WO1998041024A1 - Systeme de codage/decodage d'images - Google Patents

Systeme de codage/decodage d'images Download PDF

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Publication number
WO1998041024A1
WO1998041024A1 PCT/JP1998/001026 JP9801026W WO9841024A1 WO 1998041024 A1 WO1998041024 A1 WO 1998041024A1 JP 9801026 W JP9801026 W JP 9801026W WO 9841024 A1 WO9841024 A1 WO 9841024A1
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WIPO (PCT)
Prior art keywords
image
image signal
signal
encoding
sub
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PCT/JP1998/001026
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English (en)
Japanese (ja)
Inventor
Shinya Kadono
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Matsushita Electric Industrial Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Priority claimed from JP5727797A external-priority patent/JPH10257492A/ja
Priority claimed from JP5727697A external-priority patent/JPH10257491A/ja
Application filed by Matsushita Electric Industrial Co., Ltd. filed Critical Matsushita Electric Industrial Co., Ltd.
Publication of WO1998041024A1 publication Critical patent/WO1998041024A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/59—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution

Definitions

  • the present invention relates to an image encoding / decoding system, and in particular, to an image encoding method for encoding an image, an image encoding device, and transmitting or recording the obtained encoding result.
  • the present invention relates to a method of transmitting a coded image signal when performing the decoding, a method of decoding an coded image signal, and a method of decoding an image.
  • FIG. 13 shows a conventional technique using such image encoded data.
  • FIG. 2 is a diagram showing a configuration of an image encoding / decoding system.
  • the image encoding / decoding system according to the related art includes an image encoding device 1301 and a dual image decoding device 1302. from the encoding device 1 3 0 1 to the image decoding apparatus 1 3 0 2, the c ⁇ 1 3 Figure in which the data can be transmitted by the transmission path 1 3 0 3 and the data recording medium 1 3 0 4
  • the image encoding device and the image decoding device are shown as having one each, an image encoding / decoding system generally has an arbitrary number of image encoding devices and image decoding devices. It can be composed of an encryption device and any number of transmission lines and recording media.
  • Digital image data which is digitized image data, is input to the image encoding device 1301 as an input image signal S1311.
  • the image encoding device 1301 generates and outputs an encoded surface image signal S1312 by performing a predetermined encoding process on the input image signal S1311. .
  • the output coded image signal S1312 is transmitted via the transmission path 1303 or recorded on the data recording medium 1304 and input to the image decoding device 1302. Is done.
  • the image decoding apparatus 13 02 generates and outputs a decoded image signal S 13 13 by performing a decoding process on the encoded image signal S 13 12 .
  • the decoded image signal bow-S 13 13 is displayed and used by a user on the decoding device side.
  • the transmission capacity and transmission speed permitted by the transmission path] 303, the useful capacity of the data recording medium 134, and the recording / reading of the data recording medium 130 4 have limitations, and therefore, the encoding ⁇ ⁇ "Efficiency plays an important role in the use of the system.
  • the image quality can be improved by recording and transmission. It is hoped that there is little deterioration of the material.
  • the image signal encoding method used in the image encoding / decoding system includes IS OZ IECMPEG 1 Z2 and ITU-TH.
  • H.263 is a typical example, and is widely used because of its high coding efficiency and good image quality.
  • it is common to divide an image signal into two-dimensional or three-dimensional blocks and to perform coding in block units.
  • IS QZ IECMPEG 4 which is currently in operation as a new international standard, has a shape signal, which is a binary signal representing the shape, in addition to a color signal having pixel values indicating YUV or RGB.
  • the transparency signal which represents the ratio of combining multiple images in pixel units, as one of the image signals, it is possible to handle images in object units. Even when such encoding processing is performed, encoding is usually performed in block units.
  • the amount of the encoded signal generated in the encoding process is suppressed to a certain amount or less due to restrictions on the transmission path and the recording medium.
  • Such rate control is mainly performed by a quantization step that changes a quantization step in a quantization process performed as a part of the encoding process.
  • the quantization step If the value is increased, the distortion in the amplitude direction of the pixel value increases, but the data amount decreases.Therefore, the amount of encoded data is controlled by changing the quantization step.
  • control It can be executed only when the target is a multi-level signal that can be subjected to quantization processing.
  • the control by the sub-sampling process if the number of objects to be processed is reduced, the spatial resolution distortion is increased, but the data amount is reduced.
  • the method controls the amount of encoded data by changing the subsample ratio, and is a control method that can be used for both multilevel signals and binary signals.
  • rate control by sub-sampling processing in image coding processing since the coding processing is performed in units of blocks as described above, it is necessary to use a unit of block. In general, control was performed by deciding whether or not to perform sub-sample processing, or by changing the sub-sample ratio.
  • control is performed solely by using a block, which is a processing unit divided for encoding processing, as a unit.
  • a block which is a processing unit divided for encoding processing
  • the rate control can be performed well, the overall rate, such as when the actual coding rate is performed at a value that is significantly different from the desired coding rate, The problem is that it is difficult to smoothly execute the control to bring the value close to a desired value.
  • the optimal size with good encoding efficiency generally depends on the encoding method and the like. It exists and the control by sub-sampling processing is performed based on such a proxy size. By performing sub-sampling in units of blocks, the block size changes, moving away from the block size suitable for the original encoding process. In such a case, especially when the block size becomes extremely small due to the control, the Since the coding efficiency is reduced and the compression ratio is also reduced, the coding rate cannot be reduced despite the significant reduction in image quality, leading to a situation where good control cannot be performed. .
  • FIG. 14 is a diagram showing an example of mutually related image signals used in an image encoding / decoding system according to a conventional technique.
  • FIG. 14 (a) shows a normal image
  • FIG. 14 (b) E shows a reduced image of the image of FIG. 14 (a).
  • Figs. 14 (c) and 14 (d) show the pixel value signal (color signal) and the shape signal of the fish included in Fig. 14 (a).
  • FIG. 14 (e) and FIG. 14 (f) are diagrams showing a pixel value signal (color signal) and a shape signal of aquatic plants included in FIG. 14 (a).
  • the pixel value signal is a signal having a pixel value indicating the color signal intensity signal of the object, and the shape signal is a binary signal indicating whether the pixel is inside or outside the object.
  • the signals shown in Figs. 14 (c) to (f) are used when the image shown in Fig. 14 (a) is handled on a per-object basis as in MPEG4. It is.
  • the image coding processing by the 5fe technique is to compress using the spatial or temporal correlation of the image, and to compress the image for one screen (one frame).
  • Intra-frame (intra-frame) coding based on the spatial correlation that has the basis, but based on the temporal correlation between one screen and another screen that is temporally close to it
  • inter-frame (inter-frame) encoding it is possible to further increase the compression ratio. Therefore, in the image encoding process according to the conventional technology, for each image signal of one screen (one frame) constituting image data, one frame for performing intra-screen encoding and one inter-screen encoding are used. Perform P-frame or B-frame G was used together according to the purpose.
  • the I-frame by intra-screen coding requires a large amount of data because it processes one plane of image signal.
  • a plane image can be obtained by the decryption processing by itself, it is preferable in terms of error propagation prevention and random accessibility.
  • P-frames and B-frames by encoding encode difference signals from other image signals so the data S becomes smaller, which can contribute to the improvement of the compression ratio, but the reference signal has an error. In this case, it is impossible to obtain an image by performing decoding correctly, so if these are used frequently, they will be weak to error propagation and random access will be degraded.
  • FIG. 15 is a diagram showing a state of encoding and transmission of related image signals in an image encoding / decoding system according to a conventional technique.
  • First Fig. 5 (a) shows the signal of the normal image shown in Fig. 14 (a) and the signal of the reduced image shown in Fig. 14 (M, or , The pixel value signal shown in FIG. 14 (c) E! And the pixel signal shown in FIG. 14 (f), and the shape signal shown in FIG. Fig. 15 (a) is a timing chart showing a state of processing when a shape signal is transmitted
  • Fig. 15 (a) one of the above combinations is used as an image signal 1 and the other is used as an image signal. This signal is coded as image signal 2 and transmitted.
  • switching between intra-screen coding and inter-screen coding is performed. , I-frame, or P-frame is to be transmitted.
  • the coded signal of the I frame or the coded signal of the P-frame is represented by a rectangle, and the width of each rectangle indicates the time required for transmission and the height indicates the transmission time.
  • the rate indicates the total number of bits transmitted by the area, and the position on the chart indicates the transmission time.
  • the data of the I-frame generated by the intra-frame encoding process is transmitted at the time i and the time i14. Also, at times i + 1, 1 + 2, i + 3 and at times 15 and i + 6, P-frame data generated by the inter-picture encoding process is transmitted.
  • FIG. 15 (b) is a timing chart showing a transmission state of an encoded signal in a conventional image encoding / decoding system. As shown in the figure, the coded signal of the image signal 1 has a higher priority than the coded signal of the image signal 2, and the frames at the same time have the same priority. One is transmitted first.
  • the time required for the transmission of the first I-frame that is, the first I-frame is transmitted.
  • the time required for the transmission of the first I-frame from time t (i), which is the timing when the next I-frame is transmitted, to time t (i + 1), which is the timing when the next P-frame is transmitted.
  • a delay corresponding to the time required for the transmission of the I-frame in the image signal 2 is added, and the amount of data is large, and the delay for the I-frame required for the transmission takes a long time. Is large.
  • FIG. 16 shows the relationship between coding and transmission of related marginal image signals when a higher transmission rate can be realized in a conventional image coding and decoding system. It is a figure showing a state.
  • FIG. 16) is a timing chart showing a case where the related image signal 1 and image signal 2 are encoded and transmitted, similarly to FIG. 15 (a). As shown in the figure, in this case, the transmission rate can be twice that of the case shown in Fig. 15 (a). It can be seen that the transmission was completed quickly.
  • Fig. 16 (b) like Fig.
  • the present invention has been made in view of such circumstances, and when performing image encoding processing in an image encoding / decoding system, a sub-sample processing is performed. It is an object of the present invention to provide an image coding apparatus capable of appropriately executing rate control based on logic.
  • the present invention provides an image encoding method capable of appropriately executing a rate control by a sub-sampling process when performing a bi-image encoding process in an image encoding / decoding system. aimed to.
  • the present invention provides an image encoding / decoding system capable of appropriately decoding an image-encoded signal on which subsemble processing for rate control has been performed, in an image encoding / decoding system.
  • the purpose is to provide a decoding device.
  • the present invention is capable of appropriately decoding an image-encoded signal that has been subjected to sub-sample processing for rate control in an image encoding / decoding system. It is intended to provide an image decoding method.
  • the present invention aims to improve the efficiency of the encoding process based on the relevance when encoding and transmitting related image signals in an image encoding / decoding system.
  • the purpose of the present invention is to provide a video signal transmission method that can perform the following.
  • the present invention switches between intra-frame coding and inter-screen coding in the coding and decoding system for encoding and transmitting related image signals.
  • Another object of the present invention is to provide an image signal transmission method capable of improving transmission efficiency when transmitting and recording a generated coded signal.
  • the present invention provides an image encoding / decoding system that performs encoding processing and transmission of related image signals by switching between intra-screen encoding and inter-screen encoding.
  • an image signal transmission method capable of suppressing a change in transmission rate when transmitting and recording a generated coded signal. With the goal.
  • the present invention records an image encoding program, an image decoding program, and an image signal transmission program, and executes the program in a computer system or the like.
  • a program recording medium that realizes image encoding with appropriate rate control, image decoding of image coded signals processed with rate control, and image signal transmission with high transmission efficiency
  • an image encoding device S encodes a digitized image signal and transmits an encoded image signal generated by the encoding process.
  • a first sub-sampling means for sub-sampling the image signal for each first processing unit to generate a first sub-sampling signal; and a first sub-sampling means for generating the first sub-sampling signal,
  • a blocking means for dividing the first sub-sampled signal to generate a divided signal having a second processing unit; and a second sub-sampling processing for dividing the divided signal generated by the blocking means.
  • the sub-sample ratio used by the first sub-sampling unit in the sub-sampling process and the sub-sample ratio used by the second sub-sampling unit in the sub-sampling process are determined by the surface image encoding / decoding system.
  • the data is recorded at the device output of the image encoding device. to this By performing relatively large subsample control for each of the first processing units and relatively small subsample control for each of the second processing units, the overall coding rate control and local control are performed. And efficient coding rate control.
  • the image encoding device is the image encoding device according to claim 1, wherein the image encoding device acquires the encoding rate in the encoding means, and acquires the acquired encoding rate.
  • the second subsample means further includes a ratio determination means for determining a subsample ratio used for the subsample processing.
  • the subsample ratio in the subsample processing for each second processing unit is determined in accordance with the encoding rate, and the subsample control for each second processing unit is controlled by the encoding rate. It can be executed appropriately in response to fluctuations in
  • An image encoding device is the image encoding device according to claim 2, wherein the second subsample signal generated by the second subsample means is upsampled.
  • the up-sample means for processing and generating the up-sample signal is compared with the up-sample signal generated by the up-sample means and the divided signal generated by the blocking means.
  • a comparing means for outputting the result of the comparison to the ratio determining means, wherein the ratio determining means is configured to perform the comparison based on the result of the comparison by the comparing means and the obtained encoding rate.
  • the sub-sample ratio is determined.
  • the image distortion due to the sub-sampling processing is detected using the comparison processing, and in addition to the coding rate fluctuation, the image distortion due to the sub-sampling processing is dealt with. Since sub-sample control is performed for each processing unit, it is possible to improve the S raw image quality while performing appropriate rate control.
  • the image decoding apparatus is a digital image. Encoding the signal, transmitting / recording the encoded image signal generated by the encoding process, and decoding the transmitted / recorded encoded image signal to generate a decoded image signal; In the decoding system, the coded image signal transmitted from the image coding apparatus and the sub-sample ratio in the image coding processing are input, and the coded image signal is decoded and the decoded image is decoded.
  • An image decoding apparatus for generating a signal, the decoding means for decoding the encoded image signal to generate a decoded sub-sample signal, and First up-sampling means for performing up-sampling processing using the sub-sample ratio included in the device input of the image decoding apparatus to generate a decoded divided signal; and integrating the decoded divided signal with the first up-sampling means.
  • An inverse blocking means for generating a decoded integrated subsample signal, and an amplifying means for the decoded integrated subsample signal using a subsample ratio included in a device input of the image decoding apparatus S.
  • a second assembling means for performing up-sampling processing to generate a decoded image signal.
  • an up-sampling process corresponding to the sub-sampling process in the encoding process is performed, and the image-encoded signal generated in the encoding process with the rate control by the sub-sampling process is converted into an image signal.
  • Appropriate decoding can be performed with upsample processing corresponding to subsample processing.
  • An image encoding method comprising: encoding a digitized image signal; transmitting and recording the encoded image signal generated by the encoding process; and transmitting and recording the encoded image signal.
  • an image encoding method for encoding an image signal comprising: A first subsample step for generating a first subsample signal by performing subsample processing on the first subsample signal; A block forming step of dividing the first sub-sampled signal generated in the step and generating a divided signal having the second processing unit; and a sub-step of dividing the divided signal generated in the block A second sub-sample step for performing sample processing to generate a second sub-sample signal; and an encoding step for performing encoding processing on the second sub-sample signal to generate an encoded image signal.
  • the encoded image signal, the sub-sample ratio used in the sub-sample processing in the first sub-sample step, and the sub-sample ratio used in the sub-sample processing in the second sub-sample step Is an encoded image output transmitted / recorded in the above-mentioned image encoding / decoding system.
  • a relatively large sub-sample control for each first processing unit and a relatively small sub-sample control for each second processing unit are performed, and the overall coding rate control and local control are performed. It is possible to appropriately perform efficient coding rate control.
  • An image encoding method is the image encoding method according to claim 5, wherein the encoding rate in the encoding step is acquired, and the acquired code is acquired.
  • the method further includes a ratio determining step of determining a subsample ratio used in the subsample processing in the second subsample step based on the conversion rate.
  • the sub-sample ratio used for sub-sample processing for each second processing unit is determined according to the encoding rate, and the sub-sample control for each second processing unit is determined based on the encoding rate. It is possible to execute appropriately in response to fluctuations.
  • An image encoding method is the image encoding method according to claim 6, wherein the second sub-sampled signal generated in the second sub-sample step is used. Up-sampling process, and Comparing the sample signal for generating the sample signal, the sample signal for generating the sample signal in the above-mentioned sample step with the divided signal generated in the step for blocking, and A comparison step for outputting the result of the comparison so as to be used in the ratio determination step; and in the ratio determination step, a comparison step in the comparison step.
  • the subsample ratio is determined based on the result of the above and the obtained coding rate.
  • the distortion of the image due to the sub-sample processing is detected by using the comparison processing, and in addition to the coding rate fluctuation, the distortion of the image due to the sub-sampling processing is also dealt with. Since subsample control is performed for each processing unit, it is possible to improve reproduction image quality while performing appropriate rate control.
  • An image decoding method comprising: encoding a digitized image signal; transmitting and recording an encoded image signal generated by the encoding process; and transmitting and recording the encoded image signal.
  • an image coding / decoding system for decoding a coded image signal thus generated to generate a decoded image signal
  • the coded image signal generated and transmitted by the image coding process and the image
  • An image decoding method for decoding a coded image signal to generate a decoded image signal wherein sub-sample ratios and s in a coding process are processing targets, and a decoding process for the coded image signal.
  • the up-sampling process corresponding to the sub-sampling process in the encoding process is performed, and the coded image signal generated in the encoding process with the rate control by the sampling process is converted to the sub-sampling process.
  • up-sample processing it is possible to perform appropriate decryption processing.
  • the image signal transmission method is a method for encoding a digitized image signal, transmitting and recording the encoded image signal generated by the encoding process, and transmitting and recording the encoded image signal.
  • Image decoding that decodes the coded image signal to generate a decoded image signal.
  • an image signal transmission method that encodes and transmits multiple related image signals.
  • a partial image signal of a specific spatial region included in one image signal and a spatial query corresponding to a specific spatial region in the one image signal included in another image signal The partial image signal of the region and the partial image signal are collectively encoded, and the encoded image signal generated by the above encoding is transmitted in the above-mentioned encoding and decoding system.
  • the encoded image signal generated by the above encoding is transmitted in the above-mentioned encoding and decoding system.
  • An image signal transmission method is the image signal transmission method according to claim 9, wherein the encoding processing does not involve sub-sampling processing, or the encoding processing includes sub-sampling processing. And a second image signal related to the first image signal and the second image signal.
  • the first image signal and the second image signal associated with the first image signal are encoded and transmitted.
  • 1 transmission format and the above-mentioned first image signal A first encoded image signal generated by an encoding process with a sub-sampling process, and a second encoded image ⁇ symbol generated by encoding the second image signal.
  • the second transmission format of the specific encoded image signal based on the partial image signal in the specific spatial region included in the first image signal. Is the same as the position in the first transmission format.
  • the transmission format when the sub-sampling process is performed and the transmission format when the sub-sampling process is not performed are approximated, so that the sub-sampling process may or may not be performed.
  • a transmission format that is easy to handle can be realized, and implementation can be facilitated.
  • An image signal transmission method is a method of encoding a digitized image signal, transmitting and recording an encoded image signal generated by the encoding process, and transmitting and recording the encoded image signal.
  • an image encoding / decoding system that decodes an encoded image signal to generate a decoded image signal
  • an image signal transmission method that encodes and transmits a plurality of image signals.
  • An encoded image signal is generated by switching and using two or more image encoding methods for each of the plurality of image signals, as in the two or more image encoding methods. That is, timing for performing a specific image encoding method is controlled so as to be different for each of the plurality of image signals.
  • the image signal transmission method according to claim 12 is! Request range 1 1
  • the above-mentioned The time at which an image signal to be coded by a specific image coding method is specified, and the time at which an II image signal to be coded by the specific image coding method with respect to another image signal is calculated.
  • the specified time differs from the specified time by a predetermined time. This makes it possible to shift the timing when the amount of data increases in transmission of one encoded image signal and the timing when the amount of data increases in transmission of another encoded image signal. Therefore, it is possible to improve the transmission efficiency and the accuracy of the rate control, and to reduce the capacity of the storage device necessary for temporary storage and to utilize the device resources. It becomes.
  • An image signal transmission method is the image signal transmission method according to claim 11, wherein the specific image encoding method is used for one image signal.
  • the cycle of performing the encoding process is different from the cycle of performing the encoding process on another image signal by the above-described specific image encoding method.
  • the timing at which the amount of data increases increases is shifted to improve the transmission efficiency and the accuracy of the rate control, and at the same time, the overall amount of data for the image signal having a long period is reduced. It is possible to do this.
  • the method for transmitting an image signal according to Item 14 is that the one image signal is more important than the other image signals in the method for transmitting an image signal according to Item 85 in Item 85.
  • the cycle for the one image signal is shorter than the cycle for the other image signal. This makes it possible to improve the quality of the coded signal for important signals by using a specific coding method that is resistant to error propagation and that is suitable for random access.
  • An image signal transmitting method is the image signal transmitting method according to claim 14, wherein the one image signal is a sub-signal. It has been encoded with sample processing. This makes it possible to improve the quality of a coded signal with sub-sample processing, which is resistant to error propagation and uses many specific coding methods suitable for random access. It becomes possible.
  • An image signal transmission method is the image signal transmission method according to claim 14, wherein the image signal is a shape signal of an object, and The image signal is the pixel value of the object.
  • the method for transmitting an image signal according to claim 17 is the method for transmitting an image signal according to claim 9, wherein the plurality of image signals is a specific image of the plurality of image signals. It includes an image signal obtained by sub-sampling the signal.
  • the partial image signals in the corresponding spatial region between the image signal without sub-sampling processing and the image signal with sub-sampling processing are collectively encoded and transmitted. It is possible to improve the coding efficiency based on the correlation between the two.
  • the image signal transmission method according to claim 18 is the image signal transmission method according to claim 11, wherein the plurality of image signals are a specific one of the plurality of image signals. It includes an image signal obtained by sub-sampling the image signal.
  • the image signal transmission method according to claim 19 is the image signal transmission method according to claim 9, wherein the plurality of image signals are a shape signal for a certain object and a shape signal for the object. It includes a pixel value signal and.
  • the encoding efficiency is determined based on the correlation between the two. It can be improved.
  • An image signal transmission method is the dual image signal transmission method according to claim 11, wherein the plurality of image signals are a shape signal for an object, and a shape signal for the object. It includes the pixel value signal and.
  • a specific encoding method that increases the amount of data to be transmitted is not continuously or repeatedly performed on the shape signal and the pixel value signal, so that the transmission efficiency is improved. Therefore, it is possible to improve the accuracy of the rate control and the rate control, and it is possible to reduce the capacity of the storage device necessary for temporary storage and to utilize the power source.
  • An image encoding program recording medium encodes a digitized image signal and transmits an encoded image signal generated by the encoding process.
  • the coding step includes using the coded image signal and the first subsample step in the subsample processing.
  • the subsample ratio and the subsample ratio used in the subsample processing in the second subsample step are transmitted and recorded in the image encoding / decoding system as an image encoded output. It records an image coding program.
  • the surface image coding program is executed in a computer system or the like, and a relatively large first processing unit and a relatively small second processing unit are controlled.
  • the sub-sample control and the sub-sample control for each processing unit are performed, and the overall coding rate control and the local coding rate control can be appropriately performed.
  • An image decoding program recording medium encodes a digitized image signal and transmits an encoded image signal generated by the encoding process.
  • ⁇ Record and transmit ⁇ Image coding for decoding the recorded coded image signal to generate a decoded image signal ⁇
  • An image decoding processor that processes the transmitted encoded image signal and the subsample ratio in the image encoding process, and decodes the encoded image signal to generate a decoded image signal.
  • Sub-services included in the above processing target A first upsample step for performing a decoding sampled signal by performing an up-sampling process using the sample ratio and an integrated process of the decoded divided signal to generate a decoded integrated subsampled signal Up-sample processing using the inverse-blocking step and the sub-sample ratio included in the above-mentioned processing target for the decoded integrated sub-sample signal And a second up-sampler for generating a decoded image signal.
  • the image decoding program is executed in a computer system or the like to perform upsampling processing corresponding to the subsampling processing in the encoding processing, and perform encoding with rate control by subsampling processing.
  • the encoded image signal generated in the processing can be appropriately decoded with up-sample processing corresponding to the sub-sample processing.
  • An image signal transmission program recording medium encodes the digitized image signal, and transmits the encoded image signal generated by the encoding process.
  • Image coding for decoding the recorded encoded image signal to generate a decoded image signal ⁇ In a decoding system, a plurality of related image signals are encoded and transmitted.
  • the partial image signal in the spatial domain corresponding to the specific spatial domain in the one image signal is encoded as a whole, and the encoded image signal generated by the encoding is encoded by the encoding-decoding system.
  • Transmission in the item It records the image signal transmission program to be sent.
  • the image signal transmission program is executed in a computer system or the like, and in the image signals related to each other, a high correlation is expected in a corresponding spatial region. Since the partial signals are collectively encoded, it is possible to improve the encoding efficiency by using the correlation.
  • An image signal transmission program recording medium encodes the digitized image signal, and transmits and records the encoded image signal generated by the encoding process.
  • the transmitted and recorded encoded image In an image encoding / decoding system that decodes a signal to generate a decoded image ⁇ , a recording medium that records an image signal transmission program that encodes and transmits a plurality of image signals.
  • a coded image signal is generated by switching and using two or more image coding methods for each of the plurality of image signals. In this method, an image signal transmission program for controlling a specific image encoding method among the plurality of image signals so as to have different timings is recorded.
  • the image signal transmission program is executed in a computer system or the like so that a specific encoding method that increases the amount of data to be transmitted is not performed continuously or redundantly. Therefore, it is possible to improve the transmission efficiency and the accuracy of the rate control, and it is possible to reduce the capacity of the storage device necessary for the temporary storage and utilize the device resources. It will be possible.
  • FIG. 1 is a block diagram showing a configuration of an image encoding device a according to Embodiment 1 of the present invention.
  • FIG. 2 is a diagram for explaining sub-sample processing and division processing in the image coding method according to the embodiment.
  • FIG. 3 is a block diagram showing a configuration of an image encoding device according to Embodiment 2 of the present invention.
  • FIG. 4 is a block diagram showing a configuration of an image decoding device according to Embodiment 3 of the present invention.
  • FIG. 5 is a diagram for explaining processing and transmission of an image signal in the image signal transmission method according to the fourth embodiment of the present invention.
  • FIG. 6 shows an image signal transmission method according to Embodiment 5 of the present invention.
  • FIG. 4 is a diagram for explaining processing and transmission of an image signal.
  • FIG. 7 is a diagram for explaining processing and transmission of an image signal in the image signal transmission method according to the sixth embodiment of the present invention.
  • FIG. 8 is a diagram for explaining processing and transmission of an image signal in the image signal transmission method according to the seventh embodiment of the present invention.
  • FIG. 9 is a diagram for explaining processing and transmission of an image signal in the image signal transmission method according to the eighth embodiment of the present invention.
  • the 100th figure is a diagram for describing processing and transmission of an image signal in the image signal transmission method according to the ninth embodiment of the present invention.
  • FIG. 11 is a diagram for explaining processing and transmission of an image signal in the plane image signal transmission method according to Embodiment 10 of the present invention.
  • FIG. 12 is a diagram showing a flip-flop disk which is a program recording medium according to the eleventh embodiment.
  • FIG. 13 is a diagram showing a configuration of an image encoding / decoding system according to a conventional technique.
  • FIG. 14 is a diagram showing an example of image signals related to each other, which may be used in an image encoding / decoding system according to a conventional technique.
  • FIG. 15 is a diagram for explaining processing and transmission of an image signal in an example of an image signal transmission method according to the related art.
  • FIG. 16 is a diagram for explaining processing and transmission of an image signal in another example of the image signal transmission method according to the related art.
  • the image coding apparatus and the image coding method according to the first embodiment of the present invention perform rate control by combining two-stage subsampling. Things.
  • FIG. 1 is a block diagram showing a configuration of an image encoding device according to Embodiment 1 of the present invention.
  • the image coding apparatus according to the first embodiment includes a first sub-sampler 101, a blocker 102, a second sub-sampler 103, a ratio It is provided with a decision unit 104 and an encoder 105, takes an input image as a device input, and outputs an encoded image signal S117 and a first sub-sample ratio S Let 1 1 2 and the second sub-sample ratio S 1 1 9 be the device outputs.
  • the first sub-sampler 101 sub-samples the input image signal for each first processing unit using a first sub-sample ratio given from the outside, and converts the first sub-sample signal to the first sub-sampler. Generate.
  • the block generator 102 divides the first sub-sampled signal for each first processing unit and generates a divided signal for each second processing unit.
  • the second sub-sampler 103 sub-processes the divided signal for each second processing unit using a second sub-sample ratio given from a ratio determiner 104 described later. Generate the second subsampled signal.
  • the ratio determiner 104 receives a second sub-sampler based on a set sub-sample ratio given from the outside and an encoded bit rate obtained from an encoder 105 described later. 103 determines the second sub-sample ratio used for sub-sample processing.
  • the encoder 105 encodes the second sub-sample signal generated by the second sub-sampler 103 to generate an encoded image signal.
  • FIG. 2 is a diagram for explaining an image encoding method according to the first embodiment. Hereinafter, the operation of the image encoder according to the first embodiment configured as shown in FIG. 1 will be described with reference to FIG. 1 and FIG.
  • FIG. 2 (a) shows an image signal of a first processing unit which constitutes both input image signals S111.
  • the input image signal S111 is composed of an array of pixels that are discrete digital data. As shown in the figure, 16 horizontal pixels x 12 vertical pixels correspond to the image of the first processing unit. It constitutes a signal.
  • the first subsampler 101 converts the input image signal S111 into a first processing unit image signal using the first externally supplied subsample ratio S112. , To generate a first sub-sampled signal S 113.
  • the bit rate of the coded image signal output in the image coding apparatus a is set to a value close to the desired bit rate. In such a way, it is necessary to set the power and pre-set it and give it.
  • the setting is made with reference to the bit rate of the image signal at the time of performing the encoding process in the past in the image encoding device and the sub-sample ratio used.
  • the setting can be made in consideration of the difficulty of the encoding process and the characteristics of the image such as the activity.
  • the second (a) It is assumed that a subsample ratio is given so that a subsampling process of 1/2 in both the horizontal direction and the vertical direction is performed on the signal of the first processing unit shown in the figure. Accordingly, the signal of the first processing unit shown in FIG. 2 (a) is subjected to the sub-sampling processing, so that the first eight pixels of the horizontal X six pixels of the vertical shown in FIG. 2 (b) are obtained. A sub-sampled signal S 113 is generated. The first subsample signal S113 is output from the first subsampler 101 to the blocker 102. Also, The first subsample ratio S112 is output as a part of the device output of the image coding device.
  • the block generator 102 performs a predetermined division process on the first sub-sample signal S 113 and generates a divided signal S 1 configured as a signal for each second processing unit. Generate 1 4.
  • the second processing unit achieves the optimal block size in the division process. It is desirable to make settings in this way.
  • the size of 2 horizontal pixels x 2 vertical pixels is the optimal block size, and as shown in Fig. 2 (c), 2 horizontal pixels x 2 vertical pixels Is the second processing unit, and the division processing is to be executed.
  • the divided signal S114 divided for each second processing unit is output from the blocker 102 to the second subsampler 103.
  • the second sub-sampler 103 uses the second sub-sample ratio S 113 obtained from the ratio determiner 104 for each of the second processing units constituting the divided signal S 114. To generate a second subsample signal S116, and output the second subsample signal S116 to the encoding device 105.
  • the encoder 105 encodes the input second subsample signal S116 according to a predetermined method to generate an encoded image signal S117.
  • the encoded image signal S 117 becomes a part of the device output as a result of encoding in the image encoding device.
  • the ratio determiner 104 acquires the encoded bit rate S 118 in the encoder 105, and receives the acquired encoded bit rate S 118 from the outside.
  • a second sub-sample ratio SI 19 used for sub-sample processing in the second sub-sampler 103 is determined based on the set sub-sample ratio S 115 and the second sub-sample ratio S 1 1 9 is output to the second sub-sampler 103, and is output as a part of the device output of the image coding device.
  • the set sub-sample ratio S 115 is set so as to control the image quality deterioration due to the second sub-sampling process.
  • the local activity of the image is set. It is desirable to set in consideration of characteristics such as However, when the variation in local characteristics is small, especially when there is little need for external control, the coding bit rate S Only the sub-sample ratio in the initial state where no input of 1 18 is input is given as the set sub-sampling ratio S 115, and thereafter, in the ratio determiner 104, only the encoding bit rate is used.
  • the control can be simplified by determining the second sub-sample ratio S 119 based only on the threshold S 118.
  • FIG. 2 (d) is a diagram showing the sub-sampling process in the second sub-sampling device 103.
  • the second sub-sampling ratio is set for each second processing unit composed of two horizontal pixels and two vertical pixels constituting the divided signal S114. , 1 or 1/2 is output, and the processing unit processed according to the sub-sample ratio is 4 pixels, and is processed according to the sub-sample ratio of 1/2.
  • the processing unit subjected to the sub-sampling processing has only one pixel.
  • the first sampler 101, the blocker 102, the second subsampler 103, the ratio uses the given sub-sample ratio to perform the sub-processing for each first processing unit.
  • Sample processing and the subsample ratio in the second subsampler 103 corresponding to the encoding processing status And the sub-sampling process for each of the second processing units is performed, so that the entire coding bit rate is obtained by the sub-sampling process for each of the first processing units, which is a larger processing unit.
  • the sub-sampling process for each first processing unit using the given sub-sampling ratio and the sub-sampling ratio corresponding to the encoding processing status are used. Since the sub-sampling process for each second processing unit is performed, the entire encoding bit rate is desired by the sub-sampling process for each first processing unit, which is a larger processing unit. In addition to approaching the value, the sub-sample processing for each second processing unit, which is a smaller processing unit, performs local bit rate corresponding to the fluctuation of the encoding bit rate. In addition, it is possible to perform better bit rate control as compared with the conventional image coding processing in which control is performed in a single block unit.
  • the entire screen is used as the first processing unit to perform the sub-sampling processing.
  • a plurality of blocks corresponding to the second processing unit such as performing the first sub-sample processing using the slice obtained by dividing the slice as the first processing unit, is used as the first processing unit.
  • the same good control can be performed.
  • Rate control is performed by combining two-stage subsampling as in the first embodiment, and control is performed in accordance with the result of the subsample processing. This is intended to reduce image quality degradation.
  • FIG. 3 is a block diagram showing a configuration of an image coding apparatus according to Embodiment 2 of the present invention! ].
  • the image coding apparatus according to the second embodiment includes a first sub-sampler 301, a blocker 302, a second sub-sampler 303, It is equipped with a ratio determiner 304, an upsampler 300, a comparator 303, and a coder 307, and receives an input image signal S311 as a device input. Then, the encoded image signal S 3 ⁇ 6, the first sub-sample ratio S 3 12, and the second sub-sample ratio S 3 21 are set as device outputs.
  • the up-sampler 300 receives the second sub-sample signal “ ⁇ ” generated by the second sub-sampler 303 and performs up-sample processing, which is the inverse processing of sub-sample processing.
  • up-sample processing which is the inverse processing of sub-sample processing.
  • an upsampled signal having the same number of pixels as the signal before the sub-sample processing is generated by the comparator 303.
  • the comparator 306 generates the divided signal before the second sub-sampler 303 performs the sub-sample processing.
  • Signal is compared with the upsampled signal, the magnitude of the distortion due to the upsampling processing after the subsampling processing is obtained by calculation, and the obtained result is distorted.
  • the signal is output as a signal to the ratio determiner 304.
  • the ratio determiner 304 obtains a signal based on the distorted signal in addition to the given set subsample ratio and the encoded bit rate. Determine the second sub-sample ratio.
  • the sub-sampler 301, the blocker 302, the second sub-sampler 303, and the encoder 300 are the same as the sub-sampler 101 in the first embodiment. Same as 102, 103, and 105.
  • Embodiment 2 The operation of the thus configured image encoding apparatus according to Embodiment 2 will be described below.
  • the sub-sampling process in the first sub-sampler 301 and the division process in the blocker 302 are the same as in the first embodiment.
  • Done in The divided signal S 3 14 is input to the second sub-sampler 303 as in the first embodiment, and is also input to the comparator 30 6 in the second embodiment. Is done.
  • the second sub-sampler 303 receives a second sub-sample ratio S 3 2 1 provided from the ratio determiner 304 for each second processing unit with respect to the divided signal S 3 14. And outputs the generated second sub-sampled signal S 315 to the encoder 307 and also to the up-sampler 305.
  • the ratio determiner 304 outputs the second sub-sample ratio S 321 to the up-sampler 305.
  • the encoder 307 performs an encoding process in the same manner as in the first embodiment, and outputs an encoded image signal S 316.
  • the up-sampler 305 performs up-sampling processing on the input second sub-sample signal S 315 by using the sub-sample ratio input from the ratio determiner 304.
  • the up-sampler 305 performs up-sampling processing on the input second sub-sample signal S 315 by using the sub-sample ratio input from the ratio determiner 304.
  • the comparator 303 receives the input divided signal S314 and the upsampled signal.
  • the ratio determiner 304 adds the given set sub-sample ratio S 319 and the code bit rate S 322 obtained from the encoder 307 to the distortion signal S 340. 1 8 Then, determine the second sub-sample ratio.
  • the sub-sample ratio is determined secondly so that the magnitude of the distortion indicated by the distortion signal S 3 18 is equal to or less than a predetermined value, thereby deteriorating the image quality due to the sub-sampling processing. Can be suppressed to a certain amount or less.
  • the set sub-sample ratio S 3 19 is set in the same manner as in the first embodiment.
  • the image coding apparatus of the first embodiment is provided with the configuration in which the upsampler 300 and the comparator 303 are added.
  • the ratio determiner 304 determines the second sub-sample ratio based on the distortion signal S 318 output from the comparator 306, so that the implementation form fll 1 Similarly, in addition to being able to perform good bit rate control, it is possible to suppress distortion due to sub-sampling processing and obtain a good-quality encoding result.
  • the sub-sampling process for each first processing unit using the given sub-sampling ratio and the sub-sampling ratio corresponding to the encoding process status are performed.
  • the sub-sampling process for each of the second processing units used is performed, and compared with the conventional image coding process that performs control in a single block unit.
  • image distortion due to the sub-sample processing is taken into account in the sub-sample processing for each second processing unit.
  • An image decoding apparatus g and an image decoding method according to Embodiment 3 of the present invention appropriately decode an encoding result output from the image encoding apparatus according to Embodiment 1. .
  • FIG. 4 shows a configuration of an image decoding apparatus according to Embodiment 3 of the present invention.
  • the image decoding apparatus according to the third embodiment includes a decoder 401, a first up-sampler 402, an inverse block generator 400 , And a second upsampling device 404, which is a coded image signal S 117, which is a device output of the image coding device according to the first embodiment.
  • a decoder 401 the image decoding apparatus according to the third embodiment
  • a first up-sampler 402 an inverse block generator 400
  • a second upsampling device 404 which is a coded image signal S 117, which is a device output of the image coding device according to the first embodiment.
  • Decoder 410 executes a decoding process which is a reverse process of the encoding process performed by encoder 105 in the first embodiment.
  • the first upsampler 402 uses the second subsample ratio, which is a part of the input signal of the image decoding apparatus, to reconstruct the subsampled signal.
  • Perform processing The inverse block generator 4003 performs an integration process that is the inverse process of the division process performed by the blocker 102 in the first embodiment, and performs a small processing unit (second processing unit). ) To generate a signal of a large processing unit (first processing unit).
  • the second upsampler 404 performs an upsampling process for restoring the subsampled signal using the first subsample ratio, which is a part of the device input of the image decoding device. Go.
  • the coded image signal S 4 11 1, the first sub-sample ratio S 4 17, and the second sub-sample ratio S 4 16 are input to the image decoding apparatus according to the third embodiment.
  • the encoded image signal S 411 is to the decoder 401 and the second subsample ratio S 416 is to the first upsampler 402 and the first subsample ratio.
  • S 4 17 is the second upsampler 4 Entered in 04.
  • the decoder 410 performs a decoding process on the encoded image signal S411, which is a reverse process of the encoding process performed by the encoder 105 in the first embodiment. Then, it generates a decoded sub-sampled signal S 412 and outputs the decoded sub-sampled signal S 412 to the first up-sampler 402.
  • the first up-sampler 402 performs up-sample processing on the decoded sub-sampled signal S 4 12 using the input second sub-sampling ratio S 4 16. As a result, a decoded divided signal S 413 is generated, and the decoded divided signal S 413 is output to the inverse blocker 403.
  • the deblocker 403 generates the decoded integrated sub-sampled signal S 414 by integrating the decoded divided signal S 413, and generates the decoded integrated sub-sampled signal S 414. Output 14 to the second upsampler 4 04.
  • the second sub-sampler 40 performs an up-sampling process on the decoded integrated sub-sample signal S 414 using the input first sub-sample ratio S 417. As a result, a decoded image signal 15 is generated.
  • the decoded ghost image signal S 415 is a device output of the image decoding device S according to the third embodiment.
  • the decoding device 401, the first upsampling device 402, and the inverse blocking device 400 , And the second up-sampler 404, the encoding processing, the second sub-sampling processing, the blocking processing, and the first sub-sampling processing in Embodiment 1 are provided.
  • the decoding processing, the first up-sampling processing, the inverse block processing, and the second amplifying processing respectively corresponding to The decoded image signal can be appropriately decoded to obtain a decoded image signal.
  • the second sample processing, and the encoded image signal generated in the first embodiment can be appropriately decoded to obtain a decoded image signal.
  • the image decoding apparatus according to the third embodiment processes the output of the image encoding apparatus according to the first embodiment
  • the image decoding apparatus according to the second embodiment processes the output of the image encoding apparatus according to the second embodiment. Can also be handled appropriately.
  • the image signal transmission method encodes two or more mutually related image signals and collectively transmits corresponding portions of the encoded image signal. That is what you do.
  • FIG. 5 shows K for explaining the processing and transmission of an image signal in the fourth embodiment.
  • image signal transmission according to the fourth embodiment will be described with reference to FIG.
  • the image signal and the image signal shown in FIG. 5 (b) are related to each other.
  • the former is a pixel value signal for a certain object
  • the latter is a shape signal of the object.
  • discrete digital data constitutes a two-dimensional structure corresponding to a screen
  • FIG. 5 (a) and FIG. 5 (b) Also represents the-part of the signal corresponding to one screen.
  • Block b (0.0) corresponds to blocks a (0,0), a (0,1), a (l, 0), and a (1,1,1) in Fig. 5 (a).
  • block b (2i.2j) becomes block a (2i, 2j), a (2i, 2j + l), a (2i + l, 2j), And a (2i + l, 2j + l).
  • the block b (0, 0) in FIG. 5 (b), the block a (0, 0) in FIG. a (0, 1) a (1.0) and a (l, l) are coded together, and the obtained coded result is transmitted continuously.
  • Blocks b (2i, 2j) and a (2i, 2j), a (2i, 2j + 1), a (2i + 1.2j), And a (2i + l, 2j + l) are coded together, and the obtained coded result is transmitted continuously.
  • the image signal shown in FIG. 5 (a) is a pixel value signal and the image signal shown in FIG. 5 (b) is a corresponding shape signal, they have a correlation. However, in general, their statistical properties are very different.
  • an appropriate block size differs from the viewpoint of encoding efficiency. Therefore, if encoding is performed in units of large blocks having the size of the least common multiple based on the correspondence between the two, it is possible to use appropriate block division for each of them. The coding efficiency can be improved based on the correlation between the two.
  • Embodiment 4 of the present invention the pixel value signal for each small block suitable for encoding (Fig. 5 (a)) and the shape signal for each small block suitable for encoding (Fig. 5 (a)). (Fig. 5 (b)) and the corresponding four blocks of the former and one block of the latter are processed together to improve coding efficiency. is there.
  • FIG. 5 (c) is a diagram showing a transmission format of an encoding result in the fourth embodiment.
  • b (0, 0) is a signal obtained by encoding the image signal of block b (0, 0) in FIG. 5 (b).
  • the signal obtained by encoding the image signal of block b (0, 0) is represented by blocks a (0, 0), a (0, l), a (l, 0) and a (l, 1) are transmitted prior to the encoded signal of the image signal. That is, in the transmission format of the encoding result in the fourth embodiment, of the encoding results derived from the two corresponding image signals, the encoding result is generated from the image signal shown in FIG. 5 (b).
  • the transmission format that gives priority to This is because when the pixel value signal shown in Fig. 5 (a) is compared with the shape signal shown in Fig. 5 (b), the shape signal plays a more important role in the reproduced image. Therefore, by preferentially transmitting the encoding result generated from the shape signal, it is possible to preferentially decode important data on the decoding side, and to reduce transmission errors. The purpose of this is to make it possible to suppress the effect of error propagation due to the error.
  • the image signal transmission method when transmitting two image signals that are related to each other, a portion corresponding to the two spatially corresponds.
  • the transmission format that preferentially transmits the encoding result generated from the important image signal is used, so that the decoding side can be used. In this case, it is possible to facilitate the processing in the transmission and to suppress the influence of error propagation during transmission.
  • Embodiment 5 The image signal transmission method according to the fifth embodiment of the present invention, as in the fourth embodiment, collectively encodes and transmits corresponding portions of two or more mutually related image signals. And performs processing on a block line basis.
  • FIG. 6 is a diagram for describing processing and transmission of an image signal according to the fifth embodiment.
  • the image signal transmission in the fifth embodiment will be described with reference to FIG.
  • the image signal shown in FIG. 6 (a) and the image signal shown in FIG. 6 (b) are related to each other in the same manner as in the fourth embodiment.
  • the former is a search value signal for a certain object
  • the latter is a shape signal of the object.
  • the horizontal arrangement of the blocks of the image signal shown in FIG. 6 (a) is called a block line.
  • a (0, 0), a (0, l), a (0, 2) ... constitute one block line
  • a (l , 0), 3 (1, 1), a (1.2) ... constitute a block line different from the one described above.
  • the block b (0, 0) in FIG. 6 (b) is replaced by the block a (0, 0) in FIG. 6 (a). 0), a (0, 1), a (0, 2), and a (0, 3), generally with i and j being integers, and the block b (i, 4 j) force; And the blocks a (i, 4j), a ( ⁇ , 4j + l), a (i, 4j + 2), and a (i, 4j + 3).
  • block b (2i, 2j) in the fourth embodiment corresponds to block a (2i, 2j), a (2i, 2j + 1) a (2i + l, 2j ), And a (2i + l, 2j + l), one block in Fig. 6 (b) is identical to the block in Fig. 6 (a).
  • the point corresponding to the four blocks on the block line of Fig. 5 (b) is that one block in Fig. 5 (b) corresponds to the two block lines in Fig. 5 (a).
  • Exist on 4 This is different from Embodiment 4 corresponding to one block.
  • blocks having a corresponding relationship are collectively encoded and transmitted.
  • block b (0.0) in Fig. 6 (b) and block a (0, 0), a (0, l), a (0, 2), And a (0, 3) are encoded together, and as shown in Fig. 6 (c), the encoded result generated from block b (0, 0) is transmitted with priority.
  • the spatial interrogation of both is performed.
  • the encoding processing according to each property can be performed, and the encoding efficiency can be improved based on the correlation between the two. It is a process that collectively processes the blocks on the same block line, which makes it possible to process on a block-by-line basis. This is suitable for the case where the real-time encoding process associated with is performed.
  • a transmission format that preferentially transmits an encoding result generated from the important image signal is used. This makes it possible to facilitate the processing on the decoding side and to suppress the influence of signal propagation during transmission.
  • the image signal transmission method collects corresponding portions of two or more mutually related image signals. In addition, it is encoded and transmitted, and transmission is performed in consideration of block lines.
  • FIG. 7 is a diagram for explaining processing and transmission of an image signal according to the sixth embodiment.
  • image signal transmission in the sixth embodiment will be described with reference to FIG.
  • the image signal shown in FIG. 7 (a) and the image signal shown in FIG. 7 (b) correspond to the image signal shown in FIG. 5 (a) in the fourth embodiment and the image signal shown in FIG.
  • the image signals are related to each other as in the case of the image signals shown in the figure, and the aerial correspondence is also the same.
  • encoding is performed based on such correspondence.
  • FIG. 7 (c) is the same as FIG. 5 (c), and shows the same transmission format as in the fourth embodiment.
  • processing in the horizontal direction is often performed, that is, as shown in FIG. 7 (a).
  • a (0, 1), a (0, 2), a (0, 3) are the same. These include pixels existing on the horizontal scanning line and can be processed continuously.
  • a (1, 0), a (1, 1) ... are different pixels on the Eihei scanning line.
  • the block a (() , 0) and a (U, 1) are processed in succession, and the coding results from subsequent blocks a (l, 0) and a (1, 1) are Temporarily accumulates and... Therefore, it is necessary to temporarily store the encoding result that is not processed continuously until it is processed, and for a convenient device such as a memory, such a temporary device is required. Sufficient capacity is required for storage.
  • the transmission format as shown in FIG. 7 (d) is used.
  • the signal on the block line is transmitted continuously, and the signal on the block line, which is different from this, is a (l, 0), a (1, 1) ... Things.
  • image signals including pixels existing on the same horizontal scan line can be continuously input and processed, and thus the transmission format used in Embodiment 4 is In comparison, it is possible to reduce the capacity of the storage device necessary for temporarily storing image signals including pixels on different horizontal scanning lines.
  • the image signal transmission method according to the seventh embodiment of the present invention as in the fourth embodiment, collectively encodes and transmits corresponding portions of two or more mutually related image signals. However, this is suitable when one of them is subjected to sub-sample processing.
  • FIG. 8 is a diagram for explaining processing and transmission of an image signal according to the seventh embodiment.
  • the image signal transmission in the seventh embodiment is described below. The transmission will be described with reference to FIG.
  • the image signal shown in FIG. 8 (a) and the image signal shown in FIG. 8 (b) are mutually related signals, and the blocks included in the image signal shown in FIG. 8 (a) a (0, 0) corresponds to the block b (0, 0) included in the image signal shown in Fig. 8 (b), and the blocks included in both have a one-to-one correspondence. It has to have.
  • the image signal shown in FIG. 8 (c) is obtained by sub-sampling the image signal shown in FIG. 8 (b). Such sub-sampling is performed for the purpose of reducing the number of bits.
  • the image signal shown in FIG. 8 (c) is different from the image signal shown in FIG. 8 (b).
  • the processing is performed so that the number of pixels is halved. Therefore, regarding the relationship between the image signal shown in FIG. 8 (a) and the image signal shown in FIG. 8 (c), the block b (0, 0) in 8 (c) 13 ⁇ 4 is (a) Blocks included in both blocks, such as a (0, 0), a (0, 1), a (0, 2), and a (0, 3) It has a four-to-four correspondence.
  • FIG. 8 (e) shows that the image signal shown in FIG. 8 (a) and the image signal not subjected to the sub-sampling processing shown in FIG.
  • the figure shows a case where the data is encoded and transmitted based on the relationship.
  • the transmission format when the sub-sampling processing shown in Fig. 8 (d) was performed was similar to that when the sub-sampling processing shown in Fig. 8 (e) was not performed. Since the transmission format is used and almost the same transmission format can be realized, the design and configuration of the image processing system can be performed even when sub-sampling is performed or not. It is easy to build.
  • the two when transmitting two image signals that are related to each other, as in the case of the fourth embodiment, the two are spatially separated.
  • encoding and transmitting the corresponding parts collectively, encoding can be performed according to their respective properties, and the coding efficiency can be improved based on the correlation between the two. Since the blocks on the same block line are transmitted continuously, almost the same transmission format can be realized regardless of the presence or absence of sub-sample processing. Therefore, even when the bit rate control or the like is executed depending on the presence or absence of the sub-sampling processing, the effect that the system design and construction can be easily obtained is obtained.
  • the image signal transmission method is to process and transmit two or more image signals at different timings for performing intra-screen and inter-screen coding, respectively, and transmit the signals.
  • FIG. 9 is a diagram for explaining processing and transmission of an image signal according to the eighth embodiment.
  • image signal transmission according to the eighth embodiment will be described with reference to FIG.
  • FIG. 9 (a) is a timing chart showing an encoding process, a transmission process, and a processing procedure in the eighth embodiment.
  • the image signal 1 and the image signal 2 are encoded and transmitted.
  • the coded signal of I-frame or the coded signal of P-frame is represented by a rectangle. The width of each rectangle is the transmission time, the length is the transmission rate, and the area is the transmission And the position on the chart indicates the transmission time.
  • image signal 1 data of frame generated by screen coding at time i and at time i + 4 are transmitted. Also, at time i + i + 2, i + 3 and at time i + 5, i + 6, P-frame data generated by the inter-screen encoding process is transmitted. On the other hand, for the image signal 2, the I-frame data generated by the intra-frame encoding process is transmitted at time i + 2 and time 1 + 6, and the time i, i At +1 and at time i + 3, i + 4 and i + 5, the data of the P-frame generated by the inter-picture coding process is transmitted.
  • FIG. 9 (b) is a timing chart showing a state in which the encoding result according to Embodiment 8 is transmitted.
  • the time t (i) when the first I-frame is transmitted the time when the next P-frame is transmitted Until a certain time t (i + l), in addition to the time required for the transmission of the first I-frame, a delay corresponding to the time required for the transmission of the P-frame in image signal 2 is added.
  • a delay corresponding to the time required for the transmission of the P-frame in image signal 2 is added.
  • each image signal when transmitting two or more image signals, each image signal is transmitted with an intra-screen code.
  • the transmission of data that has been processed using intra-screen coding which requires a large amount of data and takes a long time to transmit, is not possible.
  • the delay in transmission can be reduced, and the capacity of the storage medium required for temporarily storing data can be reduced.
  • the image signal transmission method provides a method for transmitting two or more mutually related image signals at intra-screen / inter-screen codes when the transmission rate is higher than in the eighth embodiment. It is processed at a different timing and transmitted.
  • FIG. 10 is a diagram for explaining processing and transmission of a plane image signal according to the ninth embodiment.
  • transmission of image signals in Embodiment 9 will be described with reference to FIG.
  • FIG. 10 (a) is a timing chart showing an encoding process, a transmission process, and a processing procedure in the ninth embodiment.
  • the image signal 1 and the image signal 2 are coded and transmitted as in the eighth embodiment, and in the figure, the I-frame or the The rectangle indicating the encoded data of the P-frame is the same as in Fig. 9.
  • I-frame data generated by the intra-frame encoding process is transmitted at time i and time 1 + 4. Also, at time 1 + 1, i + 1 + 3 and at time 1 + 5, 1 + 6, P-frame data generated by the inter-screen encoding process is transmitted.
  • image signal 2 at time i + 2 and time i + 6, the I-frame data generated by the intra-frame encoding process is transmitted, and time i, i The data of the P-frame generated by the inter-screen encoding process is transmitted to + l and the time: i + 3, i + i + 5.
  • FIG. 10 (b) is a timing chart showing a transmission state in the ninth embodiment. As shown in the figure, the fluctuation of the data transmission amount at each timing is smaller than in the case of the conventional technique shown in FIG. 16 (b).
  • the image signal transmission method of the ninth embodiment when transmitting two or more image signals in the image encoding / decoding system having a relatively high transmission rate, the timing for transmitting the image signal after encoding it on the screen is shifted, so that the data amount is large and the transmission of the data that has been encoded on the screen that takes time to transmit does not occur repeatedly. By doing so, it is possible to reduce the rate fluctuation in transmission and to facilitate the rate control to make the transmission rate close to a constant rate.
  • the image signal transmission method performs intra-screen encoding of two or more mutually related image signals when transmitting at the same transmission rate as in the ninth embodiment. Processing is performed at different intervals and transmitted.
  • FIG. 11 is a diagram for explaining processing and transmission of an image signal according to the tenth embodiment.
  • image signal transmission according to Embodiment 10 will be described with reference to FIG.
  • FIG. 11 (a) shows the encoding processing and transmission in the tenth embodiment.
  • FIG. 4 is a timing chart showing a transmission process and a processing procedure.
  • the image signal 1 and the image signal 2 are encoded and transmitted as in the eighth embodiment.
  • the I-frame or P-frame The rectangle indicating the encoded data of frame is the same as that in Fig. 9.
  • I-frame data generated by the intra-frame encoding process is transmitted first at time i and then at time 11i + 6. Further, at time i + i + 2, i + 3, i + 4, i + 5, contrary u where P-frame data generated Ri by the inter-picture encoding processing is transmitted, For image signal 2, the I-frame data generated by the intra-frame encoding process is transmitted first at time i, and then at times i + 3 and i + 6. At and time i + 5, P-frame data generated by the inter-frame coding process is transmitted.
  • the image signal 1 is Ni would Yo t the aforementioned processing was assumed to have an interval longer Ri good image signal 2 is being performed, data of I-frame One is that the amount of data is larger than the data of the P-frame. Therefore, for the image signal 1, by suppressing the occurrence of I-frame due to intra-screen coding, The data amount of signal 1 can be reduced. Therefore, for the image signal 1, the occupation of the transmission area for transmission and the capacity of the storage medium required for recording can be reduced, and the reduced amount is used for the image signal 2. Since this is possible, the image quality of the image signal 2 can be improved.
  • a signal that is not a subsampled signal or a related signal such as a shape signal and a pixel value signal is defined as an image signal 1 and an image signal 2.
  • the processed signal and the shape signal are treated as more important signals, and are treated as the image signal 2 in Embodiment 10 of the present embodiment, and the intra-frame encoding processing is performed in a shorter cycle. can do.
  • image signal 1 by increasing the period of intra-frame encoding and reducing the amount of I-frame, it becomes weak to error propagation, and random access becomes difficult.
  • image signal 1 and the image signal 2 are related image signals, by appropriately using the image signal 2 with the improved image quality, such a problem with the image signal 1 is caused. Can be improved. For example, if the image signal 1 is a normal image and the image signal 2 is a reduced image, if an error occurs, or if random access is performed, the reduced image signal 2 is used. It can be enlarged and displayed as an alternative to image signal 1.
  • the image signal transmission method of the tenth embodiment when transmitting two or more image signals, the period for encoding each image signal in the screen is different.
  • the image signal for which the period of the intra-screen encoding is long has been subjected to the intra-screen encoding process which requires a large amount of data and takes a long time to be transmitted.
  • the allocation of the transmission bandwidth and the capacity of the storage medium for the other image signal can be increased, and the image quality can be improved.
  • the image encoding program recording medium, the image decoding program recording medium, and the image signal transmission program recording medium according to Embodiment 11 of the present invention execute the recorded program. It performs image encoding, image decoding, and image signal transmission.
  • FIG. 12 is a diagram showing a floppy disk which is a program recording medium.
  • a floppy disk is used.
  • an image coding program for performing the image coding method according to the first embodiment or the second embodiment is recorded, and the recorded image coding program is executed in a computer system or the like.
  • an image decoding program for performing the image decoding method according to the third embodiment is recorded, and the recorded image decoding program is used as a computer.
  • the image decoding according to the third embodiment can be realized by executing it in a system or the like.
  • an image signal transmission program for performing the image signal transmission method according to any one of the embodiments 4 to 10 is recorded, and the recorded image signal transmission program is recorded.
  • the transmission program By executing the transmission program in a computer system or the like, it is possible to realize the image signal transmission according to any one of the fourth and tenth embodiments.
  • the image encoding program recording medium As described above, according to the image encoding program recording medium, the image decoding program recording medium, and the image signal transmission program recording medium of the eleventh embodiment, in a computer system, etc.
  • By executing the recorded program it is possible to realize image encoding, image decoding, or image signal transmission according to any one of the first to tenth embodiments. .
  • a floppy disk is used as a program recording medium.
  • a CD-ROM, an optical disk, and the like may be used.
  • Any program that can record a program in a machine-readable format, such as a desk, an IC card, or a magnetic tape, can be used.
  • the program is recorded on a recording medium connected to a computer, etc. of a computer network system or the like, and the program is recorded on another computer or the like. It is also possible to execute Industrial applicability
  • the image encoding device and the image encoding method in the image encoding / decoding system according to the present invention can execute appropriate rate control by performing subsemble processing using different processing units. It is.
  • An image decoding apparatus and an image decoding method in an image encoding / decoding system according to the present invention provide an encoding result that has been encoded with an appropriate rate control by subsample processing. It can be processed properly and is useful.
  • the image signal transmission method in the image encoding / decoding system of the present invention when transmitting a plurality of related image signals, can improve the coding efficiency due to their relationship. It is useful.
  • the image signal transmission method in the image encoding / decoding system of the present invention is a method for switching a plurality of image signals by switching the encoding method, transmitting the signals, and performing switching control and transmission order control. Therefore, the transmission efficiency can be improved and the use of the device resources can be achieved, which is useful.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)

Abstract

La présente invention concerne un système de codage/décodage d'images doté d'un codeur d'image pouvant commander de manière appropriée le taux de codage par sous-échantillonnage au moment du codage d'images. Le codeur d'images est pourvu d'un premier élément de sous-échantillonnage qui exécute un sous-échantillonnage dans une première unité de traitement et d'un second élément de sous-échantillonnage qui exécute un sous-échantillonnage dans une seconde unité de traitement. Le codeur d'images assure la totalité de la commande de taux, par commande du sous-échantillonnage à l'aide d'une première unité de traitement, et la commande de taux locale, en fonction de la fluctuation de taux locale, par commande du sous-échantillonnage à l'aide de la seconde unité de traitement.
PCT/JP1998/001026 1997-03-12 1998-03-12 Systeme de codage/decodage d'images WO1998041024A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP5727797A JPH10257492A (ja) 1997-03-12 1997-03-12 画像符号化方法および画像復号化方法
JP9/57276 1997-03-12
JP5727697A JPH10257491A (ja) 1997-03-12 1997-03-12 画像信号の伝送形式
JP9/57277 1997-03-12

Publications (1)

Publication Number Publication Date
WO1998041024A1 true WO1998041024A1 (fr) 1998-09-17

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PCT/JP1998/001026 WO1998041024A1 (fr) 1997-03-12 1998-03-12 Systeme de codage/decodage d'images

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Country Link
WO (1) WO1998041024A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009153128A (ja) * 2001-06-05 2009-07-09 Qualcomm Inc デジタルイメージに対する選択的なクロミナンスデシメーション

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63296487A (ja) * 1987-05-27 1988-12-02 Nec Corp 画像信号帯域圧縮方式並びに符号化装置および復号化装置
JPH0211079A (ja) * 1988-06-29 1990-01-16 Nec Corp 画像信号帯域圧縮方式
JPH0389792A (ja) * 1989-09-01 1991-04-15 Hitachi Ltd 画像符号化装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63296487A (ja) * 1987-05-27 1988-12-02 Nec Corp 画像信号帯域圧縮方式並びに符号化装置および復号化装置
JPH0211079A (ja) * 1988-06-29 1990-01-16 Nec Corp 画像信号帯域圧縮方式
JPH0389792A (ja) * 1989-09-01 1991-04-15 Hitachi Ltd 画像符号化装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009153128A (ja) * 2001-06-05 2009-07-09 Qualcomm Inc デジタルイメージに対する選択的なクロミナンスデシメーション
US7965775B2 (en) 2001-06-05 2011-06-21 Qualcomm, Incorporated Selective chrominance decimation for digital images

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