WO2000025232A1

WO2000025232A1 - Method and array for coding, decoding, and transmitting a digitized image

Info

Publication number: WO2000025232A1
Application number: PCT/DE1999/003177
Authority: WO
Inventors: Thomas Riegel
Original assignee: Siemens Aktiengesellschaft
Priority date: 1998-10-23
Filing date: 1999-10-01
Publication date: 2000-05-04

Abstract

The invention relates to methods and arrays for coding and decoding a digitized image and to a method for transmitting said digitized image having image points containing coding information. To this end, the image is subdivided into image blocks. The image block is then subdivided into a corresponding first subimage block and a corresponding second subimage block. The subimage blocks are coded usingcoding information with form-adapted transformation coding. The coded image is then transmitted and decoded by carrying out decoding inversely in relation to coding.

Description

description

METHOD AND ARRANGEMENT FOR CODING, DECODING AND TRANSMITTING A DIGITALIZED IMAGE

The invention relates to an arrangement and a method for coding a digitized image and to an arrangement and a method for decoding a digitized image and to a method for transmitting a digitized image, the coding using a transform coding and the decoding using a inverse transformation coding can be performed.

Such a method and such an arrangement for encoding a digitized image and such a method and such an arrangement for decoding a digitized image are based on one of the image coding standards H.261 [1], H.263 [2] or MPEG2 [3] based on the principle of block-based image coding. For block-based image coding, the method of a block-based discrete cosine transformation (DCT) is used according to [3].

Another approach to image coding according to the MPEG4 image coding standard is the so-called principle of object-based image coding, as is known from [3].

In object-based image coding, an image template is segmented into image blocks corresponding to objects occurring in a scene and these objects are separately encoded. Components of a customary arrangement for image coding, as are also known from [7], and image decoding can be seen in FIG.

FIG. 7 shows a camera 701 with which images are recorded. The camera 701 can be, for example, any analog camera 701, which records images of a scene and either digitizes the images in the camera 701 and transmits the digitized images to a first computer 702, which is coupled to the camera 701, or else the images analog to the first computer 702. In the first computer 702 either the digitized images are processed or the analog images are converted into digitized images and the digitized images are processed.

The camera 701 can also be a digital camera 701, with which directly digitized images are recorded and fed to the first computer 702 for further processing.

The first computer 702 can also be designed as an independent arrangement with which the method steps described below are carried out, for example as an independent computer card that is installed in a further computer.

The first computer 702 is generally to be understood as a unit that can carry out image signal processing in accordance with the method described below, for example a mobile terminal (cell phone with a screen).

The first computer 702 has a processor unit 704 with which the method steps of image coding and image decoding described below are carried out. The Processor unit 704 is coupled, for example, via a bus 705 to a memory 706, in which image information is stored.

In general, the methods described below can be implemented both in software and in hardware or also partly in software and partly in hardware.

After image coding in the first computer 701 and after transmission of the coded image information via a transmission medium 707 to a second computer 708, the image decoding is carried out in the second computer 708.

The second computer 708 can have the same structure as the first computer 701. The second computer 708 thus also has a processor 709 which is coupled to a memory 710 by a bus 711.

FIG. 8 shows a possible arrangement in the form of a basic circuit diagram for image coding or image decoding. The arrangement shown can be used in the context of block-based and in part, as explained in more detail below, in the context of object-based image coding.

In block-based image coding, a digitized image 801 is divided into usually square image blocks 820 of size 8x8 pixels 802 or 16x16 pixels 802 and fed to the arrangement 803 for image coding.

Coding information is usually uniquely assigned to a pixel 802, for example brightness information (luance values) and / or color information (chrominance values). With block-based picture coding, a distinction is made between different picture coding modes.

In a so-called intra-picture coding, the digitized picture 801 is coded and transmitted with the coding information assigned to the pixels 802 of the digitized picture 801.

In a so-called inter-picture coding, only differential picture information of two successive digitized pictures 801 is coded and transmitted.

The difference information is only very small if movements of image objects in the temporally successive digitized images 801 are small. If the movements are large, there is a lot of difference information that is difficult to code. For this reason, as is known from [3], an "image-to-image" movement (motion estimation) is measured and compensated for before the difference information is determined (motion compensation).

There are different methods for motion estimation and motion compensation, as they are known from [3]. A so-called "block matching method" is mostly used for block-based image coding. It is based on the fact that a picture block to be coded is compared with reference picture blocks of the same size of a reference picture. The criterion for a match quality between the block to be coded and a reference picture block in each case is usually the sum of the absolute differences in coding information which is assigned to each picture element. In this way, movement information for the image block, for example a movement vector, is determined, which is transmitted with the difference information. Two switch units 804 are provided for switching between the intra-picture coding and the inter-picture coding. To carry out the inter-picture coding, a subtraction unit 805 is provided, in which the difference in picture information between two successive digitized pictures 801 is formed. The image coding is controlled by an image coding control unit 806. The picture blocks 820 or difference picture blocks to be coded are each fed to a transformation coding unit 807. The transformation coding unit 807 applies a transformation coding, for example a discrete cosine transformation (DCT), to the coding information assigned to the pixels 802.

In general, however, any transformation coding, for example a discrete sine transformation or a discrete Fourier transformation, can be used for image coding.

Spectral coefficients (transformation coefficients) are formed by the transformation coding. The spectral coefficients are quantized in a quantization unit 808 and fed to an image coding multiplexer 821, for example for channel coding and / or entropy coding. In an internal reconstruction loop, the quantized spectral coefficients are inversely quantized in an inverse quantization unit 809 and subjected to inverse transformation coding in an inverse transformation coding unit 810.

Furthermore, in the case of inter-picture coding, picture information of the respective temporally preceding picture is added in an adding unit 811. The images reconstructed in this way are stored in a memory 812. A unit for the motion compensation 813 is symbolically represented in the memory 812 for the sake of simplicity.

A loop filter 814 is also provided, which is connected to the memory 812 and the subtraction unit 805.

In addition to the transmitted image information 822, the mode coding multiplexer 821 is supplied with a mode index, which is used to indicate whether intra-picture coding or inter-picture coding has been carried out.

Furthermore, quantization indices 816 for the spectral coefficients are supplied to the image coding multiplexer 821.

A motion vector is assigned to an image block 820 and / or a macro block 823, which has four image blocks 820, for example, and is supplied to the image coding multiplexer 821.

Furthermore, information is provided for activating or deactivating the loop filter 814. After the image information has been transmitted via a transmission medium 818, the transmitted information can be decoded in a second computer 819. For this purpose, an image decoding unit 825 is provided in the second computer 819, which for example has the structure of a reconstruction loop of the arrangement shown in FIG. 8.

From [4] a shape-adapted transformation coding is known, such as is used in particular in the context of object-based picture coding on edge picture blocks or picture blocks which contain only partially relevant coding information. The edge image blocks coded using a form-adapted transformation coding are characterized by by from the fact that only the pixels are coded that a

Are assigned to the object or have coding information relevant to the object.

The method described in [4] is a so-called shape-adjusted discrete cosine transformation (Shape Adaptive DCT, SA-DCT).

In the context of an SA-DCT, the DCT transformation coefficients assigned to an image object are determined in such a way that

Pixels of a border image block that do not belong to the image object are hidden. A one-dimensional DCT, the length of which corresponds to the number of remaining pixels in the respective column, is then first applied to the remaining pixels. The resulting DCT transformation coefficients are aligned horizontally and then subjected to a further one-dimensional DCT in the horizontal direction with the appropriate length.

The SA-DCT regulation known from [4] is based on a DCT-N transformation matrix with the following structure:

1 π

DCT - N (p, k) = γ * cos, * ι k + - * - (i:

2) N with p, k = 0 → N-l.

N denotes a size of the image vector to be transformed, in which the transformed pixels are contained.

DCT-N denotes a transformation matrix of size NxN.

With p, k, indices are designated with p, ke [0, N-1]. After the SA-DCT, each column of the image block to be transformed is made according to the regulation

transformed vertically. The same rule is then applied to the resulting data in the horizontal direction.

