Patent Publication Number: US-2017367561-A1

Title: Capsule endoscope, image processing system including the same and image coding device included therein

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2016-0079578, filed on Jun. 24, 2016, the entire contents of which are hereby incorporated by reference. 
     TECHNICAL FILED 
     The present disclosure herein relates to a capsule endoscope, and more particularly, to a capsule endoscope that uses an image coding device to process a captured image. 
     DESCRIPTION OF THE RELATED ART 
     A capsule endoscope refers to a pill-shaped micro endoscope that has a diameter of about 9 mm to about 11 mm and a length of about 24 mm to about 26 mm. When a patient swallows the capsule endoscope, the capsule endoscope may image the inside of organs such as stomach, small intestine and large intestine. Doctors may directly examine the inside of the organs through a video screen or computer monitor. Since the capsule endoscope is significantly small, it is possible to relieve feeling of irritation and pain that patients have felt during typical endoscope examination. 
     The capsule endoscope employs a wireless communication technique in order to transmit captured image data. In order to use the wireless communication technique, the capsule endoscope transmits image data by using a high-frequency signal. However, since in order to transmit the image data by using the high-frequency signal, the capsule endoscope needs to have a modulation circuit, its volume may increase. 
     For the above reasons, the capsule endoscope employs a human-body communication technique in order to transmit the captured image data. The human-body communication may generate a current inside a human body to transmit image data to the outside of the human body. Since the human-body communication transmits data by using the human body as a medium, it does not need the high-frequency signal. However, the data rate of the human-body communication is slower than that of the wireless communication. 
     SUMMARY 
     The present disclosure provides a capsule-type device that performs coding and logical operation on captured image data to generate final data and output the generated final data to the outside of a human body, an image processing system including the same, and an image coding device included therein. 
     A capsule endoscope, image processing system including the same and image coding device included therein according to embodiments of the inventive concept include a light source, image sensor, processor and communication circuit. 
     The light source emits light to an internal surface of an organ of a human body, the image sensor receives light reflected from the internal surface of the organ to generate image data, the processor generates coded data by coding the image data provided from the image sensor and generates final data by performing logical operation on the coded data and a binary code, and the communication circuit outputs the final data to an outside of the human body. 
     An image processing system according to an embodiment of the inventive concept includes a capsule endoscope and reception device. 
     The capsule endoscope generates first image data based on an image inside an organ, performs coding on the first image data to generate coded data, and performs a logical operation on the coded data and a binary code to generate final data, and the reception device generates recovery data by performing the logical operation on the final data provided from the capsule endoscope and the binary code and to generate second image data by decoding corresponding to the coding on the recovery data. 
     A capsule endoscope, image processing system including the same and image coding device included therein according to embodiments of the inventive concept include an image sensor, image processor and communication circuit. 
     The image sensor receives light from an outside to generate image data, the image processor generates coded data by coding the image data provided from the image sensor and generates final data by performing a logical operation on the coded data and a binary code, and the a communication circuit outputs the final data. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the inventive concept and, together with the description, serve to explain principles of the inventive concept. In the drawings: 
         FIG. 1  is a block diagram that shows an image processing system including a capsule endoscope according to an embodiment of the inventive concept; 
         FIG. 2  is a block diagram that shows the capsule endoscope in  FIG. 1 ; 
         FIG. 3  is a block diagram that shows an image processor in  FIG. 2 ; 
         FIG. 4  is a conceptual view that shows a logical operation on data performed at a first logical operator in  FIG. 3 ; 
         FIG. 5  is a block diagram that shows a reception device in  FIG. 1 ; 
         FIG. 6  is a block diagram that shows a data recovery circuit in  FIG. 5 ; 
         FIG. 7  is a flow chart that shows an image coding method of the capsule endoscope in  FIG. 2 ; 
         FIG. 8  is a flow chart that shows an image decoding method of the reception device in  FIG. 5 ; and 
         FIG. 9  is a conceptual view that shows a capsule endoscope according to an embodiment of the inventive concept. 
