JP2001218208A - Image decoder and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image decoder that receives image coded data, that are hierarchically coded, grasps rough contents of the image in an earlier stage and reproduces the image with high resolution in the earlier stage. SOLUTION: This image decoding method includes a step (S1), where image coded data that are received in time series and hierarchically coded are received, a step (S2) where the data are decoded in the hierarchical order, a step (S5) where pseudo-decoded data equivalent to image coded data of a layer of no input higher than the prescribed decoded layer are generated, and a step (S6) where the pseudo-decoded data are generated on the basis of the decoded data of the prescribed layer decoded in the step S2 and the pseudo-decoded data generated in the step S5 and the image received, and decoded at that point of time is reproduced (S6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image decoding apparatus and method for inputting and decoding encoded image data encoded in units of subbands.

[0002]

2. Description of the Related Art In recent years, with the spread of personal computers and mobile terminals, digital data communication (data communication) via the Internet has been widely performed. Digital data distributed in such data communication includes:
Various contents such as texts, still images, moving images, and sounds are included, and the distribution amount of such digital data is increasing day by day. In such a situation, a communication environment has been improved and expanded so that better data communication can be performed. However, at present, the improvement and expansion of the communication environment cannot keep up with the increase in the amount of digital data distribution. Therefore, when receiving digital data via such a network, it may take a very long time to receive all of the certain digital data.

Generally, a sender (distributor) of digital data encodes the digital data and transmits the encoded digital data. For example, when a sender transmits a still image, the digital data (image data) of the still image is encoded to generate encoded image data, and the encoded image data is transmitted. Then, the receiver receives and decodes the encoded image data, and displays the image data on a display of a television or a computer device.

[0004]

As described above, in the current communication environment, a receiver may take a lot of time to receive a certain set of digital data. Therefore, when encoding the image data, the image data is hierarchically encoded and transmitted, and the receiver receiving the encoded data decodes and reproduces the encoded data of each layer every time the encoded data is received. Accordingly, it is possible to recognize the rough contents of the image data at an early stage. For example, the sender encodes the image data using the wavelet transform, and transmits the image data in order from the encoded coefficient in the lower frequency band. On the other hand, a receiver that receives and decodes the encoded data decodes the low-frequency component of the received image in order from the coefficient of the received low-frequency band, so that the low-frequency component of the image is reproduced first. Can understand the contents. Further, as the reception proceeds, higher frequency bands are decoded, so that a finer image can be decoded and viewed.

[0005] However, in receiving such coded image data, there is a problem that an image obtained at an early stage of reception has a low resolution.

[0006] The present invention has been made in view of the above conventional example, and receives image encoded data hierarchically encoded,
It is an object of the present invention to provide an image decoding apparatus and a method thereof that can grasp the rough contents of the image at an early stage and enable high-resolution image reproduction at the early stage.

Another object of the present invention is to provide an image decoding apparatus which can completely decode and reproduce a target area of an image faster than other areas, or decode and reproduce later than other areas. And a method thereof.

[0008]

In order to achieve the above object, an image decoding apparatus according to the present invention has the following arrangement.
That is, storage means for inputting and storing hierarchically encoded image encoded data input in time series, decoding means for reading and decoding the image encoded data stored in the storage means in hierarchical order, Pseudo-data generating means for generating pseudo-decoded data higher than the predetermined hierarchy decoded by the decoding means and corresponding to image input data of a non-input hierarchy, and decoding of the predetermined hierarchy decoded by the decoding means And decoding data generation means for generating pseudo image decoding data based on the data and the pseudo decoding data generated by the pseudo data generation means.

In order to achieve the above object, an image decoding apparatus according to the present invention has the following arrangement. That is, storage means for inputting and storing hierarchically encoded image encoded data input in time series, decoding means for reading and decoding the image encoded data stored in the storage means in hierarchical order,
Determining means for determining whether or not the decoded data decoded by the decoding means corresponds to image-encoded data of an attention area of an original image; and decoding by the decoding means in accordance with a determination result by the determining means And a control unit that controls generation of a decoded image based on the decoded data corresponding to the selected attention area and the decoded data corresponding to the non-interest area.

[0010] In order to achieve the above object, an image decoding method according to the present invention includes the following steps. That is, a storing step of inputting and storing hierarchically encoded image encoded data input in time series, and a decoding step of reading and decoding the image encoded data stored in the storing step in a hierarchical order,
A pseudo data generating step of generating pseudo decoded data higher than the predetermined layer decoded in the decoding step and corresponding to image input data of an uninput layer, and a pseudo data generation step of the predetermined layer decoded in the decoding step. A decoding data generating step of generating pseudo image decoded data based on the decoded data and the pseudo decoded data generated in the pseudo data generating step.

To achieve the above object, the image decoding method of the present invention comprises the following steps. That is, a storing step of inputting and storing hierarchically encoded image encoded data input in time series, and a decoding step of reading and decoding the image encoded data stored in the storing step in a hierarchical order,
A determining step of determining whether or not the decoded data decoded in the decoding step corresponds to the image encoded data of the attention area of the original image, and according to the determination result in the determining step, And a control step of controlling generation of a decoded image based on the decoded data corresponding to the decoded attention area and the decoded data corresponding to the non-interest area.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is a functional block diagram showing a functional configuration of an image decoding apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes a header / image coded data input unit which receives and inputs entropy coded image data with a header. Reference numeral 102 denotes a subband storage buffer that stores encoded data for each subband. Reference numeral 103 denotes a subband output control unit, which reads out encoded data corresponding to each subband stored in the subband storage buffer 102 and outputs the encoded data to the entropy decoding unit 104. The entropy decoding unit 104 receives and decodes entropy-coded image data. 105
Is an inverse quantization unit, 106 is an inverse transformation buffer, 107 is an inverse transformation buffer, 108 is a pseudo subband generation unit, 109
Denotes an inverse discrete wavelet transform unit, and 110 denotes a decoded data output unit. Hereinafter, the configuration and operation of each of these units will be described in detail.

[0015] It is assumed that image encoded data with a header is transmitted from the image encoding / transmission apparatus to the image decoding apparatus according to the present embodiment. First, the flow of processing for generating the header / image encoded data by the image encoding / transmission device and the configuration of the header / image encoded data will be described.

In the present embodiment, description will be made assuming that 8-bit monochrome image data is encoded. However, a monochrome image represented by a bit number other than 8 bits, such as 4 bits, 10 bits, and 12 bits for each pixel,
Alternatively, each color component (RGB / Lab / YC) in each pixel
The present invention can also be applied to a case where a color multi-valued image expressing rCb) by 8 bits is encoded. Also, the present invention can be applied to a case where multi-valued information representing the state of each pixel constituting an image is encoded, for example, a case where a multi-valued index value representing the color of each pixel is encoded. When applied to these, each type of multi-value information may be encoded as monochrome image data described later.

