DE19733466B4 - Coded marking system and coded label - Google Patents

Abstract

Marking system provided with codings corresponding to a coding system, in particular for measuring purposes, with markings (1) with
- A central circle or circle ring (2) as well
At least one code circle ring (4) surrounding the central circle or circle ring (2), divided into radial sectors (6) corresponding to the individual code bits of the coding corresponding to the coding system,
- Wherein a 1-bit of a particular color of the code circle ring sector (6) is assigned and a 0-bit of another color of the code circle ring sector (6) is assigned, so that in the code circle ring (4) at the transition point (8) between a code-circular ring sector (6a) of a bit-type to a neighboring code-circular ring sector (6a) of a different bit-type a color change takes place, and
The codings of the coding system each comprise the same number of code-circle-ring sectors (6) or bits,
characterized in that
- The coded marks (1) of the marking system each have the same number of color changes on the code circle ring (4).

Description

The The present invention relates to a coded according to a coding system provided marking system and a with a coding provided in accordance with a coding system mark.

From the CH 560 937 A5 is a device for processing information that can be converted into characters and assimilated by a machine known. The device comprises a carrier having a sequence of characters formed from segments of lines selected from a geometric figure composed of at least 16 different segments and at least one reading head comprising at least 16 exposure meters arranged such that when a sign is opposite the head at the reading location, it is distributed to at least one knife per zone of the geometric figure so that it can be traversed by a segment to locate such an existing or missing segment in the zone. Preferably, the described apparatus is used to control an automatic sorting process of letters. The carrier hereby is an envelope with numbers given in a grid, which in their entirety correspond to a postal code. By means of the read head, the numbers arranged on the grid are automatically decrypted.

marking systems according to the generic term of claim 1 and markings according to the preamble of the claim 9 are used in photogrammetry for specific points or coordinates of objects. Leave these marks these marked points are recorded in photographic or opto-electronic Pictures afterwards easily identify. By coding according to a coding system Is it possible, the photographically or opto-electronically recorded image data under Evaluate computer control. The corresponding to a coding system Coding of the markings used here serves the respective Marking point for the computer-controlled image analysis individually identifiable make and an assignment of the individual marked object points to an individual identification of this object point, for example a point number.

Around to fulfill this purpose, The aim is to obtain the coding of the marking from a computer system, which evaluates the recorded image data as simply and safely as possible to make evaluable. Here, markings have proven that a central circle or circle and at least one central circle or circular ring surrounding code circular ring, which in radial sectors is divided, which corresponds to the individual code bits of the coding correspond to the coding system. This will be a 1-bit of a particular Assigned color of the code annulus sector and a 0-bit becomes one associated with the other color of the code circle ring sector. The encodings of the used coding system each comprise the same number of code circle segments or bits.

Under Color within the meaning of the present application is any property the visual appearance or the surface structure of a considered surface element understood, which is suitable to a viewing person and / or an image-picking or scanning optical system a sensory impression or to provide a data value that is suitable for this surface element of a surface element to distinguish a different color. Under color in the sense of the present Registration is therefore not just the colloquial color concept like red, blue, green etc., but u.a. also the impression bright or dark, different shades of grey or different patterns on the considered surface element Understood.

The Evaluation of the image capturing or scanning system recorded image data is generally done in such a way that the first Central circle or circle is detected. This can alone under Utilization of image data concerning the central circle or circle happen. In general, however, the central circuits or circle rings surrounding code circle rings to identify the central district or circular rings used with.

In a further method step is then in the code circle rings evaluated information evaluated by the different Colors of the code circle ring sectors the code circle rings of the tags have different information bits be assigned and from each received bit sequence of the respective Identification code for the respective marking is determined.

In the form of stickers, markings of a marking system are commercially available, which consist of a central annulus, concentric surrounding a central ring contrast ring of a uniform color, which differs from the color of the central circle, and a concentric surrounding the contrast ring, divided into radial sectors code circular ring. The markers are black and white to provide sufficient contrast and image capture with black and white image capture devices.

