DE102005037388A1 - Code e.g. Reed-solomon code, decoding method, involves extracting partial information from cells that is to be decoded, where information is extracted by cell-tuple wise comparison of inversion cells with non-inversion cells - Google Patents

Abstract

The method involves extracting partial information from cells that is to be decoded. The partial information is extracted by cell-tuple wise comparison of inversion cells with non-inversion cells. The partial information is determined based on the comparison result. A link of inverting information with the inversion cell is determined based on the comparison result. A performance function is determined based on the comparison result. Independent claims are also included for the following: (1) a decoding device for information comprising a code (2) a receiver device with a decoding device (3) a code generated by a method for coding information (4) a storage medium with a code (5) a transmission protocol with a code (6) a labeling device with a coding method (7) a code carrier for identification purpose.

Description

The The invention relates to the channel decoding of signals on one-dimensional Signals (e.g., timing signals) as well as two-dimensional signals (e.g., images) as well as decoding equipment.

Very popular and common are Reed-Solomon (RS) codes. The decoding of RS codes is purely algebraic and very difficult for the engineer to understand and not vivid; There are no ready-made recipes for the integration of soft-decision methods. Do you want application-specific optimizations of an overall system Realize, so you have the well-known (algebraic) coding and Use decoding as a finished black box in the overall system; a System optimization can then only be realized around this box, truly interlocked modifications, e.g. in connection with the used modulation method, and the application-specific Integration of soft-decision methods are hardly possible in practice.

In Recently, the so-called turbo codes were introduced and successfully used. In Turbo Codes, two concatenated convolutional codes are separated by Interleaving, iterative using soft-in-soft-out Viterbi decoding decoded. Turbo codes can in certain cases surprisingly badly disturbed However, there are disadvantages to decoding signals: the iterative way of working leads to unpredictable computing time; Turbo codes require convolutional codes with infinite impulse response (IIR = infinite impulse response). Such codes carry the risk of catastrophic error propagation. Good convolutional codes can only computer-aided be designed; there are no systematic design methods for "good" convolutional codes (yes even the definition of a quality criterion is difficult). The effect of Turbo Codes is very difficult to see through, therefore, the design and the optimization are very much difficult.

General The object of the invention is a robust, technically easy to implement Decoding with associated Facilities available their mode of action is transparent in their individual steps is, so for the optimization of an overall system in different places application-specific Modifications possible are.

Specific Task is the integration of demodulation and decoding. Especially The data should be differentially valued for greater security against low-frequency signal fluctuations bring about.

Preliminary remarks to used here terms:

One Image is called a two-dimensional signal, a time signal as a one-dimensional signal. For one-dimensional signals, at which modulates the signal values according to several dimensions simultaneously are (for example amplitude and phase simultaneously or in quadrature amplitude modulation), is here spoken of distinguishing several feature dimensions (although these signals in the encoding literature are simply "multidimensional Signals "called become). A color image signal is accordingly as a two-dimensional Signal addressed, for example, in the three independent feature dimensions Color angle, saturation and intensity is modulated.

One Image can be preprocessed to a one-dimensional signal e.g. by scanning a barcode (1-D code).

One Matrix code is a two-dimensional array of cells, e.g. in the popular ECC-200 standard.

cell For image signals are small image areas of a few points, for example the (possibly pre-segmented) cells of a two-dimensional printed Matrix codes or the image content of small, evenly rasterizing the overall image Plots. The cells can also consist of only one pixel, then the term cell with identical to the term pixel.

The same applies to Time signals, where the cells through short signal sections and the Pixels are represented by individual signal values.

Cell values: Internal patterns of a cell (pixel pattern) are determined by cell values represents. For example, in a matrix code, a logical 0 cell (cell value 0) by a vertical bar and a logical 1 cell (cell value 1) be realized by a horizontal bar, the surface mass an otherwise unspecified patch (dot), or but simply by dark or bright pixels, different colors etc. cases with more than 2 possible Cell values are e.g. 1 for red, 2 for green, 3 for blue.

By Intermediate values can be expressed as well as the cells correspond to ideal pixel patterns.

The cell values correspond to the symbols of a conventional code. Since here, in contrast to conventional codes, intermediate values are also worked with intermediate values, this is the term used here used.

at several feature dimensions, the Cell values exist by dimension, but cell values can also represent several dimensions in summary.

The The object of the invention is achieved according to the independent claims.

advantageous Embodiments of the invention are in the subclaims described.

• – in konventioneller binärer Logik, oder
• – in mehrwertiger Logik, oder
• – in (mehrwertiger) Fuzzy-Logik.

In the claims reference is made to XOR links or case-dependent inversions; these operations (or corresponding circuits and gates) are to be understood in the general sense given below and further explained:

• - in conventional binary logic, or
• - in multivalued logic, or
• - in (multi-valued) fuzzy logic.

• A) durch teilinformationsweise Decodierschritte,
• B) dadurch, dass für mindestens einen Decodierschritt die Teilinformation aus zu decodierenden Zellen gewonnen wird durch zelltupelweisen Vergleich von Inversionszellen mit Nichtinversionszellen und vergleichsergebnisabhängiges Bestimmen der betreffenden Teilinformation,
• C) durch vergleichsergebnisabhängiges Verknüpfen einer Invertierungsinformation mit den Inversionszellen des betreffenden Decodierschrittes, sofern mindestens ein Decodierschritt gemäß B) nachfolgt.

According to the invention, therefore, a method is provided for decoding a code, wherein the information to be decoded can be represented by partial information and wherein the partial information is obtained from cells to be decoded,
marked

• A) by partial information decoding steps,
• B) in that, for at least one decoding step, the partial information from cells to be decoded is obtained by cell-cell-wise comparison of inversion cells with non-inversion cells and comparison-result-dependent determination of the relevant partial information,
• C) by comparing result-dependent linking of an inversion information with the inversion cells of the respective decoding step, provided that at least one decoding step according to B) follows.

Also provided according to the invention is a decoding device for information which can be represented by partial information, from a code in which cells are assigned cell values in each case,
marked by
a number of registers, each comprising register cells, at least one register for receiving the information to be decoded,
and wherein each register at least one register cell is decoding step by step in response to the decoded part information, preferably via XOR gates, wherein at least one invertible register cell is interpretable as an inversion cell of one or more cell tuples with inversion cells and non-inversion cells,
wherein the cells within each cell tuple are either only inversion cells or only non-inversion cells for each subsequent decoding step,
wherein the partial information can be obtained from register cells by cell-cell-wise comparison of inversion cells with non-inversion cells and comparison-result-dependent determination of the relevant partial information.

The The invention further comprises a receiving device with a decoding device according to the invention.

• a) teilinformationsweise Codierschritte,
• b) teilinformationsspezifische Einteilung der Zellen in Inversionszellen und Nichtinversionszellen, wobei jeder Teilinformation zumindest eine Inversionszelle zugeordnet ist
• c) zumindest ein teilinformationsspezifisches Zelltupel, wobei jedes Zelltupel aus mindestens einer Inversionszelle und mindestens einer Nichtinversionszelle besteht, wobei die Zellen innerhalb jedes Zelltupels für jeden vorangehenden Codierschritt entweder nur Inversionszellen oder nur Nichtinversionszellen sind.
• d) für mindestens einen Codierschritt: XOR-Verknüpfung der betreffenden Teilinformation mit den dieser Teilinformation aus b) zugeordneten Inversionszellen.

Furthermore, the invention also encompasses a code generated by a method for coding information that can be represented by partial information, in which cells are to be assigned cell values by the coding,
marked by

• a) partial information coding steps,
• b) partial information-specific division of the cells into inversion cells and non-inversion cells, wherein each partial information is assigned at least one inversion cell
• c) at least one partial information-specific cell tuple, each cell tuple consisting of at least one inversion cell and at least one non-inversion cell, wherein the cells within each cell tuple are either only inversion cells or only non-inversion cells for each preceding coding step.
• d) for at least one coding step: XOR linking of the relevant partial information with the inversion cells assigned to this partial information from b).

Of Furthermore, the invention comprises a storage medium on which data with a code according to the invention are stored.

Of Furthermore, the invention comprises a transmission protocol with a Code according to the invention.

Of Furthermore, the invention comprises a labeling device with a coding method for the Label with a code according to the invention, characterized that for signal modulation the width of bars or the size of dots or the color of dots or the size and color of Dots or the direction of bar elements is changeable.

Of Furthermore, the invention comprises a code carrier for identification purposes a code according to the invention.

Furthermore, the invention comprises a code reading device for an inventive code, characterized by an image recording device, in which at least one Bildaufnahmeparame ter, in particular lighting parameters, can be influenced via a quality measure which is dependent on an error pattern.

The Invention will be described with reference to the drawing. In the drawing demonstrate:

1 to 10 an example of the underlying coding method and

11 a hardware implementation for a simple example.

The Decoding method according to the invention can be apply to a code that is described by the following Method can be generated.

• a) teilinformationsweise Codierschritte,
• b) teilinformationsspezifische Zelltupelmengen, deren Zelltupel aus zweierlei Typen von Zellen bestehen, Inversionszellen und Nichtinversionszellen, wobei jedes Zelltupel aus mindestens einer Inversionszelle und mindestens einer Nichtinversionszelle besteht, wobei die Zellen innerhalb jedes Zelltupels für jeden vorangehenden Codierschritt entweder alle Inversionszellen oder alle Nichtinversionszellen sind,
• c) für mindesten einen Codierschritt: XOR-Verknüpfung der betreffenden Teilinformation mit den Inversionszellen der betreffenden Zelltupelmengen.

This method of encoding information represented by file information, whereby cells are to be assigned cell values by the encoding, comprises:

• a) partial information coding steps,
• b) partial information-specific cell tuple sets whose cell tuples consist of two types of cells, inversion cells and non-inversion cells, each cell tuple consisting of at least one inversion cell and at least one non-inversion cell, the cells within each cell tuple being either all inversion cells or all non-inversion cells for each preceding coding step,
• c) for at least one coding step: XORing the relevant partial information with the inversion cells of the respective cell tuple quantities.

Further embodiments of the coding procedure:

The Cell tuples can Cell pairs with an inversion cell and a non-inversion cell be.

The Cell values can Signal values, in particular pixel values of images, are assigned.

The Pixels can one of the binary ones Take values 0 or 1.

one Cell can be assigned to a plurality of pixels, wherein the pixels are the pixels of a Image or a sequence of images or the signal values of another Are signals, and the encoding method may be an association of pixel patterns to the cell values.

The Coding method may be a pre-made differential coding include the partial information processed first.

The Coding can XOR the result with a Patterns include, for images with a two-dimensional checkerboard pattern, for one-dimensional signals with a 101010 ... pattern.

The Coding method may further XOR the result with a Include random patterns.

A Coding device for a code that results from the coding method described above can, includes registers with cells that inverted in response to information bits can be preferably over XOR gate.

Of the Code that can be generated by the coding method described above is characterized by a placement of cells, each two different cell tuples with a cell tuple extent far from each other are placed separately, that they are at least one each Cell that is not part of this cell tuple is disconnected.

Of the Code may be further configured by placing the cells, in the pair of inversion and non-inversion cells of a cell tuple at most an intermediate cell are adjacent, preferably directly adjacent.

A Transmitting device using the coding method described above operates, includes a phase modulator for at least one feature dimension.

A transmission protocol with a code that results from the procedures described above is characterized by the addition of a fixed synchronization or referencing pattern, preferably in the form of a 010101 series of at least six cells.

The invention is first explained by means of a simple but instructive example, 1 to 10 ; Subsequently, based on the example, the procedure for generalization will be described, as well as special additives.

The example 1 to 10 comes from the field of image processing; the transfer of the following discussion to one-dimensional signals will be made in places where it may not be obvious.

Hardware solutions are based on a very simple example, 11 , explained.

example 1 to 10 : It should be an Infor mation, which can be represented with 10 bits, the information bits 1 to 10. In this example, the partial information is thus one bit each and 10 coding steps are required for each one bit.

(A other subdivision in sub-information would have, for example, with the possible Cell values 1, 2, 3; then you would be correspondingly fewer coding steps required. same for For example, if you combine two bits and four each potential Cell values works).

given Let be a two-dimensional image signal with 10 × 3 cells. The 30 cells should redundant for an encoding of the 10 information bits can be used. The cells consist in the example of individual binary pixels, possible cell values are initially 0 or 1.

The Arrangement of the cells does not necessarily have the final arrangement correspond; the for the data transfer or data storage (e.g., label with a dot code) Arrangement is usually of the arrangement discussed here differ because at the end there is still a scattered placement, similar to interleaving, carried out becomes (s.u.).

Also with time signals, it helps to think the cells wisely to arrange in a two-dimensional grid (auxiliary arrangements in higher dimensions are possible, have not been considered in the examples worked by the applicant useful). The underlying arrangement below is therefore only helpful for the following considerations and is usually subsequently changed, in particular through a scattered placement.

Encoding:

When Initialization will be the cell of the code to be created same basic value, e.g. 0, assigned.

We define a set M1 of cells, which in our example specifically includes all cells in 1 denoted by "i". The cells in M1 are now all inverted if the first information bit is 1; if it is 0 they are all not inverted. In other words, the cells in M1 are XORed to the first information bit (assuming the base value 0, this corresponds to a copy of I0 to the cells of M1). Cells of cell quantities treated in this way are referred to below as inversion cells and into the 1 to 10 represented by "i". By contrast, uninversion cells remain unchanged regardless of the value of the information bit 1 to 10 represented by "n".

It gives for each subinformation - and with it for each coding step a set of cell tuples, in short cell tuple amounts. A cell tuple consists of at least one inversion cell and at least a non-inversion cell.

There Define a total of 10 bits of information, we define still a total of 10 - 1 = 9 cell tuple amounts.

In In our example, each cell tuple consists of exactly one inversion cell and a non-inversion cell. Cell tuples are in the figures as double arrows between each one inversion cell and one non-inversion cell indicated.

In 2 the cell tuple M2 comprises 6 inversion cells and 6 non-inversion cells; Some cell tuples 1 are indicated by double arrows. There is no need to use any particular geometric system in choosing the distribution of inversion and non-inversion cells and in the choice of cell tuples, as indicated by the arrows. In principle, overlaps are also permitted in principle, ie one cell can belong to several cell tuplets.

The Inversion cells of M2 are XOR-linked to the second information bit. That if it already inverts due to the first information bit were inverted and now due to the second information bit will return to the original base value.

We come now to the third information bit and to the cell tuple quantity M3, see 3 , The amount M3 in our example includes exactly the same cells as M2.

In the choice of inversion cells and non-inversion cells again no special system needs to find use. However, when defining the cell pairs as of M3, an additional requirement must be observed (which is already fulfilled for M1 and M2 in each case):
The cells of a cell tuple must have all been treated the same in XOR operations of previous information bits, regardless of the current value of the preceding information bits. This is satisfied if they are either all inversion cells or all non-inversion cells for each preceding encoding step.

An illegal cell tuple in this sense is in 3 under the number 2 specified. It is illegal because its non-inversion cell has been inverted depending on the second information bit, but its inversion cell is not.

This regulation needed for the preceding In the example, their cells were always satisfied (all cells of M2 are in M1 cells inversion).

In the next step with information bit 4 and cell tuple quantity M4, see 4 , in the special choice of M4 we have again free choice of the cell pairs, as before in M2.

In the next step with information bit 5 and cell tuple quantity M5, see 5 , we again have the same situation with the special choice of M5 as with information bit 3 and cell quantity 3.

In the next step with information bit 6 and cell tuple quantity M6, see 6 , we again have the same situation with the special choice of M6 as with information bit 2 and cell quantity 2.

We come now to the information bits 7 to 10, with the cell tuple quantities M7 to M10, see 7 to 10 , Due to the special quantity selection and choice of inversion / non-inversion bit constellations, the requirement formulated for M3 for the first time is always fulfilled when the cells of a cell pair are stacked on top of each other.

The Partial information-specific division into cell tuple amounts, distribution in cell tuple and assignment of the inversion and non-inversion cells of a cell tuple is named in the following configuration and happens only once in advance, manually or with computer program.

The Encoding simply consists in applying the XOR operations to the Inversion cells according to the given configuration, partially informative, the order in which the partial information is assigned to the quantities be, basically indifferent is.

• a) sich mit jedem Informationsbit mindestens 5 Bits verändern
• b) bei Überkreuzungen von Inversionszellmengen (Rücksetzen des betreffenden Bits) mindestens zwei Informationsbits beteiligt sind, die selbst mehrere weitere Zellen invertieren.

The minimum distance of this code example is obviously 5 because

• a) change with each information bit at least 5 bits
• b) at crossovers of Inversionszellmengen (resetting the relevant bit) at least two bits of information are involved, which invert several more cells themselves.

By the addition of a parity bit to the information bits can Minimum distance generally increased.

Placement:

There geometrically seen the place where the cells of a cell pair sit, does not matter, but only the assignment to the quantities, have we still have the freedom to place the cells arbitrarily.

We to lead now a scattered placement through, so that cell tuple, the above Cell tuple quantities are interconnected, as far as possible from each other become. The effect is similar to that known interleaving, by which not only single fault, but also bundle errors can be corrected. The placement pattern must of course be the Encoder known as the decoder. The scattered placement of course also one-dimensional signals; clustered cell tuples should preferably be placed far apart, in the sense of locally performed However, comparisons should be made to the inversion and non-inversion cells of a cell tuple are close together. Leave the following considerations to simplify the scattered placement disregarded.

decoding:

The Decoding is based on comparing the content of inversion cells and non-inversion cells within cell tuples.

The Cell tuple amounts and thus the partial information are compared to the Coding processed in reverse order, here M10, M9, ... M1.

Since we have binarily encoded cells in the example, and since the cell tuples here are cell pairs with one inversion cell and one noninversion cell, the procedure here is as follows:
If the respective considered cells of a cell pair are unequal, this indicates that the associated current information bit is set; if they are the same, this indicates that the corresponding current information bit is not set. The decision is preferably made by a majority vote of the cell pairs involved in a cell tuple amount.