FIG. 2 is a functional block diagram showing a schematic functional configuration of an image encoding / transmission device for generating and transmitting header / image encoded data to be transmitted to the image decoding device according to the embodiment of the present invention. It is.

In FIG. 1, reference numeral 201 denotes an image input unit for inputting image data to be encoded. Reference numeral 202 denotes a discrete wavelet transform unit that performs a discrete wavelet transform on the image data input by the image input unit 101 and outputs coefficient values of each frequency band. Reference numeral 203 denotes a buffer that stores coefficients subjected to discrete wavelet transform by the discrete wavelet transform unit 202. Reference numeral 204 denotes a coefficient quantization unit that inputs and quantizes the coefficients stored in the buffer 203.
Reference numeral 205 denotes an entropy encoding unit that encodes the quantized coefficient values. Reference numeral 206 denotes a header / image encoded data transmission unit.

In the above arrangement, pixel data constituting image data to be encoded is input from the image input unit 201 in raster scan order. This image input unit 20
1 is an imaging device such as a scanner or a digital camera,
Alternatively, it may be an imaging device such as a CCD or an interface of a network line. The image input unit 201 includes a RAM, a ROM, a hard disk, a C
It may be a recording medium such as a D-ROM.

The discrete wavelet transform unit 202 performs a discrete wavelet transform on each pixel data of one screen input from the image input unit 201, and outputs the resulting discrete wavelet coefficients to a plurality of frequency bands (sub-bands). Band). In the present embodiment,
The discrete wavelet transform for the image data sequence x (n) is performed according to the following equation.

R (n) = floor {(x (2n) + x (2n + 1)) / 2} d (n) = x (2n + 2) -x (2n + 3) + floor {(-r (n) + r (n + 2) +2) / 4} where r (n) and d (n) are conversion coefficients, r (n) is a low-frequency subband, and d (n) is a high-frequency subband. It is a band. In the above equation, floor {X} represents the maximum integer value not exceeding X. This conversion formula is for one-dimensional data. By applying this conversion in the horizontal and vertical directions in order to perform two-dimensional conversion, LL, HL, LH, HH can be divided into four subbands. Here, L indicates a low frequency sub-band, and H indicates a high frequency sub-band.

Next, this LL sub-band is similarly
The subband is divided into four subbands (FIG. 3B), and the LL subband therein is further divided into four subbands (FIG. 3C).
In this way, a total of ten subbands are created.

Each of these ten subbands will be referred to as shown in FIG. here,
The number in the name of each subband is the level of each subband. That is, the level 1 subbands are HL1, HH1, and LH1, and the level 2 subbands are HL2, HH2, and LH2. The LL sub-band is a level 0 sub-band. Decoded data obtained by decoding the subbands up to level n is referred to as level n decoded data. The decoded image obtained from the level n decoded data is called a level n decoded image. Here, the higher the level of the decoded image, the higher the resolution of the image.

It is assumed that the encoded image data transmitted to the image decoding apparatus according to the present embodiment has the ten subbands as described above.

Here, the decoded data obtained by decoding all the subbands is called complete decoded data. A decoded image obtained by displaying the completely decoded data on an image display device is referred to as a completely decoded image. In the present embodiment, the decoded image at level 3, ie, HL
An image obtained by decoding HH3, HH3, and LH3 is a completely decoded image.

The ten subbands obtained by the discrete wavelet transform unit 202 are temporarily stored in a buffer 203, and are stored in LL, HL1, LH1, HH1, HL2, LH.
2, HH2, HL3, LH3, and HH3 are output to the coefficient quantization unit 204 in the order of low-level subbands to high-level subbands.

In the coefficient quantization unit 204, the buffer 203
Are quantized by the quantization step determined for each frequency component, and the quantized value (coefficient quantization value) is output to the entropy encoding unit 205. Here, when the coefficient value is X and the value of the quantization step for the frequency component to which the coefficient belongs is q, the coefficient value Q (X) after quantization by the coefficient quantization unit 204 is obtained by the following equation.

Q (X) = floor {(X / q) +0.5} In the above equation, floor {X} represents the maximum integer value not exceeding X.

FIG. 4 is a diagram showing the correspondence between each frequency component and the quantization step in the present embodiment.

As shown in FIG. 4, the low frequency sub-band (LL
HL1, LH1, HH1
, Etc.) are given a larger quantization step. After quantizing all the coefficients in one subband in this way, the quantized coefficient values are output to the entropy encoding unit 205.

The entropy coding unit 205 performs entropy coding of the input coefficient quantization value by arithmetic coding to generate an entropy coded value. The entropy coded value is transmitted to the header / image coded data transmitting unit 20.
6 is output.

As shown in FIG. 5A, the header / picture coded data transmitting section 206 arranges the input entropy coded values in subband units to generate coded picture data. Then, as shown in FIG.
A header is added to the head of the encoded image data,
Generate encoded image data. This header contains
The size of the image input to the image input unit 201 is 2
Information such as a type indicating whether the image is a value image or a multi-value image, a character string indicating an image encoding / transmission device to be transmitted, a transmission date and time, and the like are written. The header / image encoded data thus generated is transmitted from the header / image encoded data transmission unit 206. In addition, this header
An interface such as a public line, a wireless line, or a LAN can be used as the image encoded data transmission unit 206.

Next, processing in the image decoding apparatus according to the present embodiment will be described.

When the header / image encoded data transmitted from the image encoding / transmission device shown in FIG. 2 is input to the header / image encoded data input unit 101, it is separated into a header and image encoded data. Is done. The encoded image data is temporarily stored in the subband storage buffer 102. The stored encoded image data is output to the entropy decoding unit 104 in units of one-level subband under the control of the subband output control unit 103. An example of output of the image coded data in units of one-level subband will be described with reference to FIG.

FIG. 6 is a diagram for explaining processing levels corresponding to each sub-band when the sub-band of each level is stored in the sub-band storage buffer 102 and entropy-decoded.

When the LL sub-band of the header / image coded data transmitted from the image coding / transmission device is input to the header / image coded data input unit 101, the LL sub-band is stored in the sub-band. The data is output to the buffer 102 and stored (601). When all of the LL sub-bands are input to the sub-band storage buffer 102 in this way, the LL sub-band is
It is output to the entropy decoding unit 104 under the control of No. 3 (602). And for this LL subband:
Decoding processing by the entropy decoding unit 104 and subsequent processing are performed. This processing is referred to as level 0 processing.

Next, when the reception of the encoded image data proceeds, H
The L1 sub-band is a header / picture coded data input unit 10
1 is input. The HL1 subband is stored in the subband storage buffer 102 (603). Similarly, when the HH1 subband and the LH1 subband are sequentially input to the header / image coded data input unit 101, the HH1 subband and the LH1 subband are stored in the subband storage buffer 102 ( 604).
At this time, under the control of the sub-band output control unit 103, three sub-bands of level 1;
The HH1 subband and the LH1 subband are output to entropy decoding section 104. Then, these three level 1 subbands are subjected to decoding processing by the entropy decoding unit 104 and subsequent processing. This processing is called level 1 processing.

Similarly, level 2 and level 3 subbands are output to entropy decoding section 104. The processing of the level 2 and level 3 subbands after the entropy decoding unit 104 is referred to as level 2 and level 3 processing.

It should be noted that the processing other than the inverse transformation buffer 106, the inverse transformation buffer 107, and the pseudo subband generation unit 108 does not differ greatly in any level of processing. Therefore, the description of the other processing units does not particularly refer to the processing level.

The encoded image data is decoded by the entropy decoding unit 104 to restore the quantized value, and is output to the inverse quantization unit 105. The inverse quantization unit 105 restores the discrete wavelet transform coefficient by inversely quantizing the input quantization value, and outputs the discrete wavelet transform coefficient to the subsequent inverse transformation buffer 106. This inverse quantization is performed by the following equation.

Xr = Q × q Here, Q is a quantization value, q is a quantization step, and Xr is a restored discrete wavelet transform coefficient.

Next, the processing in the inverse conversion buffer 106, the inverse conversion buffer 107, and the pseudo subband generation unit 108 will be described with reference to FIG.

In the processing of level 0, as shown in FIG. 7A, the subband of level 0 input to the buffer 106 for inverse conversion is copied to the buffer 107 for inverse conversion. Then, as shown in FIG. 7 (B), the pseudo sub-band generation unit 108 outputs the levels 1 to 3 in which all the components are “0”.
Is generated in the inverse conversion buffer 106.

The sub-band transmitted from the image encoding / transmission apparatus with respect to this pseudo sub-band is particularly called a positive sub-band. The decoded data generated from the normal subband is called normal decoded data, and the decoded image obtained from the normal decoded data is called a normal decoded image. Further, when “subband”, “decoded data”, and “decoded image” are used without particular notice, they respectively indicate “correct subband”, “correctly decoded data”, and “correctly decoded image”.

As shown in FIG. 8, a level 0 pseudo discrete wavelet transform coefficient sequence is generated from the level 0 positive subband (LL positive subband) and the level 1 to 3 pseudo subbands. The level 0 pseudo-discrete wavelet transform coefficient sequence is output to the inverse discrete wavelet transform unit 109, where level 0 pseudo-decoded data is generated and output to the decoded data output unit 110. A decoded image obtained from the level 0 pseudo-decoded data is called a level 0 pseudo-decoded image. The processing in the inverse discrete wavelet transform unit 109 will be described later.

Next, level 1 processing will be described.

In the level 1 processing, as shown in FIG. 9A, the level 1 subbands (HL1, LH1, HH1) input to the inverse conversion buffer 106 are copied to the inverse conversion buffer 107. You. As a result, the level-0 and level-1 subbands are stored in the inverse conversion buffer 107.

Then, as shown in FIG. 9B, the LL subband stored in the inverse conversion buffer 107 is
The data is copied to the inverse conversion buffer 106. As a result, the level-0 and level-1 subbands are stored in the inverse conversion buffer 106. Subsequently, as shown in FIG. 10, the pseudo subband generation unit 108 generates pseudo subbands of levels 2 and 3 in which all components are “0” in the inverse conversion buffer 106. And as shown in FIG.
A level 1 pseudo-discrete wavelet transform sequence is generated. The level 1 pseudo-discrete wavelet transform coefficient sequence is output to the inverse discrete wavelet transform unit 109 to generate level 1 pseudo-decoded data, and the decoded data output unit 1
It is output to 10.

In the next level 2 processing, the same processing as the level 1 processing is performed using the level 0 and 1 positive subbands stored in the inverse conversion buffer 106.

Next, in level 3 processing, the level 3 positive sub-band is input to the inverse conversion buffer 106. Then, the inverse conversion buffer 107 is changed from the inverse conversion buffer 107 to the inverse conversion buffer 10.
In step 6, the positive subbands of levels 0 to 2 are copied to generate a discrete wavelet transform coefficient sequence. Then, the inverse discrete wavelet transform unit 109 generates decoded data of level 3 and outputs it to the decoded data output unit 110.

The pseudo-decoded images of levels 0 to 2 have the same resolution as the original image.

Of the pseudo-discrete wavelet transform coefficients stored in the inverse transform buffer 106 or the discrete wavelet transform coefficients (hereinafter, discrete wavelet transform coefficients include pseudo-discrete wavelet transform coefficients), discrete Let the wavelet transform coefficient be r (n) and the discrete wavelet transform coefficient of the high frequency sub-band be d (n). The inverse discrete wavelet transform for these is performed as follows.

X (2n) = r (n) + floor {p (n) / 2} x (2n + 1) = r (n) -floor {p (n) / 2} where p (n) = d (n-1) -floor {(-r (n) + r (n + 2) +2) / 4} x (n) is decoded data. Note that in the above equation,
or {X} represents the maximum integer value not exceeding X. Although this conversion formula is for one-dimensional data, two-dimensional conversion is performed by applying this conversion in the horizontal and vertical directions in this order. Then, decoded data (including pseudo-decoded data) is generated and output to the decoded data output unit 110. Here, a network line interface or the like is used for the decoded data output unit 110. RAM, RO
A recording medium such as an M, a hard disk, a CD-ROM, or the like may be used. Alternatively, an image display device such as a liquid crystal display may be used. Also, the decrypted data output unit 110
When an image display device is used, the decoded data (pseudo-decoded data) is displayed as a decoded image (pseudo-decoded image).

In the processing from the header / image coded data input unit 101 to the decoded data output unit 110, a plurality of levels of processing may be performed simultaneously. For example, the level 3 processing may be performed by the entropy decoding unit 104 in parallel with the level 2 processing performed by the inverse discrete wavelet transform unit 109.

FIG. 12 is a flowchart showing a decoding process in the image decoding apparatus according to Embodiment 1 of the present invention.

First, in step S1, encoded image data is input from the header / image encoded data input unit 101 in order from the level 0 subband. The sub-band data thus input is stored in the sub-band storage buffer 102.
Are sequentially read from the lowest level 0 and decoded by the entropy decoding unit 104 (step S2). The subband thus decoded is inversely quantized by the inverse quantization unit 105 in step S3 and stored in the inverse transform buffer 106. Next, the process proceeds to step S4, where it is checked whether or not the inverse quantization of the subband of level i (the first subband of level 0) indicated by the index i (initial value 0) has been completed. , A level i subband and a level (i + 1) to (i + 3) (first levels 1, 2, and 3) pseudo subbands are used to generate a level i pseudo discrete wavelet transform coefficient. However, levels (i + 1) to (i +
3) is to be able to take up to the maximum level 3,
When i = 3, no pseudo subband is generated.

Then, the process proceeds to a step S6, wherein the level i
Is subjected to inverse discrete wavelet transform, and the result is output as a pseudo-decoded image. Next, in step S7, the value of the index i is incremented by one, and in step S8, if the value of i is not 3 or more, step S8 is executed.
4, the above-described processing is executed.

As described above, according to the image decoding apparatus according to the first embodiment, at the early stage of receiving encoded image data, that is, at the stage of receiving low-level subbands, the low-level positive Subband and all components are “0”
, And generate pseudo-decoded data at that level from the higher-level pseudo sub-bands. Then, by displaying the pseudo-decoded image obtained from the generated pseudo-decoded data, the outline of the original image can be displayed at the same resolution as the original image at an early stage of receiving the encoded data.

[Second Embodiment] In the above-described first embodiment, in all levels of processing, the resolution of the pseudo decoded image obtained from the pseudo decoded data is the same as that of the original image. Therefore, in low-level processing, the number of pseudo subbands used for decoding increases. Therefore, a low-level pseudo-decoded image may be hardly able to represent the outline.

Therefore, in the second embodiment, in each level of processing, a pseudo subband that is higher by one level than the subband input to the inverse conversion buffer 106 is generated. Then, the pseudo-band having a resolution one level higher than the resolution (positive resolution) of the decoded image obtained from the normal sub-band input to the inverse transform buffer 106 and the normal sub-band stored in the inverse transform buffer 107 is obtained. Pseudo-decoded data for displaying the decoded image is generated.
Note that the resolution of the pseudo-decoded image is called pseudo-resolution.

FIG. 13 shows the configuration of the image decoding apparatus according to the second embodiment. In FIG. 13, portions common to those in FIG. 1 described above are denoted by the same reference numerals, and description thereof is omitted.

The image decoding apparatus according to the second embodiment differs from the image decoding apparatus used in the first embodiment in that the pseudo subband generation section 108 is replaced with a pseudo subband generation section 801. Also, the flow of processing in the two image decoding devices does not differ greatly.

In the process of level 0, when the LL sub-band is input to the inverse transform buffer 106, the LL sub-band is copied to the inverse transform buffer 107. The pseudo subband generation unit 801 generates a pseudo subband of level 1 in which all components are “0” in the buffer 106 for inverse conversion. Then, level 0 pseudo-decoded data is generated from the level 0 LL sub-band and the level 1 pseudo sub-band and output to the decoded data output unit 110.

In the case of level 1 processing, when a level 1 subband is input to the inverse transform buffer 106,
The level 1 subband is copied to the inverse conversion buffer 107. Then, the LL subband stored in the inverse conversion buffer 107 is copied to the inverse conversion buffer 106. Then, the pseudo subband generation unit 801 generates a pseudo subband of level 2 in which all the components are “0” in the buffer 106 for inverse conversion. Then, level 1 pseudo-decoded data is generated from the LL sub-band, the level 1 sub-band, and the level 1 pseudo sub-band, and output to the decoded data output unit 110.

The processing of level 2 is performed in the same manner as in level 1.

Furthermore, in the processing of level 3, no pseudo sub-band is generated, and complete decoded data is generated and output to the decoded data output unit 110.

FIG. 14 is a flowchart showing a decoding process in the image decoding apparatus according to the second embodiment. Steps common to those in the flowchart of FIG. 12 described above are denoted by the same reference numerals, and description thereof will be omitted.

The difference from the flowchart of FIG.
When the inverse quantization of the subband of level i is completed, in step S51, a positive subband of level i and a pseudo subband of level (i + 1) higher by one level than the subband are obtained. Is to perform the pseudo-discrete wavelet transform of. Also in this case, when the value of i becomes "3", the pseudo sub-band is not generated, and a level 3 positive decoded image by the level 3 positive sub-band is output.

As described above, according to the second embodiment, a pseudo subband that is higher by one level than the subband input to the inverse conversion buffer 106 is generated, and the pseudo subband input to the inverse conversion buffer 106 is generated. Pseudo-decoded data for displaying a pseudo-decoded image having a resolution one level higher than the resolution of the decoded image obtained from the sub-band and the normal sub-band stored in the inverse conversion buffer 107 is generated. The low-level pseudo-decoded image generated in this way can display the outline of the original image better than the low-level pseudo-decoded image in the first embodiment.

[Third Embodiment] In the above-described second embodiment, in each level of processing, a pseudo-subband of the next higher level is generated to obtain a pseudo-decoded image. At that time, all the components of the pseudo subband were set to “0”. In other cases, the pseudo-subband is generated by reflecting the components of the positive subband, so that the pseudo-decoded image may be suitable for representing the outline of the completely decoded image.

Therefore, according to the third embodiment, when the pseudo subband of the next higher level is generated in the processing of each level, each component of the positive subband input to the inverse conversion buffer 106 is converted into the pseudo subband. A pseudo sub-band is generated by copying the band component, and pseudo-decoded image data is output based on the pseudo sub-band.

FIG. 15 is a functional block diagram showing a schematic functional configuration of an image decoding apparatus according to the third embodiment. Portions common to the above-described embodiment are denoted by the same reference numerals. The image decoding device according to the third embodiment is the same as the image decoding device according to the second embodiment described above, except that
Is replaced by a pseudo sub-band generation unit 901, and the flow of processing in these image decoding devices is not significantly different.

Hereinafter, processing of each level in the image decoding apparatus according to the third embodiment will be described.

First, in the processing of level 0, the pseudo subband is not generated by the pseudo subband generator 901. That is, only the decoded data of level 0 is output to the decoded data output unit 110.

Next, in level 1 processing, the pseudo sub-band generating section 901 generates a level 2 pseudo sub-band.
At this time, as shown in FIG. 16, level 1 in FIG.
Are copied to the components of the pseudo subband at level 2 (FIGS. 16B and 16C). Then, pseudo-decoded data of level 1 is output to decoded data output section 110.

Generally, as the level of the subband increases by one, the number of components increases four times. Therefore, the pseudo-subband component of level 2 corresponding to each component of the positive subband of level 1 is composed of four components of the positive subband of level 1.

Next, in the level 2 processing, a level 3 pseudo subband is generated from the level 2 positive subband. At this time, as in the case of the level 1 processing, each component of the level 2 positive subband is copied to the corresponding level 3 pseudo subband component. Then, pseudo decoded data of level 2 is output to the decoded data output unit 110.

In the processing of level 3, no pseudo sub-band is generated. Then, complete decoded data is output to decoded data output section 110.

FIG. 17 is a flowchart showing decoding processing in the image decoding apparatus according to Embodiment 3 of the present invention.

First, in step S11, encoded image data is input from the header / image encoded data input unit 101 in order from the level 0 subband. The sub-band data thus input is stored in the sub-band storage buffer 10.
2 are sequentially read from the lowest level 0 and decoded by the entropy decoding unit 104 (step S12). The subband thus decoded is inversely quantized by the inverse quantization unit 105 in step S13 and stored in the inverse transformation buffer 106.

Next, proceeding to step S14, when the inverse quantization of the level 0 sub-band which is read first is completed, the pseudo-sub-band generation unit 901 does not generate the pseudo sub-band, but sends it to the decoded data output unit 110. Outputs only the level 0 normally decoded data, and a level 0 correctly decoded image is obtained.

Next, the process proceeds to level 1 processing in step S15, and a pseudo subband of level 2 is generated by the pseudo subband generation unit 901. At this time, each component of the level 1 positive sub-band is copied to the level 2 pseudo sub-band component. Then, the process proceeds to step S16 to generate and output pseudo decoded image data of level 1 from the positive sub band of level 1 and the pseudo sub band of level 2.

Next, the process proceeds to level 2 processing in step S17, and a level 3 pseudo subband is generated from the level 2 positive subband. At this time, similarly to the level 1 processing, each component of the level 2 positive sub-band is
To the pseudo-subband component of And step S
Proceeding to 18, the level 2 pseudo-decoded image data is generated and output from the level 2 positive sub-band and the level 3 pseudo sub-band.

In the last step S19, a level 3 correctly decoded image is obtained based on the level 3 correctly decoded data.

As described above, according to the third embodiment, in each level processing, a pseudo sub-band is generated by copying each component of the positive sub-band to a component of the higher-level pseudo sub-band. Pseudo-decoded data is generated from the pseudo sub-band and output. As a result, the pseudo-decoded image obtained from the pseudo-decoded data in the third embodiment is closer to the original image than the pseudo-decoded images obtained in the first and second embodiments.

[Fourth Embodiment] The first to third embodiments described above.
Therefore, an object of the present invention is to generate pseudo decoded data that can display the outline of a completely decoded image at an early stage of reception and at a low level.

On the other hand, depending on an image, at an early stage when the image decoding device receives the image encoded data, the sender completely decodes and displays a region (ROI) which the receiver particularly wants to see. And the area other than the ROI (non-R
It is conceivable that the outline of OI) is also displayed.

Therefore, the image decoding apparatus according to the fourth embodiment should completely decode and display the ROI image and display the outline of the non-ROI image at the early stage of receiving the encoded image data. I can do it.

FIG. 18 is a functional block diagram showing a schematic functional configuration of an image decoding apparatus according to Embodiment 4 of the present invention. Portions in common with the configuration of FIG. Omitted.

The image coding and transmitting apparatus according to the fourth embodiment is different from the image coding and transmitting apparatus according to the first embodiment in that a tile dividing section is provided between the image input section 201 and the discrete wavelet transform section 202. 1101 and an ROI determination unit 1102 are inserted, and the header / image encoded data transmission unit 206 is replaced with a header / image encoded data transmission unit 1103. Also, the flow of processing in the two image encoding / transmission devices does not differ greatly.

In FIG. 18, when image data for one screen is input to the image input unit 201, the tile dividing unit 110
At 1, the tile size is determined. Next, the image data is divided according to the determined tile size.
FIG. 19 shows an example in which an image is divided into tiles by dividing the image data into a plurality of tiles.

The size of each of these divided tiles is R
It is assumed that OI is small enough to be expressed in an arbitrary shape. The code string of each tile is called tile data. It is assumed that the image data to be encoded is divided into N tiles to generate N tile data. The N pieces of tile data thus generated are RO
It is input to the I determination unit 1102.

FIG. 20 is a diagram showing a specific example of the ROI determination unit 1102. A display 2000 for displaying an image and an area 2002 on the image which is displayed on the screen of the display 2000 and divided into a plurality of tiles are input. Pen 20
01, the ROI can be designated.

When such an operation is performed, 20 in FIG.
As indicated by 03, a tile (ROI tile) corresponding to the designated area 2002 is determined. Thus, the plurality of tiles are tiles including the ROI (ROI tiles) and ROIs.
Tiles that do not contain I (non-ROI tiles) are distinguished.
At this time, a header bit indicating whether each tile is a ROI tile or a non-ROI tile is added to the head of each tile data. Here, “1” is given to the header bit of the ROI tile, and “0” is given to the header bit of the non-ROI tile. These tile data are input to the discrete wavelet transform unit 202.
The processing after the discrete wavelet transform unit 202 is independent for each tile. Note that the header bits are not processed. The tile data to which the header bits are added is called tile data with header.

The processing in the discrete wavelet transform unit 202, the coefficient quantizing unit 204, and the entropy coding unit 205 is the same as that in the first embodiment, and the description is omitted.

Next, the header / picture coded data transmission section 11
In step 03, the image data is generated by rearranging the tile data. The method is described below.

First, as shown in FIG. 22, from the LL subbands of all tile data, LL subband image encoded data is generated. In FIG. 22, the subscripts of LL represent tile numbers (1 to N).

Subsequently, as shown in FIG. 23, encoded non-ROI image data is generated from the non-ROI tile data, and encoded ROI image data is generated from the ROI tile data. Then, as shown in FIG. 24, image encoded data is generated from the LL subband image encoded data, the ROI image encoded data, and the non-ROI image encoded data.

Then, a header is added to the head of the generated coded image data to generate coded header / image data. This header includes the above-described first embodiment.
It is assumed that not only the content to be written in the header in, but also the division information of the tile is written.

FIG. 25 is a block diagram showing a schematic configuration of an image decoding apparatus according to Embodiment 4 of the present invention. Portions common to the configuration of the image decoding apparatus according to the above-described embodiment are denoted by the same reference numerals. A description thereof will be omitted.

In the image decoding apparatus according to the fourth embodiment, the pseudo subband generating section 108 in the image decoding apparatus according to the first embodiment is replaced with a pseudo subband generating section 1501. Also, the flow of processing in the two image decoding devices does not differ greatly. However, the timing at which the pseudo subband is generated is different from the timing in the first embodiment.

In the fourth embodiment, decoding of encoded image data is divided into three stages. First, the first stage of decryption
The decoding of the LL subband image encoded data, the second stage decoding is the decoding of the ROI image encoded data, and the third stage decoding is the decoding of the non-ROI image encoded data.

FIG. 26 is a diagram showing an example of inputting image encoded data.
It is a figure explaining the state which decodes picture coded data of the first LL subband.

As shown in FIG. 26, when the header / picture coded data is input to the header / picture coded data input section 101, first, the first stage of decoding (decoding of the level 0 sub-band) is performed. Done. In this first stage of decryption,
No pseudo subband is generated by pseudo subband generation section 1501. Then, the decoded data of level 0 is output to the decoded data output unit 110.

When the first-stage decryption processing is completed, the second
A stage of decoding processing is performed. In the decoding process of the second stage, first, as shown in FIG. 27, the level 1 subband of the ROI tile is decoded, and decoded data (decoded ROI tile data) of the level 1 ROI tile is generated (FIG. 27). 2701). At this time, the pseudo subband generation unit 1
501 generates a level 1 pseudo subband (2702) of a non-ROI tile. And the LL positive subband (L
Lk) and pseudo-subbands of level 1 (HL1k, HH1k,
LH1k), pseudo-decoded data of a level 0 non-ROI tile (pseudo-decoded non-ROI tile data) is generated. Similarly, level 2 and 3 ROI tiles and non-RO
Decoding of the subband of the I tile is performed.

According to the fourth embodiment, in the decoding of level 2, that is, in the decoding of the second stage, the pseudo decoding RO is synchronized with the generation timing of the decoding ROI tile data.
I tile data is generated. Therefore, the resolutions of the decoded ROI tile image and the pseudo decoded ROI tile image are always the same. After the completion of the second stage decoding, the third stage decoding is performed.

In this level 3 third stage decoding,
The non-ROI image encoded data is completely decoded. The same processing as in the first embodiment is performed on the non-ROI image encoded data. For example, in level 1 processing, the pseudo subband generation unit 1501 generates level 2 and 3 pseudo subbands. Then, from the positive subbands of levels 0 and 1 and the pseudo subbands of levels 2 and 3,
Of pseudo-decoded ROI tile data.

It should be noted that in the decoding of the second stage, the resolution of the pseudo decoded non-ROI tile image increases as the decoding progresses, but the level of the decoded data is always "0".
It is. However, in the decoding of the third stage, the level of the pseudo-decoded non-ROI tile image becomes 1, 2, 3 as the decoding progresses.
And higher.

The pseudo subbands in the first to third decoding stages may be generated with all components being “0” as in the first embodiment, or may be generated as in the third embodiment. May be generated by copying the components of the positive subband.

FIG. 28 is a flowchart showing a decoding process by the image decoding apparatus according to Embodiment 4 of the present invention.

First, in step S21, the coded image data of each tile is input from the header / image coded data input unit 101 in order from the level 0 sub-band. The input subband data is sequentially stored in the subband storage buffer 102 for each tile, sequentially read from the lowest level 0, and decoded by the entropy decoding unit 104 (step S22). The sub-band of each tile decoded in this manner is obtained in step S2.
In step 3, the data is inversely quantized by the inverse quantization unit 105 and stored in the inverse transformation buffer 106. Next, proceeding to step S24, when the dequantization of the level 0 sub-band read first from each tile is completed, the pseudo-sub-band generator 901 does not generate a pseudo sub-band, and the decoded data output unit 110 , Only the level 0 normally decoded data is output, and a level 0 correctly decoded image of each tile is obtained.

When the decoding processing of the first stage is completed, the second
A stage of decoding processing is performed. In the decoding process of the second stage, it is determined in step S25 whether the tile is a ROI tile. If so, the process proceeds to step S26, where the level 1 subband of the ROI tile is decoded, and the level 1 ROB is decoded.
Decoded data of the I tile (decoded ROI tile data) is generated.

On the other hand, in the case of a non-ROI tile, step S
29, the pseudo sub-band generator 1501 outputs a non-ROI
A level 1 pseudo subband of the tile is generated. Then, from the LL positive sub-band (LLk) and the pseudo sub-band of level 1 (HL1k, HH1k, LH1k), the level 0 non-R
Pseudo-decoded data of the OI tile (pseudo-decoded non-ROI tile data) is generated.

In the same manner, steps S27 and S2
In step 8, subbands of level 2 and 3 ROI tiles are decoded. In steps S30 and S31, subbands of non-ROI tiles are decoded. As described above, in the decoding at the second stage, pseudo-decoded ROI tile data is generated in synchronization with the timing at which the decoded ROI tile data is generated. Therefore, the decoded ROI tile image and the pseudo-decoded ROI
The resolution of a tile image is always the same. After the completion of the second-stage decoding, the third-stage decoding is performed, and in step S32, the non-ROI image encoded data is completely decoded.

As described above, according to the fourth embodiment, three types of decoding are performed in accordance with the stage at which the image decoding device receives the encoded image data.
The decoded data of the entire level 0 image generated from the LL subband is generated, and in the second stage of decoding, the ROI
The tile is decoded to generate ROI tile data.
At this time, in synchronization with the decoding of the ROI tile, the non-ROI tile is decoded using the pseudo subband, and the pseudo decoded non-RO
I tile data is generated. Then, in the decoding of the third stage, the non-ROI tile is completely decoded by the same method as in the first embodiment.

As a result, the receiver of the encoded image data can see the outline of the non-ROI and the complete decoded image of the ROI at an early stage of reception.

[Other Embodiments] In the above embodiment, the description has been made assuming that the image coded data to be decoded by the image decoding apparatus has been subjected to the wavelet transform up to level 3, but the wavelet transform up to an arbitrary level is performed. The decoding of encoded image data is also included in the scope of the present invention. In that case, in each embodiment, according to the level of the wavelet transform of the image encoded data,
It is necessary to change the processing as appropriate.

In the above-described embodiment, the sub-band is processed for each level. However, the processing may be performed each time one sub-band is received. In this case, a part of the sub-band may be used as a processing unit, and the processing may be performed when a part of the sub-band which is the processing unit is input. As a part of such a sub-band, there is a sub-band line or the like.

Further, in the first embodiment, in each level of processing, pseudo subbands that can generate a pseudo decoded image having the same resolution as the original image are generated. Further, in the second and third embodiments, in each level processing, a pseudo subband having a level one level higher than the level of the input positive subband is generated. However, in the processing of each level, a method of generating an arbitrary number of pseudo sub-bands and a method of generating a different number of pseudo sub-bands for each level are also included in the scope of the present invention.

In Embodiment 4, the encoded image data is generated so that the ROI is decoded before the non-ROI. On the contrary, the non-ROI is decoded before the ROI. The encoded image data may be generated as described above.

In the decoding of the ROI image coded data in the first stage decoding and the second stage decoding in the fourth embodiment, a pseudo decoded image having a higher resolution is generated by using pseudo subbands. No problem. At that time, R
Types of pseudo subbands for the OI image encoded data;
The type of pseudo subband for non-ROI image encoded data may be different. That is, the pseudo subband component for the ROI image encoded data is “0”, and the pseudo subband component for the non-ROI image encoded data may be a copy of the positive subband component.

Even if the present invention is applied as a part of a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), one device (for example, a copying machine, a digital camera, etc.) May be applied to a part of the apparatus comprising:

Further, the present invention is not limited to only the apparatus and method for realizing the above-described embodiment, but includes a computer (CPU or M
PU) is supplied with software program code for implementing the above-described embodiment, and the computer of the system or apparatus operates the various devices according to the program code to implement the above-described embodiment. It is included in the category of the present invention.

In this case, the program code pertaining to the software implements the functions of the above-described embodiment, and the program code itself and means for supplying the program code to the computer are provided.
Specifically, a storage medium storing the above program code is included in the scope of the present invention.

As a storage medium for storing such a program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, magnetic tape, nonvolatile memory card, ROM, etc. can be used.

In addition to the case where the computer controls various devices in accordance with only the supplied program code to realize the functions of the above-described embodiments, the computer code may be used to execute the operating system running on the computer. Such a program code is also included in the scope of the present invention when the above-described embodiment is realized in cooperation with an (operating system) or other application software.

Further, after the supplied program code is stored in a memory provided in a function expansion board of a computer or a function expansion unit connected to the computer, the function expansion board is provided based on an instruction of the program code. The scope of the present invention also includes a case where a CPU or the like provided in the hardware or the function expansion unit performs part or all of the actual processing, and the above-described embodiment is realized by the processing.
As described above, according to the present embodiment, pseudo-decoded data is generated from a positive sub-band and a pseudo sub-band at an early stage of reception of encoded image data. Then, it is possible to display a pseudo-decoded image with higher resolution corresponding to the pseudo-decoded data.

[0128]

As described above, according to the present invention, it is possible to input hierarchically coded image coded data, to grasp the rough contents of the image at an early stage, Image reproduction can be performed at high resolution.

Further, according to the present invention, there is an effect that the attention area of the image can be reproduced earlier than other areas, or decoded and reproduced later than other areas.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating a functional configuration of an image decoding device according to Embodiment 1 of the present invention.

FIG. 2 is a functional block diagram showing a functional configuration of an image encoding / transmission device according to the present embodiment.

FIG. 3 is a diagram illustrating band decomposition by two-dimensional discrete wavelet transform.

FIG. 4 is an explanatory diagram of a quantization step in a coefficient quantization unit.

FIG. 5 is an explanatory diagram of image encoded data according to the present embodiment and header / image encoded data to which a header is added.

FIG. 6 is a diagram illustrating the order of processing of each subband of image encoded data.

FIG. 7 is a diagram illustrating generation of pseudo subbands of levels 1 to 3 from level 0 subbands according to the first embodiment.

FIG. 8 is a diagram illustrating a discrete wavelet transform coefficient sequence of a subband of level 0 and pseudo subbands of levels 1 to 3 according to the first embodiment.

FIG. 9 is a diagram illustrating generation of a pseudo subband according to the first embodiment.

FIG. 10 is a diagram illustrating a level 2 in which all components are “0” generated by the pseudo subband generation unit according to the first embodiment.
FIG. 3 is a diagram for explaining pseudo subband No. 3;

FIG. 11 is a diagram illustrating a discrete wavelet transform coefficient sequence of subbands of levels 0 and 1 and pseudo subbands of levels 2 and 3 according to the first embodiment.

FIG. 12 is a flowchart showing a decoding process performed by the image decoding device according to the first embodiment of the present invention.

FIG. 13 is a functional block diagram showing a functional configuration of an image decoding device according to Embodiment 2 of the present invention.

FIG. 14 is a flowchart showing a decoding process performed by the image decoding device according to the second embodiment of the present invention.

FIG. 15 is a functional block diagram showing a functional configuration of an image decoding device according to Embodiment 3 of the present invention.

FIG. 16 is a diagram illustrating pseudo subband generation according to the third embodiment.

FIG. 17 is a flowchart showing a decoding process by the image decoding device according to the third embodiment of the present invention.

FIG. 18 is a functional block diagram showing a functional configuration of an image encoding / transmission device according to Embodiment 4 of the present invention.

FIG. 19 is a diagram illustrating tile division in the fourth embodiment.

FIG. 20 is a diagram illustrating an ROI determination unit according to the fourth embodiment.

FIG. 21 is a diagram showing an RO by a ROI determining unit according to the fourth embodiment;
It is a figure explaining the determination of an I tile.

FIG. 22 is a diagram illustrating generation of encoded image data according to Embodiment 4.

FIG. 23 is a diagram illustrating generation of encoded image data according to Embodiment 4.

FIG. 24 is a diagram illustrating generation of encoded image data according to Embodiment 4.

FIG. 25 is a functional block diagram showing a functional configuration of an image decoding device according to Embodiment 4 of the present invention.

FIG. 26 is a diagram illustrating decoding of encoded data of an LL subband according to the fourth embodiment.

FIG. 27 is a diagram illustrating generation of a pseudo sub-band according to the fourth embodiment.

FIG. 28 is a flowchart showing a decoding process by the image decoding device according to Embodiment 4 of the present invention.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Kajiwara 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 5C059 KK33 MA24 MC38 MD02 ME01 SS06 TA57 TB04 TB15 TC43 TD13 UA02 UA05 UA38 5C078 BA53 BA64 CA00 DA00 DA02 DB05 5J064 AA02 BA09 BA16 BB13 BC01 BD02 9A001 EE04 HZ25 HZ27 KK56

Claims (27)

[Claims] 1. A storage unit for inputting and storing hierarchically encoded image encoded data input in a time series, and a decoding unit for reading and decoding the image encoded data stored in the storage unit in a hierarchical order. Pseudo-data generation means for generating pseudo-decoded data higher than the predetermined hierarchy decoded by the decoding means and corresponding to image encoded data of a non-input hierarchy, and the pseudo-decoding data decoded by the decoding means An image decoding apparatus, comprising: decoded data generating means for generating pseudo image decoded data based on hierarchical decoded data and pseudo decoded data generated by the pseudo data generating means. 2. The image encoded data according to claim 1, wherein the encoded image data is discrete wavelet transform of the original image data, and the transform coefficients are quantized and then entropy encoded. Image decoding device. 3. The image decoding apparatus according to claim 1, wherein the coded image data is sequentially input in time series from coded data in a low frequency band. 4. The image decoding apparatus according to claim 1, wherein the hierarchy corresponds to a subband indicating a frequency band of an image. 5. The image decoding apparatus according to claim 1, wherein the pseudo data generating unit generates the pseudo decoded data with 0. 6. The pseudo data generating unit according to claim 1, wherein the pseudo data generating unit generates the pseudo decoded data by using decoded data of a predetermined layer decoded by the decoding unit. An image decoding device according to claim 1. 7. The pseudo data generating means according to claim 1, wherein said pseudo data generating means generates pseudo decoded data one level higher than a predetermined layer decoded by said decoding means. The image decoding device according to any one of the preceding claims. 8. A storage unit for inputting and storing hierarchically encoded image encoded data input in time series, and a decoding unit for reading and decoding the image encoded data stored in the storage unit in a hierarchical order. Determining means for determining whether or not the decoded data decoded by the decoding means corresponds to image-encoded data of an attention area of an original image; and determining the decoding means in accordance with a determination result by the determining means. Decoded data corresponding to the region of interest decoded by
Control means for controlling generation of a decoded image based on the decoded data corresponding to the non-attention area. 9. The control unit includes: a unit configured to generate image decoded data of the attention area based on the decoded data of the attention area; and Means for generating pseudo-decoded data corresponding to image-encoded data of the non-interest area in a higher-ranked, non-input area; and means for generating image-decoded data of the non-interest area based on the pseudo-decoded data. The image decoding device according to claim 8, comprising: 10. The control unit includes: a unit configured to generate image decoded data of the non-attention region based on the decoded data of the non-attention region; and the predetermined layer based on the decoded data of a predetermined layer of the attention region. Means for generating pseudo-decoded data corresponding to the image-encoded data of the region of interest in a higher-ranked and uninput hierarchy; and means for generating image-decoded data of the region of interest based on the pseudo-decoded data. The image decoding apparatus according to claim 8, comprising: 11. The image encoded data according to claim 8, wherein the encoded image data is an encoded image obtained by dividing an original image into a plurality of tiles and using the plurality of tiles as a unit. An image decoding device according to claim 1. 12. The image encoded data according to claim 8, wherein the image encoded data is discrete wavelet transform of original image data, quantized transform coefficients, and then entropy encoded. Image decoding device. 13. The image decoding apparatus according to claim 8, wherein the encoded image data is sequentially input in time series from encoded data of a low frequency band. 14. A storage step of inputting and storing hierarchically encoded image encoded data input in time series, and a decoding step of reading and decoding the image encoded data stored in the storing step in a hierarchical order. A pseudo data generating step of generating pseudo decoded data that is higher than the predetermined layer decoded in the decoding step and corresponds to image encoded data of an uninput layer, and the predetermined data decoded in the decoding step. An image decoding method, comprising: a decoded data generating step of generating pseudo image decoded data based on hierarchical decoded data and pseudo decoded data generated in the pseudo data generating step. 15. The image encoded data according to claim 14, wherein the image encoded data is discrete wavelet transform of the original image data, the transform coefficient is quantized, and then entropy encoded. Image decoding method. 16. The image decoding method according to claim 14, wherein the encoded image data is sequentially input in time series from encoded data of a low frequency band. 17. The image decoding method according to claim 14, wherein the hierarchy corresponds to a sub-band indicating a frequency band of an image. 18. The image decoding method according to claim 14, wherein in the pseudo data generating step, the pseudo decoded data is generated as 0. 19. The pseudo data generating step according to claim 14, wherein the pseudo data generating step generates the pseudo decoded data by using decoded data of a predetermined layer decoded in the decoding step. 3. The image decoding method according to claim 1. 20. The pseudo-data generating step according to claim 14, wherein the pseudo-data generating step generates pseudo-decoded data one level higher than a predetermined layer decoded in the decoding step. The image decoding method described in the above. 21. A storage step of inputting and storing hierarchically encoded image encoded data input in time series, and a decoding step of reading and decoding the image encoded data stored in the storage step in a hierarchical order. A determining step of determining whether or not the decoded data decoded in the decoding step corresponds to image encoded data of a region of interest of an original image; and, in accordance with a determination result in the determining step, An image decoding method, comprising: controlling decoded data corresponding to the region of interest decoded in the step; and controlling generation of a decoded image based on the decoded data corresponding to the non-target region. 22. The control step, comprising: generating image decoded data of the attention area based on the decoded data of the attention area; and controlling the predetermined hierarchy based on the decoding data of a predetermined hierarchy of the non-interest area. Generating pseudo-decoded data corresponding to the image-encoded data of the non-interest area of the higher-ranked and uninput layer; and generating the image-decoded data of the non-interest area based on the pseudo-decoded data. The image decoding method according to claim 21, comprising: 23. The control step, comprising: generating image decoded data of the non-interest area based on the decoded data of the non-interest area; and controlling the predetermined hierarchy based on the decoded data of a predetermined hierarchy of the attention area. Generating pseudo-decoded data corresponding to the image-encoded data of the region of interest in an uninput hierarchy that is higher than the above, and generating image-decoded data of the region of interest based on the pseudo-decoded data. The image decoding method according to claim 21, comprising: 24. The image encoded data according to claim 21, wherein the encoded image data is encoded data obtained by dividing an original image into a plurality of tiles, and using the plurality of tiles as a unit.
The image decoding method according to any one of the above. 25. The coded image data according to claim 21, wherein the coded image data is discrete wavelet transform of the original image data, quantizes its transform coefficients, and is entropy coded data. Image decoding method. 26. The image decoding method according to claim 21, wherein the encoded image data is sequentially input in time series from encoded data of a low frequency band. 27. A computer-readable storage medium storing a program for performing the image decoding method according to claim 14. Description: