DK175743B1 - Polygonal information encoding article, process and system - optically scans data array of information encoded polygons to retrieve information - Google Patents

Abstract

The optically readable label (30) comprises a data array of a multiplicity of information-encoded polygons (20) arranged in a predetermined geometric pattern, polygons (20) having two different optical properties. The process encodes information in the optically-readable data array of information-encoded polygons (20) by assigning optical properties to individual polygons in a perdetermined pattern, ordering the polygons (20) in a predetermined sequence, and printing the polygons (20) with at least two optical properties. The process retrieves information by optically scanning the data array of information-encoded polygons (20), preferably hexagons, and creates an optical replica of the digital bit stream representative of the optical properties of the information-encoded polygons (20), decoding that optical replica and retrieving the decoded bit stream.

Description

in DK 175743 B1

The present invention relates to an optically readable object which stores encoded information which includes a plurality of information encoded polygons having the same shape and more than six sides, which polygons have one of at least two mutually different optical properties. The optically readable article may be provided in the form of a label attached to or printed on a substrate.

Merchandise, various components, letters, packages, containers and a whole register of corresponding parts shipped or transported must often be identifiable by origin, identification of means of transport, destination, name, price, part number and many others. information. In other applications, reading encoded information printed on labels affixed to such items may allow automatic registration of sales figures and inventory statements or the operation of electronic cash registers.

Other uses for such encoded labels include automatic routing and sorting of mail, packages, luggage, and similar items, and placement of labels with production instructions on raw materials and components in a manufacturing process. Labels for these types of items are usually marked with barcodes, one of which is the "Universal Product Code". Numerous other barcode systems are known in the art.

25 Commercially available barcode systems typically lack sufficient data density to meet the immediate and increasing need for encoding more and more information on the labels, which at the same time is becoming smaller. Attempts to reduce the overall size and spacing between bars in different barcode systems to increase data density have not solved the problem. Optical scanners of sufficient resolution to detect barcodes with contrast bars located at a distance of five mils (about 0.13 mm) or less are generally not economically suitable for fabrication because of the accompanying narrow tolerances in the label printing process

I DK 175743 B1 I

I I

and the sophisticated optical apparatus required for reading

bit encoded lines with these dimensions. Instead you

In the feed, very large barcode labels must be produced for I

B recording the increased amount of data, with the result that I

5 such labels are not sufficiently compressed to

You could be placed on a small object. Another essential I

In fact, the cost of the medium of which the label I

You are manufactured, such as paper. A small label causes less I

In paper costs, than a major label. This cost is yours

B 10 is a significant factor in operation with large quantities of objects. IN

I Instead of barcodes can be used: circular shapes

In feeder using radially spaced wedge-shaped code parts B

B mentions, as disclosed in U.S. Patent No. 3,553,438, B

I or concentric black and white bit-encoded rings, such as I

B. 15 disclosed in U.S. Patent Nos. 3,971,917 and 3,916,160. fl

In addition, networks with rows and columns of data can be used

In encoded squares or rectangles, as disclosed in U.S. Pat

B script No. 4,286,146, or microscopic points placed H

in cells constituting a network of uniform distances, such as fl B 20 disclosed in U.S. Patent No. 4,634,850, and tightly packed multiples

In colored data fields or points or elements as mentioned in

in U.S. Patent No. 4,488,679. Certain of the aforementioned I

coding systems, and other known coding systems within the range f1 are characterized by errors in the data density, as is the case

B 25 it with the encoded circular patterns and the rectangular nets

B yellow or square fields. As is the case with fl

fl nets which include microscopic points or multicolor I

For wet elements, a special orientation and special I are required

fl transport means, limiting their applicability to fl fl 30 highly controlled reading environments. . fl

fl In GB-A-1 216 539, objects are referred to with encoded informa- B

flemation related thereto, as well as methods of manufacturing fl

fl of such articles, and methods of storage and / or H

fl providing data using such objects, B

B 35 which items in particular are trade labels. On the labels B

B, at least two rows of B are printed for optical machine reading

3 DK 175743 B1 black and white areas. One row is a period of time and alternately has black and white areas indicating consecutively the following information positions. The other row (s)

J

is an information row and has a sequence of blacks and / - in 5 or white areas aligned with the time series positions and with encoded information. Each black or white area in the time series indicates a bit in the information row (s) provided. A square set of information traces may be provided with a time row along the top 10 edge and a row indicator column with alternating black and white squares along a side edge. In GB-A-1 216 539, instead of the black squares are proposed parallelograms, ovals, squares with concave sides and X-shapes. Reading is performed using emitted or reflected incident light on any kind of photocell or photosensitive device, and may involve the use of a buffer storage for retaining data from the label for subsequent recording, validation and loading into a computer.

