CA2376766A1 - Data strip and method for coding and decoding printed data - Google Patents
Data strip and method for coding and decoding printed data Download PDFInfo
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- CA2376766A1 CA2376766A1 CA002376766A CA2376766A CA2376766A1 CA 2376766 A1 CA2376766 A1 CA 2376766A1 CA 002376766 A CA002376766 A CA 002376766A CA 2376766 A CA2376766 A CA 2376766A CA 2376766 A1 CA2376766 A1 CA 2376766A1
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
- G06K19/06009—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with optically detectable marking
- G06K19/06037—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with optically detectable marking multi-dimensional coding
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Editing Of Facsimile Originals (AREA)
- Image Processing (AREA)
- Dc Digital Transmission (AREA)
- Printers Characterized By Their Purpose (AREA)
- Compression, Expansion, Code Conversion, And Decoders (AREA)
Abstract
The invention relates to a data strip for storing coded data having a high density. The printed surface of the data strip is divided up into cells and one of at least two different patterns (1, 2) having a characteristic, predefined form is respectively printed in a two dimensional cell having a predefined form. The invention also relates to a method for coding and decoding data on printed supports. Coding occurs in the form of two dimensional cells and cells are positioned at specific points on the support , respectively containing at two different patterns having a characteristic an d predefined form and the inner structure of the cells is used for decoding.</ SDOAB>
Description
Data Striu and Method for Codin4 and Decoding Printed Data The invention relates to a data strip for storing printed coded data having a high data density as well as to a process for coding and decoding data, on printed supports.
In order to store codes on products or objects, bar codes have been known for a long time and are widely used. For encoding information, bars of different widths are printed onto the object in varying spaced apart relationship. A
reading device can capture the bar pattern and decode the information. The data density of such bar codes is as little as a few bits per square centimeter of the printing area. An example is US 3 211 470, wherein data reliability is increased by the provision of redundancy.
In order to attain higher data densities data codes are used, which are composed of a plurality of data lines. WO 86/05906 describes such a data strip. This data strip contains special synchronization regions serving to adjust the optical reading device to the data lines and to control the so-called scan rate at which the reading device captures line by line while being guided over the data strip. EP 0 670 555A1 provides synchronization zones in the form of margins of sections of the data strip. The firm Cobblestone Software Inc.
describes a process at www.paperdisk.com having synchronous labels serving as a two-dimensional extension of bar codes. By this measure they aim at accommodating data densities of up to 4 megabytes on a sheet of 8 x 11 inches in the form of so-called data tiles.
It is a drawback of these known techniques that the data density attained is still too low for various applications. If it is desired, for example, to store in books or brochures sound samples of music or even speech on a data strip, then a sound sample of 10 seconds of speech or music of high quality corresponds to several hundred kilobytes of data. The size of the printed area required therefor is unacceptable.
If the data density in the known codes is increased in that the dots are progressively printed smaller, the printing process encounters limitations, e.g.
mvrinsVrle~zelle~tin pat EP 00 05211 data strip 2001 in that the dots merge. If the quality of the printing process fluctuates, the data strips are useless. At the same time, in the case of small printing points the demand on the image quality of the reading device increases. Typical and critical image errors are in this context distortion, astigmatism, coma and shadow images as they occur by reflections on parallel plates. Reading devices with simple optics can then no longer be employed. However, even high-quality image optics encounter physical limitations due to the theory of diffraction. The printing process and image optics give rise to the fact that the synchronization structures for the reading device appear blurred or distorted and that the synchronization onto the code fails despite expensive technology.
The reason for this is that the aforementioned faults occur in unpredictable intensity and combination and that the faults further vary in location. In the event of high data densities, it is impossible to correct the particularly critical effect of distortion by co-ordination transformation as soon as individual printing points demerge or the printing points are depicted in a blurred manner.
In the event that image sensors are used in a code-reading device, such as, for example, CCD-line and CCD-surface sensors, a further problem arises.
The aforementioned image sensors comprise two-dimensionally expanded sensor cells. If the sensor cells are not substantially smaller than the synchronization screen, the synchronization methods fail in this case as well.
The known methods require so-called overscanning by a factor 4 or even 6, as the synchronization screen is captured differently.
~~.~e~~~ ~c Er o0 oszt m.~.a;~ zoos depending on how the synchronization screen and the screen of the image sensor coincide. The disadvantages of small sensor cells are, however, the low light sensitivity, the high price of the sensors and the high data quantity during read-out.
US patent 4 782 221 further describes a printed data strip, wherein information is stored in many parallel, mutually adjoining data lines. The bits are stored by partially printing on areas of defined and even size. A
plurality of data lines are grouped together according to the invention into coded data zones, where the information is filed in sequence. In addition, vertical and horizontal synchronization headers are supplemented in order to adjust the optical reading device to the data lines.
This technique does not permit coding with a high data density such as is required for the present application. As described on page 4, lines 658, the so~alled bit sections have a size of 0,25 mm x 0,15 to 0,9 x 0,43 mm. The data density attainable therewith is almost two orders of magnitude below the present application. The reason for this is the fact that the described synchronization headers fail in the event of smaller dimensions of the bit regions. In particular, cheap optical scanners lose synchronization within a data cell after as little as a few bit sections.
According to US 5 170 044 data bits are transferred in that in an array of preferably 3x3 cells some cells are printed while other cells are unprinted.
By printing the so-called complementary array by exchanging the printed for the unprinted cells, coding of data bits is possible. A bit is thus coded in a plurality of cells (so-called pixels), permitting better error detection and error correction. Instead of individual data bits, complementary symbols are ~~.v~~aw w~ .~a°a ~ ~v~oorosz> > AMENDED PAGE
3a transferred. This technique, which has been known for decades in communication technology (see, e.g.: Shannon, C.E. Weaver, W.: The Mathematical Theory of Communication, University of Illinois Press, Urbana, 1949; Lbffler, H.: Information-Signal-Nachrichtenverkehr (information-signal communication tragic), Akademie-Verlag, Berlin 1990) is for the first time transferred to two-dimensional symbols. Decoding of the symbols is performed in that the symbols received are compared to the symbols transmitted and it is calculated in how many cells (pixels) the symbols differ.
This very simple method is used, in order to derive the correct data bit in spite of incorrectly transmitted cells. Correction of errors by efficient ted~niques, such as, e.g. Hamming or BCH codes is dispensed with on the grounds that the calculation efforts of the necessary, non-linear equations would be too high (column 2, lines 594). The fact that Hamming-codes form part of the linear block-codes, which can be decoded by very simple means by using shift registers (Hamming, W.R.: Information and Codierung (Information and Coding). VCH Verlag, Weinheim, 1986), is not considered in the patent.
The technique described in US 5 170 044 can likewise no longer be used for very small printing dots which, in the application described, are typically about 0,02 mm. Reasons for this are the fact that the printing dots extend differently on the paper and that, in particular, in the case of cheap scanner optics, an image is supplied where isolated dots are no longer recognizable. The image then shows heavily intersmudged printing dots. The simple decoding described in the patent then fails.
US 5 315 098 describes a technique for coding data in half tone images. This is done in that the orientation of non-rotation-symmetrical half tone dots is rotated systematically. The size of the half tone dots varies according -to the local gray shading of the image. In US 5 706 099 this technique is ~a.~ aw ~ ~. ~v~oo~osz~ ~ AMENDED PAGE
3b improved to the effect that the impression of gray shading of the image perceived by the observer, is optimized. For this purpose the half tone dots are replaced by half tone cells, in the diagonally adjoining corners of which two 90-degree circular arcs are situated. For data coding the half-tone cells are turned by 90 degrees. Varying gray shadings are attained by circular arcs of varying thickness.
Decoding of the data bit consisting of such half tone images presupposes, however, a very high-quality scanner, which must possess a very low geometrical distortion and high-quality optics with a high image definition.
Decoding by means of a cheap hand scanner is inconceivable, since the appearing images of the individual half tone cells vary considerably after the scanning process and are even different after each scanning process.
Interferences depend, e.g., on the manufacturing accuracy of the scanner, image defects of the optics, the type of paper onto which the half tone image was printed and the relative tilting between scanner and data strip. Moreover, printing of the circular arcs is difficult by the digital printing technology, as circular arcs must be composed of rectangular half tone dots.
A further drawback of the known codes is the susceptibility to dirt accumulations, wear and tear or deformations of the data carrier. In addition, the coarse data and synchronization structures are perceptible to the human eye and may be a source of problems in various applications. Moreover, the codes offer no possibility for the simultaneous transmission of visual information, such as, e.g. company logos or pictures.
It was, therefore, an object of the invention to provide a code for printed data as well as a method for coding and decoding these printed data permitting a high data density while offering simultaneously a high degree of reliability of mrindttle~aelkMin data strip amended pyqes ~u~oarosz~ ~ AMENDED PAGE
3c the code, in which context additional, in particular visual information, may be overlaying the code, ensuring reliable coding and decoding of these printed data.
This object is attained according to the invention by a data strip for storing printed coded data having a~ high data density, the printed area of the data strip being divided into cells and one of at least two different patterns having a characteristic, predefined form being respectively printed in a two dimensional cell having a predefined form and by a process for coding and decoding data on printed supports, the coding being performed in the form of two-dimensional cells and the cells being positioned at defined locations on the support, which in each case comprise at least two different patterns having a characteristic and predefined form, the inner structure of the cells being utilized for decoding.
The patterns according to the invention having a characteristic and predefined form may be so fine that the human eye, due to local resolution being too low, sees them as homogeneous dots. The typical dimension of such a pattern is approximately 0,02 mm, subject to the printing technique. According to the invention other transfer processes may, in principle, also be used, such as, for example, die stamping or die cutting techniques, in which context the supports to be printed on in these cases consist preferably of solid materials, such as plastics or metal.
The patterns are within defined, two-dimensional cells, which are repeated in a predefined manner in the horizontal and vertical directions. A pattern advantageously fills out 50°~6 of a cell, whereby in the cell the printed area equals substantially the unprinted area thus causing the two-dimensional data strip to appear to the eye as a homogeneously colored area.
~n.~aw.~.~a~a~. par~oo~osz» AMENDED PAGE
In order to store codes on products or objects, bar codes have been known for a long time and are widely used. For encoding information, bars of different widths are printed onto the object in varying spaced apart relationship. A
reading device can capture the bar pattern and decode the information. The data density of such bar codes is as little as a few bits per square centimeter of the printing area. An example is US 3 211 470, wherein data reliability is increased by the provision of redundancy.
In order to attain higher data densities data codes are used, which are composed of a plurality of data lines. WO 86/05906 describes such a data strip. This data strip contains special synchronization regions serving to adjust the optical reading device to the data lines and to control the so-called scan rate at which the reading device captures line by line while being guided over the data strip. EP 0 670 555A1 provides synchronization zones in the form of margins of sections of the data strip. The firm Cobblestone Software Inc.
describes a process at www.paperdisk.com having synchronous labels serving as a two-dimensional extension of bar codes. By this measure they aim at accommodating data densities of up to 4 megabytes on a sheet of 8 x 11 inches in the form of so-called data tiles.
It is a drawback of these known techniques that the data density attained is still too low for various applications. If it is desired, for example, to store in books or brochures sound samples of music or even speech on a data strip, then a sound sample of 10 seconds of speech or music of high quality corresponds to several hundred kilobytes of data. The size of the printed area required therefor is unacceptable.
If the data density in the known codes is increased in that the dots are progressively printed smaller, the printing process encounters limitations, e.g.
mvrinsVrle~zelle~tin pat EP 00 05211 data strip 2001 in that the dots merge. If the quality of the printing process fluctuates, the data strips are useless. At the same time, in the case of small printing points the demand on the image quality of the reading device increases. Typical and critical image errors are in this context distortion, astigmatism, coma and shadow images as they occur by reflections on parallel plates. Reading devices with simple optics can then no longer be employed. However, even high-quality image optics encounter physical limitations due to the theory of diffraction. The printing process and image optics give rise to the fact that the synchronization structures for the reading device appear blurred or distorted and that the synchronization onto the code fails despite expensive technology.
The reason for this is that the aforementioned faults occur in unpredictable intensity and combination and that the faults further vary in location. In the event of high data densities, it is impossible to correct the particularly critical effect of distortion by co-ordination transformation as soon as individual printing points demerge or the printing points are depicted in a blurred manner.
In the event that image sensors are used in a code-reading device, such as, for example, CCD-line and CCD-surface sensors, a further problem arises.
The aforementioned image sensors comprise two-dimensionally expanded sensor cells. If the sensor cells are not substantially smaller than the synchronization screen, the synchronization methods fail in this case as well.
The known methods require so-called overscanning by a factor 4 or even 6, as the synchronization screen is captured differently.
