JPH11288458A - Repeated conversion decoding device and method and repeated conversion encoding/decoding device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a zoom screen between different reduction scales by using fractal decoding. SOLUTION: A fractal encoding code and pictures on various kinds of reduced scales or layer pictures are stored in a storage medium 2. The fractal encoding code read from the storage medium 2 is inputted to a fractal decode part 7, and an enlarged or reduced image with arbitrary magnification between the pictures on a reduced scale or the layer pictures is fractal-decoded so that a fractal decoded picture can be generated. This fractal decoded picture or the picture on a reduced scale or the layer picture read from the storage medium 2 are developed in a memory part 4, and transmitted through a graphic interface part 5 to a display control part 6 so as to be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for iterative transform decoding of an image, and an apparatus and method for iterative transform coding and decoding. The present invention relates to an iterative transform decoding apparatus and method, and an iterative transform coding and decoding apparatus and method.

[0002]

2. Description of the Related Art As a conventional typical image compression method, I
The so-called JPEG standardized by SO (Joint Ph
The otographic Coding Experts Group) method is known. This JPEG method uses DCT (discrete cosine transform:
It is known that when a relatively high bit is assigned using Discrete Cosine Transform, a good encoded / decoded image is provided. However, if the number of coded bits is reduced to some extent, block distortion peculiar to DCT becomes remarkable, and deterioration is subjectively noticeable.

[0003] Apart from this, recently, iterative conversion schemes (IF
An image compression method using S (Iterated Function Systems) has been receiving attention. This method is based on the premise that if a part of the image is extracted from the whole image, another image very similar to the extracted image exists in the image in a different size. This is based on the self-similarity of images. This iterative conversion method is based on J
Since block distortion unlike PEG is not conspicuous, and since self-similarity between blocks of different sizes in an image is used, there is an advantage that decoding does not depend on resolution. This iterative transform coding is also called fractal coding, and is expected to be applied to various areas.

The basic structure of the above iterative transform coding is described in, for example, Arnaud E. Jacq
uin) 's paper "Image coding based on a fra."
ctal theory of Iterated Contractive Image Transfor
mations ", IEEE Transactions on Image Processing, Vo
l.1, No.1, pp.18-30).

In the iterative transform decoding, the reduced image mapping transformation from the domain block image to the range block image is normally performed on all the range block images constituting the screen, thereby converging the entire image. This is a technique for generating a restored image. On the encoder side, the position information and the conversion parameter of the domain block that most closely approximates each range block may be encoded.

In FIG. 11, a range block R _k is
It is obtained by performing a reduced mapping transformation on the domain block D _k . Here, the block size of R _k is m × n, and the block size of D _k is M × N. FIG. 11 shows that L × L range blocks exist in the entire screen. The block sizes of the range block and the domain block are factors that greatly affect the coding efficiency, and the size determination is important.

In order to represent the image conversion from D _k to R _k , let w _{k be} the mapping function to the block R _k , and let P be the number of domain blocks required to perform mapping conversion of the entire screen. , image f is by the mapping function W of the entire image, is mapped to the _{W (f) = w 1 (} f) ∪ w 2 (f) ∪ ... ∪ w P (f) ...... (1). Therefore, W is represented by the following equation.

[0008] _{^{W = ∪ P k = 1 w}} k ...... (2) , where the mapping function w may be converged be selected What generally contraction mapping to ensure convergence Is often used. Furthermore, affine transformation is often used because of simplification of processing. The case where D _k is mapped to R _k by the affine transformation is expressed by the following equation when the actual conversion function is set as v _i .

[0009]

(Equation 1)

By the equation (3), all conversions such as rotation, translation, reduction, and enlargement between two blocks can be expressed. The part of the fractal decoder that performs image conversion includes, for example, a circuit for performing the conversion such as rotation, translation, reduction, enlargement, and the like represented by the above equation (3). By performing the conversion processing using the conversion, a procedure for obtaining the domain block image after the conversion is performed.

Although the above example shows the transformation with respect to the spatial coordinates of the block, the pixel values, for example, the grayscale values such as luminance and chrominance information, can be similarly mapped using the affine transformation. it can. In this case, for the sake of simplicity, for example, a relational expression in which the pixel value d _i in the domain block D _k is mapped to the pixel value r _i in the range block R _k is as follows.

V _i (d _i ) = s × d _i + o (4) where s is the contrast (Contrast Sca in the above paper)
ling) and o are offset values (Luminance Sh in the above paper)
ift). In this case, the parameters s and o may be calculated so that the sum of squared differences between the error and the pixel value r _i in the range block R _k is minimized. That is _{Σ (s × d i + o} -r i) 2 → may be set so as to minimize the value ... (5).

[0013]

By the way, for example, it is frequently used in navigation maps and map figures.
A reduced-scale image having a plurality of layer structures is often used after being compressed and expanded. In a normal navigation map, when the user zooms in (enlarges), the image is switched to a layer image of the next reduced scale at a certain place. However, the zoom up to that point is a simple repetition of pixels, and there is no improvement in resolution.

The present invention has been made in view of such circumstances, and when obtaining a navigation map or the like, it is possible to improve the quality of a zoom image until the next reduced scale image or layer image is obtained. It is an object of the present invention to provide an iterative transform decoding apparatus and method and an iterative transform coding / decoding apparatus and method that can be performed.

[0015]

In order to solve the above-mentioned problems, the present invention provides a fractal coded code and a fractal coded code read from a storage medium storing a plurality of reduced scale images or layer images. Is input, and the fractal decoding is performed by performing fractal decoding on the scaled image or the enlarged / reduced image at an arbitrary magnification between the layer images, and the fractal decoded image is read from the storage medium. It is characterized in that the reduced scale image or the layer image is developed in the storage means.

Further, according to the present invention, an image read from a storage medium storing a plurality of reduced scale images or layer images is fractally encoded to generate a fractal encoded code, and the generated fractal encoded code is input. Then, the fractal decoding is performed by performing fractal decoding on the scaled image or the enlarged / reduced image at an arbitrary magnification between the layer images, and the fractal decoded image or the scaled image read from the storage medium. Alternatively, it is characterized in that the layer image is developed in the storage means.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an iterative transform decoding device according to a first embodiment of the present invention.

The iterative transform decoding apparatus shown in FIG. 1 has a central control unit 1 which is a control means for controlling the entire apparatus, and a so-called CD storing a fractal coded code and a plurality of reduced scale images or layer images. A storage medium 2 such as a ROM or a ROM cassette, and a fractal coding code read from the storage medium 2; A fractal decoding unit 7 serving as a fractal decoding unit generated by an iterative transformation decoding process
And a memory unit 4 that is a storage unit that expands a decoded image, a reduced scale image, or a layer image, and further includes an interface unit 3 for inputting / outputting a command input, a control signal, and the like. A graphics interface unit 5 for outputting a developed image, and a CRT connected to the graphics interface unit 5
(Cathode ray tube) and a display control unit 6 for displaying an image on a display unit.

Next, the operation will be described. In FIG. 1, in response to a control signal 100 issued from a central control unit 1, an image or a layer image 106 of a predetermined scale is read from a storage medium 2 and expanded in a memory unit 4. For example, in FIG. 2, an image of the N-th layer (for example, 1/1000 scale) is read from the storage medium 2 and is expanded in the memory unit 4. The developed image 104 is subjected to, for example, D / A conversion in the graphics interface unit 5 to be converted into an analog image signal 105 and displayed. Each scaled image having a layer structure is recorded on the storage medium 2 having a hierarchical structure as shown in FIG.

Next, when instruction information 102 for displaying an enlarged image of the currently displayed image is issued from the interface unit 3, the enlargement ratio is changed to the next layer image (that is, the (N + 1) th layer image). Image: eg 200 scale
The central control unit 1 determines whether or not the scale ratio exceeds (1/1).
Is determined by If the scale is 1/1000 to 200/200, the coded code 101 obtained by fractally coding the image of the Nth layer is read from the storage medium 2 and input to the fractal decoding unit 7. Then, the fractal decoding unit 7 performs fractal decoding (iterative conversion decoding) at the enlargement ratio specified by the instruction information 102, and expands the decoded image 103 into the memory unit 4. For example, if an enlarged image at a scale of 1/500 is desired, a fractal decoded image in which the image of the Nth layer, which is an image at a scale of 1/1000, is doubled both horizontally and vertically is generated. .

FIG. 4 is a flowchart showing the above processing. In FIG. 4, the first step S
At 41, the image of the N-th layer is read from the storage medium 2 and expanded in the memory unit 4. In the next step S42, the fractal encoded code of the image of the Nth layer is read from the storage medium 2. In the next step S43, the zoom ratio is determined based on the instruction information from the interface unit 3. In the next step S44, the read fractal encoded code is subjected to fractal decoding (iterative transform decoding) at the zoom rate, and is developed in the memory unit 4. In the next step S45, it is determined whether or not the zoom ratio has exceeded the scale of the next layer. If NO, the process returns to step S43, and if YES, the process proceeds to step S46. In step S46, N is incremented (N = N + 1)
That is, the process proceeds to the next layer image, and the process returns to the first step S41.

According to the first embodiment, images between different scaled images already stored in the storage medium can be generated by fractal decoding involving enlargement / reduction. The enlarged / reduced image obtained at this time has higher image quality than that obtained by a conventionally used method, and the fractal encoding code of the reduced-scale image may be stored in a storage medium. Compared with the case of storing, the capacity of the storage medium can be saved.

Next, a second embodiment according to the present invention will be described with reference to FIG. The second embodiment shown in FIG. 5 shows an iterative transform coding / decoding device including a fractal encoder and a decoder.

The iterative transform coding / decoding device shown in FIG.
A central control unit 1 which is control means for controlling the entire apparatus;
By inputting a storage medium 2 such as a so-called CD-ROM or ROM cassette storing a fractal encoded code and a plurality of types of reduced scale images or layer images, and a fractal encoded code read from the storage medium 2, A fractal decoding unit 7 for generating a scaled image or a scaled image at an arbitrary magnification between layer images by fractal decoding (iterative conversion decoding) processing, and storage for expanding the decoded image, scaled image, or layer image A fractal encoding unit 8 that performs a fractal encoding (iterative transform encoding) process on an image read from the storage medium 2 to generate a fractal encoded code, Further, an interface unit 3 for input / output of command input, control signal, etc.
A graphics interface unit 5 for outputting an image developed in the memory unit 4; and a display control unit connected to the graphics interface unit 5 for displaying an image on a display unit such as a cathode ray tube (CRT). Part 6
And is configured.

Next, the operation will be described. In FIG. 5, in response to a control signal 100 issued from the central control unit 1, an image or a layer image 106 having a predetermined scale is read out from the storage medium 2 and expanded in the memory unit 4. When an image having a scale ratio up to the next layer image is required, the current layer image 106 is fractally encoded by the fractal encoding unit 8 and the generated encoded code 107 is output to the fractal decoding unit 7. Performs fractal decoding at a zoom rate corresponding to a predetermined scale rate in the section,
A decoded image 103 is generated and expanded in the memory unit 4.
Subsequent operations are the same as those of the first embodiment shown in FIG.

According to the second embodiment shown in FIG. 5, not only the effects of the above-described first embodiment are obtained, but also the fractal encoding of the layer image is performed. 2 does not need to store the fractally encoded code in advance,
The time required for producing a storage medium can be saved, and the storage capacity can be effectively used, thereby saving money.

Here, specific examples of the configuration of the fractal encoding unit 8 and the fractal decoding unit 7 used in the first embodiment of FIG. 1 and the second embodiment of FIG. 5 will be described with reference to FIGS. This will be described with reference to FIG. Note that specific examples of the fractal encoding unit 8 and the fractal decoding unit 7 are not limited to those shown in FIGS. 6 and 7.

FIG. 6 shows the fractal encoder 8 of FIG.
FIG. 3 is a block diagram showing an example of a specific configuration of FIG. The device shown in FIG. 6 includes a first block generation unit 9, a second block generation unit 10, a control unit 11, an approximation measurement threshold processing unit 12, an image conversion / generation unit 13, a block information It comprises a storage unit 14 and an encoding / multiplexing unit 15.

Next, the operation will be described. Input image 10
In 8, a first block generation unit 9 and a second block generation unit 10 form block images, respectively. At this time, the first
Is referred to as a range block, and the second block is referred to as a domain block. Domain block 1
In 17, various feature amounts of the domain block are detected in the block information storage unit 14. For example, an average value and a variance value of the pixel values in the block are calculated and stored in the unit 14 as the feature amount of the same domain block. Next, image conversion (for example, affine transformation) is performed on the domain block 117 by the image conversion / generation unit 13, and the degree of similarity between the converted block 114 and the range block 109 is measured. . As the degree of approximation, the sum of the square errors of all the pixels in a frequently used block may be used.

In the above description, usually, before generating the range block 109, the characteristic amounts of all the domain blocks constituting the input image 108 are extracted and stored in the block information storage unit 14. There is a need. Then, the range blocks 109 that actually constitute the input image 108 are sequentially generated, and the above-described processing is performed on each of the range blocks 109 with respect to a domain block having the same or similar feature amount of the range block. Should be done. The control is performed by the control unit 11. As a result, one domain block having the maximum degree of approximation (minimum error) with each range block 109 is selected, and the position (or address) 118 of the domain block at that time, the conversion parameter 115, the position of the range block ( Or the address) 110 by the encoding / multiplexing unit 1
5, the coded bit stream 119 may be transmitted from the encoder.

FIG. 7 is a block diagram showing an example of a specific configuration of the fractal decoding unit 7 shown in FIGS. 1 and 5. The apparatus shown in FIG. 7 includes a demultiplexing section 16, a domain block generation section 17, an image conversion / generation section 13
, A control unit 11 and an image memory unit 18.

Next, the operation will be described. The multiplexing / demultiplexing unit 16 that has received the coded bit stream 119 demultiplexes the multiplexed bitstream 119 and demultiplexes the multiplexed bitstream 119.
It is divided into domain block addresses 118 and conversion parameters 115. The domain block generation unit 17 determines the position of the domain block on the screen based on the address 118 of the domain block, and performs image conversion /
It is sent to the generation unit 13. The image conversion / generation unit 13 converts the domain block image 120 using the conversion parameter 115 as in the encoder, and generates the converted domain block image 121.

The converted domain block image 121 is
Range block address 110 on the image memory unit 18
Is stored and held at the location specified by. Image memory unit 1
8 outputs an instruction signal 124 to the domain block generation unit 17 to generate the next domain block, and performs decoding as needed. When the processing of all the range blocks is completed, the image memory unit 1
The decoded image 122 written in 8 is output to the control unit 19. The control unit 19 determines again whether or not to perform the above-described decoding process from the first range block. When the decoding is to be terminated, the final decoded image 126 is sent from the decoder by the part 19.

Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment shown in FIG. 8 differs from the configuration of the first embodiment shown in FIG. 1 in that an image decoder unit 20 and a second memory unit 21 are added.

That is, the iterative transform decoding apparatus shown in FIG. 8 includes a central control unit 1 as control means for controlling the entire apparatus, a fractal coded code, an image coded code,
A storage medium 2 such as a so-called CD-ROM or ROM cassette which stores a plurality of reduced scale images or layer images;
This is a means for inputting the fractal encoded code read from the storage medium 2 to generate an enlarged / reduced image at an arbitrary magnification between the reduced scale image or the layer images by fractal decoding (iterative transform decoding) processing. A fractal decoding unit 7, a first memory unit 4 as storage means for expanding a fractal decoded image or a reduced scale image or a layer image, and a decoded image obtained by decoding an image coding code read from the storage medium 2. , And a second memory for expanding the decoded image generated by the image decoder unit 20. In addition, an interface unit 3 for inputting / outputting a command input, a control signal, and the like, a graphics interface unit 5 for outputting an image developed in the memory unit 4, and a graphics interface unit 5 connected to the graphics interface unit 5. A display controller 6 for displaying an image on a display such as a CRT (cathode ray tube).

Next, the operation will be described. The basic operation of the third embodiment shown in FIG.
This is the same as that described in the embodiment. Therefore, the following description focuses on the differences from the first embodiment.

As described with reference to FIG. 11, the basic operation of the fractal decoding requires more memory than a DCT (Discrete Cosine Transform) in which processing is completed in a block. This is because it is necessary to hold image information in a reference block: domain block. Further, when decoding while enlarging an image, more memory is required. Therefore, it is necessary to prepare the memory capacity of the first memory unit 4 to be considerably large. Further, decoding usually requires a plurality of repetitive processes, so that reading / writing of image data between the first memory unit 4 and the fractal decoding unit 7 frequently occurs. Accordingly, the first memory unit 4 cannot process the DRAM in time, and the high-speed SRAM (Sync
hronousRandom Access Memory) is required. This can be expensive if implemented in hardware.

Therefore, in order to solve the above two problems, that is, the problems of high-speed decoding and memory capacity, in the third embodiment, the image encoding code 129 read from the storage medium 2 is used. The image is decoded by the image decoder unit 20, and the generated decoded image 127 is expanded in the second memory unit 21. The image decoder section 20 is, for example, a JPEG decoder and has an IDCT circuit built therein. In this case, since the decoding process is performed in units of 8 × 8 block images, the memory capacity of the second memory unit 21 can be significantly reduced as compared with the first memory unit 4. further,
Since IDCT does not require repetitive decoding, there is no repetition of reading and writing of an image, and a relatively low-speed memory can be realized.

As described above, in order to take advantage of the characteristics of the respective decoding methods, when a high-quality enlarged image is required or when high-speed decoding is not particularly required, the fractal decoding unit 7 performs decoding. On the other hand, when high-speed processing is required or when the capacity of the first memory unit 4 is not sufficient, the image decoded by the image decoder unit 20 is simply enlarged (pixel repetition) or subjected to an interpolation operation. , And output to the second memory unit 21.

According to the third embodiment shown in FIG. 8, considering the feature of fractal decoding that requires a large amount of memory at the time of enlargement, high-speed decoding and enlargement are not necessary when high-quality enlargement is not required. Uses a decoded image obtained by decoding in the image decoder unit and, if a high-speed and large-capacity memory is installed, uses a high-quality enlarged image generated by the fractal decoding unit. , The resources of the decoder can be used effectively.

Next, a fourth embodiment according to the present invention will be described with reference to FIG. The fourth embodiment is different from the configuration of the first embodiment in that a character / graphic image generating unit 22 and an image synthesizing unit 23 are added.

That is, the iterative transform decoding apparatus shown in FIG. 9 includes a central control unit 1 as control means for controlling the entire apparatus, a fractal coded code, a character / graphic image, a plurality of reduced scale images or layers. A storage medium 2 such as a so-called CD-ROM or ROM cassette storing an image and a fractal coded code read from the storage medium 2 are input to enlarge the scaled image or the layer image at an arbitrary magnification. A fractal decoding unit 7 for generating a fractal decoded image by performing a fractal decoding (iterative conversion decoding) process on the reduced image, and enlarging a character / graphic image read from the storage medium 2 at an arbitrary magnification. Character / graphic image generation unit 22 as means for generating a reduced image
And an image synthesizing unit 23 for synthesizing the generated character / graphic image and the fractal decoded image, and a memory unit 4 for storing the synthesized image. I have. In addition, an interface unit 3 for inputting / outputting a command input, a control signal, and the like, a graphics interface unit 5 for outputting an image developed in the memory unit 4, and a graphics interface unit 5 connected to the graphics interface unit 5. A display controller 6 for displaying an image on a display such as a CRT (cathode ray tube).

Next, the operation will be described. The basic operation of the fourth embodiment shown in FIG.
This is the same as that described in the embodiment. Therefore, the following description focuses on the differences from the first embodiment.

In the fourth embodiment shown in FIG. 9, a CG image, a character image, a graphic image, and the like, which are usually weak in fractal coding, are realized by using another method. That is, in FIG. 9, the character / graphic information 130 read from the storage medium 2 is, for example, basic font information for a character, and information of coordinates and shapes constituting the graphic for a graphic. Since these can be easily described, it is obvious that they are generated by enlarging or reducing regardless of the resolution. For example, enlargement of a character frequently used in a word processor is generated by simply enlarging a basic font, for example, a black and white image in a 64 × 64 cell in accordance with the magnification.
In the case of a graphic image, by storing the relationship between sides and vertices constituting the graphic as vector data, the amount of information can be significantly reduced, and a high-quality graphic image can be obtained regardless of enlargement / reduction. The result is well known. Characters in the figure
The graphic image generation unit 22 is a part that performs the above processing. The character / graphic image 131 generated as a result is combined with the decoded image 103 decoded by the fractal decoding unit 7 in the image combining unit 23. The generated composite image 132 is developed in the memory unit 4 and displayed by the display control unit via the graphics interface unit 5 as described above.

According to the fourth embodiment of the present invention, a character / graphic image which is not good at fractal coding is generated by another component, and is finally combined with a fractal coded image. Therefore, a high-quality image can always be obtained.

Next, a fifth embodiment of the present invention will be described with reference to FIG. The fifth embodiment is different from the configuration of the first embodiment in that an image synthesizing unit 23 is added.

That is, the iterative transform decoding apparatus shown in FIG. 10 has a central control unit 1 which is a control means for controlling the whole apparatus, a fractal coded code, a plurality of scaled character / graphic images, A storage medium 2 such as a so-called CD-ROM or ROM cassette which stores a scaled image or a layer image, and a fractal coded code read from the storage medium 2 are input to the storage medium 2 so that A fractal decoding unit 7 which is means for generating a fractal decoded image by performing a fractal decoding (iterative transform decoding) process on an enlarged / reduced image at an arbitrary magnification;
An image synthesizing unit 2 for synthesizing the character / graphic image read from the storage medium 2 and the fractal decoded image
3 and a memory unit 4 as storage means for developing a synthesized image. In addition, an interface unit 3 for input / output of command input, control signal, and the like.
A graphics interface unit 5 for outputting an image developed in the memory unit 4; and a display control unit connected to the graphics interface unit 5 for displaying an image on a display unit such as a cathode ray tube (CRT). Part 6
And

Next, the operation will be described. The basic operation of the fifth embodiment shown in FIG. 10 is the same as that described in the first embodiment of FIG. Therefore,
The following description focuses on differences from the first embodiment.

In the fifth embodiment shown in FIG.
As described in the fourth embodiment, an enlarged image such as a character image, a graphic image, or the like, which is usually weak in fractal encoding, is realized without using the fractal decoding unit 7.
That is, in the fourth embodiment, an enlarged image such as a character image or a graphic image is generated by the character / graphic image generation unit 22, whereas in the fifth embodiment, the plurality of reduced scales are used. The character image and the graphic image are already stored and held in the storage medium 2, and when an image of a predetermined scale becomes necessary,
From this storage medium 2, an enlarged image having a magnification corresponding to the scale is read. The read character image and graphic image are
In the same manner as described above, the image is combined with the fractal decoded image 103 in the image combining unit 23, and the combined image 132 is developed in the memory unit 4.

According to the fifth embodiment shown in FIG. 10, each reduced-scale image of a character / graphic image which is not good at fractal coding is stored and held in a storage medium in advance, and if necessary, And read them out,
In addition to the effect of the embodiment, there is an effect that the generation unit of the character / graphic image can be omitted.

In the embodiment according to the present invention as described above, the fractal technique is used for compressing / expanding a scaled image having a plurality of layers, which is frequently used in a navigation map, a map figure, or the like. I do. This is because using fractal compression compared to the existing JPEG method,
A large compression ratio can be obtained, and a further great advantage is that an arbitrary zoom can be performed during decoding. Normally, in the navigation map, when the user zooms in (enlarges), the image is switched to a layer image of the next reduced scale at a certain place, but the zoom up to that point is a simple repetition of pixels, and there is no improvement in resolution. On the other hand, since the fractal decoding can generate pixels, there is an advantage that the resolution can be increased with zooming. Therefore, it is a main object of the embodiments of the present invention to improve the quality of the zoom image until the next layer image appears.

In the embodiment according to the present invention, a fractal encoded code is received by a storage medium such as a CD-ROM in which a bit stream or a plurality of kinds of scaled images or layer images are stored, and fractal decoding is performed. A fractal decoding unit for expanding the decoded image in the memory unit, a memory unit for expanding the decoded image, a graphics interface unit for sending the image output from the memory unit to the display control unit, and a display for controlling display The configuration includes a control unit and a central control unit that controls the entire system.

According to such a configuration, it is possible to generate an image between different scaled images already stored in the storage medium by fractal decoding involving enlargement / reduction. The image obtained at this time has an effect that the image quality is higher than that obtained by a conventionally used method. Also, since the fractal encoding code of the reduced scale image may be stored in the storage medium, there is an effect that the capacity of the storage medium can be saved as compared with the case where the image itself is stored.

According to the present invention, iterative transform coding is mainly used for iterative transform coding of maps, graphic images, and images having various layer structures, and storing the coded information in a storage medium (CD-ROM, hard disk, optical disk, etc.). Device and encoding information,
The present invention can be applied to an iterative transform decoder that decodes a map or a graphic image by decoding according to a predetermined zoom ratio, or a software module that realizes the same method. Applications include car navigation systems, map and figure searches on computers, image decompression and
Drawing and the like.

[0055]

According to the present invention, a fractal coded code and a fractal coded code read from a storage medium storing a plurality of reduced scale images or layer images are input to the reduced scale image or layer image. Fractal decoding is performed on the enlarged / reduced image at an arbitrary magnification between them to generate a fractal decoded image, and the fractal decoded image or the reduced scale image or the layer image read from the storage medium is developed in a storage unit. This makes it possible to generate an image between different scaled images already stored in the storage medium by fractal decoding involving enlargement / reduction, and the image obtained at this time has high image quality. Further, since the fractal encoding code of the reduced-scale image may be stored in the storage medium, the capacity of the storage medium can be reduced as compared with the case where the image itself is stored.

Further, an image encoding code is further stored in the storage medium, and the image encoding code read from the storage medium is decoded to generate a decoded image.
By expanding the generated decoded image in the second storage means, when high-speed decoding and expansion do not require high-quality expansion, the decoded image obtained by decoding in the image decoder unit is obtained. When a high-speed and large-capacity memory is mounted, adaptive processing of using a high-quality enlarged image generated by the fractal decoding unit is performed, so that the resources of the decoder can be effectively used.

Further, a character / graphic image is further stored in the storage medium, and an image obtained by enlarging / reducing the character / graphic image read from the storage medium at an arbitrary magnification is generated. By combining the image and the fractal decoded image, characters and characters that are not good at fractal encoding
By generating a graphic image by another component and finally combining it with a fractal-coded image, a high-quality image can always be obtained. In this case, each scaled image of the character / graphic image may be stored and held in a storage medium in advance, and read out as needed, so that the character / graphic image generation unit may be omitted.

According to the present invention, an image read from a storage medium storing a plurality of reduced scale images or layer images is fractally encoded to generate a fractal encoded code, and the generated fractal encoded code is generated. Is input, and the fractal decoding is performed by performing fractal decoding on the scaled image or the enlarged / reduced image at an arbitrary magnification between the layer images, and the fractal decoded image is read from the storage medium. By developing the reduced scale image or the layer image in the storage means, it is not necessary to previously store the fractal coding code of the reduced scale image in the storage medium, so that the time required for producing the storage medium can be saved and the storage capacity can be reduced. It can be used and saved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an iterative transform decoding device according to a first embodiment of the present invention.

FIG. 2 is a view showing a reduced-scale image having a layer structure stored in a storage medium.

FIG. 3 is a diagram showing a layer structure of a storage medium.

FIG. 4 is a flowchart illustrating a process of generating a fractal decoded image at a magnification between scaled images.

FIG. 5 is a block diagram illustrating a schematic configuration of an iterative transform coding / decoding device according to a second embodiment of the present invention.

FIG. 6 is a block diagram illustrating an example of a specific configuration of a fractal encoding unit.

FIG. 7 is a block diagram illustrating an example of a specific configuration of a fractal decoding unit.

FIG. 8 is a block diagram illustrating a schematic configuration of an iterative transform decoding device according to a third embodiment of the present invention.

FIG. 9 is a block diagram illustrating a schematic configuration of an iterative transform decoding device according to a fourth embodiment of the present invention.

FIG. 10 is a block diagram illustrating a schematic configuration of an iterative transform decoding device according to a fifth embodiment of the present invention.

FIG. 11 is a diagram showing mapping conversion between a domain block and a range block.

[Explanation of symbols]

Reference Signs List 1 central control unit, 2 storage medium, 3 interface unit, 4 fractal decoding unit, 5 memory unit, 6 graphics interface unit, 7 display control unit, 8 fractal encoding unit, 9 first
A block generator of 10; a second block generator;
11 control unit, 12 similarity measurement / threshold processing unit, 1
3 image conversion / generation unit, 14 block information storage unit,
15 encoding / multiplexing section, 16 demultiplexing section,
17 domain block generation unit, 18 image memory unit,
Reference Signs List 19 control unit, 20 image decoder unit, 21 second memory unit, 22 character / graphic image generation unit, 23
Image synthesis unit

Claims (11)

[Claims] 1. A fractal encoded code, a storage medium storing a plurality of reduced scale images or layer images, and a fractal encoded code read from the storage medium are input, and the fractal encoded code is read between the reduced scale images or the layer images. Fractal decoding means for performing fractal decoding of an enlarged / reduced image at an arbitrary magnification to generate a fractal decoded image; and developing the fractal decoded image or the reduced scale image or layer image read from the storage medium. An iterative transform decoding device, comprising: a storage unit for performing the above-mentioned operations; and a control unit for controlling each of the above units. 2. An image decoding unit that further stores an image encoding code in the storage medium, and that decodes the image encoding code read from the storage medium to generate a decoded image. 2. The iterative transform decoding device according to claim 1, further comprising: a second storage unit for expanding the decoded image. 3. An image generating means for further storing a character / graphic image in the storage medium, generating an image obtained by enlarging or reducing the character / graphic image read from the storage medium at an arbitrary magnification, An image synthesizing means for synthesizing the character / graphic image generated by the image generating means and the fractal decoded image, wherein the synthesized image by the image synthesizing means is developed in the storage means. Item 7. An iterative transform decoding device according to Item 1. 4. The storage medium further stores a plurality of scaled character / graphic images, and combines the fractal decoded image with the character / graphic image of an arbitrary scale read from the storage medium. 2. The iterative transform decoding device according to claim 1, further comprising an image synthesizing unit, wherein the image synthesized by the image synthesizing unit is developed in the storage unit. 5. The fractal decoding unit includes: a reference block generation unit that generates a reference block; an image conversion unit that converts an image in the reference block; and a storage unit that expands a converted image to a predetermined address. 2. The iterative transform decoding device according to claim 1, further comprising: control means for controlling the iterative conversion of a reference image. 6. The iterative transform decoding device according to claim 5, wherein the image transformation by said image transformation means is realized by affine transformation. 7. A fractal encoded code and a fractal encoded code read from a storage medium storing a plurality of reduced scale images or layer images are input, and an arbitrary magnification between the reduced scale image or the layer image is input. A fractal decoding step of performing a fractal decoding of the enlarged / reduced image to generate a fractal decoded image; and a step of expanding the fractal decoded image or the reduced scale image or the layer image read from the storage medium in a storage unit. And an iterative transform decoding method. 8. A storage medium storing a plurality of reduced scale images or layer images, fractal coding means for fractal coding an image read from the storage medium to generate a fractal coding code, and a fractal code Fractal decoding means for inputting the fractal coding code generated by the converting means, performing fractal decoding of the scaled image or an enlarged / reduced image at an arbitrary magnification between the layer images to generate a fractal decoded image, An iterative transform coding / decoding apparatus, comprising: storage means for expanding the fractal decoded image or the reduced scale image or the layer image read from the storage medium; and control means for controlling each of the means. . 9. The fractal encoding unit includes two different block image generation units, an image conversion unit that converts one block image, and measures an approximation degree between the converted block image and the other block image. And an approximation degree measurement / threshold processing means for performing threshold processing, and means for outputting an address of a block image having the largest degree of approximation and a conversion parameter at that time as a fractal encoded code. 9. The iterative transform coding / decoding device according to claim 8, wherein 10. The fractal decoding unit includes: a reference block generation unit that generates a reference block; an image conversion unit that converts an image in the reference block; and a storage unit that expands a converted image to a predetermined address. 9. The iterative transform coding / decoding apparatus according to claim 8, further comprising: control means for performing control for repeatedly performing image conversion processing of a reference image. 11. A fractal encoding step of fractally encoding an image read from a storage medium storing a plurality of reduced scale images or layer images to generate a fractal encoded code; A fractal decoding step of inputting the fractal encoded code and performing fractal decoding of the scaled image or the scaled image at an arbitrary magnification between the layer images to generate a fractal decoded image; Developing the image or the reduced scale image or the layer image read from the storage medium in the storage means.