US-A-3 959 613 discloses a divergent code type, in which dark, wedge-shaped code elements are used on a white j background, and data is encoded in that a wedge-shaped element j has the tip pointing to the right, representing binary 1, and The left-hand wedge-shaped elements represent binary 0. As a result, decoding a label using this known code will require a determination of the direction in which each wedge-shaped element has decreasing thickness. The optical properties of all wedge-shaped elements are the same and are not used in encoding and decoding.

Due to the magnitude of speed in modern transmission systems, where e.g. Conveyor belts with a width of 3 to 4 feet (about 90 to 120 cm) are used and the conveyor belt speed approaches 100 inches (about 250 cm) per second. second or more where packages of different heights are carried; on which information-encoded labels are affixed, and 35 due to the need for the use of a small, inexpensive,! compact label of approx. 1 square inch (approx. 6 cm2)

I DK 175743 B1 I

I 4 I

There are great demands on the optical and decoding facilities that I

You are required to locate and read the data encoded I

In labels on such fast-moving packages and the like. IN

There are difficulties in simply collecting the label car-

In 5 headed in the optical scanner. Further, when the label image reaches 4 I

Once recorded or identified, this must be decoded

exactly before the next operation with the package in transport sy- I

The voice takes place, often within a fraction of a second. IN

These problems have led to a need to provide

I 10 a simple, fast and inexpensive way to signal presence- I

In the case of a .data-encoded label within an optical scanner I

field of view which scanner is mounted so that you can

You are scanning the entire conveyor belt. It is desirable, I

In whether this property can be associated with a data set with

In 15 high density, as explained later in more detail. IN

I Datasets of registration markings are known before I

for the area, e.g. may be designed as concentrate

In geometric shapes, with rings, squares, triangles, I

hexagons and numerous variants thereof, as explained I

In U.S. Patent No. 3,513,320 and No. 3,603,728. In the US pa- I

In Tents Nos. 3-693,154 and Nos. 3,801,775, I-

clarified the use of symbols which include concentric I

In circles, for identification and position, which I

symbols are attached to objects which are to be optically scanned

For 25 res. However, in these systems two separate acids are used

In bolts for determining identification of the data area and H

In its location, which increases the complexity of the I

logical circuits required for the detection of the symbols, while also reducing the associated

3 0 data field capacity for data content. When two symbols are used I

damage to one of these will also cause problems

In locating the location of the data field as well as problems

You with the associated ability to provide information

In from the data field. In the last mentioned system, separate I is used

In 35 position and orientation markings at opposite ends I

of the data tracks with data-encoded linear markings with I

5 DK 175743 B1 a limited opportunity for data content.

The aforementioned systems are generally scanned with an optical sensor designed to produce a video output signal that corresponds to the change in intensity 5 of the light reflected from the data cell as well as from the location and orientation symbols. The video output of such a system, after being digitized, is provided with a particular bit pattern which can be juxtaposed with a predetermined bit order. These systems, however, suffer from the disadvantage that two separate symbols are required to first detect the presence of the image and then to determine its orientation. Also, the process by which the digitized output of the optical sensor is matched with a predetermined bit sequence, representing both location and orientation symbols, is such that it is more likely that erroneous readings are provided than is the case. with the method and systems provided by the present invention, which is due to the fact that known label recording systems provide an inflexible characterization of the level of the registration marking signal.

U.S. Patent No. 3,553,438 discloses a circular data set with a centrally located registration mark,

2 which includes a number of concentric circles. The registration mark provides a means for recording the circular label by the optical sensor and for determining the geometric center of the label, and thus the geometric center of the circular data set. This is done by 30 logic circuit operations to record the pulse pattern representative of the design at the center of the registration mark. However, the data set, as was also the case with barcodes, has only a limited data capacity, and the system requires a different circular scanning process. Using both a linear and a circular scan in a system with such limited data capacity,

