JP2009141617A - Imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging system for obtaining high quality dynamic images during detection of conditions within a body and during diagnosis of body by imaging the inside of the human body after embedding an imaging device into the human body. <P>SOLUTION: The imaging system includes an imaging device 2 for transmitting encoded wireless data stream by sharing dynamic image data generated by imaging an object to key frames and non-key frames, a motion compensating unit 34 for motion compensation for the non-key frames based on information about the intra-frame encoded key frames by respectively decoding the key frames and the non-key frames from the wireless data stream received from the imaging device 2, and a control device 3 including a control unit 37 for controlling the imaging device 2 via wireless communication based on the motion vector information used for motion compensation with the motion compensating means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging system suitable for realizing advanced treatment / diagnosis by wirelessly transmitting an in-vivo captured moving image to the outside of the body.

  Conventionally, MPEG-1 / 2/4 has been proposed as a compression encoding method for moving images. In the transmission apparatus in these conventional compression coding systems, the compression coding is realized by making the most effective use of the correlation within the frame and the correlation between the frames. In the frame, unnecessary high-frequency components are suppressed, DC and low-frequency components are predicted, and between frames, motion is predicted from past images. At the time of encoding, an image that approximates the current image, that is, a predicted image is created by these prediction processes, and difference information between the current image and the predicted image and control information necessary to create the predicted image are encoded. And transmit.

  In addition, in the receiving device in this conventional compression coding method, a decoded image can be obtained by creating a predicted image based on control information and adding the received difference information. Here, when the signal quality changes due to a transmission path error, normal decoding processing can be performed only when both the control information for prediction and the difference information are normal. Furthermore, since the decoded image is used again to predict the next image, if there is an error in the decoded image, the error will be propagated when decoding the subsequent image. As described above, conventional compression coding systems such as MPEG-1 / 4/4 have a drawback that they are vulnerable to transmission line errors while achieving a high compression rate.

  For this reason, in recent years, Distributed Video Coding (DVC) has been proposed as a new encoding method (see, for example, Non-Patent Document 1). As a feature of this DVC coding, error correction coding is used. As shown in FIG. 5, key frames and non-key frames are encoded based on different encoding methods. The key frame is subjected to, for example, intra-frame coding conventionally used in the encoder 71, whereas error correction coding is performed on a non-key frame, and only a so-called check bit calculated as a result is decoded. 72. In the decoder 72, the next frame image is predicted in advance, the difference (estimation error) between the estimated image and the next frame image is checked based on the check bit sent from the encoder 71, and the estimated error is detected. It is possible to obtain an image of the next frame by correcting. Thus, since the DVC is encoded without performing a motion vector search in the encoder 71, the DVC can be encoded with a smaller amount of calculation compared to the conventional compression encoding method described above.

For this reason, the encoding method by DVC can reduce the power consumption of the device as compared with the conventional compression encoding method, and it is possible to realize a lighter and smaller device.
B.Girod, et al., “Distributed Video Coding” Proceedings of The IEEE, Vol93, No.1 January 2005

  By the way, especially in recent medical treatment, there are an increasing number of cases in which an imaging device is embedded (implanted) in the human body, the human body is imaged, and the situation inside the body is grasped and diagnosed. For this reason, research on a system that establishes a wireless communication link between an imaging device embedded in the body and a control device as a base station is also attracting attention. In particular, in order to acquire patient test data in real time, the construction of a system focusing on high-speed communication, ease of use, and reliability is also progressing.

  Actually, in the wireless communication system using the human-embedded imaging device, first, it is necessary to be configured in a very small size, and it is necessary to operate at a low voltage. The imaging system using the DVC encoding method described above has been considered preferable for application to a human-embedded imaging device because it can achieve a lighter and smaller device. .

  However, this human-embedded imaging device may target a fast-moving part such as the esophagus, or may target a slow-moving organ such as the stomach. In addition, there are cases in which organs where the movement of the object to be photographed becomes faster or slower are taken as objects to be photographed. Therefore, the object to be photographed whose movement speed varies widely and may change from moment to moment is appropriately selected. Images must be taken under suitable conditions.