Out the publication "MIROS, a new software for Rollei RS1 Digital Monocomparator "by Martin Knobloch and Torsten Rosenthal, published in 1992 in the ISPRS Commission V Symposium, Close-Range Photogrammetry and Machine Vision, Volume XXIX, Part B5, page 35-42, a marking system with markings is known, those from a central circle, concentrically surrounding the central circle Contrast ring and two concentric surrounding the contrast ring Code circle rings exist. For those code circle annulus sectors that are on the same radius vector are arranged and contain coding bits, the colors are identical selected while a different color arranged on the same radius vector Code annulus sectors of the inner code annulus and the outer code annulus provides the start-stop mark for reading the code circle rings. These known markers are designed black and white.

Out the publication "Digital Close-Range Photogrammetry using artificial targets "by F.A. van den Heuvel, R.J.G.A. Kroon and R.S. Le Poole, published in 1992 in ISPRS Commission V Symposium, Close-Range Photogrammetry and Machine Vision, Volume XXIX, Part B5, pages 222-229, are black and white markings a marking system known, consisting of a central circle, a concentric surrounding the central circle code circle ring, a concentric surrounding contrasting ring and another outer concentric surrounding Code circular ring exist. The inner code circle ring is closed and serves exclusively automatic detection. The outer code circle ring contains the in 10-bit coded point number.

It It is known to provide a code annulus sector which is not immediate the coding of the marker identification is used, but its coloring from the coloring the rest Code circular ring sectors is calculated such that a parity check for the respective Coding results. In this way, single errors, i. the erroneous reading of a code circle ring sector per code circle ring (e.g., by covering or shadowing a code annulus sector), be identified.

Furthermore but there is the task, even multiple errors in which several Code annulus sectors in image acquisition or computational Image data evaluation is faulty or not identified at all preferably largely avoided.

These Task is by a with coding according to a coding system provided marking system according to claim 1 solved.

The The marking system according to the invention therefore comprises exclusively Markers, each with the same number of color changes have a code annulus. If one designates a sequence of neighboring ones Code annulus sectors of like, fixed color (i.e., others Words a sequence of adjacent code circular ring sectors between two transition points with a color change) as a code ring segment, so the principle of the invention can be also formulate in such a way that a Code circular ring of a marking of a marking system according to the invention each contains the same number of code annulus segments.

The principle of the invention is based on the 1 , which shows by way of example a marking of a preferred embodiment of a marking system according to the invention, explained in more detail.

The mark 1 of the 1 includes a central circle 2 as well as the central district 2 concentric surrounding code circle ring 4 which is in sixteen radial sectors 6 is divided, which correspond to the individual sixteen code bits of the coding according to the coding system. The mark 1 is designed in black and white to provide sufficient contrast in any case as well as to allow image capture by black and white image capture devices.

A plurality of adjacent code circular ring sectors of the same fixed color are collectively referred to as the code loop segment 7 designated. With reference to the 1 and the other figures of the application are chosen arbitrarily, but firmly, the color black. The mark 1 of the 1 thus contains four code circular ring segments 7 and two code circular ring segments, each consisting of a single code circular ring sector only 6a . 6b , (hereinafter referred to as code loop segments of length 1 for short) and two other code loop segments each consisting of three code circular ring sectors (hereinafter referred to as short code ring segments of length 3). Due to the total number of four code circle segments 7 on the code circle ring 4 arise in a cycle on the code circle ring 4 a total of four color changes from black to white and correspondingly four color changes from white to black.

Due to the invention principle that all coded markers of the marking system depending because have the same number of color changes or code ring segments on a code circle, there is the advantage that errors can be detected in the computer-controlled image analysis, which are caused by the obscuring or shadowing of complete code circle segments. This multiple error can be recognized and eliminated by the principle of the invention.

In a further development of the invention, the preferred embodiment of 1 a small central circle ring 5 in the center of the central district 2 , This central circle ring 5 serves the optical targeting of the mark, eg with a target theodolite.

In addition, in development of the invention in the marking 1 of the 1 between the central circle 2 and the code circle ring 4 a white, from the black of the central circle 2 Deviating colored contrasting ring 3 inserted. This contrast ring 3 serves to simplify the optical and the computer-controlled detection and evaluation of the marking 1 since he has the code circle ring 4 by increasing the contrast optically from the central circle 2 takes off.

According to the invention, it is further preferred that the code circle rings of all markings of an inventive system of invention each have at least one code circle sector whose color is identical to the color of the code circle segment opposite the respective code circle ring sector on the code circle ring sector in an even number of code circular ring sectors in an odd number of code circular ring sectors is identical to the color of the two code circular ring sectors opposite to the respective code circular ring sector on the code circular ring. At the mark 1 of the 1 containing a total of sixteen code circular ring sectors 6 in her code circle ring 4 There are three pairs of opposing code circle sectors. Such a pair of opposing code circular ring sectors 6a . 6b is in the 1 marked accordingly. This formation of opposing code circle sectors facilitates locating and identifying a marker, since it provides the additional criterion for proper marking, that at least one surface of the same color (namely, the opposing same-colored code ring segments) are equally spaced on both sides of the central circle. Sectors) must be present.

to Detection of single errors is further preferred that the code annulus the markers each in a conventional manner a code circle ring sector to parity check or that the Encoding system includes a bit for parity checking.

In Contains development of the invention the encoding system does not encode at the start of the read of the code annulus at any arbitrary code annulus sector any other valid Coding of the coding system supplies. In this way the definition of a start-stop-bit is superfluous; the one used in the coding Code of the coding system is rotationally invariant.

It is particularly preferred that the code annuli of the mark system markers not only have the same number of code annulus segments in the present invention, but also have the same number of code annulus segments of particular lengths. The code circle ring 4 the mark 1 of the 1 has, as stated above, two black code circular ring segments of length 1 and two further black code segments of length 3. This coding of this code circular ring 4 is referred to below as 1-1-3-3 coding. For example, if an encoding system contains only such 1-1-3-3 encodings, it can be ruled out that by covering one or more code circular ring sectors of the selected color (here black), another valid code of the encoding system arises, regardless of whether For example, by the simultaneous coverage of two code circular ring sectors a possibly existing parity check condition is still met and the inventive claim that the code annulus of the marking system each have the same number of code annulus segments is still satisfied.

The coding system of the marker 1 of the 1 which exclusively provides encodings with four black code circle segments in the coding system will hereinafter be referred to as 4-segment coding for short.

However, the aforementioned development of the invention has the disadvantage that the number of valid codings available in the coding system is considerably limited compared with a maximum number of codings possible on account of the selected bit length of the coding system. This can be advantageously compensated in part by allowing not only code loop rings of a coding system each having the same number of code loop segments of certain lengths, but allowing code loop rings each having a number of code loop segments of particular lengths selected from a group of code circle segments of certain lengths permits. However, care should be taken to ensure that only those combinations are chosen in which by covering of individual code circle Sekto From codec ring segments no other valid codings of the coding system arise.

Independent of the chosen one Coding system are also individual marks according to claim 9 Subject of the invention, in which the central circle or circle in its center a target, in particular a target point, has a target circle or a target cross. This target in the center of the central circle or circular ring serves the facilitated manual optical aiming of the central circle or ring, e.g. with a theodolite.

Further preferred embodiments of the invention are the subject of the dependent claims.

The invention will be further elucidated below with reference to marking systems consisting of markings, each with a code circle ring of 12 to 18 code circle sectors. These 12 to 18 code circle sectors then correspond to coding of the coding system of 12 to 18 bits. In practice, these bit numbers provide meaningful maximum numbers of encodings in an encoding system, namely, in the case of nCodebits, a maximum of 2 ⁿ codewords in the encoding system. In the case of 12 bits, these are 4,096, in the case of 18 bits 262,144 basically maximum possible codewords.

Reserved each one of the bits for a parity check - e.g. by the demand for even parity -, halves by the omission of a bit the number of in principle maximum available standing codewords.

By the preferred requirement for at least one pair of opposing ones Code annulus sectors of the same color - i. a couple on the code circle ring opposed set bits - and by the preferred requirement for rotational invariance of the code results in a further reduction of the available codings, e.g. (with additional Parity check) 12 bits from 4,096 to 148 and 18 bits from 262,144 to 6,767 encoding options (compare Tab. 1).