~~.~e~~~ ~c Er o0 oszt m.~.a;~ zoos depending on how the synchronization screen and the screen of the image sensor coincide. The disadvantages of small sensor cells are, however, the low light sensitivity, the high price of the sensors and the high data quantity during read-out.
US patent 4 782 221 further describes a printed data strip, wherein information is stored in many parallel, mutually adjoining data lines. The bits are stored by partially printing on areas of defined and even size. A
plurality of data lines are grouped together according to the invention into coded data zones, where the information is filed in sequence. In addition, vertical and horizontal synchronization headers are supplemented in order to adjust the optical reading device to the data lines.
This technique does not permit coding with a high data density such as is required for the present application. As described on page 4, lines 658, the so~alled bit sections have a size of 0,25 mm x 0,15 to 0,9 x 0,43 mm. The data density attainable therewith is almost two orders of magnitude below the present application. The reason for this is the fact that the described synchronization headers fail in the event of smaller dimensions of the bit regions. In particular, cheap optical scanners lose synchronization within a data cell after as little as a few bit sections.
According to US 5 170 044 data bits are transferred in that in an array of preferably 3x3 cells some cells are printed while other cells are unprinted.
By printing the so-called complementary array by exchanging the printed for the unprinted cells, coding of data bits is possible. A bit is thus coded in a plurality of cells (so-called pixels), permitting better error detection and error correction. Instead of individual data bits, complementary symbols are ~~.v~~aw w~ .~a°a ~ ~v~oorosz> > AMENDED PAGE
3a transferred. This technique, which has been known for decades in communication technology (see, e.g.: Shannon, C.E. Weaver, W.: The Mathematical Theory of Communication, University of Illinois Press, Urbana, 1949; Lbffler, H.: Information-Signal-Nachrichtenverkehr (information-signal communication tragic), Akademie-Verlag, Berlin 1990) is for the first time transferred to two-dimensional symbols. Decoding of the symbols is performed in that the symbols received are compared to the symbols transmitted and it is calculated in how many cells (pixels) the symbols differ.
This very simple method is used, in order to derive the correct data bit in spite of incorrectly transmitted cells. Correction of errors by efficient ted~niques, such as, e.g. Hamming or BCH codes is dispensed with on the grounds that the calculation efforts of the necessary, non-linear equations would be too high (column 2, lines 594). The fact that Hamming-codes form part of the linear block-codes, which can be decoded by very simple means by using shift registers (Hamming, W.R.: Information and Codierung (Information and Coding). VCH Verlag, Weinheim, 1986), is not considered in the patent.
The technique described in US 5 170 044 can likewise no longer be used for very small printing dots which, in the application described, are typically about 0,02 mm. Reasons for this are the fact that the printing dots extend differently on the paper and that, in particular, in the case of cheap scanner optics, an image is supplied where isolated dots are no longer recognizable. The image then shows heavily intersmudged printing dots. The simple decoding described in the patent then fails.
US 5 315 098 describes a technique for coding data in half tone images. This is done in that the orientation of non-rotation-symmetrical half tone dots is rotated systematically. The size of the half tone dots varies according -to the local gray shading of the image. In US 5 706 099 this technique is ~a.~ aw ~ ~. ~v~oo~osz~ ~ AMENDED PAGE
3b improved to the effect that the impression of gray shading of the image perceived by the observer, is optimized. For this purpose the half tone dots are replaced by half tone cells, in the diagonally adjoining corners of which two 90-degree circular arcs are situated. For data coding the half-tone cells are turned by 90 degrees. Varying gray shadings are attained by circular arcs of varying thickness.
Decoding of the data bit consisting of such half tone images presupposes, however, a very high-quality scanner, which must possess a very low geometrical distortion and high-quality optics with a high image definition.
Decoding by means of a cheap hand scanner is inconceivable, since the appearing images of the individual half tone cells vary considerably after the scanning process and are even different after each scanning process.
Interferences depend, e.g., on the manufacturing accuracy of the scanner, image defects of the optics, the type of paper onto which the half tone image was printed and the relative tilting between scanner and data strip. Moreover, printing of the circular arcs is difficult by the digital printing technology, as circular arcs must be composed of rectangular half tone dots.
A further drawback of the known codes is the susceptibility to dirt accumulations, wear and tear or deformations of the data carrier. In addition, the coarse data and synchronization structures are perceptible to the human eye and may be a source of problems in various applications. Moreover, the codes offer no possibility for the simultaneous transmission of visual information, such as, e.g. company logos or pictures.
It was, therefore, an object of the invention to provide a code for printed data as well as a method for coding and decoding these printed data permitting a high data density while offering simultaneously a high degree of reliability of mrindttle~aelkMin data strip amended pyqes ~u~oarosz~ ~ AMENDED PAGE
3c the code, in which context additional, in particular visual information, may be overlaying the code, ensuring reliable coding and decoding of these printed data.
This object is attained according to the invention by a data strip for storing printed coded data having a~ high data density, the printed area of the data strip being divided into cells and one of at least two different patterns having a characteristic, predefined form being respectively printed in a two dimensional cell having a predefined form and by a process for coding and decoding data on printed supports, the coding being performed in the form of two-dimensional cells and the cells being positioned at defined locations on the support, which in each case comprise at least two different patterns having a characteristic and predefined form, the inner structure of the cells being utilized for decoding.
The patterns according to the invention having a characteristic and predefined form may be so fine that the human eye, due to local resolution being too low, sees them as homogeneous dots. The typical dimension of such a pattern is approximately 0,02 mm, subject to the printing technique. According to the invention other transfer processes may, in principle, also be used, such as, for example, die stamping or die cutting techniques, in which context the supports to be printed on in these cases consist preferably of solid materials, such as plastics or metal.
The patterns are within defined, two-dimensional cells, which are repeated in a predefined manner in the horizontal and vertical directions. A pattern advantageously fills out 50°~6 of a cell, whereby in the cell the printed area equals substantially the unprinted area thus causing the two-dimensional data strip to appear to the eye as a homogeneously colored area.
~n.~aw.~.~a~a~. par~oo~osz» AMENDED PAGE
For storing a data bit, the printed area in the patterns is preferably exchanged for the unprinted area, particularly advantageously a pattern is replaced or not by its negative image.
For example, a black cross on a white background turns into a white cross on a black background. The eye still perceives the area in a homogeneous color.
The patterns themselves are so designed that after image capturing by the reading device they are readily perceptible and well distinguishable. The patterns may be characterized both by their geometrical shape and by the distribution of brightness.
In particular, sets of orthogonal patterns, e.g. a pattern and the associated negative image are in this context well suited.