  In an imaging system using a conventional DVC encoding method, an imaging device is embedded in a human body, and it is not assumed that an object to be imaged is an object in which movement of an organ or the like in the human body changes every moment. For this reason, the imaging device embedded in the human body cannot always capture the movement of the imaging target that changes in time series under optimal conditions, and the quality of the obtained image cannot be improved. was there.

  Accordingly, the present invention has been devised in view of the above-described problems, and the object of the present invention is to embed an imaging device in the human body and to capture the state of the body and diagnose the human body. An object of the present invention is to provide an imaging system capable of obtaining a higher quality moving image.

  In order to solve the above-described problems, an imaging system to which the present invention is applied has imaging means for distributing moving image data generated by imaging a subject into key frames and non-key frames, and intra-frame coding of the key frames. Intra-frame encoding means, encoding means for encoding the non-key frame and the intra-frame encoded key frame, respectively, and converting the encoded key frame and non-key frame to wireless data streams, respectively. An imaging device having a transmission means for transmitting the data, a decoding means for decoding each of the key frame and the non-key frame from the wireless data stream received from the imaging device, and the decoded key frame in the frame. Intra-frame decoding means for decoding, and intra-frame decoding A motion compensator for compensating motion of an intra-frame object with respect to the decoded non-key frame based on the information on the key frame, and a motion image by combining the motion-compensated non-key frame and the key frame. A control apparatus having a moving image generation means for generating the image data and a control means for controlling the image pickup means in the image pickup device via wireless communication based on motion vector information used for motion compensation by the motion compensation means. It is characterized by providing.

  In order to solve the above-described problems, an imaging system to which the present invention is applied has imaging means for distributing moving image data generated by imaging a subject into key frames and non-key frames, and intra-frame coding of the key frames. Intra-frame encoding means, encoding means for encoding the non-key frame and the intra-frame encoded key frame, respectively, and converting the encoded key frame and non-key frame to wireless data streams, respectively. An imaging device having a transmission means for transmitting the data, a decoding means for decoding each of the key frame and the non-key frame from the wireless data stream received from the imaging device, and the decoded key frame in the frame. Intra-frame decoding means for decoding, and intra-frame decoding A motion compensator for compensating motion of an intra-frame object with respect to the decoded non-key frame based on the information on the key frame, and a motion image by combining the motion-compensated non-key frame and the key frame. And a control unit for controlling the intra-frame encoding unit or the encoding unit in the imaging device by wireless communication based on the convergence value of the decoding of the non-key frame by the decoding unit. And a control device.

  In the present invention having the above-described configuration, it is possible to perform all of the imaging bit rate, the ratio of key frames, and the code amount control in the imaging device. In addition, motion compensation for non-keyframe intra-frame objects is not executed in the imaging device, but is executed only on the control device side, and motion vector information used for motion compensation is always acquired for control by the control unit. Can be used.

  For this reason, it is not necessary to mount a circuit for performing motion compensation and control based on this on the imaging device side, so the shape of the imaging device can be further reduced, and the weight can be reduced. It becomes.

  That is, the present invention can reduce the size and weight when embedding the imaging device in the human body, and the shooting target whose movement speed is various and may change every moment, Based on the motion vector information and the like, it is possible to control the imaging device so that a moving image can be acquired under appropriate conditions.

  Hereinafter, an imaging system for wirelessly transmitting an in-vivo captured moving image to the outside of the body will be described in detail with reference to the drawings as the best mode for carrying out the present invention.

  An imaging system 1 to which the present invention is applied includes an imaging device 2 embedded (implanted) in a human body and a control device 3 disposed outside the human body as shown in FIG. The imaging device 2 is a device for imaging a human body and grasping or diagnosing the situation inside the human body. The imaging device 2 may be inserted into the body by swallowing it from the mouth like a stomach camera, or may be an implanted device. The control device 3 transmits a moving image captured by the imaging device 2 via wireless communication. The control device 3 controls at least the imaging device 2 by wireless communication. Incidentally, the control device 3 may be configured by an electronic device such as a personal computer (PC), for example, which records image data transmitted from the imaging device 2 and records the recorded image data via a display (not shown). Display to the inspector. The control device 3 may transmit image data to another terminal device via a network system (not shown).

  In this imaging system 1, when moving images are transmitted from the imaging device 2 to the control device 3, it is assumed that encoding is performed based on the Distributed Video Coding (DVC) method.

