JP2002252853A - Image processor, method, program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid unwanted successive operations of a header information processor, without prolonging the total process time, after issuing an operation start instruction for a coding process, etc. to be applied to prescribed process units to a variable-length coder, etc., eliminate the interrupts during processings and suppress power consumption to a minimal level in the system. SOLUTION: According to the number of steps to be executed, a header information processor adaptively selects between an operation for immediately turning to a program stop state, after issuing an operation start instruction for a coding process, etc., to be applied to prescribed process units to a variable- length coder, etc., and an operation for turning to the program stop state, immediately after completing steps to be executed successively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, method, or storage medium for performing digital image encoding for compressing and encoding a digital image signal or digital video signal into an encoded data sequence, and recording, storing, or transmitting the same. Further, the present invention relates to an image processing apparatus, method, or storage medium for performing digital image decoding in which an encoded data sequence is decompressed and reconstructed into a digital image signal or digital video signal.

[0002]

BACKGROUND OF THE INVENTION Many digital cameras and digital video camcorders have been commercialized. Some of them, such as a digital camera that can capture and record moving images by switching shooting modes, and a digital video camcorder that can capture and record still images by switching shooting modes. Some of the coding methods include an encoding processing means and a decoding processing means of the above-mentioned encoding method. In general, different encoding schemes have different syntaxes for the encoded data strings. In many coding systems, a coded data sequence to be handled is composed of a mixture of variable-length codes and fixed-length codes.

[0003] The information contained in the encoded data string is roughly 2
Are classified into two types. One of them is so-called header information typified by common coding parameters of the entire video sequence or different coding parameters for each picture, and the other is image information itself. The header information includes:
Some of them are composed of variable-length codewords, but are basically composed of a plurality of continuous fixed-length codes. On the other hand, the image information is a main element constituting the coded data sequence, and is composed of a plurality of continuous variable length codes, most of which are contiguous with priority given to coding efficiency.

In order to process (encode or decode) a general coded data sequence in which fixed-length codes and variable-length codes are mixed, a dedicated processing unit that handles header information is used. 2. Description of the Related Art There is known an encoding processing device or a decoding processing device having a configuration in which a dedicated processing unit for handling image information and a dedicated processing unit for processing image information are separately provided, and these two processing units are operated in cooperation with each other.

[0005] In such an apparatus, for example, when performing a decoding process, the header information processing unit always performs the decoding process even when the variable length code decoding unit is performing the decoding process on a series of orthogonal transform coefficient sequences. Operating (the program is running on it) and performing a process that can be advanced by the header information processing unit even a little in advance, so that the entire The time required for processing is reduced. still,
Here, the orthogonal transform means frequency transform. The same applies hereafter.

However, in general, during the period when the decoding unit for variable-length codes is performing the decoding process on a series of orthogonal transform coefficient sequences as a processing unit, the processing to be advanced by the header information processing unit operating simultaneously or There aren't many processes that make sense.

The operation required for the motion vector reconstruction process, which is a typical example, requires only a small number of execution steps, and the header information processing unit that has actually completed a series of processes specified in advance by the program is variable. In most cases, the idle routine that only waits for an interruption by a decoding process end notification signal from the long code decoding unit is repeatedly executed.

[0008] Of course, when the processing unit currently being decoded is at a hierarchically special position in the syntax, such as at the boundary of a slice layer, or various compensations for a code error detected in an encoded data string. In operation, the processing required by the header information processing unit is relatively heavy.
The power consumed by the header information processing unit that is in the idle routine while waiting for an interrupt input is not negligible if the system equipped with the decoding processing device is a device that emphasizes portability. .

In general, in the interrupt processing in the header information processing unit, a predetermined number of execution steps are consumed when shifting to the interrupt processing routine and when returning to the original routine. In a system such as an image encoding processing apparatus or a decoding processing apparatus in which the number of occurrences of interrupt events per unit time is relatively large, the total overhead associated with the interrupt processing cannot be ignored.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present application is to provide an encoding process or a decoding process for a predetermined processing unit to a variable length code encoding unit or a variable length code decoding unit. Unnecessary continuous operation of the header information processing unit after issuing the operation start instruction is avoided without extending the overall processing time, eliminating interruption during processing, and reducing power consumption as a system. Is to minimize it.

[0011]

The following means are provided to solve the above-mentioned problems. Upon issuing an instruction to start the encoding process for a predetermined processing unit to the variable-length encoding unit, the header information processing unit immediately shifts to the program stop state or completes the execution step to be processed continuously. At this point, there is provided means for adaptively selecting whether to shift to the program stopped state according to the number of execution steps to be processed.

Further, when an instruction to start the decoding process for a predetermined processing unit is issued to the variable length code decoding unit, the header information processing unit immediately shifts to the program stop state or continues processing. A means is provided for adaptively selecting whether to shift to the program halt state at the time of completion of the execution step to be performed in accordance with the number of execution steps to be processed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram illustrating an embodiment of an image encoding device to which the present invention has been applied. In FIG. 1, 1 is a header information processing unit, 2 is a variable length coding unit, 3 is an original image data input signal, 4 is an image data conversion unit, 5 is a memory, 6 is a coding parameter signal, and 7 is coding. A data string output signal, 8 is an operation start instruction signal, and 9 is an operation end notification signal.

FIG. 3 is a time chart showing an operation procedure relating to the header information processing section 1 and the variable length coding section 2 in the embodiment of the image coding apparatus shown in FIG. FIG. 5 is a flowchart similarly showing the operation procedure. FIG. 6A is a flowchart of the encoding process according to the present invention.

Hereinafter, regarding the operation mode of the embodiment of the image encoding apparatus, a series of operations relating to the compression encoding process, in particular, the operation state between the header information processing section 1 and the variable length encoding section 2 will be described. The switching timing will be mainly described with reference to FIGS. 1, 3, 5, and 6a.

The original image data (S 601) input via the original image data input signal 3 is divided into rectangular blocks of a predetermined size by the image data conversion unit 4, and then an orthogonal transformation operation is performed on a block basis. The orthogonal transform coefficients obtained as a result of the calculation are arranged in a one-dimensional data sequence in a predetermined order. Thereafter, scalar quantization is performed according to a separately specified quantization step value, and a run length indicating a continuous number of insignificant coefficients having a value of 0 with respect to the orthogonal transform coefficient after quantization and a significant value having a value other than 0 are provided. The sequence is transformed into a series of orthogonal transform coefficient sequences represented by a combination with various coefficients (S602).

The image data generated by the image data converter 4
A series of orthogonal transform coefficient sequences representing image data in units of rectangular blocks are sequentially stored in the memory 5. In addition, the encoding parameters represented by the quantization step values used for the image data conversion processing in the image data conversion unit 4 are sequentially read out by the header information processing unit 1 via the encoding parameter signal 6 separately. .

The header information processing unit 1 reads out the encoding parameters from the image data conversion unit 4 via the encoding parameter signal 6 according to an internal program, and constructs header information included in the encoded data sequence. The header information is output to the encoded data string output signal 7 (t1-t
2, S501, S603).

The next code to be arranged in the output coded data sequence is obtained by coding image information, that is, a series of orthogonal transform coefficient sequences generated by the image data conversion unit 4.
If there are a plurality of continuous variable-length codes, the header information processing unit 1 issues an operation start instruction for the coding process for a predetermined processing unit (for example, a macroblock) to the variable-length code coding unit 2 ( t2, S502).

The operation start instruction of the encoding process issued by the header information processing unit 1 is notified to the variable length code encoding unit 2 by a dedicated operation start instruction signal 8 (t2, S5).
02).

When the operation start instruction signal 8 instructs the start of the operation for the encoding process, the variable-length code encoder 2 sequentially reads out a series of orthogonal transform coefficient sequences from the memory 5 and converts the sequence into orthogonal transform coefficient sequences. On the other hand, the data is sequentially converted into a corresponding variable length code while referring to a separately set variable length code table (S604), and a plurality of continuous variable length codes obtained as a result are output to the encoded data string output signal 7. (T2-t4, S514, S60
5).

When the data amount of the series of transformed orthogonal transform coefficient sequences reaches the processing unit (S515), the variable-length code encoder 2 stops reading the orthogonal transform coefficient sequence from the memory 5. Then, an operation end notification signal 9 is output to the header information processing unit 1 to notify the end of the encoding processing in the processing unit (t4, S51).
6).

On the other hand, the header information processing unit 1 issues an operation start instruction of the encoding process to the variable length encoding unit 2 and then executes the execution steps required for the encoding process of the next processing unit. Upon completion (S503, S504), an instruction to immediately shift to the program stop state is issued (t
3, S505).

The program stop state is a state generally called a suspend state. When the program is in the stopped state, all the state machines in the header information processing unit 1 are stopped, and the operation clock supplied from the outside is also stopped (S506). Therefore, the power consumed by the header information processing unit 1 when the program is stopped is very small.

The header information processing section 1 in the program stopped state can return to the normal program operation state again by the input of the resume event applied from the outside (S507). In the present embodiment, the operation end notification signal 9 output by the variable length code encoder 2 is connected to the header information processor 1 as one of the resume event input signals.

When the variable-length code encoder 2 detects the operation end notification signal 9 issued to the header information processor 1 in order to notify that the encoding process for the processing unit has been completed (S507). Then, the operation clock is supplied to the header information processing unit 1, and the internal state machine also starts its operation, and as a result, the operation of the program on the header information processing unit 1 is restarted (t4, S508).

The header information processing section 1, which has again started the program operation, constructs header information relating to the next processing unit and outputs the obtained header information to the encoded data string output signal 7 (t4-t5). , S509, S501). Thereafter, the header information processing unit 1 issues an operation start instruction of the encoding process for the next processing unit to the variable length encoding unit 2 (t5, S502).

After the header information processing unit 1 issues an operation start instruction of the encoding process to the variable length code encoding unit 2 (t
2, S502), since the processing required for the encoding processing for the next processing unit is usually slight,
The header information processing unit 1 shifts to the program stop state without a large time difference (t3, S505, S506). However, when the next processing unit is located at the boundary of a slice (MPEG encoding method),
If the syntax is at a hierarchically special position, such as at the boundary of the interval (JPEG encoding method), the execution steps required for the encoding process for the next processing unit The number is relatively large.

FIG. 3 also illustrates such a case.
Specifically, in the MPEG encoding method, when the next processing unit is the last macroblock of the slice, the header information processing unit 1 sends the encoding process for the next processing unit to the variable-length code encoding unit 2. The interval (t6−t7) between the time when the operation start instruction is issued (t6) and the time when the header information processing unit 1 actually issues the instruction to shift to the program halt state (t7−t7) is longer than in other cases. It is shown that.

FIG. 4 is a time chart showing an operation switching procedure between the header information processing section 1 and the variable length coding section 2 in the embodiment of the picture coding apparatus shown in FIG.
It is a chart. FIG. 4A shows the variable length code encoding unit 2.
Shows that the header information processing unit 1 has already transitioned to the program stopped state at the time (t11) when the notification of the end of the encoding process for the processing unit is issued (S5).
07). In this case, as described above, upon detecting the operation end notification signal 9, the header information processing unit 1 immediately returns to the program operation state (t11, S508).

On the other hand, FIG. 4B shows that the header information processing unit 1 is still in the program operating state at the time (t12) when the variable length coding unit 2 issues a notice of the end of the coding process for the processing unit. (S5)
10). In this case, the header information processing unit 1 issues an instruction to shift to the program halt state when the execution step to be processed is completed (t13), but since the resume event has already arrived (t12), The instruction following the instruction to shift to the program halt state is not executed without shifting to the halt state (S511, S51).
512, S509).

As described above, in the embodiment of the image encoding apparatus, the header information processing unit 1 which has issued the instruction to start the encoding process for the processing unit to the variable length encoding unit 2 In order to shorten the processing time of
Execution steps required for the encoding process of the next processing unit can be continued. Further, when the above-described required execution steps are completed, the program can be shifted to the program stopped state at any time for the purpose of reducing power consumption.

If the coding process for the processing unit by the variable length coding unit 2 has already been completed at the time of transition to the program halt state, the header information processing unit 1 continues without shifting to the program halt state. Since the program is executed on it, no extra overhead is generated.

[Second Embodiment] FIG. 2 is a functional block diagram showing an embodiment of an image decoding apparatus to which the present invention is applied. In FIG. 2, 11 is a header information processing unit, 12 is a variable length code decoding unit, 13 is an encoded data string input signal,
14 is a memory, 15 is an image data reconstruction unit, 16 is an encoding parameter signal, 17 is an operation start instruction signal, 18 is an operation end notification signal, and 19 is a reconstructed image data output signal.

FIG. 3 is a time chart showing an operation procedure relating to the header information processing section 11 and the variable length code decoding section 12 in the embodiment of the image decoding apparatus shown in FIG.
It is a chart. FIG. 5 is a flowchart similarly showing the operation procedure. FIG. 6B is a flowchart of the decoding process according to the present invention.

Hereinafter, a series of operations relating to the decompression decoding process, particularly the operation state between the header information processing unit 11 and the variable length code decoding unit 12, will be described with respect to the operation mode in the embodiment of the image decoding apparatus. The switching timing will be mainly described with reference to FIGS. 2, 3, 5, and 6b.

The coded data sequence (S606) input via the coded data sequence input signal 13 is supplied to both the header information processing unit 11 and the variable length code decoding unit 12, respectively. The header information processing unit 11 reads out header information included in the encoded data sequence from the encoded data sequence input signal 13 by an internal program, and analyzes the contents thereof to convert the encoding parameters into encoding parameter signals 16.
Is output to the image data reconstructing unit 15 via (t1-t)
2, S501, S607).

If the next code in the input coded data sequence is image information, that is, a plurality of continuous variable length codes obtained by encoding a series of orthogonal transform coefficient sequences, the header information processing section 11 An instruction to start a decoding process for a predetermined processing unit (for example, a macroblock) is issued to the code decoding unit 12 (t2, S502).

The operation start instruction of the decoding process issued by the header information processing unit 11 is a dedicated operation start instruction signal 1
7 to the variable-length code decoding unit 12 (t
2, S502).

When the operation start instruction signal 17 indicates that the operation for the decoding process is to be started, the variable length code decoding section 12 sequentially reads a plurality of continuous variable length codes from the coded data string input signal 13. Each variable-length code is sequentially converted into a corresponding orthogonal transform coefficient sequence while referring to a variable-length code table separately set (S607), and a series of orthogonal transform coefficient sequences obtained as a result is stored in the memory 14. Output (t2-t4, S5
14, S608).

A series of orthogonal transformation coefficient sequences representing the image data in a rectangular block unit stored in the memory 5 are sequentially read out by the image data reconstructing unit 15. Further, the encoding parameter represented by the quantization step value used in the image data conversion processing is separately transmitted to the header information processing unit 11 through the encoding parameter signal 16.
Are sequentially supplied to the same image data reconstruction unit 15.

The significant coefficients included in the series of orthogonal transform coefficients read from the memory 5 are subjected to scalar inverse quantization by a separately specified quantization step value, and are converted into a one-dimensional data sequence in a predetermined order. After the arranged orthogonal transform coefficients are returned to the two-dimensional array again, an orthogonal inverse transform operation is performed for each block unit to restore the reconstructed image data of the rectangular block (S609) and finally reconstructed. The output image data is output via the reconstructed image data output signal 19 (S610).

When the data amount of the series of transformed orthogonal transform coefficient sequences reaches the processing unit (S515), the variable-length code decoding unit 12 outputs the coded data sequence input signal 13
To stop the operation of reading the variable-length code from, and outputs an operation end notification signal 18 to the header information processing unit 11 to notify the end of the decoding processing in the processing unit (t
4, S516).

On the other hand, after issuing an operation start instruction of the decoding process to the variable length code decoding unit 12, the header information processing unit 11 executes an execution step required for the decoding process of the next processing unit. If completed (S503, S504),
An instruction to immediately shift to the program stop state is issued (t3, S505).

The program stop state is a state generally called a suspend state. When the program is stopped, all the state machines in the header information processing unit 11 are stopped, and the operation clock supplied from the outside is also stopped (S506). The power consumed by the header information processing unit 11 in the program stop state is very small.

The header information processing section 11 in the program stopped state can return to the normal program operation state again by the input of a resume event applied from the outside. In the present embodiment, the operation end notification signal 18 output from the variable length code decoding unit 12 is connected to the header information processing unit 11 as one of the resume event input signals.

When the variable-length code decoding unit 12 detects the operation end notification signal 18 issued to the header information processing unit 11 to notify that the decoding process for the processing unit has ended (S507). Then, the operation clock is supplied to the header information processing unit 11, and the internal state machine also starts its operation, and as a result, the operation of the program on the header information processing unit 11 is restarted (t4, S508).

The header information processing section 11, which has started the program operation again, reads the following header information from the coded data string input signal 13, and outputs a coding parameter relating to the next processing unit to a coding parameter signal 16. (T4-t5, S509, S501). Thereafter, the header information processing unit 11 issues an instruction to start the decoding process for the next processing unit to the variable length code decoding unit 12 (t5, S502).

After the header information processing section 11 issues an instruction to start the operation of the decoding process to the variable length code decoding section 12 (t2, S502), it is necessary for the decoding process for the next processing unit. Since the processing is usually slight, the header information processing unit 11 shifts to the program stopped state without a large time difference (t3, S505, S50).
6). However, when the next processing unit is located at the boundary of the slice (MPEG coding method) or when it is located at the boundary of the restart interval (JP
EG coding method), or when various kinds of compensation operations for code errors detected in a coded data sequence are required, or when the The number of execution steps required for the decoding process is relatively large.

FIG. 3 also illustrates such a case.
Specifically, in the MPEG encoding method, when the next processing unit is the last macroblock of the slice, the header information processing unit 11 directs the variable-length code decoding unit 12 to perform the decoding process on the next processing unit. The interval (t6−t7) between the time when the start instruction is issued (t6) and the time when the header information processing unit 11 actually issues the instruction to shift to the program stop state (t7−t7) is longer than in other cases. Is shown.

FIG. 4 is a time chart showing an operation switching procedure between the header information processing section 11 and the variable length code decoding section 12 in the embodiment of the image decoding apparatus shown in FIG. FIG. 4A shows the header information processing unit 11 at the time (t11) at which the variable length code decoding unit 12 issues a decoding process end notification for a processing unit.
Indicates that the program has already shifted to the program stopped state (S507). In this case, as described above, upon detecting the operation end notification signal 18, the header information processing unit 11 quickly returns to the program operation state (t11, S
508).

On the other hand, FIG. 4B shows that the header information processing unit 11 is still in the program operation state at the time (t12) when the variable length code decoding unit 12 issues a decoding process end notification for the processing unit. This is the case (S510). In this case, the header information processing unit 11 issues an instruction to shift to the program halt state at the time of completing the execution step to be processed (t13), but since the resume event has already arrived (t1).
2) The instruction following the instruction to shift to the program halt state is executed continuously without shifting to the program halt state (S511, S512, S509).

As described above, in the embodiment of the image decoding apparatus, the header information processing unit 11 that has issued the instruction to start the decoding process for the processing unit to the variable length code decoding unit 12 For the purpose of reducing the processing time, the execution steps required for the decoding processing of the next processing unit can be continued. Further, when the above-described required execution steps are completed, the program can be shifted to the program stopped state at any time for the purpose of reducing power consumption.

If the decoding process for the processing unit by the variable-length code decoding unit 12 has already been completed at the time of transition to the program stop state, the header information processing unit 11 continues without shifting to the program stop state. Since the program is executed on it, no extra overhead is generated.

[Other Embodiments] In the present invention, a plurality of devices (for example, a host computer, an interface device,
The present invention may be applied to a system including a reader, a printer, or the like, or may be applied to an apparatus (for example, a copying machine, a facsimile machine, or the like) including one device.

Further, an object of the present invention is to supply a storage medium (or a recording medium) in which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or an apparatus, and to provide a computer (a computer) of the system or the apparatus. Or a CPU or MPU) reads out and executes the program code stored in the storage medium,
It goes without saying that this is achieved. 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.
In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also based on the instructions of the program code,
The operating system (OS) running on the computer performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion card inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. , The CPU provided in the function expansion card or the function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

[0058]

As described above, according to the present invention, a general encoded data sequence in which fixed-length codes and variable-length codes are mixed is processed at high speed (encoding processing or decoding processing). In addition, a dedicated processing unit for handling header information (header information processing unit 1 and header information processing unit 11) and a dedicated processing unit for handling image information (variable length code encoding unit 2 and variable length code decoding unit 12) In this configuration, two dedicated processing units can be operated at the same time, if necessary, or the dedicated processing unit that handles header information can be switched to a stopped state to reduce power consumption. Can be freely selected.

Further, since the interrupt operation is eliminated, unnecessary overhead is eliminated, and the processing efficiency can be improved.

Therefore, the encoding processing apparatus and the decoding processing apparatus to which the present invention is applied in the system can operate flexibly, so that a system requiring high processing performance or low power consumption is required. The requirements can be satisfied for any of the simple systems.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating an embodiment of an image encoding device to which the present invention has been applied.

FIG. 2 is a functional block diagram illustrating an embodiment of an image decoding device to which the present invention has been applied.

FIG. 3 is a first time chart showing an operation mode in the image encoding device and the image decoding device of the present invention.

FIG. 4a is a second time chart showing an operation mode in the image encoding device and the image decoding device of the present invention.

FIG. 4B is a third time chart illustrating an operation mode in the image encoding device and the image decoding device according to the present invention.

FIG. 5 is a flowchart showing a flow of image encoding and decoding processing of the present invention.

FIG. 6A is a flowchart of an encoding process according to the present invention.

FIG. 6b is a flowchart of a decoding process according to the present invention.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Katsumi Otsuka, Inventor 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tetsuya Tateno 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Yukio Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 5C053 FA27 GB37 JA30 KA03 KA30 LA01 LA03 LA11 LA15 5C059 KK49 MA21 MC38 ME01 RC24 SS06 SS11 SS20 TA01 TB07 TC10 UA02 UA04 UA05 5C078 AA04 BA53 CA31 DA01 5J064 AA02 AA04 BA09 BA16 BC01 BD03 BD04

Claims (17)

[Claims] 1. An image data conversion unit for generating an encoding parameter and a series of orthogonal transformation coefficient sequences from input original image data, and a header for constructing header information included in an encoded data sequence based on the encoding parameter. An image processing apparatus including an information processing unit and a variable length code encoding unit that sequentially encodes the series of orthogonal transform coefficient sequences and generates image information including a plurality of continuous variable length codes included in an encoded data sequence. Instruction means for instructing a start of an encoding process for a plurality of continuous variable-length codes from the header information processing unit to the variable-length code encoding unit; and Notifying means for notifying the information processing unit of the end of the encoding process for the series of orthogonal transform coefficient sequences, and issuing an instruction to start the encoding process. The first control means controls the header information processing unit to shift to the operation stop state at an arbitrary timing after the operation, and the header information processing unit in the operation stop state receives the operation end notification of the encoding process. And a second control means for controlling to return to the operation state again. 2. The method according to claim 1, wherein the first control means shifts to an operation stop state when the operation end notification of the encoding process arrives before the header information processing section shifts to an operation stop state. The image processing apparatus according to claim 1, wherein the operation is continued. 3. When the header information processing unit is in an operation stop state, a state machine inside the header information processing unit is stopped and a clock supply from outside is stopped. The image processing device according to claim 1. 4. A header information processing section for analyzing header information of an input encoded data sequence to obtain an encoding parameter, and sequentially decoding image information comprising a plurality of continuous variable length codes of the input encoded data sequence. Image processing comprising a variable-length code decoding unit for obtaining a series of orthogonal transform coefficient sequences as a processing unit, and an image data reconstructing unit for reconstructing image data based on the encoding parameters and the series of orthogonal transform coefficient sequences In the apparatus, instructing means for instructing an operation start of a decoding process for a plurality of continuous variable-length codes from the header information processing unit to the variable-length code decoding unit, and the header from the variable-length code decoding unit A notifying unit for notifying the information processing unit of an operation end of a decoding process for a series of orthogonal transform coefficient sequences as a processing unit; After giving an operation start instruction, the first control means for shifting the header information processing unit to the operation stop state at an arbitrary timing, and the header information processing unit in the operation stop state sends the operation end notification of the decoding process to the header information processing unit. An image processing apparatus comprising: a second control unit that receives and returns to an operation state again. 5. The method according to claim 1, wherein the first control means does not shift to the operation stop state if the operation end notification of the decoding process arrives before the header information processing unit shifts to the operation stop state. The operation is continued.
An image processing apparatus according to claim 1. 6. When the header information processing unit is in an operation stop state, a state machine inside the header information processing unit is stopped and an external clock supply is stopped. An image processing apparatus according to claim 4 or claim 5. 7. An image data conversion step of generating an encoding parameter and a series of orthogonal transformation coefficient sequences from input original image data, and a header for constructing header information included in an encoded data sequence based on the encoding parameter. An image processing method comprising: an information processing step; and a variable-length code encoding step of sequentially encoding the series of orthogonal transform coefficient sequences to generate image information including a plurality of continuous variable-length codes included in an encoded data sequence. An instruction step of instructing an operation start of an encoding process for a plurality of continuous variable-length codes from the header information processing step toward the variable-length code encoding step; and A notification step of notifying the end of the encoding process for the series of orthogonal transform coefficient sequences toward the information processing step; A first control step of controlling the header information processing step to shift to an operation stop state at an arbitrary timing after giving an operation start instruction; and a header information processing step in an operation stop state, the operation of the encoding processing. A second control step of controlling to return to the operation state upon receiving the end notification. 8. The first control step shifts to an operation stop state if an operation end notification of the encoding process arrives before the header information processing step shifts to an operation stop state. The image processing method according to claim 7, further comprising: continuing the operation. 9. When the header information processing step is in an operation stop state, an internal state machine of the header information processing step is stopped and an external clock supply is stopped. An image processing method according to claim 7 or claim 8. 10. A header information processing step of analyzing header information of an input encoded data sequence to obtain an encoding parameter,
A variable-length code decoding step of sequentially decoding image information consisting of a plurality of continuous variable-length codes of an input coded data sequence to obtain a series of orthogonal transform coefficient sequences as a processing unit; and An image processing method comprising an image data reconstructing step of reconstructing image data based on an orthogonal transform coefficient sequence, wherein a plurality of variable-length codes continuous from the header information processing step to the variable-length code decoding step An instruction step of instructing a start of a decoding process for the sequence, and a notification of an end of the decoding process operation for a series of orthogonal transform coefficient sequences as a processing unit from the variable length code decoding step to the header information processing step. A notification step, and after giving an instruction to start the operation of the decryption processing, the header information processing step is brought into an operation stop state at an arbitrary timing. An image characterized by comprising: a first control step of causing a header information processing step in an operation stop state to return to an operation state again upon receiving an operation end notification of the decoding processing. Processing method. 11. The first control step shifts to an operation stop state when an operation end notification of the decoding process arrives before the header information processing step shifts to an operation stop state. 11. The image processing method according to claim 10, wherein the operation is continued. 12. When the header information processing step is in an operation stopped state, an internal state machine of the header information processing step is stopped, and an external clock supply is stopped. The image processing method according to claim 10. 13. A code for an image data conversion step of generating an encoding parameter and a series of orthogonal transform coefficient sequences from input original image data, and header information included in an encoded data sequence based on the encoding parameter. And a code for a variable-length code encoding step for sequentially encoding the series of orthogonal transform coefficient sequences to generate image information including a plurality of continuous variable-length codes included in an encoded data sequence. An image processing program for causing a computer to execute image processing, comprising: an instruction to start an operation of encoding processing for a plurality of variable-length codes continuous from the header information processing step to the variable-length code encoding step A code of an instruction step for performing the header information processing from the variable length code encoding step. A code for a notification step for notifying the end of the encoding process for a series of orthogonal transform coefficient sequences toward the step, and the header information processing step is stopped at an arbitrary timing after giving an instruction to start the encoding process. A code of a first control step for controlling to shift to a state, and a second control for controlling that the header information processing step in the inactive state receives the operation end notification of the encoding processing and returns to the operating state again. An image processing program comprising: a control step code. 14. The method according to claim 1, wherein the first control step is performed before the header information processing step shifts to an operation stop state.
When the operation end notification of the encoding process has arrived,
14. The image processing program according to claim 13, further comprising: continuing the operation without shifting to the operation stop state. 15. A code for a header information processing step of analyzing header information of an input coded data sequence to obtain a coding parameter, and sequentially decoding image information composed of a plurality of continuous variable length codes of the input coded data sequence. Code for a variable-length code decoding step for obtaining a series of orthogonal transform coefficient sequences as a processing unit, and an image data reconstructing step for reconstructing image data based on the encoding parameters and the series of orthogonal transform coefficient sequences An image processing program for causing a computer to execute image processing, the decoding processing for a plurality of variable-length codes continuous from the header information processing step to the variable-length code decoding step. A code of an instruction step for giving a start instruction, and the header information processing from the variable length code decoding step. A code of a notification step for notifying the end of the decoding process operation for a series of orthogonal transform coefficient sequences which is a processing unit toward the step, and the header information processing step is optional after giving an instruction to start the decoding process operation. The code of the first control step for shifting to the operation stop state at the timing of the second control step for returning the header information processing step in the operation stop state to the operation state again after receiving the operation end notification of the decoding process And an image processing program. 16. The method according to claim 1, wherein the first control step is performed before the header information processing step shifts to an operation stop state.
When the operation end notification of the decryption process has arrived,
16. The image processing program according to claim 15, wherein the operation is continued without shifting to the operation stop state. 17. A computer-readable information storage medium storing the image processing program according to claim 13. Description: