JP2004242357A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit image information of high definition obtained by a progressive scanning type imaging element to the outside of the apparatus without causing deterioration in the obtained image information of the high definition. <P>SOLUTION: The imaging apparatus has an imaging means for selectively generating first digital video signals of n fields per second which are mutually interlaced, and second video digital signals made of non-interlaced images of n frames per second; a compressing means for compressing the amount of information of the digital video signal generated from the imaging means; a voice-generating means for generating digital voice signals by using a microphone; and an interface for transmitting in a first transmission mode in which the first digital video signals in compressed states, together with the digital voice signals, are transmitted to the peripheral device, and in a second transmission mode in which the second digital video signals in compressed states, together with the digital video signals, are transmitted to the peripheral device. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus, and more particularly, to processing of a video signal obtained by a progressive scan type imaging device.

  2. Description of the Related Art Conventionally, a camera-integrated VTR has been known as a device for processing a video signal captured by a video camera. In the conventional device, in the NTSC system, an interlaced image is captured at a rate of 60 fields (30 frames) per second, and recorded and reproduced.

  In a device of this type, when a still image is reproduced, there is a time difference of 1/60 second between two fields constituting a frame image. The image may be blurred.

  Therefore, when a still image is reproduced, a field image may be output. However, when a field image is used, the resolution in the vertical direction is reduced.

As a countermeasure against this problem, for example, as described in JP-A-8-205193, when interpolating an image of another field in the same frame, the motion of the image between fields is detected and the motion is detected. Interpolation using the image of the other field in the same frame for the non-existing part, and interpolation using the image in the same field for the moving part can prevent the reduction in the vertical resolution. It is considered.
JP-A-8-205193

  However, in such a method, the vertical resolution can be substantially increased only in a portion of the screen where there is no motion, and the vertical resolution remains low in a portion where there is motion.

  Further, since the slow reproduction is basically a moving subject, the above-described method cannot prevent a decrease in resolution. A similar problem occurs when so-called electronic zoom processing is performed during reproduction.

  In recent years, a progressive scan type CCD (hereinafter referred to as a progressive CCD) capable of obtaining a non-interlaced image of 60 frames per second has been put into practical use as an image pickup device of a camera-integrated VTR. An image obtained by using the progressive CCD has little blurring in a moving portion even when slow reproduction is performed, and there is no decrease in vertical resolution.

  However, the conventional camera-integrated VTR cannot record all 60-frame-per-second images (hereinafter referred to as progressive images) obtained by a progressive CCD due to the problem of the data rate of recording and reproduction. Therefore, in the normal moving image shooting mode, the image is converted into an interlaced image of 60 fields and recorded, and only in the still image shooting mode, a progressive image of 30 frames is recorded.

  For this reason, the above-described problem still occurs when an image recorded in the moving image shooting mode is reproduced as a still image or as a slow image.

  As this kind of camera-integrated VTR, a digital VTR that records and reproduces a video signal as a digital signal is becoming mainstream.

  A digital VTR is compatible with a computer because of the feature that image information is handled as a digital signal. In recent years, a digital VTR has often been used for capturing an image of a personal computer (hereinafter, a PC). As the image monitor of the PC, a progressive scan type display is mainly used. However, as described above, interlaced images are recorded and reproduced in a camera-integrated VTR including a digital VTR, and when a captured moving image is captured and displayed on a PC, it is converted to a non-interlaced image before being displayed. There is a need to. Therefore, the image quality is deteriorated as described above, and a good image cannot be displayed.

  As described above, even if a progressive CCD is provided, it is not used effectively.

  An object of the present invention is to solve the above-mentioned problems.

  Still another object of the present invention is to enable high-definition image information obtained by a progressive scan type image sensor to be transmitted to the outside of the apparatus without deterioration.

  For this purpose, in the present invention, a first image composed of n (n is an integer of 2 or more) field images per second interlaced with each other using moving image information obtained by a progressive scan type image sensor. Imaging means for generating a digital video signal and a second digital video signal composed of a non-interlaced image of n frames per second, and selectively outputting the first digital video signal and the second digital video signal; Compression means for compressing the first digital video signal or the second digital video signal output from the imaging means by compressing the information amount with high efficiency, and audio for generating a digital audio signal using a microphone Generating means; and the first digital video signal or the second digital video compressed by the compression means. And an interface for multiplexing a digital audio signal output from the audio generation means and transmitting the compressed first digital video signal and second digital video signal to a peripheral device in a compressed state. A first transmission mode for transmitting the first digital video signal together with the digital audio signal in the compressed state; and transmitting the second digital video signal together with the digital audio signal in the compressed state. A configuration having the second transmission mode was adopted.

  According to the present invention, a high-definition moving image obtained by a progressive scan type imaging device can be transmitted to the outside without deterioration in image quality.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a recording system of a camera-integrated digital VTR 1 to which the present invention is applied.

  In the figure, an image capturing unit 101 captures an image of a subject using the above-described progressive CCD, and outputs obtained image information to the camera signal processing circuit 103 as a progressive image.

  FIG. 2 shows the configuration of the imaging unit 101.

  As described above, the progressive CCD provided in the present embodiment is configured to read out and output image information of all pixels on the imaging surface in one field (1/60 second), and output one channel. And two-channel output.

  In this embodiment, a progressive CCD having one channel output is used.

  In FIG. 2, subject light is applied to a CCD 203 through an optical system 201 including a lens, an iris, and the like. The drive timing of the CCD 203 is controlled by a CCD drive circuit 209 under the control of the control unit 125, and all the pixels on the imaging surface are output in the order of raster scan during one field period. The output image information is sampled by the sample-and-hold circuit 205 so as to have a predetermined pixel arrangement, converted into a digital signal of a plurality of bits per sample by the A / D converter 207, and output to the camera signal processing circuit 103.

  FIG. 3 is a diagram showing a configuration of the camera signal processing circuit 103.

  In FIG. 3, a camera processing circuit 301 performs processing such as gamma correction, color separation, and white balance on a digital video signal of a progressive image obtained by the imaging unit 101 and outputs the processed digital video signal to frame memories 303 and 305. Further, it outputs a video signal to the monitor 105 in the form of an RGB signal.

  The writing of the frame memories 303 and 304 is controlled by the control unit 125, and is controlled so that the writing state and the reading state are alternately performed each time a video signal of one frame is input (in this embodiment, every 1/60 second). You. Each of the memories 303 and 304 has an output of two ports, and video signals of one even line and one odd line of one frame are output in parallel from each port.

  That is, when the frame memory 305 is in the write state, the video signal from the even-numbered line port of the frame memory 303 shown by E in the figure is output to the E-side terminal of the switch 307, and the video signal from the odd-numbered line port shown by O Is output to the O-side terminal of the switch 309. Similarly, when the frame memory 303 is in the write state, the video signal from the even line port of the frame memory 305 is output to the E terminal of the switch 309, and the video signal from the odd line port is output to the O terminal of the switch 307. Is done.

  The switching operation of the switches 307 and 309 is controlled by the control unit 125 such that the switches are alternately connected to the E-side terminal and the O-side terminal every 1/60 second and output as ch1 and ch2 video signals.

  FIG. 4 shows the state of each video signal of ch1 and ch2 output from the camera signal processing circuit 103.

  As shown in FIG. 4, when the video signal of ch1 is output in the order of even field-odd field-even field-odd field, the video signal of ch2 is odd field-even field-odd field-even field in this order. , The images of the opposite fields are switched and output every 1/60 second. As shown in FIG. 4, the video signal of each channel can be regarded as an independent interlaced image of 60 fields per second.

  The ch1 and ch2 video signals output from the camera signal processing circuit 103 are output to the memories 113 and 115, respectively. The video signals stored in the memories 113 and 115 are subjected to processing such as compression and encoding by compression processing circuits 117 and 119, respectively, and output to the recording circuit 121 and the digital I / F 129.

  Here, the compression processing circuits 117 and 119 will be described.

  FIG. 5 is a diagram showing a configuration of a main part of the apparatus of FIG. 1 including the compression processing circuit 117 and the memory 113. In FIG. 5, only the compression processing circuit 117 will be described, but the compression processing circuit 119 has the same configuration, and the description is omitted.

  In FIG. 5, a video signal written in the memory 113 is output to the DCT circuit 401 and the motion detection circuit 403 in a predetermined order for each block of 8 horizontal pixels × 8 vertical pixels. The motion detection circuit 403 detects the motion of the image between fields for each block and outputs the motion to the DCT circuit 401. The DCT circuit 401 performs DCT processing on the video signal from the memory 113 according to the detection result of the motion detection circuit 403, and outputs the result to the quantization circuit 405 and the code amount estimation circuit 407. The code amount estimating circuit 407 estimates a code amount generated when the quantization circuit 405 performs quantization, and determines a quantization coefficient used in the quantization circuit 405. The quantization circuit 405 quantizes the output of the DCT circuit 401 with the quantization coefficient determined by the code amount estimation circuit 407, and outputs the result to the variable length coding circuit 409. The variable length encoding circuit 409 encodes the output from the quantization circuit 405 using a known variable length code such as Huffman encoding, and writes the encoded data into the memory 113.

  The error correction coding circuit 411 performs error correction coding by adding parity data to the video signal written in the memory 113, which has been subjected to variable length coding. Note that the error correction encoding circuit 411 similarly performs error correction encoding on the audio signal written in the memory 113 as described later. The recording processing circuit 413 adds synchronization data and ID data to the error-corrected encoded video signal and audio signal, and outputs the resultant to the recording circuit 121.

  The recording circuit 121 performs digital modulation processing or the like on the signals output from the compression processing circuits 117 and 119, converts the signals into a form suitable for recording, and records the signals on the tape 123.

  The operation of the recording circuit 121 will be described with reference to FIGS.

  FIG. 6 is a diagram showing the configuration of the recording circuit 121 around the head.

  In FIG. 6, reference numerals 503, 505, 507, and 509 denote magnetic heads, respectively, which are provided around the drum 501. The tape 123 is wound around the drum 501 in a range of approximately 180 degrees. The heads 503 and 509 and the heads 505 and 507 have a phase difference of 180 degrees, respectively. The heads 503 and 505 have different azimuths, and the heads 503 and 509 and the heads 505 and 507 have the same azimuth.

  FIG. 7 is a diagram showing a configuration of the recording circuit 121. Each signal of ch1 and ch2 output from the compression processing circuits 117 and 119 is subjected to digital modulation processing such as NRZI in digital modulation circuits 601 and 603, and is output to switches 609 and 611 via amplifiers 605 and 607. You. The switches 609 and 611 are controlled by the control unit 125, and are connected to the a-side terminal and the b-side terminal alternately every time the drum 501 rotates 180 degrees in a progressive recording mode described later.

  The signal output from the a-side terminal of the switch 609 is supplied to the head 503 via the a-side terminal of the switch 613 in the progressive recording mode, and the signal output from the b-side terminal of the switch 609 is supplied to the head 507. You. The signal output from the a-side terminal of the switch 611 is supplied to the head 505 via the switch 615, and the signal output from the b-side terminal is supplied to the head 509.

  The VTR according to the present embodiment is a progressive recording mode in which both ch1 and ch2 video signals, that is, all 60 frames of moving images obtained by the imaging unit 101 are recorded on the tape 123, and a normal recording mode in which only the ch1 video signal is recorded. The control unit 125 has a recording mode. When the progressive recording mode is set by the operation unit 127, the control unit 125 connects the switch 613 to the a-side terminal and connects the switch 615 to the P-side terminal. Then, the signals of ch1 and ch2 are recorded in parallel for each trace of the heads 503 and 505 and the heads 507 and 509.

  FIG. 8A shows the state of the track on the tape 123 in the progressive recording mode. In this embodiment, signals for one frame are recorded on ten tracks. In the figure, a plus azimuth track 701A is a track formed by the heads 503 and 507, and a minus azimuth track 701B is a track formed by the heads 505 and 509. In the progressive recording mode, 10 tracks are formed at a track pitch Tp in 1/60 second and signals are recorded.

  Next, in the normal recording mode, the control unit 125 connects the switch 609 to only the a-side terminal and connects the switch 615 to the N-side terminal. Then, each time the drum 501 makes one rotation, the switch 613 is alternately connected to the a-side terminal and the b-side terminal.

  In the normal recording mode, the tape 123 is transported at half the speed as in the progressive recording mode, and recording is performed using only the heads 503 and 505. That is, a signal is alternately supplied to the heads 503 and 505 for each rotation of the drum 501 to perform recording.

  FIG. 8B shows a state of a track on the tape 123 in the normal recording mode. In the drawing, a plus azimuth track 703A is a track formed by the head 503, and a minus azimuth track 703B is a track formed by the head 505. As shown in the figure, the signal for one frame is recorded on ten tracks also in the normal recording mode. In the normal recording mode, the tape 123 is conveyed at half the speed in the progressive recording mode, and Since recording is performed using only 503 and 505, ten tracks are formed at a track pitch Tp in 1/30 second, and a signal for one frame is recorded.

  Next, processing of an audio signal will be described.

  The audio signal obtained by the microphone 107 is amplified by the microphone amplifier 109 and output to the audio signal processing circuit 111. The audio signal processing circuit 111 converts the audio signal from the microphone amplifier 109 into a digital signal, and rearranges the digital signal into a format suitable for recording and outputs the digital signal to the memories 113 and 115. The audio signals written in the memories 113 and 115 are processed as described above, and output to the recording circuit 121 together with the video signals.

  The digital VTR 1 of the present embodiment includes a digital I / F 129 for outputting a video signal of a progressive image of each channel stored in the memories 113 and 115 to the personal computer 10 in a state where the video signal is compression-encoded.

  That is, the digital I / F 129 is coded by the variable length coding circuit 409 in FIG. 5 and written into the memory 113, the ch1 video signal similarly written into the memory 115, and the audio The audio signals written to the memories 113 and 115 from the signal processing circuit 111 are multiplexed, and these signals are packetized for each predetermined amount of data, converted into a format conforming to the IEEE 1394 serial bus standard, and transmitted through a terminal 131. To a personal computer (hereinafter referred to as PC) 10.

  Here, in the present embodiment, the video signal is compressed in accordance with the format determined by the Digital VCR Council, which is the format of a consumer digital VTR, and a normal 60-field image is compressed to a data rate of 25 Mbps. are doing. In addition, the data rate becomes about 50 Mbps in total by adding the audio signal and the subcode. In the present embodiment, since the video signal of 60 frames is compressed, the transmission rate becomes about 50 Mbps for the video signal alone, and becomes about 100 Mbps when the audio signal and the subcode data are added thereto.

  As the interface conforming to the IEEE 1394 serial bus standard, three types of transmission rates of about 100 Mbps (S100), 200 Mbps (S200), and 400 Mbps (S400) are prepared. Therefore, by using the 200 Mbps interface, even when the audio signal and the subcode data are multiplexed and transmitted with respect to the video signal obtained by the progressive CCD as in the present embodiment, the moving image signal is converted to the progressive image. It is possible to transmit with sufficient margin.

  That is, when a request for transmitting a progressive moving image is input to the digital I / F 129 via the terminal 131 by the PC 10, the digital I / F 129 outputs a signal indicating this to the control unit 125.

  The control unit 125 receives the request from the PC 10 and controls the respective units of the VTR 1 as described above to write the compression-encoded moving image signal and the audio signal to the memories 113 and 115, and to store the respective signals stored in the memories 113 and 115. The control signal is output to the digital I / F 129 to transmit the control signal. In the progressive moving image transmission mode, the digital I / F 129 reads out the compressed / encoded video signals of the ch1 and ch2 progressive images stored in the memories 113 and 115 and stores the video signals in the memories 113 and 115. Read the audio signal. Then, the video signal and the audio signal are packetized, converted into a predetermined format conforming to the IEEE 1394 serial bus standard, and output to the PC 10 via the terminal 131.

  As described above, according to the present embodiment, a moving image signal can be transmitted to the PC 10 with a progressive image (60 frames / sec). The PC 10 can display the transmitted high-definition progressive image as it is on the display without converting the transmitted video signal into a non-interlaced image.

  Further, when a normal interlace moving image transmission request is input from the PC 10, the control unit 125 outputs a control signal to the digital I / F 129 to transmit the signal written in the memory 113. When the normal transmission mode is instructed by the control unit 125, the digital I / F 129 reads the compression-coded video signal and audio signal of ch1 stored in the memory 113. Then, these signals are packetized, converted into a predetermined format, and output to the PC 10.

  Thus, by having two transmission modes, for example, in a normal image display, transmitting images in the normal transmission mode reduces the load on the device, suppresses power consumption, and requires high-definition moving images. It is also possible to adopt a method of transmitting in a progressive moving image transmission mode at an appropriate timing.

  As described above, in this embodiment, since all the video signals obtained by the progressive CCD are output to the PC 10 by the digital I / F 129 without thinning out, when the VTR 1 is used as a device for capturing images of the PC 10, the progressive The advantages of using a CCD can be fully utilized.

  In recent years, progressive scan-type television receivers have also been found. According to the VTR 1 of this embodiment, if a progressive monitor of this type is connected instead of the PC 10, the image capturing unit 101 can operate. It is possible to monitor the obtained progressive image on an external display.

  Furthermore, in this embodiment, since the video signal and the audio signal are transmitted in a compressed state, the transmission rate can be extremely low.

  In the present embodiment, the audio signal from the audio processing circuit 111 is written to both the memories 113 and 115, and the audio signal is multiplexed and transmitted to the video signal of each channel. Even when only the video data of one channel is used in the PC 10 among the data transmitted from 131, audio can be obtained.

  In this embodiment, a signal from the PC 10 can also be input by the digital I / F 129. That is, the PC 10 transmits a control signal for transmitting a progressive moving image to the digital I / F 129 via the terminal 131 before transmitting the image signal. The digital I / F 129 outputs the control signal from the PC 10 to the control unit 125. The control unit 125 outputs a control signal to the digital I / F 129 to receive an image signal from the PC 10 and outputs a control signal to the recording circuit 121 to perform recording.

  The digital I / F 129 receives a packetized signal from the PC 10 via the terminal 131 and writes the signal into the memories 113 and 115. The control unit 125 controls the compression processing circuits 117 and 119 and the recording circuit 121 to process and record each signal transmitted from the PC 10 and written in the memories 113 and 115 as described above.

  Next, the operation at the time of reproduction will be described.

  FIG. 9 is a diagram showing the configuration of the reproduction system of the VTR 1 in FIG. 1. Components similar to those in FIG.

  When a reproduction instruction is given by the operation unit 127, the control unit 125 controls the reproduction circuit 133 to start reproduction of a signal. At this time, the above-described progressive recording mode / normal recording mode is determined based on the additional signal recorded together with the video signal, and the tape 123 is transported at a speed suitable for each mode according to the determination result. The configuration of the head is as shown in FIG. 6, and the head to be used is switched according to the determined mode.

  When the recording mode is the progressive recording mode, the reproducing circuit 133 reproduces a signal for each trace of each of the heads 503, 505, 507 and 509, and detects an original digital signal from the reproduced signal. Then, the signals of ch1 and ch2 are output to decompression processing circuits 135 and 137, respectively. The decompression circuits 135 and 137 respectively perform decompression processing corresponding to the video signals of ch1 and ch2 at the time of recording.

  FIG. 10 shows the configuration of the decompression circuits 135 and 137.

  FIG. 10 is a diagram showing a configuration of a main part including a decompression processing circuit 135. Since the decompression processing circuit 137 has the same configuration, the description is omitted.

  10, a reproduction processing circuit 801 detects synchronization and ID data in a signal output from the reproduction circuit 133, and writes a reproduction signal into the memory 113 based on these data. Further, it detects additional data from the reproduced signal and outputs it to the control circuit 125. As described above, the control circuit 125 determines the recording mode based on the additional data output from the reproduction processing circuit.

  The error correction decoding circuit 803 performs an error correction decoding process on the reproduction signal stored in the memory 113 using the parity data added at the time of recording, and corrects an error in the reproduction signal. The reproduced video signal subjected to the error correction processing is sequentially processed by a variable length code decoding circuit 805, an inverse quantization circuit 807, and an inverse DCT circuit 809, and the data amount is expanded and written to the memory 113.

  The decompressed video signal is output from the memories 113 and 115 to the output circuit 139. The audio signal is read from the memories 113 and 115 and output to the audio signal processing circuit 141, where it is converted into a one-channel signal and output to the output circuit 139. The output circuit 139 multiplexes the video signal and the audio signal, outputs the multiplexed signal to the outside via the terminal 143, converts the video signal into an RGB signal, and outputs the RGB signal to the monitor 105. At this time, if the device connected to the terminal 143 is a device capable of processing a progressive image, the output circuit 139 outputs the video signal as a progressive image, and if the progressive image cannot be processed, the output circuit 139 outputs 30 frames or It is converted to a 60-field interlaced image and output.

  As described above, in this embodiment, a reproduced video signal can be output as a progressive image of 60 frames or an interlaced image of 30 frames or 60 fields, depending on the type of the device connected to the terminal 143. Therefore, when performing still image reproduction or slow reproduction, by outputting a 60-frame progressive image or a 30-frame interlaced image, it is possible to obtain a high-definition still image and a slow reproduction image without blurring. it can. In addition, in the case of performing moving image reproduction, by outputting a 60-frame progressive image or a 60-field interlaced image, a reproduced moving image with smooth motion can be obtained.

  Note that signals can be exchanged with the digital I / F 129 also in the reproduction system shown in FIG.

  That is, the reproduction signal reproduced by the reproduction circuit 133 and written in the memories 113 and 115 is transmitted to the digital I / F 129 in a state of being compression-coded in the progressive moving image transmission mode or the normal transmission mode in accordance with a request from the PC 10. It can be output, packetized and formatted by the digital I / F 129 as described above, and transmitted to the PC 10. Further, the signal transmitted from the PC 10 can be processed by the decompression processing circuits 135 and 137 and output from the terminal 143 to the outside.

  Further, in the apparatus shown in FIG. 1, the video signal is recorded on the magnetic tape. However, the present invention is not limited to this.

FIG. 1 is a diagram illustrating a configuration of a recording system of a VTR to which the present invention is applied. FIG. 2 is a diagram illustrating a configuration of an imaging unit in FIG. 1. FIG. 2 is a diagram illustrating a configuration of a camera signal processing circuit in FIG. 1. FIG. 2 is a diagram illustrating a state of a video signal output from the camera signal processing circuit in FIG. 1. FIG. 2 is a diagram illustrating a configuration of a compression processing circuit in FIG. 1. FIG. 2 is a diagram illustrating a head configuration of the recording circuit in FIG. 1. FIG. 2 is a diagram illustrating a configuration of a recording circuit in FIG. 1. FIG. 2 is a diagram showing a recording format of the apparatus of FIG. FIG. 1 is a diagram illustrating a configuration of a reproduction system of a VTR to which the present invention is applied. FIG. 10 is a diagram illustrating a configuration of a decompression processing circuit of FIG. 9.

Claims (3)

Using a moving image information obtained by a progressive scan type image pickup device, a first digital video signal composed of images of n fields per second (n is an integer of 2 or more) interlaced with each other, and a non-interrupt signal of n frames per second. Imaging means for generating a second digital video signal composed of a race image and selectively outputting the first digital video signal and the second digital video signal;
Compression means for compressing the first digital video signal or the second digital video signal output from the imaging means by compressing the information amount with high efficiency;
Voice generating means for generating a digital voice signal using a microphone;
The first digital video signal or the second digital video signal compressed by the compression means is multiplexed with the digital audio signal output from the audio generation means, and the first digital video signal and the second digital video signal are multiplexed. An interface for transmitting the video signal to the peripheral device in a compressed state,
The interface includes a first transmission mode for transmitting the first digital video signal together with the digital audio signal in the compressed state, and the digital audio signal in the compressed state for the second digital video signal. And a second transmission mode for transmitting the image data together with the image data.   A memory, wherein the audio generation means writes the digital audio signal into the memory; and the compression means encodes the first digital video signal or the second digital video signal output from the imaging means with high efficiency encoding. A high-efficiency encoding circuit for performing processing and writing to the memory, wherein the interface reads the high-efficiency-encoded digital video signal and the digital audio signal from the memory and transmits the digital video signal and the digital audio signal to the peripheral device. The imaging device according to claim 1, wherein:   The imaging apparatus according to claim 1, wherein the interface multiplexes the digital audio signal and the digital video signal in a format conforming to the IEEE 1394 serial bus standard and transmits the multiplexed digital audio signal and the digital video signal.

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