  Hereinafter, the configuration of the imaging device 2 and the control device 3 will be described in detail with reference to the drawings.

  As shown in FIG. 2, the imaging device 2 includes a camera 21 for imaging a subject, a distributor 22 connected to the camera 21, and an image encoder connected to the distributor 22. 23, a second encoder 25, a first encoder 24 connected to the image encoder 23, and a second encoder 25, and a wireless data stream via the wireless transmission system 5. 3 is provided.

  The control device 3 includes a receiving unit 31 that receives a wireless data stream transmitted from the imaging device 2 via the wireless transmission system 5, a decoder 32 that is connected to the receiving unit 31, and a motion compensation unit 34a. A key frame reconstruction unit 34b, an SNR (Signal-to-Noise Ratio) detection unit 38, an image decoder 33 connected to the decoder 32, an image decoder 33, and a synthesis connected to the motion compensation unit 34 A unit 35, a video display unit 36 connected to the synthesis unit, a non-keyframe reconstruction unit 34b, and a control unit 37 connected to the video display unit 36, respectively.

  The camera 21 includes a lens for forming image light from a subject, a diaphragm driving unit that adjusts a diaphragm amount by a shutter blade or the like that shields image light incident through the lens, and an input subject image. And a CCD (Charge Coupled Device) image sensor that generates an electrical imaging signal based on the image sensor.

  The camera 21 also has a CDS (Correlated Double Sampling) circuit for compensating for variations in the imaging signal C1 generated by the CCD image sensor, and an A / A that performs analog / digital conversion processing on the imaging signal supplied from the CDS circuit. A digital signal processor (DSP) that performs predetermined processing on image data as digitized imaging signals supplied from the D conversion unit and A / D conversion unit, and temporarily stores the image data from the connected DSP An image RAM or the like may be provided.

  As will be described later, the camera 21 is controlled with respect to the imaging conditions and the like from the control unit 37 in the control device 3.

  The distributor 22 distributes the image data sent from the camera 21 for each frame. As will be described later, from the viewpoint of encoding based on the DVC method, the distributor 22 distributes the moving image frame sequence into two types of key frames and non-key frames. For example, the distributor 22 may perform distribution so that a key frame is generated at a frequency of one frame every few frames, and the rest are non-key frames. The key frames distributed by the distributor 22 are sent to the image encoder 23, and the non-key frames are sent to the second encoder 25. As will be described later, the distributor 22 may adjust the ratio of key frames and non-key frames from the control unit 37 in the control device 3 in some cases.

  The image encoder 23 performs normal intra-frame encoding on the key frame sent from the distributor 22 in the same manner as an I frame in the conventional MPEG-1 / 2/4 or the like. At this time, the image encoder 23 may realize irreversible image compression by quantizing the transmitted key frame after DCT (Discrete Cosine Transform) conversion. In the image encoder 23, Huffman coding may be applied.

  The first encoder 24 performs turbo encoding or LDPC (Low Density Parity Check) encoding necessary for further transmitting the key frame encoded by the image encoder 23 via the communication path. Etc., so-called error correction coding is performed, and this is output to the transmitter 26.

  The second encoder 25 receives only non-key frames from the distributor 22. The second encoder 25 generates an error correction code for the non-key frame using convolutional coding, turbo coding, LDPC coding, or the like. The second encoder 25 sends only the redundant component or the syndrome component obtained as a result of the error correction coding to the transmitter 26 as data for streaming the wireless data.

  The transmission unit 26 converts the key frame sent from the first encoder 24 and the redundant component or syndrome component sent from the second encoder 25 into a wireless data stream and controls it via the wireless transmission system 5. Transmit to device 3. The transmission unit 26 is configured with, for example, a small antenna and the like, and configured to be able to radiate electromagnetic waves to the outside through a tissue in the human body.

  The wireless transmission system 5 may transmit a wireless data stream by a wireless communication scheme based on a specific low power wireless station or a weak wireless station. At this time, it may be configured as a system capable of transmitting a wireless data stream in the 401 to 406 MHz band, preferably in the 402 to 405 MHz band. By using the frequency band of 402 to 405 MHz, communication can be realized at a low voltage with priority given to reducing the influence on the human body.

  The receiving unit 31 includes an antenna for receiving a wireless data stream transmitted from the imaging device 2 via the wireless transmission system 5. The receiving unit 31 receives the received wireless data stream from the decoder 32 for key frames, and the non-key frame reconstructing unit 34b for redundant components or syndrome components generated when encoding non-key frames. Send to.

  The decoder 32 performs a decoding process on the key frame component sent from the receiving unit 31. The image decoder 33 further performs intra-frame decoding on the key frame component decoded by the decoder 32. This intra-frame decoding may be executed on the basis of the same processing procedure as the decoding processing to the I frame in the conventional MPEG-1 / 2/4 or the like. Further, the image decoder 33 transmits data generated based on the motion vector of the key frame decoded in the frame to the motion compensation unit 34a. In addition, the image decoder 32 transmits the key frame decoded in the frame to the synthesis unit 35.

  The motion compensation unit 34a receives an error correction code such as a redundant component or a syndrome component for the non-key frame component from the receiving unit 31, and decodes it. In addition, the motion compensation unit 34 a performs processing such as obtaining a motion vector based on data transmitted from the image decoder 33. The non-key frame reconstruction unit 34b performs motion compensation on the non-key frame from the reception unit 31 based on the motion vector obtained by the motion compensation unit 34a. The non-key frame reconstruction unit 34 b transmits the non-key frame subjected to the motion compensation to the synthesis unit 35. The motion compensation unit 34a and the non-key frame reconstruction unit 34b may be combined to form a single non-key frame reconstruction unit unit 34.

  The combining unit 35 combines the sent key frame and non-key frame. The frame synthesis in the synthesis unit 35 is performed with reference to the allocation rate in the distributor 22.

  The video display unit 36 includes a display or the like for generating a moving image composed of key frames and non-key frames sent from the combining unit 35 and displaying the moving images to the examiner. Further, the video display unit 36 may be used to display information for prompting the examiner to control the entire imaging system 1 under the control of the control unit 37.

  The control unit 37 serves as a central control unit for controlling the entire imaging system 1 including the imaging device 2 and the control device 3. The control unit 37 detects motion vector information used for motion compensation in the non-key frame reconstruction unit 34b, and controls the imaging device 2 based on the motion vector information. Specifically, the control unit 37 controls the camera 21, the distributor 22, and the like in the imaging device 2 based on the motion vector information.

  The control unit 37 may control the imaging device 2 based on the convergence value of the decoding of the non-key frame in the non-key frame reconstruction unit 34b. In such a case, the control unit 37 controls the second encoder 25 based on the convergence value of the decoding.

  The SNR detection unit 38 detects and identifies the reception status of the wireless data stream in the reception unit 31 via the S / N ratio and the like, and controls the imaging device 2, specifically, the output and the like in the transmission unit 6 based on this. .

  Next, the operation of the imaging system 1 having the above-described configuration will be described.

  First, a moving image is picked up using a camera 21 in the imaging device 2 embedded in the human body as a subject to be imaged, such as a tissue or organ in the body. As shown in FIG. 3, the moving image frame sequence 44 as image data captured by the camera 21 is divided into a key frame 41 and a non-key frame 42. The ratio of the key frame 41 and the non-key frame 42 is controlled by the control device 3 as will be described later. FIG. 3 shows a state in which four non-key frames 42 are inserted between the key frames 41. Yes.

  The key frame 41 is subjected to intra-frame coding in the image encoder 23, and further, so-called error correction coding is performed in the first encoder 24, and the control device via the wireless transmission system 5 as a coded bit string (K). 3 is transmitted. The non-key frame 42 is supplied to the second encoder 25 to generate an error correction code, and the wireless transmission system 5 is used with only the obtained redundant component or the syndrome component as a coded bit string (WZ). And transmitted to the control device 3.

  The key frame component constituting the encoded bit string (K) transmitted to the control device 3 is decoded by the decoder 32 using an estimation algorithm (eg, Bayes algorithm, posterior probability maximization algorithm, etc.), and In-frame decoding is performed in the image decoder 33. At this time, the image decoder 33 transmits information on the decoded key frame to the motion compensation unit 34a. For example, the pixel value likelihood ratio of the key frame may be transmitted as the information.

