JP2004289601A - Dynamic image encoder, dynamic image encoding method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic image encoder, a dynamic image encoding method and a program for encoding a dynamic image in a processing time shorter than before. <P>SOLUTION: When a motion detecting section 102 is detecting a reference block having a high correlation with a noticed block from an encoded reference image, a discrete cosine transform section 106 begins intra-encoding by receiving the noticed block and an inter/intra deciding section 103 makes a decision which of inter-encoding and intra-encoding is selected for the noticed block from correlation of the noticed block and the reference block. When a decision is made that the intra-encoding is selected, the noticed block is encoded and outputted as processing data. When a decision is made that the inter-encoding is selected, the discrete cosine transform section 106 performs inter-encoding by receiving the difference between the noticed block and the reference block. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a moving image encoding apparatus, a moving image encoding method, and a program that divide a moving image into blocks of m × n in a screen and adaptively select inter-coding or intra-coding. .
[0002]
[Prior art]
As a moving image encoding method, for example, there is an MPEG (Moving Picture Experts Group) which is an international standard. In such a moving picture coding method, a moving picture is divided into m × n blocks in a frame or a field screen, and coding is performed for each of the divided blocks.
[0003]
The coding applied to the target block to be coded includes inter coding using the correlation between the target block and a reference block detected from the coded reference image, and intra coding using the correlation in the original image. There is encoding.
[0004]
A conventional technique of adaptively selecting whether to apply inter-coding or intra-coding to a target block to be encoded and encoding a moving image will be described with reference to FIGS. 4, 5, and 6. explain. FIG. 4 shows a moving picture coding apparatus according to a conventional method. FIG. 5 shows a flow when encoding a moving image in the conventional method. FIG. 6 shows an order relationship of each processing when encoding a moving image in the conventional method.
[0005]
First, the target block 101 and an encoded reference image stored in a frame memory 112 described later are input to the motion detection unit 102, and motion detection S201 in FIG. 5 is performed. By this processing, a reference block that is the block having the highest correlation with the input block of interest 101 is detected from the encoded reference image.
[0006]
Next, the target block 101 and the reference block detected by the motion detection unit 102 are input to the inter / intra determination unit 103, and the inter / intra determination S202 in FIG. 5 is performed. By this processing, it is determined whether to apply the inter coding or the intra coding to the block of interest 101.
[0007]
If the inter / intra determination unit 103 determines that inter coding is to be applied to the block of interest 101, the selector 105 selects the difference between the block of interest 101 and the reference block (FIG. 4B) and sets the discrete cosine It is input to the conversion unit 106.
[0008]
On the other hand, if the inter / intra determination unit 103 determines that intra coding is to be applied to the block of interest 101, the selector 105 selects the block of interest 101 (A in FIG. 4), and the discrete cosine transform unit 106 Input.
[0009]
The discrete cosine transform unit 106 performs the discrete cosine transform S206 of FIG. 5 on the given input, and inputs the result to the quantization unit 107.
[0010]
The quantization unit 107 performs the quantization S207 of FIG. 5 on the given input, and inputs the result to the entropy encoding unit 109.
[0011]
The entropy coding unit 109 performs the entropy coding S208 of FIG. 5 on the given input, and obtains a codeword string as a result.
[0012]
Further, the following processing is performed to obtain an encoded reference image required by the motion detection unit 102. First, the result obtained by the quantization unit 107 is input to the inverse quantization unit 110 to perform an inverse quantization process. Next, the result obtained by the inverse quantization unit 110 is input to the inverse discrete cosine transform unit 111 to perform an inverse discrete cosine transform process, and the resulting image is stored in the frame memory 112 as an encoded reference image. Keep it.
[0013]
In the conventional method, as shown in FIG. 6, the motion detection processing is completed, and it is not after determining whether to apply the inter-encoding or the intra-encoding to the target block to be encoded. Processing, quantization processing and entropy coding processing cannot be performed.
[0014]
[Problems to be solved by the invention]
As described above, in the conventional method, the motion detection processing is completed, and it is not after determining whether to apply the inter-encoding or the intra-encoding to the target block to be encoded. Processing, quantization processing and entropy coding processing could not be performed. If the processing time for motion detection is short, it does not matter if the discrete cosine transform processing, quantization processing, and entropy coding processing are awaited, but in actuality, the processing time for motion detection is much shorter than other processing. Because of the long length, the processing time of moving image encoding also becomes long.
[0015]
SUMMARY An advantage of some aspects of the invention is to provide a moving image encoding device, a moving image encoding method, and a program that encode a moving image in a shorter processing time than a related art.
[0016]
[Means for Solving the Problems]
In order to solve such a problem, the moving image encoding apparatus of the present invention divides a moving image into blocks of m × n in a screen, and encodes a block of interest in a target block in an original screen to be encoded. A moving image encoding apparatus that selectively performs inter-encoding using a correlation with a reference block detected from a reference image and intra-encoding using a correlation in an original image, and has a high correlation with the block of interest. A motion detection unit that detects a reference block from the encoded reference image; and, based on a correlation between the block of interest and the reference block, which of inter-coding and intra-coding is selected for the block of interest. Determining means for determining, a difference between the block of interest and the reference block, or encoding processing means for inputting the block of interest and performing encoding processing; While detecting the reference block, the encoding processing unit starts encoding processing of the target block, and when it is determined that the intra-coding is to be selected by the determination unit, the encoding processing unit Outputting processing data obtained by encoding the block of interest, and determining that the inter-encoding is to be selected by the determination unit, the encoding processing unit encodes the difference between the block of interest and the reference block. It is characterized by.
[0017]
In order to solve such a problem, a moving image encoding method apparatus according to the present invention divides a moving image into blocks of m × n in a screen, and, for a target block in an original screen to be encoded, Moving image coding for selectively using inter-coding for performing differential processing on a reference block detected from a coded reference image and intra-coding for performing coding without performing the differential processing A motion detection process for detecting a reference block having a high correlation with the block of interest from the encoded reference image; and inter-coding the block of interest with a correlation between the block of interest and the reference block. And a coding process for coding the block of interest. In the coding process, the motion detection process is performed. During the operation of, the intra-encoding processing of the block of interest is started, and when it is determined that the intra-encoding is to be selected in the determination processing, the processing data of the intra-encoding processing started before the determination is output. If it is determined in the determination process that inter-coding is to be selected, the inter-coding process of the target block is started.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments according to the present invention will be described in detail.
[0019]
(Example 1)
The moving picture coding apparatus of the present invention divides a moving picture into blocks of m × n in a frame or a field screen and performs coding for each of the divided blocks as in the conventional technique. Then, the coding to be applied to the block of interest is adaptively selected from inter-coding and intra-coding, and the moving picture is coded.
[0020]
A method for encoding a moving image using the moving image encoding device of the present invention will be described with reference to FIGS. 1, 2, and 3. FIG. FIG. 1 shows a moving picture coding apparatus according to the method of the present invention. FIG. 2 shows a flow when encoding a moving image in the method of the present invention. FIG. 3 shows an order relation of each processing when encoding a moving image in the method of the present invention. In FIG. 1, the same components as those of the conventional video encoding device are denoted by the same reference numerals as those in FIG.
[0021]
First, the block of interest 101 and the encoded reference image stored in the frame memory 112 are input to the motion detection unit 102, and motion detection S101 in FIG. 2 is performed.
By this processing, a reference block that is the block having the highest correlation with the input block of interest 101 is detected from the encoded reference image.
[0022]
While it is determined that intra-coding is to be applied to the block of interest 101 while the motion detection unit 102 is detecting the reference block, the selector 105 determines that the block of interest 101 (FIG. 1, A ) Is selected as an input to the discrete cosine transform unit 106. Then, the discrete cosine transform unit 106 performs the discrete cosine transform S104 in FIG. 2, and the quantization unit 107 performs the quantization S105 in FIG. 2, and stores the result in the buffer unit 108.
[0023]
When the reference block is detected after the processing in the motion detection unit 102 is completed, the target block 101 and the detected reference block are input to the inter / intra determination unit 103, and the inter / intra determination S102 in FIG. 2 is performed. By this processing, it is determined whether to apply the inter coding or the intra coding to the block of interest 101.
[0024]
When the inter / intra determination unit 103 determines that the inter coding is applied to the block of interest 101, the selector 105 determines the difference between the block of interest 101 and the reference block (FIG. 1, B) in S108 of FIG. The selected cosine transform is input to the discrete cosine transform unit 106 again. Then, the discrete cosine transform unit 106 performs the discrete cosine transform S109 in FIG. 2, and the quantization unit 107 performs the quantization S110 in FIG. 2, and inputs the result to the buffer unit 108.
[0025]
In addition, the inter / intra determination unit 103 notifies the activation unit 104 that it has determined that the inter coding is to be applied to the block of interest 101. Then, when the discrete cosine transform S109 of FIG. 2 by the discrete cosine transform unit 106 and the quantization S110 of FIG. 2 by the quantizer 107 are completed, the activation unit 104 performs entropy encoding processing on the buffer unit 108 and entropy encoding unit 109. Tell them you can start. When performing inter-coding, the buffer unit 108 does not store the input from the quantization unit 107 but inputs the input to the entropy coding unit 109.
[0026]
On the other hand, when the inter / intra determination unit 103 determines that intra coding is to be applied to the block of interest 101, the fact is transmitted to the activation unit 104. At this time, since the discrete cosine transform S104 of FIG. 2 by the discrete cosine transformer 106 and the quantization S105 of FIG. 2 by the quantizer 107 have already been performed, the activation unit 104 immediately sends the buffer 108 and the entropy encoder 109 to Informs that entropy coding may be started. When performing intra coding, the result stored in the buffer unit 108 is input to the entropy coding unit 109.
[0027]
When the start of processing is transmitted from the activation unit 104, the entropy encoding unit 109 performs entropy encoding S112 in FIG. 2 on the input provided from the buffer unit 108, and obtains a codeword string as a result.
[0028]
Also, an encoded reference image required by the motion detection unit 102 is obtained in the same manner as in the conventional method. However, after the start of the process is notified from the activation unit 104, the inverse quantization unit 110 performs the inverse quantization process using the result stored in the buffer unit 108 as an input.
[0029]
In the present embodiment, the discrete cosine transform process and the quantization process of the block of interest are performed and stored in the buffer unit during the motion detection process. However, as another embodiment, the discrete cosine transform process of the block of interest is performed. After the quantization process, an entropy coding process may be performed and stored in the buffer unit. At this time, if the entropy encoding process is not completed before the motion detection process is completed, the process data is output after the entropy encoding process without storing the data in the buffer unit when performing intra encoding.
[0030]
Further, in the present embodiment, the orthogonal transform processing has been described as the discrete cosine transform processing, but the present invention is not limited to this. Also, the encoding has been described with entropy encoding, but is not limited to this.
[0031]
According to the present invention, if the coding process of the block of interest is started during the motion detection process, if it is determined in the inter / intra determination that intra coding is to be applied to the block of interest, the intra-coding is performed before the determination. Since the encoding process has been started, the encoding process can be performed on the block of interest in a shorter processing time than the conventional method. On the other hand, when it is determined in the inter / intra determination that inter coding is to be applied to the block of interest, the processing time is approximately the same as when coding is performed by the conventional method.
[0032]
<Other embodiments>
Further, in the above embodiment, although the hardware and the like configuring the network are included, each processing unit can be actually realized by software. That is, an object of the present invention is to supply a storage medium (or a recording medium) in which software program codes for realizing the functions of the above-described embodiments are recorded to a system or an apparatus, and to provide a computer (or a computer) of the system or the apparatus. , CPU and MPU) read out and execute the program code stored in the storage medium. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0033]
When the computer executes the readout program codes, not only the functions of the above-described embodiments are realized, but also an operating system (OS) or the like running on the computer based on the instructions of the program codes. However, it goes without saying that a case is also included in which a part or all of the actual processing is performed, and the processing realizes the functions of the above-described embodiments.
[0034]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0035]
【The invention's effect】
As described above, according to the present invention, since the intra-encoding process of the block of interest is started during the motion detection process, the processing time when intra-encoding is selected is reduced, and as a result, The processing time required for encoding an image can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing a moving picture coding apparatus according to the present invention.
FIG. 2 is a diagram showing a flow when encoding a moving image in the present invention.
FIG. 3 is a diagram showing an order relation of each processing when encoding a moving image in the present invention.
FIG. 4 is a diagram illustrating a moving image encoding device according to a conventional method.
FIG. 5 is a diagram showing a flow when encoding a moving image in the conventional method.
FIG. 6 is a diagram showing an order relation of each processing when encoding a moving image in a conventional method.

Claims (5)

Inter-coding, in which a moving image is divided into m × n blocks in a screen, and a block of interest in the original screen to be coded is used for correlation with a reference block detected from a coded reference image; A moving image encoding device that selectively performs intra encoding using correlation in an original image,
Motion detection means for detecting a reference block having a high correlation with the target block from the encoded reference image,
Judging means for judging whether to select inter-coding or intra-coding for the target block from the correlation between the target block and the reference block,
Encoding processing means for inputting the difference between the block of interest and the reference block, or the block of interest, and performing an encoding process;
While the motion detection means is detecting the reference block, the encoding processing means starts encoding processing of the block of interest,
When it is determined that the intra-encoding is selected by the determination unit, the encoding processing unit outputs processing data obtained by encoding the block of interest,
The moving picture coding apparatus according to claim 1, wherein the coding processing means performs coding processing of a difference between the target block and the reference block when the determination means determines that the inter coding is to be selected. The moving picture coding apparatus according to claim 1, wherein said coding processing means includes an orthogonal transform means and a quantization means. The moving picture coding apparatus according to claim 1, wherein the coding processing means includes an orthogonal transform means, a quantization means, and a coding means. The moving image is divided into m × n blocks on the screen, and the target block in the original screen to be coded is subjected to difference processing with the reference block detected from the coded reference image to perform coding. A moving image encoding method for encoding by selectively using encoding and intra encoding to perform encoding without performing the difference processing,
A motion detection process for detecting a reference block having a high correlation with the target block from the encoded reference image,
From the correlation between the block of interest and the reference block, a determination process of determining whether to select inter-coding or intra-coding for the block of interest,
Encoding processing for encoding the block of interest,
In the encoding process, during the operation of the motion detection process, the intra-coding process of the block of interest is started, and when it is determined that intra-coding is to be selected in the determination process, the process is started before the determination. A moving image coding method, wherein the processing data of the intra coding process is output, and if it is determined in the determining process that the inter coding is to be selected, the inter coding process of the block of interest is started. A computer program for executing the moving picture encoding method according to claim 4.

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