Provided more decoding steps are pending each time a decision is made then like it was that the information bit is set, the inversion cells inverted the current cell set (alternatively, of course, corresponding flags be set). In this way, therefore, the information bits are successively 10, 9, ... 2 decoded.

The Information bit 1 again represents a special case: Here is the decision does not have one Comparison of different cells brought about, but over a direct (preferably by majority decision) comparison with the values 0 and 1.

If the cells have each been directly inverted (work without corresponding markers, see above), a matrix completely occupied by 0 remains at the end before decoding undisturbed cells. At original Disturbed cells are then formed with correct decoding at the end of a fault (or 1D error signal). This error image can be used to assess the quality of the decoding or the signal.

apart of information bit 1 so in this example all comparisons realized directly between current cell contents, without reference to any reference dimensions. Would you For example, invert all cells against each other (with phase modulation for example, by an undesirable global phase shift by 180 degrees), all bits would still be 2..10 be correctly decoded.

in the Following are generalizations based on the example described.

The first generalization is the transition from conventional logic to a fuzzy approach.

We went so far from a binary representation the cells out.

In The practice is disrupted which the demodulator can numerically evaluate and which it provides for a reliability-optimizing Evaluate decoding applies.

We go first assume that by a demodulator of each cell a (fuzzy) value is assigned between 1 and 9, where 1 means "sure black (horizontal ..)", 9 means "sure white (vertical ..)", 5 means "unknown", 7 means "more white (horizontal)", 8 means "almost certainly white (horizontal)", etc.

A odd number of rating levels is preferable because then you (as here with the value 5) the possibility of a neutral rating Has.

digit Numerical values were chosen because of the better view, the Value 1 as the lowest value was chosen, because with an odd number of potential Values one exactly in the middle and the 5 as the middle value is particularly vivid.

According to the invention, the XOR operation is replaced by the following operation, with the numbers 1 and 9 to be considered as examples:
XOR (A, B) = ABS (A - B) + 1; (ABS = absolute amount)

It For example, XOR (3,3) = 1 ('equal'), XOR (1,9) = 9 ('unequal'), XOR (3,7) = 5 ('indefinite').

The inversion is carried out by:
INV (A) = (9-A) + 1.

For the sake of completeness, we still specify the AND and OR operations:
AND (A, B) = Min (A, B), OR (A, B) = Max (A, B).

The Equality query on decoding is replaced by an XOR operation to the values concerned and the query whether the relevant value is> 5 or <5.

Advantageous and according to the invention, the equality query not directly to the cells of a cell tuple, but instead the values of several identical cells (inversion cells or non-inversion cells) is conventionally added and thereafter first, with appropriate standardization on the number of cells involved, the> 5 / <5 query carried out. In between, it may still be advisable to use suitable non-linear characteristics to be used to suppress single small errors. Advantageously as a majority decision is also the application of the median operator over the results of several Cell pairs, followed by> 5 / <5 comparison.

It So, for each bit of information advantageously a majority vote on several "individual opinions" instead, where unsafe cells due to their value "proximity 5 "automatically off withhold the decision-making process (the more, the closer they are at 5), contrary to algebraic decoding, which are also very close to the limit values forcibly can lead to individual wrong decisions, which then costly again have to be done well or to rejections to lead.

Lies the value that leads to the decision 5 or too close to the value 5, then either a rejection carried out or the decoding process is continued for both alternatives and the final Decision is made by additional criteria dependent made as known from soft-decision systems.

The second generalization is the integration of demodulation through direct comparison at the signal level.

So far we have made a comparison between every two cells via an "analog" XOR function. Of the Comparison may be preferred in addition directly on the signal level (pixel level), that is realized pictorially. This has obvious advantages, especially if the Properties of cell contents (locally or temporally) low-frequency change.

Has For example, cells with a small cross against those with to distinguish a small ring, so the question is "are the cells A and B rather equal or rather unequal? "Technically much more reliable too answer as the calculation of good individual evaluation measures ("similar cross?" ...), because the latter sets the availability a reference cross and a reference ring ahead: put Imagine that the diameters of circles due to any Disturbing themselves slowly change can; then good once a given reference circle nothing more.

It is therefore not worked by comparison with given references, but by comparison between different signal parts; Interference, the these different signal parts are common (this is almost always the case with low-frequency or locally adjacent signal parts) automatically calculated. In image processing applications, signal comparisons be realized for example by normalized correlation.

It So no reference patterns for cell demodulation are needed; The System leads automatic a self-referencing by in the course of decoding.

The previously described analog rating is still based on a in principle binary logic (Logic to base 2), except that between TRUE and FALSE just intermediate values gives.

A third generalization is from logic to basis 2 to pass to a multi-valued logic to base 3, etc. The occasional inversions (XOR operations) in this case are to be replaced by modulo-3 additions (in coding) and subtractions (when decoding), or vice versa, around the controlling value.

This is dependent on the subinformation in coding, it is on decoding the difference value between the compared cells (in multicellular Compare after suitable normalization).

The transition from bivalent to trivalent etc. Logic can be motivated through unusual data formats, e.g. Coding of 65 ... 81 possible values (81 = 3 x 3 x 3 x 3), through the need to optimize existing transmission channels or by several feature dimensions of the realization of cells.

polyvalent Fuzzy realization is explained with an example: value set is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 with the safe values 1, 5, 9 and the uncertain intermediate values 3, 7, 11. The inversion happens as described above, but with four times the increment, (with wrap around from 12 to 1).

A inventive extension is, preferably after completion of the encoding the data with a grid XOR-, e.g. with a chessboard or in one-dimensional with a 010101 ... Episode, or even a random sequence. This will be in the following grid operation called. As a result, a certain structuring of the data can be achieved become, such that independent from the coded information, (local) always a certain minimum number of cells with logical 1 and a minimum number with logical 0 is (at the above listed Example will be - too after scattered placement - by Using a simple checkerboard grid achieves that in the 3x10 field always at least 7 logical 1 cells and at least 7 logical 0 cells are located). The code receives thereby a certain pattern. This property can be beneficial for the Demodulation can be used, especially for synchronization, with a retroactive effect from decoding to demodulation. Most primitive example would be that Traversing a binarization threshold until the minimum numbers Fulfills are. Also for a rejection criterion this property is useful; primitive example: a completely black picture becomes so without additional special queries automatically rejected. Before the actual decoding, a grid operation is performed to to undo them again do.

alternative or in addition Of course you can also introduce a fixed synchronization or referencing pattern, for example a sequence of alternating symbols like 0101010 ... or 012012012012 ... Etc.

One important issue is the optimal design of the configuration.

• 1) Man zerlege sukzessive in kleine Bereiche unterschiedlicher (X-)Koordinaten, denen Inversions- und Nichtinversionszellen zugeordnet sind, wie dies aus 2 bis 6 erkennbar ist.
• 2) Aus unserem Beispiel 1 bis 10 ist ersichtlich, dass eine dimensionsweise Organisation der Zellen hilfreich sein kann: die Mengen M1 bis M6 sind vertikal orientiert, d.h. vertikal untereinander stehende Zellen sind alle gleichartig, während die Mengen M7 bis M10 horizontal orientiert sind. Auch Hilfsanordnungen mit mehr als 2 Dimensionen sind grundsätzlich möglich.

Two systematic approaches to configuration, both from the example 1 to 10 can be recognized, can be combined with each other:

• 1) Disassemble successively into small areas of different (X) coordinates, which are associated with inversion and non-inversion cells, like this 2 to 6 is recognizable.
• 2) From our example 1 to 10 It can be seen that a dimensional organization of the cells can be helpful: the quantities M1 to M6 are vertically oriented, ie vertically standing cells are all similar, while the quantities M7 to M10 are oriented horizontally. Also auxiliary arrangements with more than 2 dimensions are possible in principle.

11 shows a hardware implementation for a simple example. 11 is a scheme, details such as control signals are omitted. The coding is shown above, the decoding below.

Encoding:

Again, we start with binary cells. It is a signal with 3 pieces of information to encode one bit each, I0, I1, I2. A total of 4 bits are available for coding. The coding path is a pipeline consisting of three registers 11 with 4 binary cells each 10 ,

The cells are numbered 1 to 4 for each register from left to right for the following description, as well as from left to right; these numbers are in 11 for the sake of clarity not shown. From coding step to coding step, the cells are transferred, from left to right, from register to register (cell parallel with 4 shift registers of length 3 or cell serial with a shift register of length 12). In the first step, the information bit I0 is transferred into the first register (formally this can be regarded as an XOR operation with a logical value of "0".) If these XOR operations are actually implemented, then the logical basic value "1 " be used).

in the second encoding step, the information bit I1 is XOR-linked with the contents of the first two cells of the second register, the result becomes written back to the cells concerned. in the third coding step, the information bit I2 is XOR-linked with the contents of the first and third cell of the third register, the Result is written back to the cells concerned.

Parallel editing I1 in the second tab allows editing the next I0 value in the first register, etc. (pipeline).

The generated code is as follows (c1 ... c4 corresponds to the cell numbers 1 ... 4 of the registers):

apparent comes "1" only in even number before, the minimum distance is therefore 2.

decoding:

to Decoding registers are edited in reverse order. In the first decoding step, the information bit I2 is obtained by XORing the Contents of the first and second cell of the third register and by XOR linking the Contents of the third and fourth cell of the third register. are the comparison results both 1, it is decoded to I2 = 1, if they are both 0, then I2 = 0 is decoded.

It is advantageous to work with fuzzy cell values, and for this decision, both comparison results are considered together by simple summation of the fuzzy XOR values, followed by a threshold decision, as described in the first example. Such summation and threshold terms are in 11 with no. 14 characterized.

Depending on I2 inverts the first and third cells of the third register, by XORing I2 with the relevant cell values (fuzzy) and the result is written back to the cells.

Corresponding is moved to the other registers: In the second decoding step becomes the contents of the first and third cell of the second register (Fuzzy) XOR linked, as well the contents of the second and fourth cell of the second register, and I1 is preferably followed by summation of fuzzy XOR values won by a threshold decision. Depending on I1, the first one will be and the second cell of the second register is inverted by I1 with the relevant cell values (fuzzy) XOR-linked and the result is written back to the cells.

in the third decoding step, the information bit I0 by (fuzzy) XOR operation of the Contents of the four cells linked to the basic value. I0 is preferably by Summation of the fuzzy XOR values followed by a threshold decision, won.

If an error signal ("error picture", see above) won become dependent here of I0 the four cells of the first register inverted by I0 with the relevant cell values (fuzzy) XOR are linked and the result in the cells are written back becomes. This return branch is in the last step for the decoding itself is not necessary.

For example 11 we have the following configuration:
For partial information I1, the cell tuple quantity consists of the cell tuples A1 with inversion cell 1 and noninversion cell 3, and cell tuple A2 with inversion cell 2 and noninversion cell 4. For partial information I2, the cell tuple consists of cell tubers B1 with inversion cell 1 and noninversion cell 2, and cell tuber B2 with inversion cell 3 and non-inversion cell 4.

I0 is a special case and consists only of inversion cells: here is after 11 the decision is not made on the basis of a cell comparison. This can be remedied in a simple manner by a differential coding of (preferably successive) I0 values: during coding, the I0 values are replaced by XORing successive I0 values; in decoding, accordingly, before the summation and threshold terms 14 to I0, a (fuzzy) XOR comparison with cells cached from the last I0 decision built-in.

The Simple example shown here has a code rate of 3/4.

Also the decoding can be done in a pipelined way.

The Error image can be evaluated cell by cell as deviation from the logical basic value "0" or "1" (s.o.) become.

The method has the following advantages:
The mode of operation of the method is transparent and clear with its individual steps. System-specific adaptations can be realized in a targeted manner, eg modifications of the comparison functions, integration of characteristic curves, placement of cells, dimensioning of tuple quantities, so that a reliability-optimizing optimally adapted to the given application Decoding can be realized with considerations directly on the signal level in the course of decoding. Demodulation and decoding are coupled and cooperative.

The Information bits can be obtained by suitable configuration (various Number of cell tubers and / or cells of a cell tuple) different decoding security can be assigned (e.g. important in the coding of numerical data).

As a simple example of reliability-optimized decoding, the example serves 11 : the minimum distance of the code is 2, so with algebraic decoding methods only error detections, but no error corrections are possible. Even the described procedure with fuzzy logic (without signal comparisons over several pixels within the cells) allows for error corrections, in some cases even for several cells, by automatically blocking in the threshold elements insecure cells from the decision process and being "overruled" by secure cells ,

decisions are induced in the decoding solely by comparison; it is therefore always about relative considerations within the interpretive signal; The system references itself based on the current signal, even a signal inversion pays off automatically out. The latter is especially important for phase-modulation links and optically readable codes where the cells are dependent on Lighting and viewing direction experienced a contrast reversal can.

A further increase of the decoding quality results from that the comparison directly on the signal level (pixel level), so pictorially is realized. This has obvious advantages, especially when the properties of the cell contents (locally or temporally) are low-frequency change.

Claims (28)

Method for decoding a code, wherein the Information to be decoded represented by partial information is and where the partial information from cells to be decoded be won, marked A) by partial information Decoding steps, B) in that for at least one decoding step the partial information from cells to be decoded is obtained by Cellular comparison of inversion cells with non-inversion cells and comparison result dependent Determining the relevant part information, C) by comparison result dependent linking a Inversion information with the inversion cells of the relevant Decoding step, if at least one decoding step according to B) follows. Decoding method according to claim 1, characterized that the comparison of inversion cells and non-inversion cells by comparing cell values derived from the cells become. Decoding method according to claim 1, characterized that the comparison of inversion cells and non-inversion cells by comparing the contents of the cells concerned. A decoding method according to claim 2, characterized in that a comparison result is determined by evaluating a plurality of comparisons of cell values according to a merit function, preferably - over the median of individual comparison measures. - by the arithmetic mean of individual comparison measures. Decoding method according to claim 2, characterized in that that a comparison result by evaluating cell values according to a Quality function determined will, over the comparison of means over Inversion cells, on the one hand, with averages over non-inversion cells, on the other hand. Decoding method according to claim 3, characterized that a comparison result by evaluating multiple comparisons is determined, preferably - on the median of comparison functions on each several pixels of the cells or - about the Arithmetic mean of comparison functions per several pixels the cells in question. Decoding method according to one of claims 1 to 6, characterized in that also in the last decoding step a link is performed with an inversion information that the cell values after the last decoding step as an error or error signal be interpreted for a quality assessment. Decoding method according to one of claims 1 to 7, with a multi-valued logic in the coded cell values, in particular with correspondingly multi-valued phase modulation at the signal level by multi-valued fuzzy logic in the cell values to be decoded. Decoding device for information that can be represented by partial information from a code in which cells are respectively assigned cell values, characterized by a number of registers ( 11 ), each register cell ( 10 ), of which at least one register ( 11 ) is used to receive the information to be decoded, and wherein each register ( 11 ) at least one register cell is decoding step by step in response to the decoded part information invertible, preferably via XOR gate ( 13 ), wherein at least one invertible register cell is interpretable as an inversion cell of one or more cell tubers with inversion cells and noninversion cells, wherein the cells within each cell tuple are either only inversion cells or only noninversion cells for each subsequent decoding step, said partial information being obtainable from cell registers by cell cell wise comparison of inversion cells with non-inversion cells and comparison-result-dependent determination of the relevant partial information. Decoding device according to claim 9, characterized by summation and threshold value elements ( 14 ), which can be used to decide on partial information to be decoded. Decoding device according to claim 9 or 10, wherein at least one comparison by a fuzzy XOR gate ( 13 ) is realized. Decoding device with a decoding method according to one of the claims 1 to 8, for a code different in the first coded partial information (I0) coded, characterized by a circuit with the decoded Partial information (I0) for cached the inverse of the differential encoding can be. Receiving device with a decoding device according to one of the claims 9 to 12. Code generated by a method of coding an information that can be represented by partial information, in which by assigning cells cell values to be assigned, marked by a) partial information coding steps, b) partial information specific Classification of cells in inversion cells and non-inversion cells, wherein each sub-information is associated with at least one inversion cell is c) at least one sub-information-specific cell tuple, wherein each cell tuple comprises at least one inversion cell and at least a non-inversion cell exists, where the cells are inside every cell tuple for each preceding encoding step is either only inversion cells or only non-inversion cells. d) for at least one coding step: XOR linking the relevant partial information with the part of this information b) associated inversion cells. Code according to claim 14, characterized in that in the at least one coding step of the method for generating of the code all inversion cells of the coding step at least one Belong to cell tuples. The code of claim 14 or 15, wherein the cell tuples Cell pairs with an inversion cell and a non-inversion cell are. The code of any one of claims 14 to 16, wherein the cell values Signal values, in particular pixel values of images, are assigned. The code of claim 17, wherein the pixels each comprise one Value of binary Can accept values. Code according to one of claims 14 to 16, wherein one Cell are assigned to multiple pixels, with the pixels being the pixels a picture or a picture sequence or the signal values of another Signals are characterized by assignment of pixel patterns the cell values. Code according to one of claims 14 to 19, characterized by a differential encoding made in advance of the first edited part information. Code according to one of claims 14 to 19, characterized by XOR linking of the result with a predetermined pattern, wherein the predetermined Pattern in pictures is a two-dimensional checkerboard pattern and for one-dimensional signals is a 101010 ... pattern. Code according to one of claims 14 to 21, characterized by XOR linking of the result with a random pattern. Code according to one of claims 14 to 22, characterized by: for at least one step a placement of the cells, at least 3 quantities of cell telltale are formed, which over at least one cell from each other are separated. Storage medium on which data is stored with a code according to any one of the claims 14 to 23. transfer protocol with a code according to one of claims 14 to 23. transfer protocol according to claim 25, wherein after coding a fixed synchronization or referencing pattern is added, preferably in the form a 010101 series of at least 6 cells. Labeling device with a coding method for the Label with a code according to one of claims 14 to 23, characterized for signal modulation, the width of bars or the size of dots or the color of dots or the size and color of dots or the direction of bar elements is changeable. code carrier for identification purposes with a code according to one of claims 14 to 23.