Various methods are used in computer graphics to display an object on a screen. One method of representing an object is the so-called texture mapping.

Such a texture mapping is known from [5].

In the context of texture mapping, a digital image is generated which contains a brightness information (luminance values) and / or a

Contains color information (chrominance values) of the object to be displayed, mapped onto a surface of a three-dimensional model of an object to be displayed.

The three-dimensional model 301 of the object to be displayed, which model 301 is shown in FIG. 3, consists of a spatial triangular lattice structure 301, the corner points 302 of the triangles 303 being present as points 304 of a Cartesian coordinate system 305.

As is shown in FIG. 3, each triangle 303 is assigned a so-called block-shaped structure card 306, which is made up of rectangular or block-shaped pixels 307. Each pixel 307 is more common - assign brightness information (luminance values) and / or color information (chrominance values).

The triangle 303 is assigned the brightness or color information in such a way that an associated image point 307 of the associated structure map 306 is assigned to a corner point 302 and 308 of the triangle 303 and 309.

The position of a corner point 308 of the triangle 309 is determined by specifying coordinates (ui, vj_) 310 in a two-dimensional one

Coordinate system (u, v) 311, which is assigned to the structure map 306. The coordinates (u_, vi) 310 are usually standardized.

Each corner point 302 of each triangle 303 of the three-dimensional model 301 is assigned the corresponding point 310 in the associated structure map 306 via a transformation rule (assignment).

Furthermore, as shown in FIG. 4, all structure maps 401 are combined to form a digitized image 402, a so-called super structure map 402, by arranging the individual structure maps 401 in rows and columns. If necessary, the structure cards 401, which contain coding information relevant for the representation of the object, must be supplemented with structure cards 404, which contain no coding information relevant for the representation of the object.

However, the method described above has a particular disadvantage. The structure maps and also the super structure map have image points that do not contain any brightness or color information relevant for the representation of the object. If the superstructure card is encoded as part of an image transmission, the data rate occurring during the transmission is unnecessarily increased by the irrelevant pixels.

To improve the method described above, a structure map is processed in the following way (see FIG. 5):

Those pixels 501 of a structure map 502 which

Pixels containing coding information relevant to the representation of the object are transformed into a new triangular structure map 503 with pixels 506, which are arranged in a predetermined shape, which is usually a right-angled triangle, and in a predetermined size. The transformation is carried out in such a way that the pixels 501, which are corner pixels 504 of the triangle 505, coincide with pixels 506, which are corner pixels 507 of the triangular structure map 503.

In the course of the transformation, pixels may have to be generated by extrapolation or interpolation of values which contain brightness or color information, or pixels may have to be deleted.

The triangular structure map 503 thus only has pixels 506 which are relevant for the representation of an object.

As shown in FIG. 6, all triangular structure maps 601, which contain brightness or color information relevant to the representation of the object, are arranged to form a new super structure map 602. For this purpose, two triangular structure cards 601a and 601b are arranged to form a block-shaped structure card 603.

Furthermore, all block-shaped structure cards 603 are grouped in rows and columns, with which a digitized image is generated.

It is also known from [5] that such a superstructure map, as it is generated in the context of texture mapping, is encoded and decoded during image transmission.

The coding and / or decoding of a superstructure card is usually carried out using a block-oriented transformation in the intra-picture coding mode, as described above.

This procedure is not very efficient with regard to a lower data rate to be targeted for transmission or a higher image quality.

The invention is therefore based on the problem of specifying a method for image coding and a method for image decoding and an arrangement for image coding and an arrangement for image decoding as well as a method for transmitting a digitized image with which more efficient coding and decoding and transmission of a digitized image can be achieved Picture becomes possible.

The problem is solved by the method with the features according to the independent claims and the arrangements with the features according to the independent claims.

In the method for coding a digitized picture with pixels that contain coding information, the picture is at least partially divided into picture blocks. Furthermore, an image block is subdivided into at least a first sub-image block and a second sub-image block. The sub-picture blocks determined in this way are encoded using the encoding information using a shape-adapted transformation encoding.

In the method for decoding a digitized picture with pixels that contain coding information, coded sub-picture blocks are identified. The coded sub-picture blocks are decoded using the coding information using an inverse shape-adapted transformation coding. An associated image block is formed using at least two of the associated sub-image blocks. Furthermore, the image is formed using the image blocks.

In the arrangement for coding a digitized image with pixels which contain coding information, a processor is provided which is set up in such a way that the following method steps can be carried out as part of the coding:

The image to be encoded is at least partially divided into image blocks. One image block is divided into at least a first sub-image block and a second sub-image block. The sub-picture blocks determined in this way are encoded using the encoding information using a shape-adapted transformation encoding.

In the arrangement for decoding a digitized image with pixels which contain coding information, a processor is provided which is set up in such a way that the following method steps can be carried out:

Coded sub-picture blocks are identified. The encoded sub-picture blocks are encoded using the encoding formation is decoded with an inverse shape-adapted transformation coding. An associated image block is formed using at least two of the associated sub-image blocks. The image is formed using the image blocks.

In the method for transmitting a digitized image with pixels that contain coding information, the image is encoded. As part of the coding, the image is at least partially divided into image blocks. Furthermore, in the context of the coding, an associated image block is subdivided into at least one associated first sub-image block and an associated second sub-image block. The sub-picture blocks are encoded using the encoding information with a conformal transform encoding. The encoded picture is transmitted. Furthermore, the encoded image is decoded using a method inverse to the encoding.

The particular advantage of the invention is that specially adapted methods for coding and decoding a digital image are used which take into account the special structure of the digital image. This achieves efficient coding and decoding of the digitized picture with regard to a low data rate to be aimed at for transmission or a larger amount of transferable coding information for better picture quality.

Preferred developments of the invention result from the dependent claims.

In a further development, the first sub-picture block and / or the second sub-picture block have a different shape than the picture block. By using a form-adapted transformation coding for coding or an inverse matched transformation coding for decoding an efficient coding and / or decoding is possible.

A further advantage is obtained if the first sub-picture block and / or the associated second sub-picture block have a triangular shape. In this case, the use of a shape-adaptive discrete cosine transformation (SA-DCT) for coding and / or the use of an inverse shape-adaptive discrete cosine transformation (SA-DCT) for decoding leads to an increase in the efficiency of the Coding and / or decoding.

It is particularly advantageous if the triangular shape has a right angle. This means that by using a triangle-adaptive discrete-cosmos transformation (TA-DCT) as part of the coding or by using an inverse triangle-adaptive discrete-cosmos transformation (TA-DCT) as part of the decoding, an extremely efficient coding is achieved and / or decoding possible.

In a further embodiment, the first sub-picture block or the second sub-picture block is changed such that the relative position of the associated first sub-picture block with respect to the associated picture block and the relative position of the associated second sub-picture block with respect to the associated picture block is identical. It is thus possible to use an identical, form-adapted transformation coding for the coding of the first sub-picture block and for the coding of the second sub-picture block.

A further development can advantageously be used for the coding and / or decoding of a triangular structure card. Since such a structure map has triangular sub-picture blocks, the use of a triangle-adaptive discrete-cosmus transformation (TA-DCT) in the context of the coding or the use of an inverse triangle-adaptive discrete-cosmus transformation (TA-DCT ) in the An extremely efficient coding and / or decoding is possible within the framework of the decoding.

An exemplary embodiment of the invention is shown in figures and is explained in more detail below.

Show it:

1 shows an arrangement for image coding and image decoding with a picture of an object by means of a camera and a representation of the object on a screen

Figure 2 Schematic representation of the procedure for image coding and decoding with an image of an object by means of a camera and a representation of the object on a screen Figure 3 triangular lattice structure of the three-dimensional model with an associated structure map

Figure 4 representation of a superstructure map

FIG. 5 shows a transformation of a structure map to a triangular structure map. FIG. 6 shows a super structure map consisting of triangular structure maps

Figure 7 Arrangement for image coding or decoding with a camera, two computers and a transmission medium. Figure 8 Sketch of an arrangement for block-based image coding or image decoding

Figure 9 shows the breakdown of the block-shaped structure map

FIG. 1 shows an arrangement for image coding and image decoding with a picture of an object by means of a camera and a representation of the object on a screen. FIG. 1 shows a camera 101 with which images of an object 152 are recorded. The camera 101 is an analog color camera, which records images of the object 152 and transmits the images in analog form to a first computer 102. In the first computer 102, the analog images are converted into digitized images, wherein pixels of the digitized images contain color information of the object 152, and the digitized images are processed.

The object 152 is centered on a slide 153. The relative position of the slide 153 with respect to the camera 101 is fixed. By rotating the object carrier 153 around its center, the object 152 can be moved in such a way that the viewing angle at which the camera 101 takes up the object 152 changes continuously when the object 152 remains at a constant distance from the camera 101.

The first computer 102 is designed as an independent arrangement in the form of an independent computer card, which is installed in the first computer 102, with which computer card the method steps described below are carried out.

The first computer 102 has a processor 104 with which the method steps of image coding described below are carried out. The processor unit 104 is coupled via a bus 105 to a memory 106 in which image information is stored.

The method for image coding described below is implemented in software. It is stored in memory 106 and executed by processor 104.

After image coding in the first computer 101 and after transmission of the coded image information via a Transmission medium 107 to a second computer 108, the image decoding is carried out in the second computer 108. Then, using the decoded image information of the object 152, a model of the object 152 is displayed on a screen 155 linked to the second computer 108.

The second computer 108 has the same structure as the first computer 101. The second computer 108 also has a processor 109, which processor is coupled to a bus 110 with a memory 110.

The method described below for image decoding is implemented in software. It is stored in the memory 110 and is executed by the processor 109.

FIG. 2 schematically shows the procedure for coding and decoding with the recording of an object by means of a camera and the representation of the object on a screen.

This procedure for coding and decoding is implemented by the arrangement shown in FIG. 1 and the arrangement described above.

Step 1 recording the object (201)

Using the camera 101, as described in [7], images of the object 152, which is rotated in a predetermined rotation angle by means of the object holder 153 in its position with respect to the camera 101, are recorded. The images are transmitted in analog form to the first computer 102.

Before the object 152 is recorded, the

Camera 101, as described in [7], calibrated, whereby a spatial geometry of the arrangement and the Aufnahmepa ^¬ parameters of the camera 101, for example, the focal length of the camera 101 are determined.

The geometry data and the camera parameters are transmitted to the first computer 102.

2. Digitize the images (202)

In the first computer 102, the analog images are converted into digitized images 103 and the digitized images 103 are processed.

3.Image editing (203)

The processing of the digitized images 103 takes place according to the method of automatic three-dimensional modeling using several images of an object, as described in [7].

As part of the process of automatic three-dimensional modeling using several images of an object, two process steps are carried out:

In the first step of the method, a volume model 301 of the object 152 is determined by means of a method for determining a contour of an object in a digitized image, as mentioned in [7], using the camera parameters and the digitized images 103.

The volume model 301 of the object 152, as shown in FIG. 3, consists of a spatial triangular lattice structure 301, the corner points 302 of the triangles 303 being present as points 304 of a Cartesian coordinate system 305. In the second step of the method, a so-called structure map 306 is determined for each triangle 303 using the digitized images 103 and the color information contained in pixels of the digitized images 103.

The structure map is constructed from pixels 307 arranged in block form. Each pixel 307 contains color information (chrominance values) of the object 152.

The color information is assigned to the triangle 303 in that an associated image point 307 of the associated structure map 306 is assigned to a corner point 302 and 308 of the triangle 303 and 309.

The position of a corner point 308 of the triangle 309 is determined by the

Specification of coordinates (UJ_, VJ_) 310 in a two-dimensional

Coordinate system (u, v) 311, which is assigned to the structure map 306. Then the coordinates (UJ_, V_) 310 are standardized.

Each corner point 302 of each triangle 303 of the three-dimensional model 301 is assigned the corresponding point 310 in the associated structure map 306 via a transformation rule.

Those pixels 501 of a structure map 502 which pixels contain color information relevant to the representation of the object 152 are transformed into a new triangular structure map 503. The pixels 506 of the triangular structure card are arranged such that they form a right-angled and isosceles triangle, one leg having five pixels. The transformation is carried out so that the pixels 501, which are corner pixels 504 of triangle 505, correspond to pixels 506, which are corner pixels 507 of triangular structure map 503.

As part of the transformation, pixels may have to be generated by extrapolation or interpolation of values that contain the color information, or pixels may have to be deleted.

The triangular structure map 503 thus only points

Pixels 506 that are relevant for the representation of an object.

As shown in FIG. 6, all triangular structure maps 601, which contain the color information relevant for the representation of the object, are arranged to form a new super structure map 602.

For this purpose, two triangular structure cards 601 are arranged to form a block structure card 603. Furthermore, all block-shaped structure cards 603 are grouped row and column, whereby a digitized image is generated.

Due to the uniform and predetermined shape of the triangular structure map 601, the row and column arrangement of the block-shaped structure map 603 and a predetermined size of the super structure map 602, there is a simplified transformation rule or a simplified assignment key, which is referred to as texture binding:

Each triangle 303 of the spatial triangular lattice structure 301 of the three-dimensional model of the object 152 has a first value ns that corresponds to the column number of the Triangle 303 associated triangular structure map 601 within superstructure map 602, a second value nz indicating the line number of triangular structure map 601 associated with triangle 303 within superstructure map 602, and a third value

which indicates the relative position of the triangular structure map 601a or 601b with respect to the block-shaped structure map 603.

Using the spatial for each triangle 303

Grid structure 301 of specified triples (n _$ , nz, nx,) and of the specified values with regard to the height H (number of pixels, for example 80 pixels) and the width B (number of pixels, for example 80 pixels) of the superstructure map with the Size HxW and the predetermined number of pixels Z, for example Z = 5 pixels, arranged in one leg of the right-angled and isosceles triangle, an assignment of a triangular structure map 601 of the superstructure map 602 to the associated triangle 303 of the volume model 301 of the object is determined according to the following relationships :

A _x = (Z / B) * (n _s -1)

A _y = (Z / H) * (n _Z -l)

B _x = (Z / B) * n _S

B _y = Ay

^c x ^{= B} x

C _y = (Z / H) * n _z

Dx = A _x D _v = C,

The corner pixels (Ax, Ay), (Cx, Cy) and (Dx, Dy) are relevant for the value nL = 0, which describes a triangular structure map 601a arranged on the left within the block-shaped structure map 603.

For the value n, = 1, which describes a triangular structure map 601b arranged on the left within the block-shaped structure map 603, the corner points (A _x , Ay), (C _{X /} Cy)

and (B _x , By) relevant.

The two values, which are identified by the index x and the index y, indicate the coordinates of a point on the superstructure map 602 with respect to a Cartesian coordinate system 610 which is arranged on the upper left corner 611 of the superstructure map 602.

4.Coding (204)

A so-called triangle-adaptive discrete-cosmos transformation (SA-DCT) is used for coding the superstructure card 602. This method for coding a digitized image is based on the method of a shape-adaptive discrete-cosmos transformation (SA-DCT), as described in m [4].

In the context of a TA-DCT, the transformation coefficients assigned to an image object are determined in such a way that pixels of a boundary image block that do not belong to the image object are hidden. A one-dimensional DCT, the length of which is the number of the remaining pixels, is then first applied to the remaining pixels in the respective column. The resulting

Transformation coefficients are then subjected to a further one-dimensional DCT in the horizontal direction with a corresponding length.

The TA-DCT process is based on a DCT-N transformation matrix with the following structure:

11π

DCT - N (p, k) = γ * cos * ι k + - 2) * -N with p, k = 0 → N-l.

DCT-N denotes a transformation matrix of size NxN.

With p, k, indices are designated with p, k e [0, N-1].

According to the TA-DCT, each column of the image block to be transformed is in accordance with the regulation

cj = (2)

As part of the coding of a superstructure card 602 using the TA-DCT, the superstructure card 602 is divided into the block-shaped structure cards 603. A block-shaped The structure card 603 and 901 will be converted into a first new one

902 and the second new block-shaped structure map 903, as shown in FIG. 9, are divided so that the pixels of the second triangular structure map 601b and 904 are deleted for the determination of the first new block-shaped structure map 602. The second new block-shaped structure map 903 is determined by deleting the pixels of the first triangular structure map 601a and 905.

Furthermore, the second new block-shaped structure map 903 is changed by moving pixels 906 such that the relative position of the pixels 906 of the second block-shaped structure map 903 with respect to the second new block-shaped structure map 903 with the relative position of the pixels 907 of the first new block-shaped structure map 902 with respect to the first new block-shaped structure map 902.

The TA-DCT can thus be applied accordingly to the first new block-shaped 902 and to the second new block-shaped structure card 903.

Due to the special relative position of the pixels 906 and 907 with respect to the first new block-shaped 902 and the second new block-shaped structure card 903, the TA-DCT can be used.

5th transmission (205)

The image information coded using the TA-DCT (image information of the superstructure map) is combined with data of the volume model of the object and the assignment (n _$ , nz, nχ,) χ (i = 1 ... N, with N = number of triangles the lattice Structure of the volume model) to the second computer 108 via a transmission medium 107.

6. Decoding (206)

After the coded image information has been transmitted, image decoding is carried out.

For this purpose, the spectral coefficients cj are fed to an inverse TA-DCT.

In the case of the inverse TA-DCT in the context of image coding in the intra-image coding mode, pixels XJ are made from the spectral

coefficients cj formed according to the following rule (4):

2 i 3 * [DCT - N (p, k)], -1

X "* Cj (4)

whereby the transformation matrix DCT-N has the following structure:

1) π

DCT - N (p, k) = γ * cos p * | k + - * - ¹ 2 / N with p, k = 0 → Nl.

where with:

N denotes a size of the image vector to be transformed, in which the pixels to be transformed are contained;

- [DCT-N (p, k)] denotes a transformation matrix of size NxN;

- p, k indices are denoted by p, ke [0, Nl]; - () ^_1 denotes an inversion of a matrix.

The decoded image or the superstructure map 602 is determined using the ascertained pixels XJ.

7. Presentation of the object (207)

Using the superstructure map, the data of the solid model of object 152 and the assignment (ns, n, nχ,) χ (i = 1 ... N, with N = number of triangles of the lattice structure of the solid model), as described in [ 6], the model of the object 152 is shown on the screen 108.

The following documents were cited in the context of this document:

[1] D. Le Gall, "The Video Compression Standard for Multimedia Applications", Communications of ACM, Vol. 34, No. 4, pp. 47-58, April 1991

[2] G. Wallace, "The JPEG Still Picture Compression Standard," Communications of ACM, Vol. 34, No. 4, pp. 31-44, April 1991

[3] De Lameillieure, J., et al. , "MPEG-2 image coding for digital television", in TELEVISION AND CINEMA TECHNOLOGY, 48th year, No. 3/1994, 1994

[4] T. Sikora, B. Makai, "Shape Adaptive DCT for Generic Coding of Video", IEEE Transactions on Circuits and Systems for Video Technology, Vol. 5, pp. 59-62, Feb. 1995

[5] JD Foley, et al. "Computer graphics: principles and practice", 2 ^nd ed, Adison-Wesley, ISBN 0-20112110-7, p 741-744.

[6] PANORAMA technical support, available on October 12, 1998 at: http: //www.tnt.uni- hannover.de/project/eu/panorama/TS .html

[7] W. Niem, et al. , "Mapping texture fro multiple Camera Views onto 3D Object Models for Computer Animation", Proc. Of International Workshop on Stereoscopic and Three Dimensional Imaging, 6-8.9.1998, Santorini, Greece, 1998

Claims

claims

1. Method for coding a digitized picture with pixels which contain coding information, a) in which the picture is at least partially divided into picture blocks; b) in which an associated image block is subdivided into at least one associated first sub-image block and an associated second sub-image block; c) in which the sub-picture blocks are encoded using the encoding information using a shape-adapted transformation encoding.

