality of images captured in different accumulation times, and detects a move area of the subject image from the image. An image synthesis circuit 203 synthesizes a plurality of images by changing a synthesis rate in accordance with whether it is a move area.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image processing apparatus, a control method thereof, and a program.

  A moving image imaging apparatus using an imaging element has been widely spread. An imaging device such as a CCD or a CMOS image sensor converts an incident light into a charge in each pixel and accumulates it, and amplifies the accumulated charge to perform photoelectric conversion to output an electric signal to generate an image. These imaging apparatuses obtain a proper exposure image by appropriately performing diaphragm mechanism control, charge accumulation time control in the image sensor, and gain control of the imaging signal. However, when shooting a dark subject such as a night view, it may not be possible to compensate for the underexposure even if the aperture is controlled to open and long exposure is performed. In this case, since the gain of the imaging signal is increased to obtain an appropriate signal, noise increases and the quality of the captured image is degraded. In addition, if the exposure is controlled to be excessively long in order to compensate for the underexposure, the resolution of the area where the subject is a moving object is lowered.

In view of this, there has been proposed an image pickup apparatus that performs control for reviewing the charge accumulation time, analyzes the movement of the subject to be photographed, and performs different image processing in the moving area and the still area of the image.
In Patent Document 1, the readout cycle of the image sensor is set to be longer than the moving image recording rate, and exposure control is performed so that the accumulation time is variable, thereby avoiding deterioration in image quality due to an increase in gain to compensate for insufficient illuminance of the subject. A method is disclosed.
In Patent Document 2, the image signal read from the image sensor and the imaging region are divided into a plurality of blocks based on the image signal, and the motion of the subject is detected for each block. Then, a method is disclosed in which the noise characteristics of the stationary part and the resolution of the moving part are made compatible by controlling the synthesis ratio for each block area of the image signal subjected to accumulation time control and signal processing for each block. .

Japanese Patent No. 3155830 Japanese Patent No. 2550045

In Patent Document 1, it is possible to avoid an increase in noise due to an increase in gain immediately due to insufficient subject illuminance by performing exposure control in which the readout cycle of the image sensor is set longer than the recording frequency and the accumulation time is variable. Yes. However, since the exposure is long, the resolution for a moving subject is lowered.
In Patent Document 2, the image signal read from the image sensor and the imaging region are divided into a plurality of blocks based on the image signal, and the motion of the subject is detected for each block. Then, by controlling the synthesis ratio of the image signal that has been subjected to accumulation time control and signal processing for each block for each block area, it is possible to achieve both the noise characteristics of the stationary part and the resolution of the moving part. However, since motion detection of the subject is performed based on the difference between the image signal read at a certain time and the image signal read immediately before, motion detection is performed in a long cycle over two frames.

  Accordingly, the present invention provides an image processing apparatus that further improves the resolution of a region where a subject is a moving object (hereinafter referred to as “dynamic resolution”), and at the same time suppresses a decrease in dynamic resolution and suppresses an increase in noise in a stationary region even at low illuminance. The purpose is to provide.

  In order to solve this problem, an image processing apparatus of the present invention includes an acquisition unit that acquires a plurality of images captured in parallel with different charge accumulation times, a control unit that controls the charge accumulation times, and the image Detection means for detecting a motion region of the subject image from the image, and combining means for combining the plurality of images by changing the composition ratio depending on whether or not it is the motion region.

  According to the image processing apparatus of the present invention, it is possible to capture a moving image that satisfies both the dynamic resolution of the moving region and the noise characteristics of the still region.

It is a figure which shows schematic structure of the imaging device of this embodiment. It is a figure which shows an example of a structure of the digital signal processing circuit 108 in FIG. It is a flowchart figure of imaging | photography operation | movement of the imaging device of this embodiment. FIG. 4 is a flowchart of a shooting subroutine in FIG. 3. It is the schematic which shows an example which performs a motion detection and object composition. It is the schematic which shows an example which controls charge accumulation time according to brightness.

(First embodiment)
Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an imaging apparatus to which an embodiment of the present invention is applied.
The imaging apparatus according to the present embodiment images a subject by forming an image of light incident from the optical system 101 on the imaging element 103. The optical system control circuit 102 controls the aperture, mechanical shutter, zoom, focus, optical blur correction, and the like of the optical system 101. The image sensor 103 photoelectrically converts the formed optical image into an electric signal. The imaging system control circuit 104 controls an accumulation operation, a reading operation, a reset operation, and the like of the imaging element 103.

  The analog signal processing circuit 105 performs processes such as clamping and gaining on the output of the image sensor 103. The gain control circuit 106 controls the analog signal processing circuit 105 to designate a gain amount for the imaging signal. An A / D (analog / digital) converter 107 performs A / D conversion from an analog signal to a digital signal. The digital signal processing circuit 108 performs development processing of the A / D converted digital signal to generate output image data.

  The internal storage medium 109 temporarily stores image data for generating output image data by the digital signal processing circuit 108, image data for an electronic viewfinder (hereinafter referred to as EVF) for displaying a live image, and the like. . It is also used for temporary storage of various calculation data such as motion detection area information detected by a motion detection circuit 112 described later. The I / F (interface) 110 is connected to an external recording device for finally storing the generated output image data. The image display 111 has an EVF display function, and displays various setting information of the imaging apparatus in addition to a live image.

The motion detection circuit 112 performs motion detection on the output image data developed by the digital signal processing circuit 108 by a motion detection method described later, and outputs region information and motion amount information in which the motion of the subject is detected.
The system control circuit 113 controls the optical system control circuit 102, the imaging system control circuit 104, and the gain control circuit 106 in accordance with a flow chart of photographing operation described later, and provides the control information to the digital signal processing circuit 108. Take control. A switch 114 is a switch (hereinafter referred to as SW1) for performing a photographing standby operation. The switch 115 is a photographing switch (hereinafter referred to as SW2) that performs photographing after the operation of SW1. The switch 116 is a main switch (hereinafter referred to as main SW) for turning on the system.

  The image sensor 103 according to the present embodiment is configured by a pixel group that can be controlled to be divided into a first pixel group and a second pixel group, performs exposure control at different charge accumulation times in parallel at the same time, and reads out separately. Can operate. Therefore, the control system of the imaging system control circuit 104 performs different control for each of the first pixel group and the second pixel group. Therefore, for example, in the case of a CMOS structure, the storage charge transfer signal line and the reset signal line are switched and controlled for the first pixel group and the second pixel group. Since the parallax between the imaging signal obtained by the first pixel group and the imaging signal obtained by the second pixel group should be small, the first pixel group and the second pixel group are lined up for each line. It is desirable to distribute. Needless to say, a configuration in which pixels belonging to the first pixel group and pixels belonging to the second pixel group are alternately arranged is not necessary for each line. Alternatively, a structure in which separate signal lines are wired may be employed. In addition, image processing is performed on the imaging signal read from the first pixel group and the imaging signal read from the second pixel group. Therefore, the analog signal processing circuit 105, the A / D converter 107, and the digital signal processing circuit 108 in this embodiment are configured to be able to individually process the image signals of the respective pixel groups.

FIG. 2 is a diagram showing an example of the configuration of the digital signal processing circuit 108 in FIG.
The development parameter setting circuit 201 acquires shooting condition information and shooting settings from the system control circuit 113, and sets development parameters for performing optimum development processing accordingly. The development processing circuit 202 performs development processing using the development parameters set by the development parameter setting circuit 201 and generates output image data.

Based on the result of motion detection by the motion detection circuit 112, the image composition circuit 203 converts the output image data from the first pixel group developed by the development processing circuit 202 and the output image data signal from the second pixel group into an image region. The composition ratio is changed for each composition. When the composition processing by motion detection is not performed, the output image data input from the development processing circuit 202 is output as it is.
The image compression circuit 204 compresses the output image data of the image composition circuit 203, and records and stores it in the external recording device via the I / F 110. The imaging apparatus of the present embodiment can capture still images and moving images by recording output image data of the development processing circuit 202 singly or continuously in a plurality of frames.

FIG. 3 is a flowchart showing the photographing operation of the imaging apparatus to which the embodiment of the present invention is applied.
First, in step S301, the state of the main SW for turning on the system is detected. If it is ON, the process proceeds to step S302.
In step S302, the remaining capacity of the external recording device is checked via the I / F 110. If the remaining capacity is 0, the process proceeds to step S303, and if not, the process proceeds to step S304. In step S303, a warning is given that the remaining capacity is 0, and the process returns to step S301. The warning may be displayed on the image display 111 and / or a warning sound may be emitted from an audio output device (not shown).

  In step S304, the EVF operation for displaying the live image output from the imaging unit on the image display 111 is started. In the EVF operation, an AE operation for obtaining proper exposure and an AF operation for obtaining an appropriate focus state are performed at a predetermined cycle. In the AE operation, the output of the A / D converter 107 is integrated and compared with a predetermined value to check whether the exposure is appropriate, and if necessary, aperture setting, charge accumulation time (electronic shutter) setting, or imaging The signal gain setting is controlled according to a predetermined diagram. For example, even when the illuminance of the subject is low by the AE operation, it is possible to obtain image data with appropriate exposure by increasing the gain by the gain control circuit 106. In the AF operation, the optical system control circuit 102 appropriately controls the focus lens, for example, by comparing the strength of the high frequency component of the output image data of the digital signal processing circuit 108 with the previous frame. The motion detection circuit 112 performs motion detection.

In step S305, the state of SW1 is checked. If ON, the process proceeds to step S307, and if not, the process proceeds to step S306. Here, the function of SW1 is to perform a shooting standby operation such as AF or AE. In step S306, the state of the main SW is checked. If it is ON, the process proceeds to step S304, and if not, the process proceeds to step S301.
In step S307, AE processing is performed by controlling exposure via the optical system control circuit 102, the imaging system control circuit 104, or the gain control circuit 106. In step S308, the focus lens is controlled via the optical system control circuit 102 to perform AF processing. The AE process in step S307 and the AF process in step S308 are shooting standby operations, and AE and AF control are performed with better accuracy than during the EVF operation in step S304.
Step S309 is a preparatory state before starting the photographing operation by turning on SW2, displays a live image on the image display 111, and waits for a photographer's SW2 operation. Further, as in step S304, the motion detection circuit 112 performs motion detection.

In step S310, the state of SW2 is checked, and if it is ON, that is, if SW2 is pressed to start shooting, the process proceeds to step S311; otherwise, the process proceeds to step S305. The function of SW2 here is to start a photographing operation after operation of SW1.
In step S311, the photographing operation is performed according to the flowchart of FIG. When the photographing operation is completed, the process returns to step S302.

FIG. 4 is a flowchart of a shooting subroutine in the flowchart of FIG.
First, in step S401, it is checked whether still image shooting or moving image shooting is performed. If still image shooting is performed, the process proceeds to step S402, and if moving image shooting is performed, the process proceeds to step S408. In moving image shooting, processing during recording is performed at a cycle of a recording frame rate such as 60 FPS (Frame per second) set before shooting.

If it is determined in step S401 that still image shooting is to be performed, in step S402, preparation for still image shooting such as drive switching of the image sensor is performed. When shooting still images, it is necessary to pay attention to the subject blur, but there is no need to worry about the dynamic resolution. For the purpose of obtaining a high resolution image using all the pixels of the image sensor, etc. Instead, the drive is switched to read out all pixels.
In step S403, the image sensor 103 is exposed. The image formed on the image sensor surface is photoelectrically converted into an analog signal and sent to the A / D converter 107.
In step S404, the A / D converter 107 performs preprocessing such as output noise removal and nonlinear processing, and then converts the analog signal into a digital signal. In step S405, the digital signal processing circuit 108 performs digital signal development processing to generate output image data. In step S406, the output image data is converted by the image compression circuit 204 into an image format such as a JPEG format. In step S407, the data is transferred to an external storage medium such as a memory card attached to the camera via the I / F 110 and recorded.