The use of colored patterns in combination with a color reading device permits in this context particularly high data densities. In a pattern with areas having the basic colors red, green and blue, three orthogonal patterns come about by exchanging the colors. To the eye the cell appears in a homogeneous color, irrespective of the respective pattern.
By using a plurality of different patterns, a plurality of bits or bit sequences may be stored in a two-dimensional cell.
Distortions, coming about by the printing process or by image properties of the optics, may already be taken into account when selecting the patterns. The patterns are designed according to known processes in such a manner that they can be transferred as well as possible and are well distinguishable after transfer.
Thus, the problem of merging of printing points by printing smaller dots can be avoided.
With the data strip according to the invention and the process according to the invention the effects of astigmatism or coma can likewise be suppressed.
muins1L1e1zelladin pd EP 00 05211 lots strip 2001 In known transfer properties of the print and reading device an optimal arrangement of the patterns is thus possible with the aid of the system theory.
It must be taken into consideration in this context that the spatial frequency of the patterns after image recording should, if possible, not coincide with the spatial frequencies of accidental noise.
Systematic interferences during printing and in the reading device are, on the other hand, not critical, such as, for example, the occurrence of a shadow image, since the function of the decoder is not affected. It is even possible for the images of the patterns to overlap.
Coding of the data is performed in accordance with the invention in the form of two-dimensional cells, in which context the cells are positioned at defined locations on the support, containing in each case one of at least two different patterns having a characteristic, predefined form. During decoding, the defined patterns are searched for by methods of pattern recognition and after recognition are applied to the underlying bit information.
For pattern recognition correlations with determined search patterns are in the process carried out advantageously in order to look for the images of the characteristic two-dimensional patterns on the strip with the input data.
The number of correlators corresponds substantially to the number of the defined patterns If the brightness of the image of a pattern is described by the function m(x,y) and the brightness of the image of the data memorized on the data tape by d(x,y), then the correlator calculates the integral kor(x,y) _ INTEGRAL {d(d',y') m(x'+x,y'+y)} dx' dy'. By comparing the con-elation integrals, the underlying search pattern can be derived. The correlation integral kor(x,y) indicates an extreme value at those locations where the cell was repeated in a predefined manner.
Instead of the correlation integral other methods of pattern recognition may also be employed.
merina~trlelzelkntin pd EP 00 05211 data strip 2001 Advantageously, the data are entered for decoding by a device the spatial resolution of which is above the highest spatial frequency of the data strip by at least a factor 2.
Preferably, the patterns used for coding are positioned on the support in predefined cells and/or predefined sequence so that deviations from the pattern structure caused by distortions in the event of bad quality print, poor image quality of the optics of the reading device and/or tilting of the data strip, may be recognized. As a result, it is possible to establish how the patterns are transferred realistically and to control in this manner linear and non-linear transfer properties of the data transfer channel. This permits, in the aforementioned cases as well, decoding which is largely reliable.
Further increased decoding reliability is attained in that the location of the maximum of the correlation function is compared to the defined positions of the cells. In this manner it can be determined which geometrical transformations took place during printing and during the reading process.
Examples for this are distortion, tilting and size variations. The search patterns may thus be adapted accordingly to the transformation.
The patterns positioned in predefined cells and/or predefined sequence on the support are used particularly advantageously as search patterns for pattern recognition, so that greater deviations from the desired structure may be compensated for as well.
With the code according to the invention in conjunction with the process according to the invention decoding is, in principle, possible in the event of any distortions as long as the patterns remain recognizable.
Since the patterns are situated at defined locations in a cell, a further advantage of the solution according to the invention results from the fact that it is possible to measure the local distortion or tilting by determining during marinadrlelzelle~in pd EP 00 05211 data strip 2001 pattern recognition the location where the pattern is situated and by comparing it to the defined desired position.
With this information the search patterns are adapted, e.g. turned or changed in size. By means of a parameterized, mathematical model of distortion and tilting, the parameters of this model may be estimated by way of a Kalman-filter. As a result, detection becomes even more immune to noise.
The adaptation according to the invention of the patterns during pattern recognition permits distinctly increased decoding reliability at a simultaneously increased data density.
Experiments have shown that, by means of the patterns according of the invention and the method according to the invention, a completely unexpected increase in the data density is made possible. Data densities of over 10 kilobytes per square centimeter of printing area could be attained. As a result, it is possible, for example, to store up to 20 minutes of music by printing on the inside and the outside of a CD cover after the music data were compressed by way of conventional procedures.
Decoding of data bits becomes surprisingly reliable and safe by the coding according to the invention in combination with modem image processing, despite the high data density. It has been shown that espeaally in the case of small cell sizes and in the case of patterns having a fine structure, which can no longer be resolved by the human eye, particularly reliable decoding is possible.
In contrast to known codes, a wavy support or unevenness in the movement of the reading device are not critical. Dirt accumulations in the optics may likewise be compensated for.
The data strip according to the invention has the advantage that, in principle, it can manage without synchronization regions.
muina~trle~zelle~in pd EP 00 05211 lots ~orip 2001 As synchronization in the conventional sense is dispensed with, high overscanning by a factor 2 to 6, required for synchronization during decoding, is likewise dispensed with.
Pattern recognition searches for the most probable pattern in a cell and derives therefrom the underlying information bits. For pattern recognition, overscanning is, in principle, not necessary. However, overscanning by a factor of 1,5 to 2 has proved to be advantageous.
As overscanning is performed in the horizontal and vertical directions, the amount of data to be processed in the reading device, in comparison with known methods, drops by more than a factor of 7.
The method according to the invention permits largely reliable decoding, even in the event that the printed patterns, e.g. due to a poor image, intermingle substantially. Since each of the defined patterns per se influences the neighboring cells in the same manner, it is possible, after a pattern has been recognized once, to take into account the influence on the neighboring cells in a decision feedback duang pattern recognition.
According to the invention, additional, in particular visual information may be overlaid on the coded data without the data density being reduced.
This may be done in that the cell or even the pattern in the cell are changed in size. As a result, the cell appears lighter or darker to the observer. From a printing-technical point of view, size variations of up to 50% of the characteristic pattern or cell are possible without any problems.
Particularly advantageous, however, is the overlay of image information by changing the printing ink. This may be done in such a manner that it remains largely unnoticeable to the reading device. If, e.g., an optical reading device with a red filter is used, green, yellow or black panting ink appear likewise at a low image intensity. The brightness of the patterns may likewise be varied for overlaying visual information.
msrinaYrlelzellen<ia pd EP 00 0521 I dais strip 2001 Experiments show that fluctuations in the image intensity are acceptable up to 50%.
In the data strip according to the invention it is possible for overlaying visual information to also leave data-free sections. This is, for example, possible if full-surface image structures, such as, for example, black eyes in depicted faces or the like are overlaid on the coded data and, due to large, very dark areas, coding is not possible. In this case, it is preferred to code markers in defined cells, defining the limits of data-free sections on the data strip.
The invention is explained in what follows by way of drawings and working examples. There are shown in:
Fig. 1 the possibility to code an individual data bit, Fig. 2 the periodic repetition of the cells which cannot be resolved by the eye, Fig. 3 the bringing about of a defined line shift in the case of periodic repetition of the cells which cannot be resolved by eye, Fig. 4 the possibility for coding a 3 bit sequence and .nw.wN'l.1m11~.w:.. ....r GD M !It'f 1 1 A.f. elfin 'fM 1 1~
Fig. 5 the process steps for decoding the code.
Fig. 1 illustrates, by way of example, a possibility to code simultaneously a logic ZERO or ONE and pictorial information. The printing patterns 1 or 3 represent in this case a logic zero, the printing patterns 2 or 4 represent a logic ONE. The patterns are printed so small that they cannot be resolved by the eye and appear merely as a gray dot. The reading device can, however, recognize the shape of the patterns. Overlaying of pictorial -like information is brought about in that the color or brightness in the printing pattern 1" or 2"
is changed. In the printing pattern 1' or 2' the characteristic pattern is reduced in order to create a lesser impression of brightness for the eye.
Fig. 2 shows how the pattern pair 1 and 2 in defined spaced apart relationship is periodically repeated in two directions 5 and 6, thus forming the two-dimensional data strip.
In Fig. 3 the pattern pair 1 and 2 is periodically repeated in diagonal direction 7. Each second line, structured by patterns, appears, therefore, off set. This facilitates pattern recognition in the reading device.
The use illustrated in Fig. 4 of four complex patterns 8, 9, 10 and 11 permits, together with the inverted-inverted patterns 8', 9', 10' and 11', coding of a 3 bit sequence, as shown in fields 8", 9", 10' and 11 ". Other typical, two-dimensional patterns may, of course, also be used. The decisive factor in the process is that the patterns differ clearly so as to be readily recognizable by the reading device.
A comparison of Fig. 4 with Fig. 5 shows: Each pattern in Fig. 2 codes one bit in a 2x2 printing cell. Each pattern in Fig. 4 codes 3 bits in a 2x3 printing cell, the data density thus being twice as large. In the case of the decoding ~~~ aw ~.~m~a ~ ~u~oo~osz~ i AMENDED PAGE
10a of the data strip according to Fig. 5, the code having the higher data density surprisingly shows a lesser bit error rate - the patterns are recognized better.
The principal function of a corresponding reading device is shown in Fig. 5 in a block diagram. The image recorded by the reading device of the data strip 15 first enters a processing block 12, performing pattern recognition. This may be performed, e.g., by a correlation of the image data 15 with the printed patterns. The correlator is in this context so designed that it remains unaffected by fluctuations in brightness or colors of the pattern, permitting an overlay of the data strip with graphics or images. Should the data strip contain different patterns, correlation with different patterns is then performed.
Other methods of pattern recognition can also be used. After the pattern has been recognized, the coded bit in block 16 or the coded bit sequence are derived and the bits are issued 14. Block 13 determines the location where the pattern was recognized, comparing it with the predefined location 17 where the pattern was expected. If both locations differ from one another, the image of the data strip is shifted, turned or distorted. In block 12 for pattern recognition the search patterns are then adapted accordingly and pattern recognition is performed again. In addition, the locations, where the patterns are expected, are newly determined. These new pattern locations 18 are used in the next processing cyGe as defined pattern locations 18.
~~~~~~ ~ ~ w~~ o~~s2~ ~ AMENDED PAGE
For example, a black cross on a white background turns into a white cross on a black background. The eye still perceives the area in a homogeneous color.
The patterns themselves are so designed that after image capturing by the reading device they are readily perceptible and well distinguishable. The patterns may be characterized both by their geometrical shape and by the distribution of brightness.
In particular, sets of orthogonal patterns, e.g. a pattern and the associated negative image are in this context well suited.
The use of colored patterns in combination with a color reading device permits in this context particularly high data densities. In a pattern with areas having the basic colors red, green and blue, three orthogonal patterns come about by exchanging the colors. To the eye the cell appears in a homogeneous color, irrespective of the respective pattern.
By using a plurality of different patterns, a plurality of bits or bit sequences may be stored in a two-dimensional cell.
Distortions, coming about by the printing process or by image properties of the optics, may already be taken into account when selecting the patterns. The patterns are designed according to known processes in such a manner that they can be transferred as well as possible and are well distinguishable after transfer.
Thus, the problem of merging of printing points by printing smaller dots can be avoided.
With the data strip according to the invention and the process according to the invention the effects of astigmatism or coma can likewise be suppressed.
muins1L1e1zelladin pd EP 00 05211 lots strip 2001 In known transfer properties of the print and reading device an optimal arrangement of the patterns is thus possible with the aid of the system theory.
It must be taken into consideration in this context that the spatial frequency of the patterns after image recording should, if possible, not coincide with the spatial frequencies of accidental noise.
Systematic interferences during printing and in the reading device are, on the other hand, not critical, such as, for example, the occurrence of a shadow image, since the function of the decoder is not affected. It is even possible for the images of the patterns to overlap.
Coding of the data is performed in accordance with the invention in the form of two-dimensional cells, in which context the cells are positioned at defined locations on the support, containing in each case one of at least two different patterns having a characteristic, predefined form. During decoding, the defined patterns are searched for by methods of pattern recognition and after recognition are applied to the underlying bit information.
For pattern recognition correlations with determined search patterns are in the process carried out advantageously in order to look for the images of the characteristic two-dimensional patterns on the strip with the input data.
The number of correlators corresponds substantially to the number of the defined patterns If the brightness of the image of a pattern is described by the function m(x,y) and the brightness of the image of the data memorized on the data tape by d(x,y), then the correlator calculates the integral kor(x,y) _ INTEGRAL {d(d',y') m(x'+x,y'+y)} dx' dy'. By comparing the con-elation integrals, the underlying search pattern can be derived. The correlation integral kor(x,y) indicates an extreme value at those locations where the cell was repeated in a predefined manner.