2. The method of claim 1, wherein the associated picture block is divided into a plurality of associated sub-picture blocks.

3. The method of claim 1 or 2, wherein the associated first sub-picture block or the associated second sub-picture block has a different shape than the associated picture block.

4. The method of claim 1 or 2, wherein the associated first sub-picture block and the associated second sub-picture block have a different shape than the associated picture block.

5. The method according to any one of claims 1 to 4, wherein the associated first sub-picture block or the associated second sub-picture block has a triangular shape.

6. The method according to any one of claims 1 to 4, wherein the associated first sub-picture block and the associated second sub-picture block have a triangular shape.

7. The method according to claim 5 or 6, wherein the triangular shape has a right angle.

8. The method according to any one of claims 1 to 7, in which the associated first sub-picture block or the second associated sub-picture block are changed such that the relative position of the associated first sub-picture block with respect to the associated picture block and the relative position of the associated second sub-picture block with respect to the associated picture block is identical.

9. The method according to any one of claims 1 to 8, in which a form-adapted discrete cosmos transformation (DCT) is used for coding.

10. The method according to claim 9, in which a shape-adaptive discrete cosmos transformation (SA-DCT) is used for coding.

11. The method according to claim 10, in which a triangle adaptive discrete cosine transformation (TA-DCT) is used for coding.

12. The method according to any one of claims 1 to 11, wherein the image has at least partially triangular structure cards.

13. A method for decoding a digitized picture with pixels which contain coding information, a) in which coded sub-picture blocks are identified; b) in which the coded sub-picture blocks using the coding information with an inverse shape-matched

Transform coding to be decoded; c) in which an associated image block is formed using at least two of the associated sub-image blocks; d) in which the image is formed using the image blocks.

14. The method according to claim 13, wherein the associated image block is formed from a plurality of associated sub-image blocks.

15. The method according to claim 13 or 14, in which an inverse shape-adapted discreet-cosine transformation (DCT) is used for decoding.

16. The method according to claim 15, in which an inverse shape-adaptive discreet-cosine transformation (SA-DCT) is used for the decoding.

17. The method according to claim 16, in which an inverse triangle-adaptive discrete-cosine transformation (TA-DCT) is used for the decoding.

18. Arrangement for coding a digitized image with pixels that contain coding information, in which a processor is provided which is set up in such a way that the following method steps can be carried out: a) the image is at least partially divided into image blocks; b) an associated image block is subdivided into at least one associated first sub-image block and an associated second sub-image block; c) the sub-picture blocks are encoded using the encoding information with a shape-adapted transform encoding.

19. The arrangement as claimed in claim 18, in which the associated image block can be subdivided into a plurality of associated sub-image blocks.

20. Arrangement for decoding a digitized image with pixels that contain coding information, in which a processor is provided which is set up in such a way that the following method steps can be carried out: a) coded sub-picture blocks are identified; b) the coded sub-picture blocks are converted using the coding information with an inverse shape

Transformation coding decoded; c) using at least two of the associated sub-picture blocks, an associated picture block is formed in each case; d) the image is formed using the image blocks.

21. The arrangement as claimed in claim 20, in which the associated image block can be formed from a plurality of associated sub-image blocks.

22. Method for transmitting a digitized image with pixels which contain coding information, a) in which the image is coded in the following way:

- The picture is at least partially divided into picture blocks;

an associated image block is subdivided into at least one associated first sub-image block and an associated second sub-image block;

- The sub-picture blocks are encoded using the coding information with a shape-adapted transformation coding; b) in which the coded image is transmitted; c) in which the encoded image is decoded using a method inverse to the encoding.

23. The method according to claim 22, in which the associated image block is divided into a plurality of associated sub-image blocks.