By the inventive claim that the coded Markers of the marking system each have the same number of Have color changes or of code-circle segments on the code-circle ring, results in a further reduction of the available coding possibilities in the coding system.

table 1 shows the code word lengths 12, 14, 16 and 18 bit encoding options dependent on from the number of code circle ring segments, with an additional one Parity check, one Rotational invariance as well as at least one pair opposite bits set in the coding system has been requested. For the particular practice-relevant codings with 14 and 16-bit codeword length remains the largest number of coding possibilities when specifying four segments per code ring, namely 201 or 755 valid ones Coding possibilities.

The described selection processes can be advantageously carried out by a data processing system, since they can be easily programmed for a computer implementation. For example, the requirement for rotational invariance of all encodings of the encoding system, ie the requirement that no encoding be included in the encoding system, may be present at the start of reading the code loop at any arbitrary code circular ring sector 6 provides another valid coding of the coding system, to be checked by a data processing system in the following manner:
First of all, one assigns code words corresponding to the basically possible code circle rings, eg the coding corresponds to the marking 1 of the 1 the codeword 0010001110100111 (black was set equal to 1, white as 0, the starting point of the reading of the code circle ring is chosen arbitrarily). This is done for all basically possible code circle rings of the coding system. Subsequently, the bits of each code word are cyclically shifted in the respective code word, until at the beginning of the code word results in a maximum number of zeros. For the coding of the marking 1 of the 1 then results in the bit sequence 0001110100111001 (by the cyclic shift of the code bits, their ranking among each other, of course, is maintained, a rotation of the code circle ring 4 simulated). If this operation has been carried out for all codewords of the coding system which are available for selection, the codewords obtained are compared. If two or more codewords of the coding system now agree, they must be eliminated except for one from the coding system, since otherwise the corresponding codec ring is not rotationally invariant.

On similar Way, the other requirements that the inventive coding system mandatory or preferred to fulfill in an advantageous development, simply check by computer. For example means the demand that is on the code ring at least two opposite each other identically colored Sectors must be located with an 8-bit codeword that either the first and fifth or the second and sixth or the third and seventh or the fourth and eighth bits of the codeword are "0" or "1" at the same time.

Around an even greater security the coding evaluation can be provided that the coding system contains only certain types of n-segment code-circle rings.

table 2 contains for 4-segment codes with 12, 14, 16 and 18 bit codeword length information about the valid codewords taking into account the further o.g. Restrictions (a parity bit, rotation invariance of the code; at least one pair of opposite set bits), if the four code loop segments each have specific lengths. Table 2 shows that for the code segment configuration 1-1-1-3 at a codeword length of 14 bits (the code loop sectors take on equal sharing then each an angle of 25.7 ° on) 31 possible code words remain while it for one 1-1-1-9 code segment configuration with a codeword length of 12 bit at all valid Codeword gives more.

Maximum possible Numbers valid codewords kick for 12-bit code word length (due to the parity check bit then 11 significant bits remain) in the code segment configuration 1-1-2-2, at 14 bit code word length (equivalent to 13 significant bits) in the same code segment configuration, at 16 bit in the configurations 1-1-2-4 and 1-2-2-3 and at 18 Bit (which means an angular size of the individual in case of equal division) Code circle sector of 20 °) in the same code segment configurations. It turns out then at 16 bit 16 different usable codewords, at 14 bits 48 codewords, at 16 bit 105 codewords and at 18 bits, 240 codewords.

Around the number of usable codewords for a given codeword length and Retention of the rest To increase requirements, one can in an encoding system also codings with the same number of Code annulus segments, but different but still fixed lengths of these Combine code loop segments. This possibility is also in this table 2 laid down. The combination only needs to be taken care of be that through Covering or shadowing of parts of code circle segment no other valid codewords of the coding system arise.

As from Fig. 2, for example, at 12 bits of codeword length (i.e. 11 significant bits on a parity check bit) the number of possible ones valid codewords increased to 26 when Combine the code segment configurations 1-1-1-3 and 1-1-2-2 in a coding system (combination 2 of Table 2 for 12 bits). The combination 1 of Table 2 for 14 bits (consisting of the five possible Code segment configurations 1-1-1-5, 1-1-2-4, 1-1-3-3, 1-2-2-3 and 2-2-2-2) provides e.g. 89 possible valid Code words.

table 3 shows by way of example a combination matrix for various Code segment configurations of a 4-segment code at 14-bit codeword length (i.e. 13 significant bits), which code segment configurations respectively in pairs can be combined with each other. For example, the Code segment configuration 1-1-1-7 with 23 other 4-segment code segment configurations in pairs combinable while the 4-segment code segment configuration 1-1-2-2 only with four other code segment configurations in pairs can be combined.

It can be seen from Table 2 that with a combination of two or more different 4-segment code segment configurations with a code word length of 12 bits ( 11 a maximum of 26 different valid codewords ("combination 2"), 14 bits maximum of 89 codewords ("combination 1"), 16 bits maximum 309 codewords ("combination 1") and 18 bits (17 significant bits) a maximum of 738 possible valid codewords ("combination 3").

Finally shows Table 4 (assuming the same requirements as Table 1) all valid codewords in a 14-bit 4-segment coding. It results in total 201 possible valid Code words, according to the corresponding value from Table 1. "*" indicates the codewords, leading to a combination of the code segment configurations 1-1-2-2 and 1-1-1-3 belong. These are 79 codewords, according to the "combination 2 "from Table 2.

In 2 By way of example only, preferred embodiments of the tags belonging to the codewords number (* 36- * 44) of Table 4 are shown.

• – Der Zentralkreis der Markierungen enthält einen zentralen kleinen Zielkreisring zur optischen Anmessung mit einem Theodoliten.
• – Der Codekreisring ist in unmittelbarer Nähe des Zentralkreises angeordnet, dadurch wird eine Fehlzuordnung eines Codekreisrings zu einer benachbarten Markierung ausgeschlossen.
• – Ein Codekreisring-Sektor bzw. ein Code-Bit zur Paritätsprüfung ist vorhanden, so daß Einfachfehler erkannt werden.
• – Es ist eine für fotogrammetrische Zwecke ausreichende Anzahl von möglichen gültigen Codewörtern, nämlich 79 Codewörter, vorhanden.
• – Der Codekreisring ist rotationsinvariant angelegt, so daß auf ein Start- und Stop-Bit verzichtet werden kann.
• – Mindestens ein Paar einander gegenüberliegender schwarz gefärbter Codekreisring-Sektoren erleichtert das Identifizieren einer Markierung.
• – Die Tatsache, daß das Markierungssystem ausschließlich Markierungen mit Codekreisringen mit jeweils vier Segmenten enthält, verhindert Mehrfachfehler durch ein Abdecken oder Abschatten kompletter Codesegmente.
• – Die Tatsache, daß das Codierungssystem ausschließlich die Codesegment-Konfigurationen 1-1-2-2 und 1-1-1-3 enthält, erhöht die Auslese-Sicherheit der codierten Information noch weiter.

The in Table 4 and 2 As shown in a particularly preferred embodiment, a 14-bit 4-segment coding system of "*" code words shown in the combined code segment configurations 1-1-2-2 and 1-1-1-3 satisfies a whole series of requirements a particularly simple and reliable identification of the encodings of coded markings allow:

• - The central circle of markers contains a central small target circle ring for optical measurement with a theodolite.
• - The code circle ring is arranged in the immediate vicinity of the central circle, thereby misalignment of a code circle ring is excluded to an adjacent marker.
• - A code loop segment or code bit for parity check is present so that single errors are detected.
• There is a sufficient number of possible valid codewords, namely 79 codewords, for photogrammetric purposes.
• - The code circle ring is created rotationally invariant, so that can be dispensed with a start and stop bit.
• At least one pair of opposing black colored code circle sectors facilitates identification of a mark.
• The fact that the marking system contains only four-segment coded ring markers prevents multiple errors by covering or shadowing entire code segments.
• The fact that the coding system contains only the code segment configurations 1-1-2-2 and 1-1-1-3 further increases the read-out security of the coded information.

Claims (11)

Marking system provided with codes corresponding to a coding system, in particular for measuring purposes, with markings ( 1 ) with - a central circle or circle ring ( 2 ) and - at least one central circle or circle ring ( 2 ) surrounding code circle ring ( 4 ), which is divided into radial sectors ( 6 ), which correspond to the individual code bits of the coding according to the coding system, - whereby a 1-bit of a certain color of the code-circle-ring sector ( 6 ) and a 0-bit of a different color of the code circle ring sector ( 6 ), so that in the code ring ( 4 ) at the crossing point ( 8th ) between a code circle ring sector ( 6a ) of a bit-type to an adjacent code-circle sector ( 6a ) of a different bit type a color change takes place and - whereby the coding of the coding system in each case the same number of code circle ring sectors ( 6 ) or bits, characterized in that - the coded markings ( 1 ) of the marking system in each case the same number of color changes on the code circle ring ( 4 ) exhibit. Marking system according to claim 1, characterized in that the central circle or ring ( 2 ) in its center a target, in particular a target point, a Zielkreisring ( 5 ) or a target cross. Marking system according to claim 1 or 2, characterized in that between the central circle or -kreisring ( 2 ) and code circle ring ( 4 ) a contrast ring ( 3 ), which has a uniform color, of the color of the central circle or circle ( 2 ) has different color. Marking system according to one of the preceding claims, characterized in that the code circle rings ( 4 ) of the markings ( 1 ) at least one code circular ring sector ( 6a ) whose color in an even number of code-circle sectors is identical to the color of the respective code-circle sector ( 6a ) on the code circle ring ( 4 ) opposite code circular ring sector ( 6b ) or in the case of an odd number of code circle sectors ( 6 ) identical to the color of the two respective code circle annulus sector respectively on the code annulus ( 4 ) is opposite code circular ring sectors. Marking system according to one of the preceding claims, characterized in that the coding system comprises a bit for parity checking or the code loop rings ( 4 ) of the markings ( 1 ) each have a code circle ring sector ( 6c ) for parity checking. Marking system according to one of the preceding claims, characterized in that there is no coding in the coding system which, when the read-out of the code loop formed according to the coding system starts ( 4 ) at any arbitrary code circular ring sector ( 6 ) provides another valid coding of the coding system. Marking system according to one of the preceding claims, characterized in that the code circle rings ( 4 ) of the markings ( 1 ) of the marking system in each case the same number of code circular ring segments ( 7 ) of certain lengths, being used as the code loop segment ( 7 ) a series of adjacent code circular ring sectors ( 6 ) is designated the same, fixed selected color. Marking system according to one of the preceding claims, characterized in that the code circle rings ( 4 ) of the markings ( 1 ) of the marking system each have a number of code circle segments ( 7 ) of certain lengths selected from a group of code loop segments ( 7 ) of certain lengths, being used as the code loop segment ( 7 ) a series of adjacent code circular ring sectors ( 6 ) is designated the same, fixed selected color. Marking provided with an encoding corresponding to an encoding system ( 1 ), characterized in that the central circle or circle ( 2 ) in its center a target, in particular a target point, a Zielkreisring ( 5 ) or a target cross. Marking ( 1 ) according to claim 9, characterized in that between the central circle or -kreisring ( 2 ) and code circle ring ( 4 ) a contrast ring ( 3 ) at which is a uniform, of the color of the central circle or circle ( 2 ) has different color. Marking ( 1 ) according to claim 9 or 10, characterized in that the code annulus ( 4 ) at least one code circle ring sector ( 6a ) whose color in an even number of code circular ring sectors is identical to the color of the code circular ring sector ( 6a ) on the code circle ring ( 4 ) opposite code circular ring sector ( 6b ) is identical with the color of the two the code circular ring sector on the code circular ring (in the case of an odd number of code circle ring sectors) 4 ) is opposite code circular ring sectors.