On the other hand, if it is determined in step S401 that moving image shooting is to be performed, in step S408 preparation for moving image shooting such as switching of driving of the image sensor is performed. At the time of moving image shooting, in order to obtain two types of images, that is, an image with a high dynamic resolution and an image with a low noise, the driving is switched to driving that performs reading divided into two pixel groups.
In step S409, recording of a moving image is started and the image sensor 103 is exposed. The image formed on the image sensor surface is photoelectrically converted into an analog signal and sent to the A / D converter 107. In step S410, the A / D converter 107 performs preprocessing such as output noise removal and nonlinear processing, and then converts the analog signal to a digital signal. In step S411, the digital signal processing circuit 108 develops the digital signal to generate output moving image data.
As will be described later with reference to FIG. 5, in step S412, the motion detection circuit 112 detects the motion of the subject image based on the acquired moving image data. In step S413, the image composition circuit 203 synthesizes moving images based on the motion detection result.

FIG. 5 is a schematic diagram showing an example of performing motion detection and subject synthesis from moving images obtained by the first pixel group and the second pixel group in the imaging apparatus of the present embodiment at the time of moving image shooting.
The field angles of the image signal read from the first pixel group and the image read from the second pixel group are set to substantially the same angle of view. In addition, the image signals read from the respective pixel groups are controlled by the charge accumulation time and the ISO sensitivity so as to achieve appropriate exposure.

As shown in FIG. 5A, the image signal read from the first pixel group is set to give priority to the dynamic resolution. Therefore, the charge accumulation time is shorter than the recording frame rate, and the gain amount in the analog signal processing circuit 105 is large, that is, controlled by a combination of short second exposure and high sensitivity.
On the other hand, as shown in FIG. 5B, the image signal read from the second pixel group is set to give priority to noise characteristics. Therefore, the charge accumulation time is longer than the recording frame rate, and the gain amount in the analog signal processing circuit 105 is small, that is, controlled by a combination of long-second exposure and low sensitivity.

FIG. 5C is a diagram illustrating an image read in the T and T + 1 frames of the first pixel group and an image read in the same time T & T + 1 frame of the second pixel group. In any of the images, the subject image is blurred due to the movement of the subject, but the amount of the blur is larger in the image read in the T & T + 1 frame. As shown in FIG. 5C, a subject image that moves even during the accumulation time can be detected by comparing images at different times or by comparing images with different accumulation times.
The motion detection circuit 112 detects the motion of the subject image based on any two images of the acquired T frame, T + 1 frame of the first pixel group, and the same time T & T + 1 frame of the second pixel group. The motion detection method can be divided into blocks and evaluated for each block. In order to detect with high accuracy, each pixel value difference between comparison images is compared with a predetermined threshold value. What is necessary is just to use the method of judging that it is an area | region. Note that the motion detection means may be configured not only to detect whether or not it is a motion region, but also to acquire the amount of motion of the subject image.

When motion detection is performed using images having different charge accumulation times, for example, comparison between images having different charge accumulation times, for example, the T frame or T + 1 frame of the first pixel group shown in FIG. 5A and FIG. The images of the frames of the same time T & T + 1 of the second pixel group shown in FIG. When motion detection is performed with images having the same charge accumulation time, comparison between images having the same charge accumulation time, for example, frames for continuous images such as the T frame and the T + 1 frame of the first pixel group shown in FIG. Compare images.
Note that since the first pixel group and the second pixel group are read from different pixels of the same image sensor, the first pixel group and the second pixel group even when the image signals have substantially the same angle of view. Affects the result of motion detection. Therefore, the thinning rate is set appropriately at the time of reading in each pixel group so as to cancel out the phase difference between the first pixel group and the second pixel group.

FIG. 5D shows a composite image output by the image composition circuit 203.
In synthesizing the image obtained from the first pixel group and the image obtained from the second pixel group, the region set as the motion region in motion detection suppresses a decrease in dynamic resolution. The ratio of the first pixel group that is short and has high dynamic resolution is increased. In regions other than the motion region where no motion is detected, the ratio of the second pixel group having a long charge accumulation time, low sensitivity, and low noise is increased in order to suppress an increase in noise.
In the case of detecting the amount of motion of the subject image in the motion detection, the composition ratio of the images may be changed according to the amount of motion. In this case, the larger the amount of movement, the larger the ratio of the first pixel group having a short charge accumulation time and high dynamic resolution.

  Returning to the description of FIG. 4, in step S414, the image compression circuit 204 converts the output moving image data to the MPEG-4 format or the like. The output moving image data may be only the combined moving image data after combining, and may further include moving image data obtained from the first pixel group and the second pixel group. . In S415, the data is transferred and recorded via the I / F 110 to an external storage medium such as a memory card attached to the camera.

In step S416, the state of SW2 is checked, and if it is ON, that is, if SW2 is pressed to finish moving image shooting, the process proceeds to step S418, and if not, the process proceeds to step S417. The function of SW2 here is to end the photographing operation.
The internal storage medium 109 during recording mainly functions as a buffer memory, and the data is transferred to an external storage medium via the I / F 110 and recorded. If the transfer speed of the recording medium is low, the buffer memory It becomes impossible to continue recording beyond the processing capacity. Also, recording cannot be continued even when the remaining capacity of the recording medium runs out. In order to avoid the above situation, in step S417, the remaining capacity of the buffer memory and the recording medium is confirmed and the transfer status to the recording medium is confirmed. If the transfer is OK, the process proceeds to step S409. Otherwise, the process proceeds to step S418. move on.
In step S418, it is confirmed that the recording is finished, the data in the buffer memory is transferred to the recording medium, and the saving process is finished.

In this embodiment, the charge accumulation time of the first pixel group is shorter than the processing time per frame set by the recording frame rate, and the charge accumulation time of the second pixel group is one frame set by the recording frame rate. It was set as the structure set longer than the per process time. However, it is not limited to this.
For example, it is assumed that the subject is very dark and there is almost no movement of the subject. In this case, in order to suppress the increase in noise while ensuring the brightness, the charge accumulation time is set to 2 and 6 times the processing time per frame, and the image taken with a long charge accumulation time and low sensitivity is synthesized. There is a method for further improving noise characteristics.
Also, it is assumed that the subject is bright, the subject motion detection is desired to be performed at high speed, or the recording frame rate is long. In this case, there is a method in which the charge accumulation time is set to 倍 times and ½ times the processing time per frame, motion detection within one frame is possible, and the dynamic resolution is prioritized.

  In the case of dividing the pixels, in the present embodiment, in step S408, all the pixels are divided into two pixel groups in order to obtain two types of images, that is, an image with high dynamic resolution and an image with low noise. However, the number of pixel groups is not limited to two as long as the pixel group is divided into two or more pixel groups having different charge accumulation times. In addition, when the subject image is sufficiently bright and noise characteristics can be obtained only by shooting with a short charge accumulation time setting giving priority to dynamic resolution, it is not necessary to divide the pixel group, and the entire image sensor has one image. You may control to obtain.

  As described above, according to the image processing apparatus of the present invention, it is possible to capture a moving image that satisfies both the dynamic resolution of the moving region and the noise characteristics of the still region.

(Second Embodiment)
In the first embodiment, the control for changing the charge accumulation time of the image sensor during imaging is not performed. However, in the second embodiment, the imaging element is controlled according to the brightness of the subject image even during imaging. Drive switching control for performing charge accumulation time and division is performed. The image synthesis circuit 203 synthesizes moving images in consideration of the brightness of the subject image in addition to the result of motion detection.
FIG. 6 is a schematic diagram illustrating an example in which charge accumulation time is controlled and an image sensor is divided according to brightness.

In FIG. 6A, priority is given to dynamic resolution. Therefore, the charge accumulation time is shorter than the recording frame rate, and the gain amount in the analog signal processing circuit 105 is large, that is, controlled by a combination of short second exposure and high sensitivity. This is suitable for shooting in a bright place.
FIG. 6B is controlled by a combination of medium-second exposure and medium sensitivity. This is suitable for shooting in a place with standard brightness.
FIG. 6C is a setting that gives priority to noise characteristics. Therefore, the charge accumulation time is longer than the recording frame rate, and the gain amount in the analog signal processing circuit 105 is small, that is, controlled by a combination of long-second exposure and low sensitivity. This is suitable for shooting in a dark place.

As shown in FIG. 6D, the imaging system control circuit 104 performs drive switching control for dividing the image sensor and control of the charge accumulation time of each pixel group in accordance with the brightness of the subject image.
For example, when the subject image is sufficiently bright (bright × 3), it is not necessary to divide the image sensor to synthesize images with different charge accumulation times in order to achieve both dynamic resolution and noise characteristics, and short exposure- An image with proper exposure can be obtained only with a combination of high sensitivity. Therefore, the imaging system control circuit 104 controls the entire imaging device as one pixel group without performing drive switching control that divides the imaging device into pixel groups having different charge accumulation times. When the subject image is bright (bright), the imaging system control circuit 104 performs drive switching control that divides the imaging device into pixel groups having different charge accumulation times. The charge accumulation time is controlled so that the first pixel group has short-second exposure-high sensitivity and the second pixel group has medium-second exposure-medium sensitivity. When synthesizing an image in the image synthesizing circuit 203, the synthesizing ratio of the image obtained with short-second exposure-high sensitivity is increased (main).

When the subject image is dark (dark), the image obtained by the short-time exposure is too dark to be used for composition, and thus the charge of the first pixel group that has been controlled to be short-time exposure-high sensitivity. The accumulation time is controlled by switching so that long-second exposure-low sensitivity. Therefore, the charge accumulation time is controlled so that long-second exposure-low sensitivity is achieved in the first pixel group and medium-second exposure-medium sensitivity is achieved in the second pixel group. When synthesizing an image in the image synthesizing circuit 203, the synthesis ratio of the images obtained with medium-second exposure-medium sensitivity is increased (main).
The brightness of the subject image is determined by integrating the output of the A / D converter 107 and comparing it with a predetermined value.

  According to the second embodiment, even when the brightness of the subject image changes during shooting, the drive switching control for dividing the image sensor during shooting and the charge accumulation time control of each pixel group are obtained. Synthesize the image at the proper composition ratio. As a result, it is possible to capture a moving image with proper exposure that satisfies both the dynamic resolution of the moving area and the noise characteristics of the stationary area.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

104 Image pickup system control circuit 112 Motion detection circuit 203 Image composition circuit

Claims (10)

Acquisition means for acquiring a plurality of images captured in parallel with different charge accumulation times;
Control means for controlling the charge accumulation time;
Detecting means for detecting a movement region of the subject image from the image;
An image processing apparatus comprising: a combining unit configured to combine the plurality of images by changing a combining ratio depending on whether the region is the motion region. The image processing apparatus according to claim 1, wherein the detection unit detects the motion region by comparing the images having different charge accumulation times. The detection means further detects the amount of movement of the subject image,
The image processing apparatus according to claim 1, wherein the synthesizing unit changes the synthesis ratio according to the amount of motion. The control means divides pixels so that a plurality of images having different charge accumulation times can be simultaneously photographed according to the brightness of a subject image, and controls the charge accumulation time for each divided pixel group. The image processing apparatus according to any one of claims 1 to 3. The image processing apparatus according to claim 4, wherein the control unit further controls the charge accumulation time according to the amount of movement. The control means performs drive switching control to divide an image sensor into a first pixel group and a second pixel group having a longer charge accumulation time than the first pixel group, and controls the charge accumulation time. And
The synthesizing unit synthesizes the image acquired from the first pixel group and the image acquired from the second pixel group at the first synthesis ratio in the motion region, and in the region other than the motion region. The composition according to any one of claims 1 to 5, wherein the composition is performed at a second composition ratio that is lower than the composition ratio of the image acquired from the first pixel group than the first composition ratio. Image processing device.   The image processing apparatus according to claim 1, wherein the plurality of images are moving images.   An imaging apparatus comprising the image processing apparatus according to claim 1. A control method for an image processing apparatus, comprising:
An acquisition step of acquiring a plurality of images captured in parallel with different charge accumulation times;
A control step for controlling the charge accumulation time;
A detection step of detecting a motion region of the subject image from the image;
A control method for an image processing apparatus, comprising: a combining step of combining the plurality of images by changing a combining ratio according to whether or not the region is the motion region.   A program for causing a computer to execute each step of the control method for an image processing apparatus according to claim 9.

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