     
    
    
     DETAILED DESCRIPTION 
     In the following, embodiments of the inventive concept are described clearly and in detail so that a person skilled in the art to which the inventive concept pertains may easily practice the inventive concept. 
       FIG. 1  is a block diagram that shows an image processing system including a capsule endoscope according to an embodiment of the inventive concept. An image processing system  1000  according to an embodiment of the inventive concept may include a capsule endoscope  100  and a reception device  200 . 
     As shown in  FIG. 2 , a human being  20  may swallow the capsule endoscope  100  for endoscopy. When the human being  20  swallows the capsule endoscope  100 , the capsule endoscope  100  may move the inside of an organ to image the internal surface of the organ to generate image data. As an example, the capsule endoscope  100  may start imaging from when entering the inside of the organ. As an example, the capsule endoscope  100  may start imaging from when entering the inside of the organ. 
     The capsule endoscope  100  may generate data by coding the captured image data. The capsule endoscope  100  may output the generated data to the outside of the human being  20 . As an example, the capsule endoscope  100  may transmit the generated data to the reception device  200  that is installed outside the human being  20 . The configuration of the capsule endoscope  100  is described with reference to  FIGS. 2 to 4  below. 
     The reception device  200  may receive data from the capsule endoscope  100 . The reception device  200  may decode the received data to generate image data. As an example, the reception device  200  may be implemented in at least one of a personal computer, desktop, laptop, tablet computer, digital camera, camcorder, smart phone, mobile device, and wearable device. 
     The reception device  200  may display image data. In addition, the reception device  200  may analyze and read the image data. As an example, the reception device  200  may implement various functions, such as image enlargement, continuous-viewing, and edition by using an image reader. The configuration of the reception device  200  is described in detail with reference to  FIGS. 5 and 6 . 
       FIG. 2  is a block diagram that shows the capsule endoscope in  FIG. 1 . Referring to  FIGS. 1 and 2 , the capsule endoscope  100  may include an image coding device A, a controller  150 , and a battery  160 . 
     The image coding device A may include an image sensor  110 , an image processor  120 , a first memory  130 , and a first communication circuit  140 . The image coding device A may be included in the capsule endoscope  100  for image data processing. The embodiment is not limited thereto and the image coding device A may be included in at least one of the personal computer, desktop, laptop, tablet computer, digital camera, camcorder, smart phone, mobile device, and wearable device, for the image data processing. 
     The image sensor  110  may receive light from a lens (not shown). The image sensor  110  may be one of a charge coupled device (CCD) and complementary metal-oxide semiconductor (CMOS). As an example, it is assumed that the image sensor  110  is the CCD. The image sensor  110  incorporates a plurality of photo-diode elements. When light enters the plurality of photo-diodes, each of the plurality of photo-diodes may generate an electron according to an amount of incident light. The image sensor  110  may generate image data based on the amount of electron generated. 
     The image processor  120  may receive the image data from the image sensor  110 . The image processor  120  may use the image data to generate residual data, and process the generated residual data. The image processor  120  may convert and quantize the residual data. The conversion and quantization of the residual data and image data are further described with reference to  FIG. 3 . 
     The image processor  120  may perform coding and a logical operation by using the converted and quantized residual data. The image processor  120  may transmit, to the first memory  130 , final data that is generated through the coding and the logical operation process. The embodiment is not limited thereto and the image processor  120  may transmit the final data directly to the first communication circuit  140 . The configuration of the image processor  120  is described with reference to  FIG. 3 . 
     The first memory  130  may receive the final data from the image processor  120 . The memory  130  may store the final data. The first memory  130  may be at least one of a nonvolatile memory and volatile memory. In the case where the first memory  130  is the nonvolatile memory, the memory may store data that needs preservation. As an example, the first memory  130  may include a NAND-type flash memory, phase-change RAM (PRAM), magneto-resistive RAM (MRAM), resistive RAM (ReRAM), ferro-electric RAM (FRAM), and NOR-type flash memory. 
     Alternatively, the first memory  130  may include a memory of a different kind together. As an example, the first memory  130  may include at least one of a static random access memory (SRAM), dynamic RAM (DRAM), and synchronous dynamic random access memory (SDRAM) that may temporarily store data, in addition to the nonvolatile memory. The first memory  130  may output stored final data in response to the control of the controller  150 . The embodiment is not limited thereto and the first memory  130  may regularly output the stored final data. Alternatively, the first memory  130  may transmit final data to the first communication circuit in response to an input external request. 
     The first communication circuit  140  may output received final data to the outside of a human body. The first communication circuit  140  may receive a data request from the reception device  200 , and provide final data to the reception device  200  in response thereto. Alternatively, the first communication circuit  140  may provide the received final data to the reception device  200  in real time. 
     The controller  150  may control the general operations of the image processor  120 , the first memory  130 , the first communication circuit  140 , and the battery  160 . In addition, the battery  160  may supply power for the actuation of the capsule endoscope  100 . In order for the controller  150  to perform a control operation, the battery  160  may continuously supply power to the controller  150 . As an example, the battery  160  may supply power in response to the control of the controller  150 . When the capsule endoscope  100  arrives at a desired location for performing imaging, the controller  150  may control the power supply of the battery  160  in order to supply power to the image sensor  110 , the image processor  120 , the first memory  130 , and the first communication circuit  140 . 
     As another example, by the control of the controller  150 , the battery  160  may supply power to the image sensor  110 , the image processor  120 , and the first memory  130  for a first time. In addition, after image is performed for the first time, the battery  160  may supply power to the first communication circuit  140  during a second time so that final data may be output to outside. As such, the controller  150  may control the power supply of the battery  160  in order to extent the imaging time of the capsule endoscope  100 . 
       FIG. 3  is a block diagram that shows the image processor in  FIG. 2 . Referring to  FIG. 3 , the image processor  120  may include a second memory  121 , an address generator  122 , an intra mode determination circuit  123 , an intra predictor  124 , an adder  125 , a transformer/quantizer  126 , a coder  127 , and a first logical operator  128 . 
     The second memory  121  may receive image data from the image sensor  110 . The second memory  121  may be a nonvolatile memory. As an example, the second memory  121  may include at least one of the NAND flash memory, PRAM, MRAM, ReRAM, FRAM and NOR flash memory. The second memory  121  may receive an address from the address generator  122 . The second memory  121  may selectively output final data according to the received address. Also, the second memory  121  may store a binary code needed for logical operation. 
     The address generator  122  may generate an address according to the control of the controller  150 . The address generator  122  may provide the generated address to the second memory  121 . 
     The intra mode determination circuit  123  may determine a mode for performing intra prediction. As an example, the intra mode determination circuit  123  may select at least one of nine prediction modes in order to decrease the difference between a prediction block and a block to be coded. The intra mode determination circuit  123  may transmit, to the intra predictor  124 , information on the selected prediction mode among the nine prediction modes. 
     The intra predictor  124  may perform intra prediction on image data on a macro block basis. The macro block is a process unit of an image compression format. As an example, the macro block may have a size of 4×4 or 16×16. The intra predictor  124  may use a macro block adjacent to the prediction target macro block of the current frame of the image data to obtain prediction data on the prediction target macro block. That is, intra prediction may be performed based on macro blocks that are included in a single frame. The intra predictor  124  may generate prediction data by the intra prediction. 
     The adder  125  may receive image data from the second memory  121 , and receive prediction data from the intra predictor  124 . The adder  125  may add the image data and the prediction data. The adder  125  may generate residual data based on the prediction data and the image data. The residual data may be generated as a result of the operation between the prediction data and the image data. The adder  125  may provide the residual data to the transformer/quantizer  126 . 
     The transformer/quantizer  126  may receive the residual data. The transformer/quantizer  126  may transform the residual data to frequency-domain data and quantize the frequency-domain data. As an example, the transformation may be one of discrete cosine transform (DCT), discrete sine transform (DST), and integer transform. The transformer/quantizer  126  may provide the transformed and quantized residual data to the coder. 
     The coder  127  may receive the transformed and quantized residual data. The coder  127  may perform coding on the transformed and quantized residual data. As an example, the coding may be entropy coding. As an example, the entropy coding may be one of Huffman coding, arithmetic coding, range encoding, universal coding, Shannon-Fano coding, and Tunstall coding. The coder  127  may generate coded data using the entropy coding. The coder  127  may provide the generated coded data to the first logical operator  128 . 
     The first logical operator  128  may receive the coded data. The first logical operator  128  may perform a logical operation on the coded data. As an example, the first logical operator  128  may perform the logical operation on a binary code and the coded data. The first logical operator  128  may receive the binary code from the second memory  121 . The logical operation method of the first logical operator  128  is described with reference to  FIG. 5 . The first logical operator  128  may use the logical operation to generate final data. The first logical operator  128  may provide the generated final data to the first memory  130 . 
       FIG. 4  is a conceptual view that shows a logical operation on data performed at the first logical operator in  FIG. 3 . Referring to  FIGS. 3 and 4 , the first logical operator  128  may perform exclusive OR (XOR) operation on the coded data and any binary code. As an example, any binary code may be a 16-bit code in which digits “1” and “0” are alternately arranged. The embodiment is not limited thereto, and any binary code may be configured in various forms. 
     Since human-body communication is a communication method in which a human body is used as a medium, there is the probability that an error occurs. Also, the coded data in which the same values are continuously arranged may be vulnerable to an error that may occur in a communication process. By performing XOR operation on the coded data and the binary code, generated final data may experience a decrease in the continuous arrangement of the same values. Thus, the final data has high resistance to an error. In addition, since the XOR operation needs no complicated operation, the first logical operator  128  consumes low power. 
     The capsule endoscope  100  according to an embodiment of the inventive concept may generate final data by performing entropy coding and XOR operation on image data. Since the capsule endoscope  100  transmits the image data in the form of final data, the probability that an error occurs may decrease. 
       FIG. 5  is a block diagram that shows the reception device in  FIG. 1 . The reception device  200  may include a second communication circuit  210 , a data recovery circuit  220 , a display unit  230 , and a controller  240 . 
     The second communication circuit  210  may communicate with the capsule endoscope  100 . As an example, the second communication circuit  210  may receive final data from the capsule endoscope  100 . Also, the second communication circuit  210  may request the final data from the capsule endoscope  100  in response to the control signal of the controller  240 . The second communication circuit  210  may deliver the received final data to the data recovery circuit  220 . 
     The data recovery circuit  220  may decode the final data. The data recovery circuit  220  may perform a logical operation and decoding on the final data to generate decoded data. In addition, the data recovery circuit  220  may recover residual data by performing inverse transformation and dequantization on the decoded data. In addition, the data recovery circuit  220  may perform intra prediction on the decoded data. The data recovery circuit  220  may use the residual data and the intra-predicted data to output image data to the display  230 . The structure of the data recovery circuit  220  is described with reference to  FIG. 6 . 
     The display  230  may display the image data. As an example, the display  230  may be implemented in one of a liquid crystal display (LCD), organic light emitting diode (OLED) display, active matrix OLED (AMOLED) display, and LED. 
     The controller  240  may control the operations of the second communication circuit  210 , the data recovery circuit  220 , and the display unit  230 . As an example, the controller  240  may generate a control signal for requesting final data from the capsule endoscope  100 . The generated control signal may be provided to the capsule endoscope  100  through the second communication circuit  210 . 
       FIG. 6  is a block diagram that shows the data recovery circuit in  FIG. 5 . The data recovery circuit t  220  may include a second logical operator  221 , a decoder  222 , an inverse transformer/dequantizer  223 , a memory  224 , an intra predictor  226 , and an adder  227 . 
     The second logical operator  221  may use a binary code used for the logical operation in the capsule endoscope  100  to perform the logical operation. At this point, the second logical operator  221  may receive the binary code from the memory  224 . As an example, the second logical operator  221  may perform XOR operation on final data and the binary code. The second logical operator  221  may perform XOR operation to generate recovery data. In the case where there is no communication error, the recovery data may be the same as the coded data of the capsule endoscope  100 . The second logical operator  221  may provide the recovery data to the decoder  222 . 
     The decoder  222  may generate decoded data by decoding the recovery data. The decoder  222  may provide the decoded data to the inverse transformer/dequantizer  223 . 
     The inverse transformer/dequantizer  223  may inversely transform the decoded data and dequantize the inversely transformed data. Accordingly, the inverse transformer/dequantizer  223  may recover the residual data. The inverse transformer/dequantizer  223  may provide the residual data to the adder  227 . 
     The memory  224  may store the decoded data. As an example, the memory  224  may be a nonvolatile memory. The memory  224  may provide the decoded data to the intra predictor  226 . In  FIG. 6 , the memory  224  is installed outside the decoder  222  and the intra predictor  226 . However, the memory  224  may be included in one of the decoder  222  and the intra predictor  226 . 
     The intra predictor  226  may generate prediction data by performing intra prediction on the decoded data. The configuration and function of the intra predictor  226  are those of the intra predictor  124  in  FIG. 4 . 
     The adder  227  may receive residual data recovered by the inverse transformer/dequantizer  223  and prediction data generated by the intra predictor  226 . The adder  227  may add the residual data and the prediction data. The adder  227  may provide data corresponding to a result of operation (e.g., image data) to the display  230 . 
       FIG. 7  is a flow chart that shows an image coding method of the capsule endoscope in  FIG. 2 . Referring to  FIGS. 2 and 7 , the image sensor  110  of the capsule endoscope  100  receives light through a lens in step S 110 . The image sensor  110  may use the received light to generate image data. 
     In step S 120 , the capsule endoscope  100  may perform coding on the image data. The coding may be performed by the image processor  120  of the capsule endoscope  100 . As an example, the coding may be entropy coding. The image processor  120  may generate coded data by coding the image data. 
     In step S 130 , the capsule endoscope  100  may perform a logical operation on the coded data. The logical operation may be performed by the image processor  120  of the capsule endoscope  100 . As an example, the logical operation may be XOR operation. The image processor  120  may generate final data by performing the logical operation on the coded data. 
     In step S 140 , the capsule endoscope  100  may output final data to the outside of a human body. The final data may be output through the first communication circuit  140  of the capsule endoscope  100 . The first communication circuit  140  may output the final data by using a human-body communication method. 
     Referring to  FIG. 7 , the capsule endoscope  100  according to an embodiment of the inventive concept may generate final data by performing coding and logical operation on image data. Accordingly, the final data may have high resistance to an error that may occur in human-body communication. 
       FIG. 8  is a flow chart that shows an image decoding method of the reception device in  FIG. 5 . Referring to  FIGS. 5 and 8 , in step S 210 , the reception device  200  may receive final data. As an example, the reception device  200  may receive the final data through the second communication circuit  210 . 
     In step S 220 , the reception device  200  may perform a logical operation on the final data. The logical operation may be performed by the data recovery circuit  220  of the reception device  200 . As an example, the logical operation may be XOR operation. The data recovery circuit  220  may generate recovery data by performing the logical operation on the final data. 
     In step S 230 , the reception device  200  may perform decoding on the recovery data. The decoding may be performed by the data recovery circuit  220  of the reception device  200 . As an example, the decoding may be entropy decoding. The data recovery circuit  220  may perform decoding on the recovery data to generate decoded data. In addition, the data recovery circuit  220  may generate image data using the decoded data. 
     In step S 240 , the reception device  200  may display the image data. The display  230  of the reception device  200  may display the image data. 
     The reception device  200  according to an embodiment of the inventive concept may perform the logical operation and decoding on the final data that is received from the capsule endoscope  100 . Accordingly, it is possible to provide recovered image data through the display  230 . 
       FIG. 9  is a conceptual view that shows a capsule endoscope according to an embodiment of the inventive concept. A capsule endoscope  2000  may include capsule portions  2100  and  2100   a , a lens  2200 , a light source  2300 , an image sensor  2400 , a power source  2500 , a processor  2600 , and a communication circuit  2700 . 
     The capsule portions  2100  and  2100   a  may be formed from a material harmless to a human body. As an example, the capsule portion  2100   a  of the capsule portions  2100  and  2100   a  that surrounds the lens  2200  may be formed from a semi-spherical transparent material that is in the shape of an optical dome. As an example, the capsule portion  2100   a  may be a transparent plastic material. The capsule portions  2100  and  2100   a  may include the lens  2200 , the light source  2300 , the image sensor  2400 , the power source  2500 , the processor  2600 , and the communication circuit  2700  therein. As an example, there may be a space between the capsule portion  2100   a  and the lens  2200 . Thus, even when an organ contracts, the lens  2200  may perform imaging while maintaining a certain distance from the inner wall of the organ. 
     The lens  2200  may receive light reflected from the internal surface of an organ inside a human body. As an example, the lens  2200  for endoscope may be a short focal length lens that includes a small aperture. The light source  2300  may be located around the lens  2200 . As an example, the light source  2300  may be an LED. There may be included one or more light source  2300 . Since the inside of an organ is dark, there may be a need for the light source  2300  for endoscopy. While the light source  2300  emits light, it may illuminate the inside of the organ. As an example, the light source  2300  may regularly emit light. 
     The image sensor  2400  may obtain light received from the lens  2200 . The image sensor  2400  is similar or the same as the image sensor  110  in  FIG. 2 . The image sensor  2400  may generate image data. The image sensor  2400  may deliver the generated image data to the processor  2600 . 
     The power source  2500  may supply power for the actuation of the capsule endoscope  2000 . The power source  2500  may supply power to the light source  2300 , the image sensor  2400 , the processor  2600 , and the communication circuit  2700 . 
     The processor  2600  may perform various logical operations and/or logical operation in order to process operations. To this end, the processor  2600  may include one or more processor cores. As an example, the processor core of the processor  2600  may include a special purpose logic circuit (e.g., field programmable gate array (FPGA), an application specific integrated chip (ASIC) or the like). 
     The processor  2600  may be similar or the same as the image processor  120  in  FIG. 2 . The processor  2600  may receive image data from the image sensor  2400 . The processor  2600  may process the received image data. Since the operation of the processor  2600  has been described with reference to  FIG. 2 , a detailed description is omitted. The processor  2600  may deliver, to the communication circuit  2700 , final data that is generated through the processing of the image data. 
     The communication circuit  2700  may receive the final data from the processor  2600 . The communication circuit  2700  may transmit the final data to the outside of a human body through human-body communication. 
     According to an embodiment of the inventive concept, data loss may decrease and image processing efficiency may be enhanced when image data inside an organ is transmitted to the outside of a human body. 
     The above-described details are particular examples for practicing the inventive concept. The inventive concept would include not only the above-described embodiments but also embodiments that may be simply changed in design or easily changed. Also, the inventive concept would also include techniques that may be practiced through an easy variation in the future by the using of the above-described embodiments.