JP2012011123A - Electronic endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope apparatus restraining image quality deterioration caused by a transmission error while reducing the outer diameter of a distal end.SOLUTION: An imaging unit 11 provided at the distal end 10 images a subject and generates image signals. An A/D conversion unit 12 provided at the distal end 10 quantitizes the image signals and generates image data. An ECC encoding unit 13 provided at the distal end 10 encodes the image data using error correction codes and generates encoding data. An ECC decoding unit 21 provided at a body unit 20 corrects the transmission errors of the image data by decoding the encoding data. An image processing unit 22 provided at the body unit 20 corrects the transmission errors left in the image data after the correction made by the ECC decoding unit 21.

Description

  The present invention relates to an electronic endoscope apparatus.

  In recent years, it has been proposed to mount a CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) image sensor on an electronic endoscope apparatus. Since the CMOS image sensor is manufactured using a CMOS LSI (Large Scale Integration) technology, an A / D converter and other logic circuits can be mounted on the CMOS image sensor to manufacture an image pickup unit. . Therefore, it is easy to reduce the size of the image sensor.

  In the CMOS image sensor, the image signal is quantized in the imaging unit and output as digital data. Therefore, the image is transmitted as digital data from the distal end portion of the electronic endoscope apparatus to the main body portion, so that noise is being transmitted. Image quality degradation can be suppressed. However, transmission using digital data has a problem that the number of signal lines is increased as compared with the transmission of analog image signals, and the signal line diameter is increased due to an increase in transmission band.

  As a method for solving this problem, there is known a method of reducing the number of signal lines by converting RGB image data into a YCbCr image signal and reducing the number of bits of the color difference CbCr signal (see, for example, Patent Document 1).

  In addition, an error correction code (ECC, Error Check and Correct) is added to the RGB image data, the code portion added in the blank section existing for each scanning line is transmitted, and further, PSK modulation (Phase Shift Keying, Phase A method of suppressing an increase in the number of signal lines by combining signal lines by shift modulation is known (for example, see Patent Document 2).

  In addition, after transmitting image data encoded with an error correction code, error correction is performed on the receiving side, and the number of data that could not be corrected is fed back to the transmitting side. Is known (for example, see Patent Document 3).

  Further, a method of protecting an image data and related data by using an error correction code or a cyclic check code when transmitting the data wirelessly is known (for example, see Patent Document 4).

JP-A-5-316513 JP 2008-200344 A JP 2003-348391 A JP 2007-330794 A

  However, the above-described method has a problem that it is necessary to reduce the image quality by reducing the transmission speed when downsizing is important. In addition, when a method of increasing the transmission speed in order to maintain the image quality is used, there is a problem that the number of signal lines and the signal line diameter increase, and the outer diameter of the distal end portion increases. Further, in order to reduce the number of signal lines and the transmission speed while maintaining the image quality, there is a problem that it is necessary to have a carrier wave generation unit, a pixel buffer, and a high compression encoding unit at the tip. In addition, in order to reduce errors, it is necessary to have a large-scale error correction coding circuit that adds long redundant bits to long information bits at the tip, and there is a problem that the tip becomes large from the viewpoint of circuit scale.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic endoscope apparatus in which image quality deterioration due to a transmission error is suppressed while reducing the outer diameter of the distal end portion.

  The present invention is an electronic endoscopic apparatus comprising a distal end portion, a main body portion, and a transmission section that connects the distal end portion and the main body portion so that they can communicate with each other. An image pickup unit that generates an image signal, an A / D conversion unit that is provided at the tip and generates image data by quantizing the image signal, and an error correction code that is provided at the tip An encoding unit that encodes the image data to generate encoded data; a decoding unit that is provided in the main body unit and corrects a transmission error of the image data by decoding the encoded data; An electronic endoscope apparatus comprising: an image processing unit that is provided in a main body unit and corrects a transmission error remaining in the image data after correction by the decoding unit.

  Further, in the electronic endoscope apparatus of the present invention, the decoding unit generates error pixel position information indicating a position of a pixel included in the image data in which a transmission error cannot be corrected, and the image processing unit Is characterized in that the pixel data specified by the error pixel position information is interpolated by image interpolation.

  In the electronic endoscope apparatus of the present invention, the image processing unit replaces the data of the pixel specified by the error pixel position information with a value calculated based on values of pixels around the pixel. It is characterized by.

  In addition, the present invention includes a determination unit that is provided in the main body, determines a type of the tip, and generates determination information that uniquely specifies the type of the tip, and the encoding unit includes: The encoded data is generated using an error correction code determined for each type of tip, and the decoding unit is provided at the tip based on the type of the tip determined by the determination unit. The electronic endoscope apparatus is characterized in that the error correction code used in the encoded unit is specified, and the encoded data is decoded using the error correction code.

  In addition, the present invention provides a puncture unit provided at the front end portion for reducing the encoded data length by thinning out a part of the encoded data, and a signal provided at a portion provided in the main body portion and thinned by the puncture portion. And a code interpolation unit that restores the encoded data length to the original value.

  The present invention further includes a mode selection unit that is provided in the main body unit and outputs a mode selection signal that sets the number of bits of the encoded data to be thinned out by the puncture unit, and the puncture unit includes the encoded data Among them, the electronic endoscope apparatus is characterized in that data of the number of bits specified by the mode selection signal is thinned out.

  Further, the present invention provides a puncture unit provided at the tip part, which thins out data at a position determined for each type of the tip part from the encoded data to reduce the encoded data length, and the main body part. A discriminator for discriminating the type of the tip and generating discriminating information for uniquely identifying the type of the tip; and a type of the tip provided by the discriminator and discriminated by the discriminator. And a code interpolation unit that specifies a position at which the puncture unit provided at the tip part thins out the data, adds a signal to the specified position, and restores the encoded data length. An electronic endoscope apparatus characterized by the above.

  The present invention is also an electronic endoscope apparatus including a distal end portion and a main body portion, provided at the distal end portion, and provided at the distal end portion, an imaging portion that captures an image of a subject and generates an image signal. An A / D conversion unit that quantizes the image signal to generate image data; and an encoding unit that is provided at the tip and encodes the image data using an error correction code to generate encoded data. A transmission unit that is provided at the front end and transmits the encoded data to the main body; a reception unit that is provided at the main body and receives the encoded data transmitted from the front end; and the main body A decoding unit that corrects a transmission error of the image data by decoding the encoded data, and a transmission error that remains in the image data after correction by the decoding unit. Image processing to correct When an electronic endoscope apparatus characterized by having a.

  In the electronic endoscope apparatus of the present invention, the transmitting unit and the receiving unit transmit data using wireless communication.

  In the electronic endoscope apparatus of the present invention, the error correction code used in the encoding unit and the decoding unit is an error correction code that is encoded and decoded for each pixel.

  In the electronic endoscope apparatus of the present invention, the imaging unit is a single-plate color imaging element having a primary color filter or a complementary color filter.

  In the electronic endoscope apparatus of the present invention, the image processing unit generates color image data based on the decoded image data.

  According to the present invention, the encoding unit provided at the front end encodes image data using an error correction code to generate encoded data. In addition, a decoding unit provided in the main body unit corrects transmission errors in the image data by decoding the encoded data. An image processing unit provided in the main body corrects transmission errors remaining in the image data after correction by the decoding unit. As a result, the amount of data transmitted from the tip portion to the main body portion can be reduced, so that deterioration in image quality due to a transmission error can be suppressed while reducing the outer diameter of the tip portion.

It is the schematic which showed the structure of the electronic endoscope apparatus in the 1st Embodiment of this invention. It is the schematic which showed the example of data at the time of the transmission error correction process using the error correction code | symbol in the 1st Embodiment of this invention. It is the schematic which showed the data example at the time of the interpolation process of the decoded RAW image data in the 1st Embodiment of this invention. It is the flowchart which showed the interpolation procedure of the decoded RAW image data in the 1st Embodiment of this invention. It is the schematic which showed the data example at the time of the interpolation process of the decoded RAW image data in the 1st Embodiment of this invention. It is the schematic which showed the example of data at the time of the transmission error correction process using the error correction code | symbol in the 1st Embodiment of this invention. It is the schematic which showed the structure of the electronic endoscope apparatus in the 2nd Embodiment of this invention. It is the schematic which showed the structure of the electronic endoscope apparatus in the 3rd Embodiment of this invention. It is the schematic which showed the circuit structure of the puncture part in the 3rd Embodiment of this invention. It is the schematic which showed the data example at the time of the transmission error correction process using the thinning-out process of the redundant bit of the error correction code in the 3rd Embodiment of this invention. It is the schematic which showed the structure of the electronic endoscope apparatus in the 4th Embodiment of this invention. It is the schematic which showed the structure of the electronic endoscope apparatus in the 5th Embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of an electronic endoscope apparatus according to the present embodiment. In the illustrated example, the electronic endoscope apparatus 1 includes a distal end portion 10, a main body portion 20, and a transmission portion 30. The distal end portion 10 includes an imaging unit 11, an A / D conversion unit 12, and an ECC encoding unit 13 (encoding unit). The main body unit 20 includes an ECC decoding unit 21 (decoding unit), an image processing unit 22, and a display unit 23.

  The imaging unit 11 includes a CMOS, a CCD (Charge Coupled Device), and the like, shoots a subject, and generates a RAW image signal in which the received light intensity of each pixel is arranged. The A / D converter 12 quantizes the RAW image signal that is an analog signal to generate RAW image data that is digital data.

  The ECC encoding unit 13 generates encoded data from the RAW image data using an error correction code. At this time, redundant bits (redundant information) proportional to the bit error correction capability are added. The ECC encoding unit 13 converts the RAW image data into encoded data for each pixel of the RAW image data. As a result, it is not necessary to temporarily store data of a plurality of pixels as compared with the case of converting into encoded data in units of a plurality of pixels, so that it is not necessary to provide an extra storage area in the tip portion 10, and the ECC encoding unit 13 can also be made smaller, so that the circuit scale of the tip 10 can be made smaller.

  Further, in ECC decoding by the ECC decoding unit 21 that corrects a transmission error, which will be described later, by setting the unit of data that cannot be corrected to one pixel, it is possible to suppress the transmission error from spreading to a plurality of consecutive pixels. , Image quality deterioration can be made inconspicuous. When the unit of data that cannot be error corrected is a single pixel unit, the delay circuit is reduced by using a block code, so that the circuit scale can be reduced. However, the encoding method is such that the error correction unit is a single pixel unit. If so, the encoding method may not be a block code.

  The transmission unit 30 transmits the encoded data from the distal end portion 10 to the main body portion 20. When the transmission unit 30 transmits the encoded data from the distal end unit 10 to the main body unit 20, a transmission error occurs depending on the condition during transmission. This transmission error means that the bits in the encoded data are inverted.

  The ECC decoding unit 21 corrects and detects a transmission error included in the encoded data by using an error correction code, and generates decoded data and error pixel position information. For example, when the number of transmission errors included in the encoded data is within the range of the error correction capability, the ECC decoding unit 21 corrects the transmission error with the error correction code. If the number of transmission errors included in the encoded data is greater than the error correction capability and less than or equal to the error detection capability, the ECC decoding unit 21 cannot detect the error but detects it. Therefore, error detection information indicating that the pixel data includes an error is generated. The error detection information is managed in association with the pixel position, and is input to the subsequent image processing unit as error pixel position information.

  Based on the error pixel position information, the image processing unit 22 interpolates, by image interpolation, pixel data having errors that could not be corrected by the ECC decoding unit 21 and included in the decoded data, and generates output data. The display unit 23 displays an image based on the output data.

  Next, an error correction and error detection method using an error correction code will be described. In this embodiment, a linear code which is one method of error correction code is used. A linear code is a generic name of an encoding method in which a code word is generated by performing a matrix operation on each information word using an information word obtained by collecting a plurality of information bits as a processing unit.

  In the following examples, it is assumed that information bits are expressed by two numbers 0 and 1, and an operation between the information bits follows a Galois field GF (2). In other words, an operation modified so that 1 + 1 = 0 is used for normal arithmetic addition and multiplication. The information word and the code word can be represented by a vector in which a plurality of information bits are collected. Specifically, when the number of information bits is m and the code length is n, the information word w can be expressed as w = {w1, w2, w3,..., Wm}, and the codeword c is c = {C1, c2, c3,..., Cn}.

  An error during transmission can be expressed as an error position vector as e = {e1, e2, e3,..., En}, and the sum of the codeword and the error position vector is a received codeword r = c + e = { r1, r2, r3,..., rn}. Here, n> m.

  In a linear code, a conversion matrix that converts an information word into a code word is called a generator matrix, and is hereinafter expressed as G. At this time, the encoding process can be expressed by c = wG. When an error occurs during transmission, the codeword r at the time of reception can be expressed by r = c + e. For example, if the first bit of the code word is incorrect, e = {1, 0, 0,..., 0}. When no error occurs, e = {0, 0, 0,..., 0}.

In the decoding process, rH ^T is calculated using a parity check matrix with GH ^T = 0.
rH ^T = cH ^T + eH ^T = wGH ^T + eH ^T = eH ^T
When there is no error, that is, when e = 0, eH ^T = 0, but when there is an error, it is a value other than 0, and it can be seen that an error exists. Also, the value for uniquely determined by the error position vector e regardless the information word, can determine the error location knowing the value of eH ^T, errors can be corrected. This value is called a syndrome.

  Hereinafter, a Hamming code is given as an example of an error correction code, and a specific error correction and error position detection method using a syndrome will be described. As an example, consider a Hamming code defined by a generator matrix of equation (1) and a parity check matrix of equation (2).

  This code has an information bit number m = 4 and a code length n = 8. The correspondence table between the error position vector and the syndrome in this code is as shown in Table 1.

Hereinafter, a case where an information word indicated by w = {0, 1, 0, 1} is encoded and transmitted will be considered. When encoded with the above code, c = {0, 1, 0, 1, 1, 0, 1, 1}. If a 1-bit error e = {1, 0, 0, 0, 0, 0, 0, 0} occurs in this, the received code word is r = {1, 1, 0, 1, 1, 0, 1 , 1}. When the syndrome is calculated in the decoding process, rH ^T = {1, 1, 1, 1}, which indicates that an error exists.

Comparing based on the correspondence table between the error position vector and the syndrome shown in Table 1, the error position vector where rH ^T = {1, 1, 1, 1} is e = {1, 0, 0, 0, 0 , 0, 0, 0}, the code word {0, 1, 0, 1, 1, 0, 1, 1} in which the error is corrected can be obtained from r and e. Thereby, an error can be corrected.

Also, consider a case where a 2-bit error occurs in the above code, for example, the error position vector is e = {1, 1, 0, 0, 0, 0, 0, 0}. The syndrome eH ^{T at} this time is {0, 0, 1, 0}. However, even when another error position vector e = {0, 0, 0, 1, 0, 1, 0, 0}, the syndrome is { 0, 0, 1, 0}, the correspondence between the syndrome and the error position vector cannot be uniquely specified, and error correction cannot be performed. However, since the syndrome is not 0, the presence of an error can be detected. Therefore, in this code, the error detection capability is 2 bits and the error correction capability is 1 bit.

  Although the Hamming code has been described as an example of the encoding method, the encoding method used in the present embodiment is not limited to the Hamming code. For example, a Reed-Solomon code or a BCH code may be used as the encoding method.

  Next, transmission error correction processing using an error correction code will be described. FIG. 2 is a schematic diagram showing an example of data at the time of transmission error correction processing using the error correction code in the present embodiment. In the illustrated example, when RAW image data is transmitted from the distal end portion 10 to the main body portion 20, an example of data input to and output from each portion is illustrated.

  In the present embodiment, the RAW image data generated by the A / D conversion unit 12 has 8 information bits for each pixel. This information bit indicates a quantized received light intensity value in the RAW image data. The encoded data generated by the ECC encoding unit 13 is data obtained by adding 4 redundant bits to each pixel data of the RAW image data. As a result, when there is a 1-bit error in the data of each pixel to which redundant bits are added, the ECC decoding unit 21 can correct the error into correct data. Further, when a 2-bit error exists in the data of each pixel to which redundant bits are added, the ECC decoding unit 21 can detect that the data includes an error.

  FIG. 2A is a schematic diagram illustrating an example of RAW image data generated by the A / D conversion unit 12. In the example shown in the drawing, data of three pixels having pixel numbers p1 to p3 among the RAW image data generated by the A / D conversion unit 12 is illustrated. The data of each pixel with pixel numbers p1 to p3 is data including information bits D1 to D8. Information bits D1 to D8 each indicate 1-bit data.

  FIG. 2B is a schematic diagram illustrating an example of encoded data in which redundant bits are added by the ECC encoding unit 13 to the RAW image data generated by the A / D conversion unit 12. In the example shown in the figure, among the encoded data generated by the ECC encoding unit 13, data of three pixels having pixel numbers p1 to p3 is illustrated. Further, the data of each pixel with pixel numbers p1 to p3 is data including information bits D1 to D8 and redundant bits C1 to C4, respectively. The redundant bits C1 to C4 each indicate 1-bit data.

  FIG. 2 (3) is a schematic diagram illustrating an example of encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30. In the illustrated example, data of three pixels of pixel numbers p1 to p3 among the encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30 is illustrated. Also, error data generated during transmission of encoded data through the transmission path 30 is shown. Specifically, the information bit D4 indicates that the data of the pixel having the pixel number p1 is incorrect. Further, it is indicated that the information bit D2 and the information bit D6 are incorrect data among the data of the pixel of the pixel number p2. In addition, among the data of the pixel having the pixel number p3, the redundant bit C1 indicates incorrect data.

  FIG. 2 (4) is a schematic diagram illustrating an example of decoded data obtained by decoding the encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30 by the ECC decoding portion 21. . In the example shown in the figure, data of three pixels having pixel numbers p1 to p3 among the decoded data decoded by the ECC decoding unit 21 is shown. In FIG. 2 (3), the pixel data of the pixel numbers p1 and p3 each contain 1 bit of incorrect data, but the ECC decoding unit 21 corrects the incorrect data. In FIG. 2 (3), since the pixel data of pixel number p2 includes 2 bits of erroneous data, the ECC decoding unit 21 determines that the data of pixel number p2 is incorrect data. Identify and generate error pixel location information.

  As described above, when there is a 1-bit error in each pixel data of the encoded data transmitted from the front end 10 to the main body 20 via the transmission path 30, the ECC decoding unit 21 corrects the error. Data can be corrected. When there is a 2-bit error in each pixel data to which redundant bits are added, the ECC decoding unit 21 can detect and specify that the data contains an error.

  Next, a method of interpolating decoded RAW image data executed by the image processing unit 22 will be described. FIG. 3 is a schematic diagram showing an example of data at the time of interpolation processing of decoded RAW image data in the present embodiment. In the example shown in the drawing, RAW image data in which a total of 16 pixels are arranged in 4 pixels each in the vertical direction and the horizontal direction is shown as the RAW image data. In addition, all data included in the original RAW image data is expressed as 0 in order to express the error easily. That is, the original RAW image data is a black image.

  FIG. 3A is a schematic diagram illustrating an example of RAW image data generated by the A / D conversion unit 12. In the illustrated example, RAW image data of a black image generated by the A / D conversion unit 12 is illustrated. Note that pixel numbers p11 to p26 are assigned to the respective pixels. The pixel data of the pixel numbers p11 to p26 are “00000000” indicating black.

  FIG. 3B is a schematic diagram illustrating an example of RAW image data included in the encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30. In the example shown in the figure, one bit of erroneous data is included in the pixel data of pixel numbers p12, p19, and p26 due to a transmission error. Further, due to a transmission error, the pixel data of the pixel number p21 includes 2 bits of erroneous data. Since a transmission error means bit inversion, it is expressed as a numerical value “1” other than 0 in FIG. Although redundant bits are not described, it is assumed that there is no error in redundant bits.

  Specifically, the pixel data of the pixel number p12 changes to “00100000”, the pixel data of the pixel number p19 changes to “00000100”, the data of the pixel of the pixel number p21 changes to “01000010”, The pixel data of the pixel number p26 is changed to “00000001”.

  FIG. 3 (3) shows an example of RAW image data included in the decoded data obtained by decoding the encoded data transmitted from the front end 10 to the main body 20 via the transmission path 30 by the ECC decoding unit 21. It is the shown schematic. The ECC decoding unit 21 removes bit errors below the error correction capability using redundant bits. In addition, the ECC decoding unit 21 generates error pixel position information indicating a pixel position having a bit error that exceeds the error correction capability and is below the error detection capability.

  Specifically, in the example shown in FIG. 3 (2), the pixel data of the pixel numbers p12, p19, and p26 includes 1 bit of incorrect data, but in the example shown in FIG. 3 (3). , It is corrected to “00000000” by the ECC decoding unit 21. In the example shown in FIG. 3 (3), since the pixel data of the pixel number p21 includes 2 bits of erroneous data, the ECC decoding unit 21 erroneously sets the pixel data of the pixel number p21. The error pixel position information for identifying the data is generated.

  FIG. 3 (4) is a schematic diagram illustrating an example of RAW image data in which erroneous data included in the RAW image data specified by the ECC decoding unit 21 is interpolated by the image processing unit 22. The image processing unit 22 ignores erroneous data included in the RAW image data and performs interpolation based on data around the erroneous data. In the present embodiment, the image processing unit 22 uses an average value of data of pixels adjacent to erroneous data as interpolation data.

  Specifically, in the example shown in FIG. 3 (3), the pixel data of the pixel number p21 is incorrect data, but in the example shown in FIG. 3 (4), the image processing unit 22 sets “00000000”. Has been interpolated. This data is an average value of the data of the pixels with pixel numbers p17, p20, p22, and p25.

FIG. 4 is a flowchart showing an interpolation procedure of decoded RAW image data executed by the image processing unit 22 in the present embodiment.
(Step S <b> 101) The image processing unit 22 sets a row position i specifying the pixel row position to 0, and sets a column position j specifying the pixel column position to 0. Thereafter, the process proceeds to step S102.
(Step S102) The image processing unit 22 determines whether or not the data of the pixel (i, j) is incorrect data based on the error pixel position information generated by the ECC encoding unit 13. If the image processing unit 22 determines that the data of the pixel (i, j) is incorrect data, the process proceeds to step S103. Otherwise, the process proceeds to step S104.

(Step S103) The image processing unit 22 converts the data of the pixel (i, j) to the average value [{(i, j-1) + (i −1, j) + (i, j + 1) + (i + 1, j)} / 4]. Thereafter, the process proceeds to step S104.
(Step S104) The image processing unit 22 determines whether or not the row position i is the last row of the RAW image data. If the image processing unit 22 determines that the row position i is the last row of the RAW image data, the process proceeds to step S106. Otherwise, the process proceeds to step S105.

(Step S105) The image processing unit 22 adds 1 to the row position i (i = i + 1). Thereafter, the process returns to step S102.
(Step S106) The image processing unit 22 determines whether or not the column position j is the last column of the RAW image data. If the image processing unit 22 determines that the column position j is the last column of the RAW image data, the process ends, otherwise the process proceeds to step S107.
(Step S107) The image processing unit 22 adds 1 to the column position j (j = j + 1). Thereafter, the process returns to step S102.

  In the conventional electronic endoscope apparatus, even when a transfer error is included when transferring RAW image data from the distal end portion to the main body portion, the pixel data exceeding the error correction capability is output as it is. For this reason, the color of the pixel including the error data may be displayed as a color significantly different from the surroundings. This is a phenomenon called a bright spot or a dark spot, and was a very conspicuous image noise. If the error correction capability is increased in order to solve this problem, the amount of data transmitted from the front end portion to the main body portion increases. Therefore, in order to transmit a large amount of data, it is necessary to use a large-diameter signal line for the transmission part, and the outer diameter of the tip part connected to the signal line is also large.

  However, as described above, in the present embodiment, the ECC decoding unit 21 corrects data having a bit error below the error correction capability to a correct value. Further, the image processing unit 22 interpolates the erroneous data indicated by the error pixel position information with a value calculated based on the surrounding non-error data. Therefore, even if the error correction capability is lowered, erroneous data can be interpolated, so that the amount of data transmitted from the distal end portion 10 to the main body portion 20 can be reduced.

  Further, in the endoscope apparatus 1 of the present embodiment, since the amount of data transmitted from the distal end portion 10 to the main body portion 20 can be reduced, a small-diameter signal line can be used for the transmission portion 30. Therefore, the outer diameter of the tip 10 connected to the transmission unit 30 can also be reduced.

  Further, the ECC decoding unit 21 completely corrects pixel data having a bit error below the error correction capability. In addition, the pixel data having a bit error below the error detection capability is replaced by the image processing unit 22 with a value calculated based on the surrounding non-error pixel data. Therefore, bright spots and dark spots can be reduced.

  Next, a method for interpolating pixels including transmission errors in decoded RAW image data when the received light intensity value of an image sensor having a primary color filter with a Bayer array is used as RAW image data will be described. In the present embodiment, when an image sensor that generates a color image is used, the received light intensity value is encoded and transmitted from the distal end portion 10 to the main body portion 20 without transmitting the color image data after the development processing.

  Conventionally, since image interpolation is performed at the leading end and then sent to the transmission unit, it has been necessary to transmit all RGB data in order to maintain image quality. Therefore, when transmitting an image having three color components, the number of signal lines is tripled or the transmission speed is one third. Further, when the number of signal lines is not increased or the transmission speed is not reduced, it is necessary to reduce the amount of information to be transmitted. In order to reduce the amount of information to be transmitted, irreversible compression must be performed, so that the image quality deteriorates.

  In the present embodiment, by performing development processing in the image processing unit 22 of the main body unit 20, the same information is obtained with one-third signal lines as compared to the case where all the RGB data is transmitted from the distal end unit 10. Can be transmitted. Therefore, even when an image sensor that generates a color image is used, a decrease in transmission speed can be suppressed while maintaining the image quality while maintaining the number of signal lines in the transmission unit.

  FIG. 5 shows an example of data at the time of interpolation processing of decoded RAW image data when the received light intensity value of an image sensor having a primary color filter with a Bayer array is used as RAW image data in this embodiment. FIG. In the example shown in the drawing, RAW image data in which a total of 9 units are arranged as 3 units of Bayer arrays in the vertical and horizontal directions is shown as the RAW image data. One unit of the Bayer array includes one pixel (R pixel) that detects red light, two pixels (G pixels) that detect green light, and one pixel (B pixel) that detects blue light. Included.

  FIG. 5A is a schematic diagram illustrating an example of RAW image data generated by the A / D conversion unit 12. In the illustrated example, no error is included in the data of any pixel.

  FIG. 5B is a schematic diagram illustrating an example of RAW image data included in encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30. In the example shown in the figure, due to a transmission error, the pixel data of pixel numbers p51, p52, and p53 includes 1 bit of erroneous data. In addition, due to a transmission error, the pixel data of the pixel number p54 includes 2 bits of erroneous data.

  FIG. 5 (3) shows an example of RAW image data included in the decoded data obtained by decoding the encoded data transmitted from the front end 10 to the main body 20 via the transmission path 30 by the ECC decoding unit 21. It is the shown schematic. The ECC decoding unit 21 removes bit errors below the error correction capability using redundant bits. In addition, the ECC decoding unit 21 generates error pixel position information indicating a pixel position having a bit error that exceeds the error correction capability and is below the error detection capability.

  Specifically, in the example shown in FIG. 5 (2), the pixel data of the pixel numbers p51, p52, and p53 includes one bit of erroneous data, but in the example shown in FIG. 5 (3). The data of the pixels with pixel numbers p51, p52, and p53 are corrected by the ECC decoding unit 21. In the example shown in FIG. 5 (3), since the pixel data of the pixel number p54 includes 2 bits of erroneous data, the ECC decoding unit 21 erroneously sets the pixel data of the pixel number p54. The error pixel position information for identifying the data is generated.

  FIG. 5 (4) is a schematic diagram illustrating an example of RAW image data in which erroneous data included in the RAW image data specified by the ECC decoding unit 21 is interpolated by the image processing unit 22. The image processing unit 22 ignores erroneous data included in the RAW image data and performs interpolation based on data around the erroneous data. In this embodiment, the image processing unit 22 is a pixel that detects light of the same color as that of erroneous data, and uses an average value of data of pixels that are close to the erroneous data as interpolation data.

  Specifically, in the example shown in FIG. 5 (3), the pixel data of the pixel number p54 is incorrect data, but in the example shown in FIG. 5 (4), the data is interpolated by the image processing unit 22. Yes. This data is an average value of the data of the pixels of the pixel numbers p55, p56, p57, and p58 that detect the light of the same color as the pixel of the pixel number p54 and are the closest to the pixel of the pixel number p54.

  The error pixel interpolation process described above is the same process as the defective pixel correction process. In this embodiment, in the defective pixel determination process, in addition to the information from the defective pixel position recorded in advance, the error pixel position information is referred to, and the transmission is performed while using the existing defective pixel correction process as it is. It is possible to correct errors.

  In addition, the error pixel interpolation processing method is not limited to the above-described example. For example, the same pixel value as the error pixel included in the image one frame before may be used as the interpolation data.

  As described above, in this embodiment, even when a color image is transmitted, the ECC decoding unit 21 corrects data having a bit error below the error correction capability to a correct value. Further, the image processing unit 22 interpolates erroneous data indicated by the error pixel position information with a value calculated based on the surrounding non-error value. Therefore, a pixel having a bit error less than the error correction capability is completely corrected, and data of a pixel having a bit error less than the error detection capability is replaced with surrounding non-error pixel data. Therefore, bright spots and dark spots can be reduced. Therefore, since the RAW image data can be transmitted without slowing down the transmission speed and without degrading the image quality, a thin signal line can be used, and the outer diameter of the distal end portion 10 can be reduced.

  In the above-described example, 4-bit data is added as a redundant bit. However, the present invention is not limited to this, and a redundant bit may be added to further increase the error correction capability. FIG. 6 is a schematic diagram showing an example of data at the time of transmission error correction processing using an error correction code when the error correction capability is increased in the present embodiment. In the illustrated example, when RAW image data is transmitted from the distal end portion 10 to the main body portion 20, an example of data input to and output from each portion is illustrated.

  In the example shown in the drawing, the RAW image data generated by the A / D conversion unit 12 has 8 information bits for each pixel. The encoded data generated by the ECC encoding unit 13 is data obtained by adding 6 redundant bits to each pixel data of the RAW image data. As a result, when there is an error of up to 2 bits in the data of each pixel to which redundant bits are added, the ECC decoding unit 21 can correct the error into correct data. When there is a 3-bit error in the data of each pixel to which redundant bits are added, the ECC decoding unit 21 can detect that the data contains an error.

  FIG. 6A is a schematic diagram illustrating an example of RAW image data generated by the A / D conversion unit 12. In the example shown in the drawing, data of three pixels having pixel numbers p1 to p3 among the RAW image data generated by the A / D conversion unit 12 is illustrated. The data of each pixel with pixel numbers p1 to p3 is data including information bits D1 to D8. Information bits D1 to D8 each indicate 1-bit data.

  FIG. 6B is a schematic diagram illustrating an example of encoded data in which redundant bits are added by the ECC encoding unit 13 to the RAW image data generated by the A / D conversion unit 12. In the example shown in the figure, among the encoded data generated by the ECC encoding unit 13, data of three pixels having pixel numbers p1 to p3 is illustrated. The data of the pixels with pixel numbers p1 to p3 are data including information bits D1 to D8 and redundant bits C1 to C6, respectively. Redundant bits C1 to C6 each indicate 1-bit data.

  FIG. 6 (3) is a schematic diagram illustrating an example of encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30. In the illustrated example, data of three pixels of pixel numbers p1 to p3 among the encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30 is illustrated. Also, error data generated during transmission of encoded data through the transmission path 30 is shown. Specifically, the information bit D4 indicates that the data of the pixel having the pixel number p1 is incorrect. Further, it is indicated that the information bit D2 and the information bit D6 are incorrect data among the data of the pixel of the pixel number p2. In addition, among the data of the pixel having the pixel number p3, the redundant bit C1 indicates incorrect data.

  FIG. 6 (4) is a schematic diagram illustrating an example of decoded data obtained by decoding the encoded data transmitted from the distal end portion 10 to the main body portion 20 via the transmission path 30 by the ECC decoding portion 21. . In the example shown in the figure, data of three pixels having pixel numbers p1 to p3 among the decoded data decoded by the ECC decoding unit 21 is shown. In FIG. 2 (3), the pixel data of the pixel numbers p1 and p3 each contain 1 bit of incorrect data, but the ECC decoding unit 21 corrects the incorrect data. In FIG. 2 (3), the pixel data of the pixel number p2 includes 2 bits of erroneous data, but the ECC decoding unit 21 corrects the erroneous data.

  As described above, the error correction capability of the ECC encoding unit 13 can be increased by increasing the number of redundant bits.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The difference between this embodiment and the first embodiment is that the tip of the electronic endoscope apparatus of this embodiment transmits data to the main body by wireless transmission.

  FIG. 7 is a schematic diagram illustrating the configuration of the electronic endoscope apparatus according to the present embodiment. In the illustrated example, the electronic endoscope apparatus 2 includes a distal end portion 40 and a main body portion 50. The distal end portion 40 includes an imaging unit 41, an A / D conversion unit 42, an ECC encoding unit 43, and a transmission unit 44. The main unit 50 includes a receiving unit 51, an ECC decoding unit 52, an image processing unit 53, and a display unit 54.

  The functions of the imaging unit 41, the A / D conversion unit 42, and the ECC encoding unit 43 are the same as the functions of the respective units of the first embodiment. The transmission unit 44 transmits the encoded data generated by the ECC encoding unit 43 to the main body unit 50 using wireless communication.

  The receiving unit 51 receives the encoded data transmitted from the front end unit 40 and inputs the received encoded data to the ECC decoding unit 52. The functions of the ECC decoding unit 52, the image processing unit 53, and the display unit 54 are the same as the functions of the respective units in the first embodiment.

  For example, in the case of a product that uses wireless communication between the distal end portion 40 and the main body portion 50, such as a capsule endoscope, the transmission speed is more limited than in wired communication, and transmission errors due to noise occur. Is likely to occur. Furthermore, since the capsule endoscope is equipped with a power source at the distal end portion 40 and is independent of the power source of the main body portion 50, it is necessary to mount a large power source at the distal end portion 40 when the power consumption of the distal end portion 40 is large. Therefore, the outer shape of the distal end portion 40 is increased.

  However, in the present embodiment, as in the first embodiment, the ECC decoding unit 52 corrects data having a bit error below the error correction capability to a correct value. Further, the image processing unit 53 interpolates erroneous data indicated by the error pixel position information with a value calculated based on the surrounding non-error data. Therefore, even if the error correction capability is lowered, erroneous data can be interpolated, so that the amount of data transmitted from the distal end portion 40 to the main body portion 50 can be reduced.

  Moreover, in the endoscope apparatus 2 of the present embodiment, the amount of data transmitted from the distal end portion 40 to the main body portion 50 can be reduced, so that the power consumption of the distal end portion 40 can be reduced. Further, the distal end portion 40 of the present embodiment having the imaging unit 41, the A / D conversion unit 42, the ECC encoding unit 43, and the transmission unit 44 can reduce power consumption by reducing the circuit scale. . Thereby, since the battery provided in the front-end | tip part 40 can be made small, it also becomes possible to make the external shape of the front-end | tip part 40 small.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The difference between this embodiment and the first embodiment is that the electronic endoscope apparatus of this embodiment performs a thinning-out process of redundant bits and makes error correction capability variable according to the photographing mode. .

  For example, when the bit error rate of the transmission unit is large and the ratio of pixels exceeding the error correction capability increases, the image quality deteriorates. Therefore, depending on the situation of the transmission unit, it is necessary to increase the error correction capability. Further, when the error correction capability is increased, the added redundant bits also increase. For this reason, if the error correction capability is simply increased, the number of redundant bits to be added is increased, which causes problems such as a delay in transmission speed and an increase in the number of signal lines.

  In the electronic endoscope apparatus according to the present embodiment, an image processing unit exists in the main body, and even when error data occurs during transmission, it is possible to suppress deterioration in image quality to some extent by interpolation processing of error pixels. Even if the ability is reduced somewhat, it does not directly lead to a significant deterioration in image quality. Therefore, in a situation where some image quality degradation is allowed, the error correction capability can be reduced.

  In this embodiment, the user can select one mode from a plurality of shooting modes. For example, from a video shooting mode in which some image quality degradation is allowed but real-time transmission is required, and a still image shooting mode in which image quality degradation needs to be suppressed as much as possible even if some transmission waiting time occurs. Select one according to the operation. Then, when the shooting mode is “still image shooting mode” when shooting a still image, the redundant bit is not thinned out, and when the shooting mode is “movie shooting mode” when shooting a movie, it is redundant. Performs bit thinning processing. Thereby, when the shooting mode is the moving image shooting mode, the amount of data transmitted from the tip portion to the main body portion can be reduced.

  FIG. 8 is a schematic diagram illustrating a configuration of the electronic endoscope apparatus according to the present embodiment. In the example illustrated, the electronic endoscope apparatus 3 includes a distal end portion 60, a main body portion 70, and a transmission portion 80. The front end 60 includes an imaging unit 61, an A / D conversion unit 62, an ECC encoding unit 63, and a puncture unit 64. The main body unit 70 includes a shooting mode selection unit 71 (mode selection unit), a code interpolation unit 72, an ECC decoding unit 73, an image processing unit 74, and a display unit 75.

  The functions of the imaging unit 61, the A / D conversion unit 62, and the ECC encoding unit 63 are the same as the functions of the respective units of the first embodiment. The puncturing unit 64 thins out the thinned data by thinning out redundant bits at specific positions among the redundant bits attached by the ECC decoding unit 63 according to the shooting mode specified by the mode selection signal transmitted from the main body unit 70. Generate. For example, when the shooting mode is “still image shooting mode”, redundant bits are not thinned out, and when the shooting mode is “moving image shooting mode”, the last redundant bit is thinned out. Details of the puncture unit 64 will be described later.

  The transmission unit 80 transmits the thinned data from the front end 60 to the main body 70. When the transmission unit 80 transmits the thinned data from the front end 60 to the main body 70, a transmission error occurs depending on the condition during transmission. This transmission error means that bits in the thinned data are inverted.

  The shooting mode selection unit 71 receives a user operation and generates a mode selection signal for specifying the shooting mode. For example, when the electronic endoscope apparatus 3 includes “still image shooting mode” and “moving image shooting mode” as shooting modes, the shooting mode selection unit 71 receives the operation of the user, and receives the “moving image shooting mode”. And “still image shooting mode” are selected, and a mode selection signal for uniquely specifying the shooting mode is generated. In addition, the shooting mode selection unit 71 transmits the generated mode selection signal to the distal end portion 60 via the transmission unit 80. In addition, the shooting mode selection unit 71 inputs the generated mode selection signal to the code interpolation unit 72. The code interpolation unit 72 generates post-interpolation data by adding an appropriate bit to the redundant bit position thinned out by the puncture unit 64 based on the thinned data and the mode selection signal. The code interpolation unit 72 inputs the generated post-interpolation data as encoded data to the ECC decoding unit 73.

  The functions of the ECC decoding unit 73, the image processing unit 74, and the display unit 75 are the same as the functions of the respective units in the first embodiment.

  Next, details of the puncturing unit 64 will be described. FIG. 9 is a schematic diagram illustrating a circuit configuration of the puncturing unit 64 in the present embodiment. The puncture unit 64 simply disconnects the connection at the point to be thinned out when the redundant bit is thinned out according to the mode selection signal. By skipping the disconnected bit at the time of transmission, the thinning-out number can be changed with a simple circuit.

  In the illustrated example, the puncture unit 64 receives input of information bits D1 to D8 and redundant bits C1 to C6 as encoded data. The puncture unit 64 is configured to output the information bits D1 to D8 and the redundant bits C1 to C3 as they are. The puncture unit 64 switches ON / OFF of the switches 641 to 643 according to the mode selection signal, and the redundant bits C4 to C4. C6 is output as it is, or one or a plurality of redundant bits C4 to C6 can be thinned out. For example, when the shooting mode is “still image shooting mode”, the puncturing unit 64 outputs the redundant bits C4 to C6 as they are. When the shooting mode is “moving image shooting mode”, the puncture unit 64 outputs the redundant bits C4 to C5 as they are, disconnects the circuit that transmits the redundant bit C6, and thins the redundant bit C5.

  Next, the transmission error correction process using the redundant bit thinning process of the error correction code will be described. FIG. 10 is a schematic diagram showing an example of data at the time of transmission error correction processing using thinning-out processing of redundant bits of the error correction code in the present embodiment. In the illustrated example, when RAW image data is transmitted from the distal end portion 60 to the main body portion 70, an example of data input to and output from each portion is shown.

  In the present embodiment, the RAW image data generated by the A / D conversion unit 62 has 8 information bits for each pixel. This information bit indicates a quantized received light intensity value in the RAW image data. The encoded data generated by the ECC encoding unit 63 is data obtained by adding 6 redundant bits to each pixel data of the RAW image data. As a result, when there is a 2-bit error in the data of each pixel to which redundant bits are added, the ECC decoding unit 73 can correct the error to correct data. When there is a 3-bit error in the data of each pixel to which redundant bits are added, the ECC decoding unit 73 can detect that the data contains an error.

  FIG. 10A is a schematic diagram illustrating an example of RAW image data generated by the A / D conversion unit 62. In the illustrated example, data of three pixels having pixel numbers p1 to p3 is shown in the RAW image data generated by the A / D conversion unit 62. The data of each pixel with pixel numbers p1 to p3 is data including information bits D1 to D8. Information bits D1 to D8 each indicate 1-bit data.

  FIG. 10B is a schematic diagram illustrating an example of encoded data in which redundant bits are added by the ECC encoding unit 63 to the RAW image data generated by the A / D conversion unit 62. In the example shown in the figure, data of three pixels having pixel numbers p1 to p3 among the encoded data generated by the ECC encoding unit 63 is shown. The data of the pixels with pixel numbers p1 to p3 are data including information bits D1 to D8 and redundant bits C1 to C6, respectively. Redundant bits C1 to C6 each indicate 1-bit data.

  FIG. 10 (3) is a schematic diagram illustrating an example of thinned data in which redundant bits are thinned out by the puncture unit 64 from the coded data generated by the ECC coding unit 63. In the example shown in the figure, the puncture unit 64 thins out the redundant bit C6. Specifically, the data of each pixel with pixel numbers p1 to p3 is data including information bits D1 to D8 and redundant bits C1 to C5, respectively.

  FIG. 10 (4) is a schematic diagram illustrating an example of the thinned data transmitted from the distal end portion 60 to the main body portion 70 via the transmission path 80. In the illustrated example, data of three pixels of pixel numbers p <b> 1 to p <b> 3 among the thinned data transmitted from the distal end portion 60 to the main body portion 70 via the transmission path 80 is illustrated. Further, error data generated during transmission of thinned data by the transmission path 80 is shown. Specifically, the information bit D4 indicates that the data of the pixel having the pixel number p1 is incorrect. Further, it is indicated that the information bit D6 and the redundant bit C3 are erroneous data among the data of the pixel of the pixel number p2. In addition, among the data of the pixel having the pixel number p3, the redundant bit C1 indicates incorrect data.

  FIG. 10 (5) is a schematic diagram showing an example of post-interpolation data in which the code interpolation unit 72 interpolates redundant bits in the thinned data transmitted from the front end 60 to the main body 70 via the transmission path 80. . The code interpolation unit 72 adds post-interpolation data by adding an appropriate bit to the place where the puncture unit 64 thins out redundant bits so that the thinned data has the same number of bits as the encoded data. In the present embodiment, when the shooting mode is “still image shooting mode”, the redundant bits are not thinned out, so the code interpolation unit 72 does not add bits to the thinned data. When the shooting mode is “moving image shooting mode”, since the redundant bit C6 is thinned, an appropriate bit “0” is added to the position of the redundant bit C6.

  In the example shown in the figure, data obtained by interpolating the redundant bit “0” by the code interpolation unit 72 at the position of the redundant bit C6 thinned out by the puncture unit 64 is shown. Specifically, the data of each pixel having pixel numbers p1 to p3 is data including information bits D1 to D8 and redundant bits C1 to C5 and “0”, respectively. Further, since it cannot be determined whether or not the redundant bit “0” interpolated by the code interpolation unit 72 is a correct value, it is regarded as erroneous data. Therefore, the pixel data of the pixel number p1 includes 2-bit error data. The pixel data of pixel number p2 includes 3-bit error data. In addition, the pixel data of the pixel number p3 includes 2-bit error data.

  FIG. 10 (6) is a schematic diagram illustrating an example of decoded data obtained by decoding the post-interpolation data obtained by interpolating redundant bits by the code interpolation unit 72 by the ECC decoding unit 73. In the example shown in the figure, data of three pixels having pixel numbers p1 to p3 among the decoded data decoded by the ECC decoding unit 73 is shown. In FIG. 10 (5), the pixel data of the pixel numbers p1 and p3 each include 2 bits of erroneous data. However, as shown in FIG. 10 (6), the ECC decoding unit 73 stores the incorrect data. I am correcting. In FIG. 10 (5), the pixel data of pixel number p2 includes 3 bits of erroneous data, so that ECC decoding unit 73 determines that the data of pixel number p2 is incorrect data. Identify and generate error pixel location information.

  A method in which the image processing unit 74 interpolates the decoded RAW image data and generates output data is the same method as in the first embodiment.

  As described above, in this embodiment, the puncture unit 64 thins out some redundant bits included in the encoded data in accordance with the mode selection signal generated by the shooting mode selection unit 71. Further, the code interpolation unit 72 interpolates “0” at the position where the redundant bit thinned out according to the mode selection signal exists, and generates post-interpolation data.

  Further, the ECC decoding unit 73 decodes the post-interpolation data by regarding “0” interpolated by the code interpolation unit 72 as error data. Thereby, in the error correction processing in the ECC decoding unit 73, the error correction capability is reduced as compared with that before the thinning, but the data amount to be transmitted in the transmission unit 80 is smaller than that before the thinning. The number of signal lines used for transmission can be reduced.

  If the shooting mode is “moving image shooting mode”, the transmission band can be suppressed by increasing the number of thinning-outs. Also, if the shooting mode is “still image shooting mode”, the transmission error rate can be reduced even if it takes time to transmit all the pixels of the still image by reducing the number of thinning out or leaving it undecimated. Can be suppressed.

  The ECC decoding unit 73 corrects data having a bit error below the error correction capability to a correct value. Further, the image processing unit 74 interpolates erroneous data indicated by the error pixel position information with a value calculated based on the surrounding non-error data. Therefore, even if the error correction capability is lowered, erroneous data can be interpolated, so that the amount of data transmitted from the front end portion 60 to the main body portion 70 can be reduced.

  Further, in the endoscope apparatus 3 of the present embodiment, the amount of data transmitted from the distal end portion 60 to the main body portion 70 can be reduced, so that a small-diameter signal line can be used for the transmission portion 80. Therefore, the outer diameter of the tip 60 connected to the transmission unit 80 can also be reduced.

  Further, the ECC decoder 73 completely corrects pixel data having a bit error less than the error correction capability. Also, the pixel data having a bit error below the error detection capability is replaced by the image processing unit 74 with a value calculated based on the surrounding non-error pixel data. Therefore, bright spots and dark spots can be reduced.

  As described above, in this embodiment, the transmission error correction capability can be varied as necessary, and an image can be output in accordance with a required difference in image quality.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. The difference between this embodiment and the third embodiment is that in the electronic endoscope apparatus of this embodiment, the redundant bit to be thinned out by the puncture portion is determined according to the type of the tip portion, and the main body portion is connected. The type of the tip portion that is connected is specified, and the redundant bits thinned out by the puncture portion of the connected tip portion are interpolated.

  For example, the puncture part of the leading end of type A thins out the last bit of the redundant bit, and the puncture part of the leading end of type B thins out the second bit from the last bit of the redundant bit and the last bit. In this case, the main body unit specifies the type of the connected tip part, and if the connected tip part is of type A, it interpolates the last bit of the redundant bit. Further, when the connected front end is of type B, the main body interpolates the last bit of the redundant bit and the second bit from the last bit.

  FIG. 11 is a schematic diagram illustrating a configuration of the electronic endoscope apparatus according to the present embodiment. In the example illustrated, the electronic endoscope apparatus 4 includes a distal end portion 90, a main body portion 100, and a transmission portion 110. The leading end 90 includes an imaging unit 91, an A / D conversion unit 92, an ECC encoding unit 93, a puncturing unit 94, and a tip type storage unit 95. The main body 100 includes a tip type discriminating unit 101 (discriminating unit), a code interpolating unit 102, an ECC decoding unit 103, an image processing unit 104, and a display unit 105.

  The functions of the imaging unit 91, the A / D conversion unit 92, and the ECC encoding unit 93 are the same as the functions of the respective units of the third embodiment. The puncturing unit 94 generates thinned data by thinning out bits at a specific position determined in advance according to the type of the leading end portion 90 among the redundant bits attached by the ECC decoding unit 93. For example, when it is predetermined that the last bit of the redundant bit is to be thinned out, the puncture unit 94 thins out the last bit of the redundant bit. The configuration of the puncturing unit 94 is the same as the configuration of the puncturing unit 64 of the third embodiment. The tip type storage unit 95 stores tip type information that uniquely identifies the type of tip.

  The transmission unit 110 transmits the tip type information stored in the tip type storage unit 95 from the tip unit 90 to the main body unit 100. Further, the transmission unit 110 transmits thinned data from the distal end portion 90 to the main body portion 100. When the transmission unit 110 transmits the thinned data from the front end 90 to the main body 100, a transmission error occurs depending on the condition during transmission. This transmission error means that bits in the thinned data are inverted.

  The tip type discriminating unit 101 discriminates redundant bits that the puncture unit 94 of the tip unit 90 thins out based on the tip type information transmitted by the transmission unit 110, and uniquely specifies the position of the redundant bit that the puncture unit 94 thins out A selection signal is generated. The tip type discriminating unit 101 inputs the generated mode selection signal to the code interpolation unit 102.

  The code interpolation unit 102 generates post-interpolation data by adding an appropriate bit to the redundant bit position thinned out by the puncture unit 94 based on the thinned-out data and the mode selection signal. Further, the code interpolation unit 102 inputs the generated post-interpolation data as encoded data to the ECC decoding unit 103. The functions of the ECC decoding unit 103, the image processing unit 104, and the display unit 105 are the same as the functions of the units in the third embodiment.

  As described above, in the present embodiment, redundant bits to be thinned out by the puncture unit 94 are determined for each type of the tip portion 90. The puncturing unit 94 thins out predetermined redundant bits among the redundant bits included in the encoded data. Further, the tip type determining unit 101 determines the type of the connected tip 90. Then, since the redundant bits to be thinned out are uniquely determined according to the type of the tip portion 90, the code interpolation unit 102 interpolates “0” at the position where the thinned redundant bits existed, Generate post-interpolation data.

  The ECC decoding unit 103 also decodes the post-interpolation data by regarding “0” interpolated by the code interpolation unit 102 as error data. As a result, in the error correction processing in the ECC decoding unit 103, the error correction capability is reduced as compared with that before the thinning, but the amount of data to be transmitted by the transmission unit 110 is smaller than that before the thinning. The number of signal lines can be reduced.

  Further, since the redundant bits to be thinned out can be determined in advance according to the type of the tip portion 90, if the tip portion 90 is of a certain type, the transmission band can be suppressed by increasing the thinning number. In the case of other types of leading end portions 90, it takes time to transmit all the pixels of the still image by reducing the number of redundant bits or by not performing redundant bit thinning. Can also reduce the transmission error rate. Thus, the number of redundant bits to be thinned out can be set in accordance with the characteristics of the leading end 90.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. The difference between this embodiment and the fourth embodiment is that the electronic endoscope apparatus of this embodiment differs in the encoding method used depending on the type of tip, and the main body is connected to the tip. The type of the part is specified, and decoding is performed by a method corresponding to the encoding method used by the connected tip part.

  For example, it is assumed that the encoding method used by the ECC encoding unit included in the type A tip is a Hamming code, and the encoding method used by the ECC encoding unit included in the type B tip is a BCH code. In this case, the main body unit specifies the type of the connected tip part, and when the connected tip part is type A, the ECC decoding unit decodes using the Hamming code. In addition, when the connected front end is of type B, the ECC decoding unit decodes using the BCH code.

  FIG. 12 is a schematic diagram illustrating a configuration of the electronic endoscope apparatus according to the present embodiment. In the example illustrated, the electronic endoscope apparatus 5 includes a distal end portion 120, a main body portion 130, and a transmission portion 140. The front end 120 includes an imaging unit 121, an A / D conversion unit 122, an ECC encoding unit 123, and a front end type storage unit 124. The main body 130 includes a tip type determination unit 131, an ECC decoding unit 132, an image processing unit 133, and a display unit 134.

  The functions of the imaging unit 121, the A / D conversion unit 122, and the tip type storage unit 124 are the same as the functions of the units of the fourth embodiment. The ECC encoding unit 123 generates encoded data from the RAW image data by a predetermined encoding method according to the type of the front end portion 120.

  The transmission unit 140 transmits the tip type information stored in the tip type storage unit 124 from the tip part 120 to the main body part 130. In addition, the transmission unit 140 transmits the encoded data from the tip part 120 to the main body part 130. When the transmission unit 140 transmits the encoded data from the front end 120 to the main body 130, a transmission error occurs depending on the condition during transmission. This transmission error means that a bit in the encoded data is inverted.

  The tip type discriminating unit 131 discriminates the encoding method used by the ECC encoding unit 123 of the tip unit 120 based on the tip type information transmitted by the transmission unit 140 and uniquely identifies this encoding method. Is generated. Further, the tip type determination unit 131 inputs the generated mode selection signal to the ECC decoding unit 132.

  The ECC decoding unit 132 corrects a transmission error included in the encoded data by using an error correction code by using an encoding method uniquely specified by the mode selection signal, and converts the decoded data and the error pixel position information. Generate. The functions of the image processing unit 133 and the display unit 134 are the same as the functions of the respective units in the fourth embodiment.

  As described above, in the present embodiment, the encoding method used by the ECC encoding unit 123 is different for each type of the tip portion 120. Further, the tip type determining unit 131 determines the type of the connected tip 120. Since the ECC decoding unit 132 uniquely determines the encoding method used in accordance with the type of the leading end portion 120, the ECC decoding unit 132 performs encoding using the encoding method used for encoding by the ECC encoding unit 123. Generate decrypted data from the data.

  Thereby, even when a plurality of types of tip portions 120 having different encoding methods used when generating encoded data are used, one main body portion 130 can be shared.

  The first to fifth embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and does not depart from the gist of the present invention. Range design etc. are also included.

  For example, in the first embodiment and the third to fifth embodiments, data is transmitted between the main body and the transmission unit via the transmission unit, but the second embodiment is used. As described above, a transmission unit may be provided at the tip, and a reception unit may be provided in the main body so that transmission is performed using wireless communication.

  1, 2, 3, 4, 5... Electronic endoscope device 10, 40, 60, 90, 120... Tip portion, 11, 41, 61, 91, 121. 42, 62, 92, 122... A / D converter, 13, 43, 63, 93, 123... ECC encoding unit, 20, 50, 70, 100, 130. 52, 73, 103, 132 ... ECC decoding unit, 22, 53, 74, 104, 133 ... image processing unit, 23, 54, 75, 105, 134 ... display unit, 30, 80, 110, 140 ... transmission unit, 44 ... transmission unit, 51 ... reception unit, 64, 94 ... puncture unit, 71 ... shooting mode selection unit, 72, 102 ... code interpolation unit , 95, 124 ... tip type storage unit, 101, 131 ... tip type discriminating unit

Claims (12)

An electronic endoscope apparatus comprising a distal end portion, a main body portion, and a transmission portion that connects the distal end portion and the main body portion so as to communicate with each other,
An imaging unit that is provided at the tip and that captures an image of the subject to generate an image signal;
An A / D converter that is provided at the tip and generates image data by quantizing the image signal;
An encoding unit that is provided at the front end and generates encoded data by encoding the image data using an error correction code;
A decoding unit that is provided in the main body and corrects a transmission error of the image data by decoding the encoded data;
An image processing unit which is provided in the main body unit and corrects transmission errors remaining in the image data after correction by the decoding unit;
An electronic endoscope apparatus comprising: The decoding unit generates error pixel position information indicating a position of a pixel included in the image data in which a transmission error cannot be corrected,
The electronic endoscope apparatus according to claim 1, wherein the image processing unit interpolates data of the pixel specified by the error pixel position information by image interpolation. The electronic processing unit according to claim 2, wherein the image processing unit replaces the data of the pixel specified by the error pixel position information with a value calculated based on values of pixels around the pixel. Endoscopic device. A discriminator provided on the main body, discriminating the type of the tip, and generating discrimination information for uniquely identifying the type of the tip;
The encoding unit generates the encoded data using an error correction code determined for each type of the tip,
The decoding unit identifies the error correction code used in the encoding unit provided at the front end based on the type of the front end determined by the determination unit, and determines the error correction code The electronic endoscope apparatus according to any one of claims 1 to 3, wherein the encoded data is decoded using the electronic endoscope apparatus. A puncture unit provided at the front end portion for reducing the encoded data length by thinning out a part of the encoded data;
A code interpolation unit that is provided in the main body unit and adds a signal to a portion thinned out by the puncture unit to restore the encoded data length;
The electronic endoscope apparatus according to any one of claims 1 to 4, wherein the electronic endoscope apparatus is provided. A mode selection unit that is provided in the main body unit and outputs a mode selection signal that sets the number of bits of the encoded data to be thinned out by the puncture unit;
The electronic endoscope apparatus according to claim 5, wherein the puncturing unit thins out data of the number of bits specified by the mode selection signal from the encoded data. A puncture unit that is provided at the front end and thins out the encoded data length by thinning out data at positions determined for each type of the front end from the encoded data;
A discriminator provided in the main body, discriminating the type of the tip, and generating discriminating information for uniquely identifying the type of the tip;
Based on the type of the tip portion that is provided in the main body portion and is discriminated by the discriminating portion, the position of the puncture portion provided in the tip portion is thinned out and the signal is added to the specified position. A code interpolation unit for restoring the encoded data length,
The electronic endoscope apparatus according to any one of claims 1 to 3, further comprising: An electronic endoscope device comprising a tip portion and a main body portion,
An imaging unit that is provided at the tip and that captures an image of the subject to generate an image signal;
An A / D converter that is provided at the tip and generates image data by quantizing the image signal;
An encoding unit that is provided at the front end and generates encoded data by encoding the image data using an error correction code;
A transmission unit provided at the tip, and transmitting the encoded data to the main body;
A receiver that is provided in the main body and receives the encoded data transmitted from the tip;
A decoding unit that is provided in the main body and corrects a transmission error of the image data by decoding the encoded data;
An image processing unit which is provided in the main body unit and corrects transmission errors remaining in the image data after correction by the decoding unit;
An electronic endoscope apparatus comprising: The electronic endoscope apparatus according to claim 8, wherein the transmission unit and the reception unit perform data transmission using wireless communication. 10. The error correction code used in the encoding unit and the decoding unit is an error correction code that is encoded and decoded for each pixel. 10. Electronic endoscope device. The electronic endoscope apparatus according to any one of claims 1 to 10, wherein the imaging unit is a single-plate color imaging element having a primary color filter or a complementary color filter. The electronic endoscope apparatus according to claim 11, wherein the image processing unit generates color image data based on the decoded image data.

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