Instead of the correlation integral other methods of pattern recognition may also be employed.
merina~trlelzelkntin pd EP 00 05211 data strip 2001 Advantageously, the data are entered for decoding by a device the spatial resolution of which is above the highest spatial frequency of the data strip by at least a factor 2.
Preferably, the patterns used for coding are positioned on the support in predefined cells and/or predefined sequence so that deviations from the pattern structure caused by distortions in the event of bad quality print, poor image quality of the optics of the reading device and/or tilting of the data strip, may be recognized. As a result, it is possible to establish how the patterns are transferred realistically and to control in this manner linear and non-linear transfer properties of the data transfer channel. This permits, in the aforementioned cases as well, decoding which is largely reliable.
Further increased decoding reliability is attained in that the location of the maximum of the correlation function is compared to the defined positions of the cells. In this manner it can be determined which geometrical transformations took place during printing and during the reading process.
Examples for this are distortion, tilting and size variations. The search patterns may thus be adapted accordingly to the transformation.
The patterns positioned in predefined cells and/or predefined sequence on the support are used particularly advantageously as search patterns for pattern recognition, so that greater deviations from the desired structure may be compensated for as well.
With the code according to the invention in conjunction with the process according to the invention decoding is, in principle, possible in the event of any distortions as long as the patterns remain recognizable.
Since the patterns are situated at defined locations in a cell, a further advantage of the solution according to the invention results from the fact that it is possible to measure the local distortion or tilting by determining during marinadrlelzelle~in pd EP 00 05211 data strip 2001 pattern recognition the location where the pattern is situated and by comparing it to the defined desired position.
With this information the search patterns are adapted, e.g. turned or changed in size. By means of a parameterized, mathematical model of distortion and tilting, the parameters of this model may be estimated by way of a Kalman-filter. As a result, detection becomes even more immune to noise.
The adaptation according to the invention of the patterns during pattern recognition permits distinctly increased decoding reliability at a simultaneously increased data density.
Experiments have shown that, by means of the patterns according of the invention and the method according to the invention, a completely unexpected increase in the data density is made possible. Data densities of over 10 kilobytes per square centimeter of printing area could be attained. As a result, it is possible, for example, to store up to 20 minutes of music by printing on the inside and the outside of a CD cover after the music data were compressed by way of conventional procedures.
Decoding of data bits becomes surprisingly reliable and safe by the coding according to the invention in combination with modem image processing, despite the high data density. It has been shown that espeaally in the case of small cell sizes and in the case of patterns having a fine structure, which can no longer be resolved by the human eye, particularly reliable decoding is possible.
In contrast to known codes, a wavy support or unevenness in the movement of the reading device are not critical. Dirt accumulations in the optics may likewise be compensated for.
The data strip according to the invention has the advantage that, in principle, it can manage without synchronization regions.
muina~trle~zelle~in pd EP 00 05211 lots ~orip 2001 As synchronization in the conventional sense is dispensed with, high overscanning by a factor 2 to 6, required for synchronization during decoding, is likewise dispensed with.
Pattern recognition searches for the most probable pattern in a cell and derives therefrom the underlying information bits. For pattern recognition, overscanning is, in principle, not necessary. However, overscanning by a factor of 1,5 to 2 has proved to be advantageous.
As overscanning is performed in the horizontal and vertical directions, the amount of data to be processed in the reading device, in comparison with known methods, drops by more than a factor of 7.
The method according to the invention permits largely reliable decoding, even in the event that the printed patterns, e.g. due to a poor image, intermingle substantially. Since each of the defined patterns per se influences the neighboring cells in the same manner, it is possible, after a pattern has been recognized once, to take into account the influence on the neighboring cells in a decision feedback duang pattern recognition.
According to the invention, additional, in particular visual information may be overlaid on the coded data without the data density being reduced.
This may be done in that the cell or even the pattern in the cell are changed in size. As a result, the cell appears lighter or darker to the observer. From a printing-technical point of view, size variations of up to 50% of the characteristic pattern or cell are possible without any problems.
Particularly advantageous, however, is the overlay of image information by changing the printing ink. This may be done in such a manner that it remains largely unnoticeable to the reading device. If, e.g., an optical reading device with a red filter is used, green, yellow or black panting ink appear likewise at a low image intensity. The brightness of the patterns may likewise be varied for overlaying visual information.
msrinaYrlelzellen<ia pd EP 00 0521 I dais strip 2001 Experiments show that fluctuations in the image intensity are acceptable up to 50%.
In the data strip according to the invention it is possible for overlaying visual information to also leave data-free sections. This is, for example, possible if full-surface image structures, such as, for example, black eyes in depicted faces or the like are overlaid on the coded data and, due to large, very dark areas, coding is not possible. In this case, it is preferred to code markers in defined cells, defining the limits of data-free sections on the data strip.
The invention is explained in what follows by way of drawings and working examples. There are shown in:
Fig. 1 the possibility to code an individual data bit, Fig. 2 the periodic repetition of the cells which cannot be resolved by the eye, Fig. 3 the bringing about of a defined line shift in the case of periodic repetition of the cells which cannot be resolved by eye, Fig. 4 the possibility for coding a 3 bit sequence and .nw.wN'l.1m11~.w:.. ....r GD M !It'f 1 1 A.f. elfin 'fM 1 1~
Fig. 5 the process steps for decoding the code.
Fig. 1 illustrates, by way of example, a possibility to code simultaneously a logic ZERO or ONE and pictorial information. The printing patterns 1 or 3 represent in this case a logic zero, the printing patterns 2 or 4 represent a logic ONE. The patterns are printed so small that they cannot be resolved by the eye and appear merely as a gray dot. The reading device can, however, recognize the shape of the patterns. Overlaying of pictorial -like information is brought about in that the color or brightness in the printing pattern 1" or 2"
is changed. In the printing pattern 1' or 2' the characteristic pattern is reduced in order to create a lesser impression of brightness for the eye.
Fig. 2 shows how the pattern pair 1 and 2 in defined spaced apart relationship is periodically repeated in two directions 5 and 6, thus forming the two-dimensional data strip.
In Fig. 3 the pattern pair 1 and 2 is periodically repeated in diagonal direction 7. Each second line, structured by patterns, appears, therefore, off set. This facilitates pattern recognition in the reading device.
The use illustrated in Fig. 4 of four complex patterns 8, 9, 10 and 11 permits, together with the inverted-inverted patterns 8', 9', 10' and 11', coding of a 3 bit sequence, as shown in fields 8", 9", 10' and 11 ". Other typical, two-dimensional patterns may, of course, also be used. The decisive factor in the process is that the patterns differ clearly so as to be readily recognizable by the reading device.
A comparison of Fig. 4 with Fig. 5 shows: Each pattern in Fig. 2 codes one bit in a 2x2 printing cell. Each pattern in Fig. 4 codes 3 bits in a 2x3 printing cell, the data density thus being twice as large. In the case of the decoding ~~~ aw ~.~m~a ~ ~u~oo~osz~ i AMENDED PAGE
10a of the data strip according to Fig. 5, the code having the higher data density surprisingly shows a lesser bit error rate - the patterns are recognized better.
The principal function of a corresponding reading device is shown in Fig. 5 in a block diagram. The image recorded by the reading device of the data strip 15 first enters a processing block 12, performing pattern recognition. This may be performed, e.g., by a correlation of the image data 15 with the printed patterns. The correlator is in this context so designed that it remains unaffected by fluctuations in brightness or colors of the pattern, permitting an overlay of the data strip with graphics or images. Should the data strip contain different patterns, correlation with different patterns is then performed.
Other methods of pattern recognition can also be used. After the pattern has been recognized, the coded bit in block 16 or the coded bit sequence are derived and the bits are issued 14. Block 13 determines the location where the pattern was recognized, comparing it with the predefined location 17 where the pattern was expected. If both locations differ from one another, the image of the data strip is shifted, turned or distorted. In block 12 for pattern recognition the search patterns are then adapted accordingly and pattern recognition is performed again. In addition, the locations, where the patterns are expected, are newly determined. These new pattern locations 18 are used in the next processing cyGe as defined pattern locations 18.
~~~~~~ ~ ~ w~~ o~~s2~ ~ AMENDED PAGE
Claims (17)
1. Data strip for storing printed, coded data having a high data density, the printed area of the data strip being divided into cells and one of at least two different patterns having a characteristic, predefined shape being respectively printed in a two-dimensional cell having a predefined shape, characterized in that the patterns are of such dimensions that they cannot be resolved by the human eye and that the said data strip comprises search patterns at defined locations for comparison with the information-carrying patterns used.
2. Data strip according to claim 1, characterized in that the patterns differ from one another in that the printed area is exchanged for the unprinted area.
3. Data strip according to at least one of claims 1 to 2, characterized in that within the cell the printed area equals substantially the unprinted area.
4. Data strip according to at least one of claims 1 to 3, characterized in that the patterns are characterized by geometrical configuration and/or distribution of brightness.
5. Data strip according to at least one of claims 1 to 4, characterized in that more than two different patterns are used and that each pattern codes a sequence of information bits.
6. Data strip according to at least one of claims 1 to 5, characterized in that the stored information is overlaid by information, preferably visual information, which can be perceived by man.
7. Data strip according to at least one of claims 1 to 6, characterized in that for the overlay of the visual information the size of individual cells is varied accordingly.
8. Process for decoding data on printed supports, the coding being performed in the form of two-dimensional cells, the cells being positioned on the support at defined locations, the cells for storing data containing in each case at least two different patterns and some defined cells storing no data, but containing in a defined manner one each of the different patterns as a search pattern, characterized in that the two-dimensional search patterns are captured by a device and the recorded signals are used for the recognition of the information-carrying patterns.
9. Process according to claim 8, characterized in that the position, rotation and appearance of the recognized, information-carrying patterns are compared to the defined position, rotation and form of appearance, in order to adjust position, rotation and form of appearance of the search patterns.
10. Process according to claim 8 or 9, characterized in that the patterns are inverted.
11. Process according to at least one of claims 8 to 10, characterized in that within the cells printed and unprinted areas of about the same size are used.
12. Process according to at least one of claims 8 to 11, characterized in that the patterns are varied by geometrical configuration and/or distribution of brightness.
13. Process according to at least one of claims 8 to 12, characterized in that patterns having at least two different colors are brought about, being coded by exchanging the color.
14. Process according to at least one of claims 8 to 13, characterized in that the stored information is overlaid by information, in particular visual information, which can be perceived by man.
15. Process according to at least one of claims 8 to 14, characterized in that the size of the cells and/or the patterns is varied.
16. Process according to at least one of claims 8 to 15, characterized in that that the patterns used for coding are positioned on the support in predefined cells and/or predefined sequence.
17. Process according to at least one of claims 8 to 16 characterized in that by recording of parameters, predetermined sections of the support are not coded.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19926194.6 | 1999-06-09 | ||
| DE19926194A DE19926194C2 (en) | 1999-06-09 | 1999-06-09 | Data strips and methods for encoding and decoding printed data |
| PCT/EP2000/005211 WO2000077724A1 (en) | 1999-06-09 | 2000-06-07 | Data strip and method for coding and decoding printed data |
Publications (1)
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| CA2376766A1 true CA2376766A1 (en) | 2000-12-21 |
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| CA002376766A Abandoned CA2376766A1 (en) | 1999-06-09 | 2000-06-07 | Data strip and method for coding and decoding printed data |
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| EP (1) | EP1190375B1 (en) |
| JP (1) | JP2003502741A (en) |
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| HU (1) | HUP0201382A3 (en) |
| PL (1) | PL352095A1 (en) |
| WO (1) | WO2000077724A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2416894A (en) * | 2004-07-29 | 2006-02-08 | Hewlett Packard Development Co | Products with data encoding pattern cells |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10307775B4 (en) * | 2002-02-22 | 2008-04-17 | Tropf, Hermann, Dipl.-Ing. | Patterned code with robust decoding, in particular signal code, decoding method, decoding device, reading device, and data carrier with program |
| US20080197203A1 (en) | 2004-07-29 | 2008-08-21 | Bernhard Wirnitzer | Matrix Print Data Storage and Method for Encoding the Data |
| DE102004038601B4 (en) * | 2004-08-07 | 2006-08-24 | Tropf, Hermann | Channel coding method and coding device |
| DE102004063950B4 (en) | 2004-08-07 | 2009-02-19 | Tropf, Hermann | channel coding |
| WO2006080031A1 (en) * | 2005-01-28 | 2006-08-03 | Kumar Raju G Praveen | New method of digital data representation using colors |
| US7427018B2 (en) | 2005-05-06 | 2008-09-23 | Berkun Kenneth A | Systems and methods for generating, reading and transferring identifiers |
| US7775428B2 (en) | 2005-05-06 | 2010-08-17 | Berkun Kenneth A | Systems and methods for generating, reading and transferring identifiers |
| DE102005037388B4 (en) * | 2005-08-08 | 2007-05-16 | Tropf Hermann | Channel decoding with associated code |
| US8226007B2 (en) | 2007-03-23 | 2012-07-24 | Ltt, Ltd | Method and apparatus for using a limited capacity portable data carrier |
| US8662396B2 (en) | 2007-03-23 | 2014-03-04 | Labels That Talk, Ltd | Method for reproducing and using a bar code symbol |
| CN101101631B (en) * | 2007-07-02 | 2014-06-18 | 天津市阿波罗信息技术有限公司 | Multimedia printing system realization method for multi-resolution printer |
| DE102007045933A1 (en) | 2007-09-25 | 2009-04-09 | Eins Gmbh Entwicklung Interaktiver Software | Visiting card has optically readable data represented in written form and another optically readable data represented in coded form |
| JP2012523598A (en) * | 2009-04-08 | 2012-10-04 | コンチネンタル・テベス・アーゲー・ウント・コンパニー・オーハーゲー | Two-dimensional symbol code and method for reading the symbol code |
| MD4151C1 (en) * | 2010-01-19 | 2012-09-30 | ШКИЛЁВ Думитру | Method for the application of the individual identification tag and individual identification tag |
| CA2812286A1 (en) * | 2010-09-24 | 2012-03-29 | Sicpa Holding Sa | Two-dimensional identification pattern, article including such a pattern and methods for marking and identifying such a pattern |
| CN102254141B (en) * | 2011-06-08 | 2013-12-18 | 汕头市东方科技有限公司 | Peripheral coding positioning system |
| ES2628458T3 (en) * | 2011-11-15 | 2017-08-02 | Sicpa Holding Sa | Coding pattern of digital information on a surface and marking and reading methods |
| GB2558789B (en) * | 2014-05-09 | 2019-01-09 | Smartglyph Ltd | Method of authentication |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4782221A (en) * | 1985-04-01 | 1988-11-01 | Cauzin Systems, Incorporated | Printed data strip including bit-encoded information and scanner control |
| US5241166A (en) * | 1990-07-02 | 1993-08-31 | Chandler Donald G | Low resolution target acquisition |
| AU642540B2 (en) * | 1990-09-19 | 1993-10-21 | Philips Electronics N.V. | Record carrier on which a main data file and a control file have been recorded, method of and device for recording the main data file and the control file, and device for reading the record carrier |
| NL9002108A (en) * | 1990-09-19 | 1992-04-16 | Koninkl Philips Electronics Nv | Record carrier for information retrieval system - has main and control data file derived from signals in conformity with same predetermined formatting and encoding rule |
| US5170044A (en) * | 1990-11-09 | 1992-12-08 | Pitney Bowes Inc. | Error tolerant 3x3 bit-map coding of binary data and method of decoding |
| KR0148130B1 (en) * | 1992-05-18 | 1998-09-15 | 강진구 | Apparatus and method for encoding/decoding due to restrain blocking artifact |
| CN1104791A (en) * | 1993-12-30 | 1995-07-05 | 富冈信 | Two dimensional code for processing data |
| US5706099A (en) * | 1995-06-05 | 1998-01-06 | Xerox Corporation | Method and apparatus for generating serpentine halftone images |
| RU2090011C1 (en) * | 1995-06-28 | 1997-09-10 | Закрытое акционерное общество "Техно-ТМ" | Video signal encoding-decoding device |
| DE19612406C2 (en) * | 1996-03-28 | 2000-01-20 | Anitra Medienprojekte Gmbh | Information carriers and methods for superimposing and processing information |
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1999
- 1999-06-09 DE DE19926194A patent/DE19926194C2/en not_active Expired - Fee Related
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2000
- 2000-06-07 HU HU0201382A patent/HUP0201382A3/en unknown
- 2000-06-07 AU AU50759/00A patent/AU5075900A/en not_active Abandoned
- 2000-06-07 JP JP2001503126A patent/JP2003502741A/en active Pending
- 2000-06-07 EP EP00935178A patent/EP1190375B1/en not_active Expired - Lifetime
- 2000-06-07 DE DE50004798T patent/DE50004798D1/en not_active Expired - Fee Related
- 2000-06-07 CA CA002376766A patent/CA2376766A1/en not_active Abandoned
- 2000-06-07 KR KR1020017015857A patent/KR20020013574A/en not_active Application Discontinuation
- 2000-06-07 EA EA200200011A patent/EA003380B1/en not_active IP Right Cessation
- 2000-06-07 CZ CZ20014390A patent/CZ20014390A3/en unknown
- 2000-06-07 ES ES00935178T patent/ES2214277T3/en not_active Expired - Lifetime
- 2000-06-07 WO PCT/EP2000/005211 patent/WO2000077724A1/en not_active Application Discontinuation
- 2000-06-07 PL PL00352095A patent/PL352095A1/en unknown
- 2000-06-07 AT AT00935178T patent/ATE256896T1/en not_active IP Right Cessation
- 2000-06-07 CN CN00810293A patent/CN1360710A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2416894A (en) * | 2004-07-29 | 2006-02-08 | Hewlett Packard Development Co | Products with data encoding pattern cells |
| GB2416894B (en) * | 2004-07-29 | 2009-04-29 | Hewlett Packard Development Co | Products with data encoding pattern |
| US7559484B2 (en) | 2004-07-29 | 2009-07-14 | Hewlett-Packard Development Company, L.P. | Products with data encoding pattern |
Also Published As
| Publication number | Publication date |
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| DE50004798D1 (en) | 2004-01-29 |
| CN1360710A (en) | 2002-07-24 |
| HUP0201382A3 (en) | 2003-07-28 |
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| ES2214277T3 (en) | 2004-09-16 |
| DE19926194C2 (en) | 2001-05-10 |
| ATE256896T1 (en) | 2004-01-15 |
| EP1190375A1 (en) | 2002-03-27 |
| HUP0201382A2 (en) | 2002-08-28 |
| EA200200011A1 (en) | 2002-06-27 |
| PL352095A1 (en) | 2003-07-28 |
| EP1190375B1 (en) | 2003-12-17 |
| JP2003502741A (en) | 2003-01-21 |
| WO2000077724A1 (en) | 2000-12-21 |
| AU5075900A (en) | 2001-01-02 |
| KR20020013574A (en) | 2002-02-20 |
| DE19926194A1 (en) | 2000-12-21 |
| CZ20014390A3 (en) | 2002-08-14 |
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