At this time, as shown in FIG. 4, the pixel value likelihood ratio logP _{c, p} ^K0 (i, j) for the key frame K _{0 and the} pixel value likelihood ratio logP _{c, p} ^K1 for the subsequent key frame K _1. (i, j) is calculated respectively. Here, c is a gradation indicating the density of the color, and is represented by a numerical value of 0 to 256. C represents the three primary colors of light of R, G, and B (Red, Green, Blue). Incidentally, although this example is a case of 8-bit RGB, it is not limited to this. The superscript character specifies the type of key frame (·· K ₀ , K ₁ ...). Further, (i, j) represents the coordinates of the pixels in the frame, and is for specifying the pixels in i rows and j columns as shown in FIG.

Such a pixel value likelihood ratio logP _{c, p} ^K (i, j) is obtained for each pixel constituting each key frame, and this is sent to the motion compensation unit 34.

The motion compensation unit 34a acquires the pixel value likelihood ratio logP _{c, p} ^K (i, j) obtained for each pixel constituting each key frame from the information sent from the image decoder 33, and this As shown in FIG. 4, motion compensation is performed on the non-key frame WZn between the key frame K ₀ and the key frame K ₁ . This motion compensation is performed in the log likelihood region. Expression (1) shows a relational expression of the pixel value likelihood ratio between the non-key frame to be motion compensated and the key frames positioned before and after the non-key frame in the log likelihood region.

logP _{c, p} ^WZn (i, j) = f (logP _{c, p} ^K0 (i, j), logP _{c, p} ^K1 (i, j), r _{c, p} ^WZn (i, j), m (i, j)) ... (1)

In equation (1), r _{c, p} ^WZn (i, j) is a log likelihood value of the frame reception data in the non-key frame WZn. This ^rc _{, p} ^WZn (i, j) is actually calculated based on the non-key frame in the motion ^{recompensation} unit 34b. The motion vector m (i, j) is the non-key frame WZn a motion vector to be used for motion compensation, which is predicted based on the key frame K ₀ and keyframes K ₁ in the motion compensation unit 34a It is a thing. The motion vector m (i, j) is defined as a vector direction in which the vector direction is shifted from the origin by i pixels in the horizontal direction and j pixels in the vertical direction.

The pixel value likelihood ratio logP _{c, p} ^WZn (i, j) for the non-key frame WZn is expressed by logP _{c, p} ^K0 (i, j), logP _{c, p} ^K1 (i, j) in equation (1). , r _{c, p} ^WZn (i, j), m (i, j).

By applying motion compensation to the non-key frame WZn based on the motion vector obtained in this way, a non-key frame image can be completed. At this time, in the non-key frame WZn shown in FIG. 4, an object whose motion is compensated based on the position of the object in the key frame K ₀ and the position of the object in the key frame K ₁ is drawn.

  The key frame and the non-key frame are combined by the combining unit 35 and a moving image to be displayed on the video display unit 36 is generated.

  Further, the control unit 37 detects motion vector information related to the motion vector used for motion compensation in the motion compensation unit 34. This motion vector information means a motion vector amount, but is not limited to this, and includes any information related to a motion vector.

  The control unit 37 controls the camera 21 in the imaging device 2 via wireless communication based on the acquired motion vector information.

  At this time, the control unit 37 controls the camera 21 and the distributor 22 so as to adjust the ratio of key frames and non-key frames per unit time based on the amount of motion vectors used for motion compensation by the motion compensation unit 34. Control.

  In particular, the imaging device 2 embedded in the human body may target a fast-moving part such as the esophagus, or may target a slow-moving organ such as the stomach. In addition, since an organ in which the movement of the photographing target becomes fast or slow may be taken as the photographing target, the speed of the motion is various and may change every moment. In such a case, by first identifying the motion vector amount used for motion compensation in the motion compensation unit 34, the motion amount of the subject itself can be identified. That is, it is possible to identify whether the subject to be photographed is a fast moving object or a slow moving object through this motion vector amount.

  The ratio of key frames and non-key frames per unit time is adjusted according to the movement speed of the subject. Specifically, when the motion vector amount used for motion compensation by the motion compensation unit 34 is large, the ratio of key frames per unit time is increased, and when the motion vector amount is small, The camera 21 and the distributor 22 are controlled so as to reduce the ratio of key frames per unit time.

  In the case of a shooting target with a large amount of motion, it is possible to prevent the accuracy of motion compensation from being lowered by increasing the ratio of key frames and decreasing the ratio of non-key frames inserted therebetween. It becomes possible. On the other hand, in the case of a shooting target with a small amount of motion, even if the proportion of key frames is reduced and the proportion of non-key frames inserted between them is increased, the accuracy of motion compensation may be reduced. Therefore, it is possible to increase the compression rate and contribute to power saving.

  Actually, when the motion vector amount used for motion compensation is greater than or equal to a predetermined value, the camera 21 and the distributor 22 are controlled so as to increase the ratio of key frames per unit time, and used for motion compensation. When the motion vector amount is less than a predetermined value, the camera 21 and the distributor 22 may be controlled so as to reduce the ratio of key frames per unit time.

  Further, the control unit 37 may control the camera 21 so as to adjust the frame rate of the key frame and the non-key frame based on the motion vector amount used for motion compensation by the motion compensation unit 34. Good. Specifically, the frame rate may be improved for a shooting target with a large amount of motion, and the ratio of key frames may be decreased for a shooting target with a small amount of motion.

  For fast-moving subjects, by increasing the frame rate and increasing the amount of frames per unit time, it is possible to capture even finer movements of fast-moving subjects with high accuracy. . For a subject that moves slowly, the processing speed may be increased by reducing the frame rate, thereby reducing the amount of frames per unit time.

  At this time, the control unit 37 controls the camera 21 to increase the frame rate when the motion vector amount used for motion compensation by the motion compensation unit 34 is equal to or greater than a predetermined value, and the motion compensation by the motion compensation unit 34 In the case where the motion vector amount used in the above is less than a predetermined value, the camera 21 may be controlled so as to reduce the frame rate.

Furthermore, the present invention is not limited to the case where the imaging device 3 is controlled based on the motion vector information including the motion vector amount as described above, and the convergence of the decoding of the non-key frame in the motion compensation unit 34 is not limited. The imaging device 3 may be controlled based on the value. At this time, the control unit 37 controls the image encoder 23, the first encoder 24, and the second encoder 25 in the imaging device 3 based on the convergence value of the decoding of the non-key frame in the motion compensation unit 34. It may be. The convergence value of decoding here means a log likelihood value for each pixel in the non-key frame WZn. If the log likelihood value logP _{c, p} ^WZn (i, j) is not sufficiently converged, the error correction capability of the second encoder 25 may be low, so the mode is switched to a higher correction mode. The high correction mode means processing such as switching a thinning pattern, sending more information, and switching encoding parameters.

  Further, whether or not the log likelihood value is sufficiently converged is determined by calculating a statistic such as the variance of the log likelihood value and comparing it with a predetermined threshold value. .

  When the convergence value of decoding of the non-key frame by the motion compensation unit 34 is less than a predetermined value, the image encoder 23 performs code amount control for the key frame that is intra-coded. At this time, the control unit 37 performs code amount control on the image encoder 23 so that the bit rate when the key frame is converted into the wireless data stream becomes higher.

  Thereby, at the time of decoding in the motion compensation unit 34, the log likelihood value can be converged more sufficiently, and the pixel interpolation of the non-key frame can be performed with high accuracy.

  As described above, in the present invention, the imaging device 2 can perform all of the imaging bit rate, the ratio of key frames, and even the code amount control on the control device 3 side. Also, motion compensation for non-key frames is not executed in the imaging device 2, but is executed only on the control device 3 side, and motion vector information used for the motion compensation is always acquired and used for control by the control unit 37. can do.

  Therefore, it is not necessary to mount a circuit for performing motion compensation and control based on this on the imaging device 2 side, so that the shape of the imaging device 2 can be further reduced and the weight can be reduced. Is also possible.

  That is, according to the present invention, it is possible to reduce the size and weight when the imaging device 2 is embedded in a human body, and to capture an imaging target whose movement speed is various and may change from moment to moment. The imaging device 2 can be controlled so that a moving image can be acquired under appropriate conditions based on motion vector information and the like.

1 is an overall configuration diagram of an imaging system to which the present invention is applied. 1 is a block configuration diagram of an imaging system to which the present invention is applied. It is a figure for demonstrating operation | movement of the imaging system to which this invention is applied. It is a figure for demonstrating the example of the motion compensation in the imaging system to which this invention is applied. It is a figure for demonstrating a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging system 2 Imaging device 3 Control apparatus 5 Wireless transmission system 21 Camera 22 Distributor 23 Image encoder 24 1st encoder 25 2nd encoder 26 Transmitter 31 Receiver 32 Decoder 33 Image decoder 34a Motion Compensation unit 34b Non-key frame reconstruction unit 35 Composition unit 36 Video display unit 37 Control unit 38 SNR detection unit

Claims (11)

Imaging means for distributing moving image data generated by imaging a subject into key frames and non-key frames, intra-frame encoding means for intra-coding the key frames, and non-key frames and intra-frame encoding An imaging device having encoding means for encoding each of the encoded key frames, and transmission means for transmitting the encoded key frames and non-key frames as wireless data streams, respectively;
Decoding means for decoding the key frame and the non-key frame from the wireless data stream received from the imaging device, intra-frame decoding means for further decoding the decoded key frame in the frame, and the frame Motion compensation means for compensating motion of an intra-frame object with respect to the decoded non-key frame based on information on the inner decoded key frame, and the motion-compensated non-key frame and the key frame are synthesized A moving image generating unit that generates a moving image, and a control unit that controls the imaging unit in the imaging device via wireless communication based on motion vector information used for motion compensation by the motion compensation unit. An imaging system comprising: a control device. The control means controls the imaging means so as to adjust a ratio of key frames and non-key frames per unit time based on a motion vector amount used for motion compensation by the motion compensation means for the intra-frame object. The imaging system according to claim 1, wherein: The control unit controls the imaging unit to adjust a frame rate of the key frame and the non-key frame based on a motion vector amount used for motion compensation by the motion compensation unit of the intra-frame object. The imaging system according to claim 1, wherein: The control means controls the imaging means so as to increase the frame rate when a motion vector amount used for motion compensation by the motion compensation means for the intra-frame object is a predetermined value or more. The imaging system according to claim 3. Imaging means for distributing moving image data generated by imaging a subject into key frames and non-key frames, intra-frame encoding means for intra-coding the key frames, and non-key frames and intra-frame encoding An imaging device having encoding means for encoding each of the encoded key frames, and transmission means for transmitting the encoded key frames and non-key frames as wireless data streams, respectively;
Decoding means for decoding the key frame and the non-key frame from the wireless data stream received from the imaging device, intra-frame decoding means for further decoding the decoded key frame in the frame, and the frame Motion compensation means for compensating motion of an intra-frame object with respect to the decoded non-key frame based on information on the inner decoded key frame, and the motion-compensated non-key frame and the key frame are synthesized Then, based on the convergence value of the decoding of the non-key frame by the decoding unit, the intra-frame encoding unit or the encoding unit in the imaging device is controlled by wireless communication based on the moving image generation unit that generates a moving image. An imaging system comprising: a control device having control means. The encoding means performs error correction encoding on the non-key frame, and uses only the redundant component or the syndrome component as data for the wireless data stream,
The control means, based on the convergence value of the decoding of the non-key frames by said decoding means, the imaging system according to claim 5, wherein the switching the error correction encoding method in the encoding means. When the convergence value of the decoding of the non-key frame by the decoding unit is less than a predetermined value, the control unit is configured to increase the bit rate of the wireless data stream of the key frame that is intra-coded. The imaging system according to claim 5, wherein code amount control is performed on the intra-frame encoding means. The encoding means performs encoding based on the Distributed Video Coding (DVC) system,
The imaging system according to any one of claims 1 to 7, wherein the decoding unit performs decoding based on a DVC method. The imaging device is embedded in the human body,
The imaging system according to claim 1, wherein the transmission unit transmits a wireless data stream based on a wireless communication scheme based on a specific low power wireless station or a weak wireless station.   An imaging device applied in the imaging system according to claim 1.   The control apparatus applied in the imaging system of any one of Claims 1-10.

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