I DK 175743 B1 I

I I

In turn, you create an unwanted complexity in the plant

I for a slight increase in data capacity compared to I

In known barcodes. IN

I To increase the data capacity of data sets, I

In 5 developed codes with a multiplied high density of colored * I

In dots, as disclosed in U.S. Patent No. 4,488,679. IN

Systems of this kind disclosed in U.S. Pat

4,488,679, however, requires the use of manual optical I

In scanners, which scanners cannot detect and decode I

10 fast-moving data sets on packets transported on an I

H fast-moving conveyor belt. Similarly, you require

In high density coding systems using microscopic I

H data-encoded dots, as disclosed in U.S. Pat

I 4,634,850 special transport agencies so as to ensure that;

15 that the data set is moved in a designated direction and not with an additional I

poor orientation, as will be the case with I

In a package transported on a conveyor belt or the like

body. Thus, the encoded label must be read track I

for tracks using a linear scanner which is pre- I

I 20 bonded with the label conveyor to provide an I

suitable decoding of the information encoded on eti- I

decal. In the said patent, the location of the card I shall be

relative to the sensor is very carefully controlled to be I

readable. IN

25 Various colors have also been used within I

In the area of manufacture of barcode systems, thus I

to overcome the optical problems of scanning a lot

small strokes. A barcode to which more than two I is used

In optical properties for encoding data in a data set, I

E.g. use of alternating black, gray and white lines

is disclosed in U.S. Patent No. 4,443,694. However, you can

systems of this kind, although they constitute an improvement

ring compared to prior art barcode systems, not I

nevertheless, it does not achieve the compression and data density,. IN

35 provided by the invention explained herein. IN

H According to the invention, an optically readable object of I

7 DK 175743 B1 the species previously mentioned at the outset, characterized in that the polygons are located with the geometrical centers of neighboring polygons lying on the angular tips of a predetermined two-dimensional grid, and thus each 5 polygon is formed substantially as a hexagon.

Preferred embodiments of the invention provide: compact, high information density, optically readable labels, 10 optically readable labels which can be encoded with approx.

100 highly error-protected alphanumeric characters per square empty label area, compact large information density on optically readable labels which can be read with an optical sensor when the label is attached to a package or other similar object and transported by a high speed conveyor system, regardless of the orientation of the package on the system or the difference in heights for such packages on which the optically readable label is attached.

An optical so-called field sensing and decoding apparatus for reading such an optical readable object which stores encoded information is advantageously provided with: (a) means for illuminating a predetermined area, 25 (b) means for optical imaging of the predetermined illuminated region through which the object is arranged to pass, producing analog electrical signals corresponding to the intensity of light reflected from the polygons to the imaging means, (30) c) means for converting the analog electrical signals to a sequenced digital bit stream corresponding to the intensity of the light recorded by the image-forming means, (d) means for storing the digital bit stream for subsequent decoding of the object, (e) means for decoding the digital bit stream,

I DK 175743 B1 I

IN

which decoding means produce an electrical output

corresponding to the encoded information. IN

In a preferred embodiment of the invention, you can

In a label that is reliably decoded, even if it pours, you are

H 5 curled, crooked, partially destroyed or partially torn Λ I

In pieces. IN

In using preferred embodiments of I

the invention allows the placement of a label which passes under I

a high speed optical sensor, and the decoding of I

The label is determined with a high degree of data integrity. IN

I Optically readable labels with compact large informa- I

density can be encoded by dividing the information that I

You can encode, in messages of high and low priority to you

generating a hierarchy of messages which separately I

I 15 is error protected to ensure the integrity of the encoded I

information, I

and optically readable compact high density labels

may be encoded and decoded by methods including I

error correction options so that a restore can occur, I

20 erroneous reading or missing information, which happens j I

with a priority of the high priority encoded 1 I

H notice, I

Optically readable labels can be made on known I

show by printing means and decoded with relatively cheap I

25 logic circuits. IN

A preferred embodiment of the present invention

The invention includes an optically readable label for storage I

of data encoded in bit form, the label including-

are a number of information-encoded polygons that are placed

H 30 ready to touch each other is in partial contact with each other

second or not at all adjacent to each other at least

Have two different optical properties. IN

Optically readable labels according to the invention may be included

grasp predetermined two-dimensional geometric polygon sets, I

35 where the geometric center of such polygons lies in I

the intersections of the intersecting axes, which explain I

In more detail later, in a predetermined two-dimensional set, the polygons are provided with at least one of at least two different optical properties. The polygons on such optically readable labels may be regular or irregular polygons, and the two-dimensional set of polygons on the optically readable labels may be provided with two or more same or different angles spaced apart in the plane of the label.

Optically readable labels may be printed on assemblies 10 of polygons which are adjacent to each other which are partially clashing or which do not touch each other. Thus, the last two structures will be provided with a number of intermediate regions on the optically readable label between adjacent polygons. Such intermediate regions may have the same or different optical properties as the two or more optical properties of the polygons.

In addition to the aforementioned various designs of geometric polygonal cells, the location of such polygonal cells, and the geometric design of the optically readable labels provided by such arrays of polygonal cells, the optically readable labels provided by the present invention may include a capturing marking consisting of a series of concentric rings to aid in locating the optically readable labels on the articles to which they are attached, especially in dynamic label reading systems.

European patent no. 0 336 769 discloses a data set which includes a largely square set of approx. 1 square inch (approx. 6 cm2) with adjacent hexagons, 30 forming rows and columns, and a centrally located capture mark with a geometric center indicating the geometric center of the data array. The capture mark may be provided with a design which is selected from a number of geometric shapes with optical properties capable of producing an easily recognizable video signal when scanning with an optical

I DK 175743 B1 I

I 10 I

In sensor along a linear scan line through capture capture

In the geometric center of the marking. In a preferred embodiment I

shape, the intercept mark is formed with a number of cones

In centric rings with contrasting reflection properties,

I 5 thereby providing a periodic video signal when the scan I

the ring is made linearly. By using analog filteror- ^ I

In palates as part of the method of locating and in I

In the decode data set, the signal generated is compared

You are given directly by the optical sensor with a predetermined I

10 frequency, allowing for a fast and I

In exact comparison of the frequencies with subsequent I

In determining the location of the data set attached I

In for a backing. The analog electrical output from I

In the optical sensor which represents the information input I

In the 15th label, it is then digitized and decoded. When used I

In the late stage of an analog bandpass filter, I have been created

The possibility of capturing the label can be exercised without H

H needs decoding of the information encoded label. H

By locating the capture marking center can

20 a reference point is defined on the data set. If the center H

of the capture marking is located in the center of the label, I

You can exercise a simultaneous determination of the center of education

the capture tag and for the data set. It must be preferred, I

H that the capture mark is located in the center of the label, I

25, but in practicing the present invention, it is not

a demand. IN

I The Optically Readable Dataset in European Tent No. 0 336 I

769 is designed so that 100 or up I can be encoded

to hundreds or even more fail-safe alphanu- I

In 30 meric grades in an area of approx. 1 square inch (approx.

6 cm2) when the hexagons are encoded using three I

reflection properties, such as the colors black, white and gray. IN

H For a sensor with a given optical resolution, it enables I

In the invention, a much closer gasket I is provided by the invention

In 35 of the information than is possible with barcode systems. IN

I If e.g. a high resolution optical sensor is used in I

In connection with the system provided by the present invention, several hundred alphanumeric characters may be encoded on a square inch (about 6 cm 2). Alternatively, one hundred characters per square inch (about 6 cm 2) is easily detected with a relatively low-resolution sensor in the system provided by EP-A-0 336 769.

Optically readable labels in said European patent can be produced with varying data densities using as few as two or more contrasting optical properties.

Larger data densities and the inclusion of a capture tag in the system provided by the invention require a scanning apparatus of increasing complexity as well as the addition of more elaborate decoding algorithms for reading the encoded message, compared to a barcode reading system.

In the present invention, data encoding can be provided by encoding a plurality of bits from a binary bitstream in a set of opposite hexagons, each hexadec being provided with one of at least 20 two different optical properties, although the encoding could alternatively be practiced on a hexagon-by-hexagon basis.

The digital bit stream may be generated by a computer based on manually entered data or data which is otherwise converted to a binary bit stream, or provision 25 may have occurred as a pre-recorded digital bit stream.

Data to be encoded is arranged in bits in a predetermined order and in predetermined geographical areas of the data set to increase the number of transitions between hexagons with different optical properties.

30 The messages to be encoded are subdivided into high and low priority messages, which are arranged separately in different geographical areas of the data set. High priority messages can be repeated in low priority message areas to reduce the possibility of a high priority message being lost due to scanning errors that may be triggered

I DK 175743 B1 I

I 12 I

by fouling, tears, creases and other species damage I

I of the dataset. High priority messages are encoded in an I

In the center area of the data set, near the capture mark. IN

In the preferred embodiment, to protect the med

In the division against damage, which damage with greater 'I

Probably takes place in the peripheral areas of the data set

ment. It is preferable that in the data set there are I-

Provided opportunities for error correction using I

In the large provided by the present invention

I 10 information capacity to ensure a high degree of data error- I

In freedom by decoding the message. A pixel grid I is used

I of suitable density when printing the hexagonal label

I with different optical properties, although other printing processes I

You can use it without deviating from the present

The spirit of invention. The pixel network is arranged so that when the eti

In the chain, pressure is the optical properties of each hexagon I

predetermined so that they can later be decoded for repetition

providing the data identified by the encoding

In the ring of the individual hexagons. This type of printing process is I

H 20 is well known in the art and standard pressure can be used

machines and bit-setting techniques for hexagonal printing

with the required optical properties. IN

By capturing data encoded in bit order I

hexagon arrays constituting the data set must be included

H 25 coded labels are passed through a pre-designated illuminated envelope

and optically scanned using an electronically driven I

optical sensor or manual scanning means can be guided

across the labels. The optical sensor produces an I

output signal which is an analog electrical signal which receives

30 corresponds to the intensity of the individual reflectance of a label area

tion properties, as recorded by the individual H

H pixel in the optical sensor. Using an analog filter I

H, the analog signal from the optical sensor must first be

You are compared to a predetermined frequency size corresponding to I

In the predetermined signal frequency from a capture signal! IN

If this is present in the data set. There is! IN

In accordance with the label, the label is accepted and the center of the capture marking is determined, thereby also defining a reference point in the data set. The analog signal is simultaneously digitized continuously using an analog-to-5 digital converter and stored in an image buffer store. The stored digitized data, which represents the total in the label, is available for further processing under decode! process.

For stored logic circuits, the digital data is changed

10 for an ordered series of transitions between hexagons with different optical properties. In a preferred embodiment of the invention, this is accomplished by calculating the standard deviation of the intensities of the reflective properties recorded by the optical sensor in each pixel and a predetermined group of pixels surrounding the first pixel. Large standard deviations therefore correspond to transition ranges on the transitions between contrasting hexagons.

Further data transformations involving filtering programs to determine the orientation, direction and distance between the hexagons are performed on the digital data. The main steps in this process are: (1) Filtering the non-linear translated version of the digitized image.

(2) Determining the orientation of the label, preferably by locating the three axes of the image (as shown in Figure 2) and determining which axis is parallel to two sides of the label.

(3) Determining the center of each hexagon and determining the gray level in each center.

30 (4) Conversion of the gray levels into a bit stream. : (5) After designation, initiate error correction of the bitstream, i (6) After designation, change the bitstream to a predetermined character set.

The method of EP-A-0 336 769 which is explained in connection with hexagons with two or more optical properties.

I DK 175743 B1 I

I i

creating, and in particular, the steps of adjusting the optical image I

For each skewed label, tear and similar phenomena, I apply

In addition to other species of polygonal cells used in export I

In embodiments of the present invention. IN

The invention is explained in greater detail below by an I

By way of example, with reference to the drawing, in which:

FIG. 1 is a plan view of an intercept mark I

Compound formed with concentric rings of the present invention

In the invention, I

In FIG. 2 shows part of an optically readable label with I

hexagonally arranged for encoding data I

In accordance with the present invention, I

In FIG. 3 is a plan view of an entire optical readable I

hexagon label positioned against each other with three front I

In 15 different optical properties for encoding binary data I

With an intercept marking according to the present invention

In the invention, I

Fig. 4 is a plan view of three cell at cell I

H placed groups of hexagons, opposite one another, I

20 which may act as a base encoding unit in a preferred I

embodiment of the present invention;

FIG. 5 is a group overview showing a geographical I

representation of a data set including 33 I

rows and 30 columns, providing a grid of 11 µl

25 rows and 10 columns with 3x3 encoding cell group units I

with hexagons, I

In FIG. 6 is a schematic representation of a camera setting

system according to the present invention

I for setting the position of the optical light sensor in I

In accordance with the height of the package being recorded,

In FIG. 7 is an arrangement of the steps in it by the I

The present invention provided the decoding process, I

FIG. 8 is a flow chart illustrating progress. IN

the method of locating the capture mark, il

FIG. 9 is a flow chart showing the structure of I

15 DK 175743 B1 the encoding and decoding program and the data stream, fig. 10 is a flow chart showing the sequence of image processing steps; FIG. Figure 11 is a plan view of a group of up to 5 regular hexagons positioned with the geometric center of adjacent hexagons located at the angular tips of a regular hexagon; 12 is a plan view of a group of irregular hexagons positioned adjacent to each other! 10 geometric centers of adjacent hexagons lying on the angular tips of an irregular hexagon; Figure 13 is a plan view of a group of partially juxtaposed substantially hexagonal shapes positioned with the geometric centers of adjacent 15 polygons located at the angular tips of a hexagon; 14 is a plan view of a group of polygons positioned opposite each other and substantially shaped as hexagons with the geometric center of adjacent polygons located at the angular tips of a hexagon, FIG. 15 is a plan view of an optically readable label with adjacent polygons formed essentially as hexagons with the geometric centers of adjacent polygons located on the angular tips of a hexagon and including a capture mark.

By encoding information using contrasting colors in juxtaposed hexagons or "cells" placed in a honeycomb pattern in a predetermined order and arrangement, the information can be stored on the label so that it can be recalled by an electric -30 trooptic sensor. Polygonal cells other than hexagons, which are located with the geometrical centers of adjacent polygons disposed on the angular tips of a hexagonal or other pre-fixed array, can similarly be used to encode information on an optically readable label. Such polygonal cells, when positioned with their centers at predetermined locations in a two-dimensional

I DK 175743 B1 I

I I

In geometric arrangement and when encoded in a predetermined I

In order using different optical properties

In one number of such polygonal cells, "read" by an I

electro-optical sensor and subsequently decoded in accordance with I

I by the method of the invention, which I

The following is explained. H

In the polygonal cells, information-encoded units, I

You are formed by a closed broken line, which cells are I

You placed in a predetermined two-dimensional pattern on an I

In 10 optically readable label. The label designs include an I

In large number of different polygonal shapes and arrangements with I

In various geometric designs, such as hexagonal, rectangular

In yellow and square arrangements, what designs

Useful in practicing the invention. "Adjacent" poly- I

In 15 gonal cells can completely bump into each other, in I

To some extent, lie against each other or do not lie H

In opposition to each other on the optical I provided by the invention

In readable label. IN

"Polygons that are completely opposite to each other"

In 20, polygons are located with the geometric centers of adjacent I

In reverse polygons placed on the angular tips of a prior I

In fixed two-dimensional arrangement, and with the edges of polygo-H

In contact with the edges of immediately adjacent I

In polygons so that there is no space. "Partly up against I

25 spaced polygons "are polygons located in

with the geometric centers of adjacent polygons lying H

In the angular tip of a predetermined two - dimensional array,

In that the polygons are spaced apart somewhere 'I

along the edges concerned from the surrounding polygons, whereby H

In 30, a number of spaces are provided between the polygons on the H

optically readable label. "Polygons which do not line up with H

In each other "are polygons which are placed singly with the I

In geometric centers of adjacent polygons located on the wine- I

At the tips of a predetermined two-dimensional arrangement and I

I 35 without any contact between the edges of a single polygon and I

In the polygons that surround this polygon. Further, they can H

17 DK 175743 B1 polygonal cells and the predetermined two-dimensional grids or arrays on which the centers of adjacent polygons are located, be irregular, be spaced apart between the axes, or be regular with axes spaced evenly. Such two-dimensional alignment axes may be independent of the axes of symmetry, if any, in the polygonal cells.

The hexahts, as used in the label provided by the invention, exhibit significant advantages 10 in encoding information on a label. These advantages are: (1) For a given optical resolution, the hexagons can be packed closer than other polygons. Eg. , with a given resolution, the vertices of squares are more difficult to resolve, so that an otherwise unnecessarily large optical resolution is required to "read" squares. Circles should be optimal for optical resolution, but the space between adjacent circles is wasted and will complicate the processing and printing of the label image, as there is a need to attribute the spaces to an optical property. Hexagons 20 allow for maximum information packing in comparison with the circles or with other polygons, including octagons, squares, triangles, etc. Squares and triangles cause problems due to the sharp corners. Circles and octagons create problems because of the unused space between adjacent circles or octagons.

(2) A grid of hexagonally opposite sides has three axes. Using a square or rectangular shape label, the hexagon's main axis can be located from its predetermined ratio to a side of the label. This location of the main axis in a hexagon grid facilitates reading of the data encoded in the hexagon based on their relationship to the main axis.

As used herein, "label" means a single unit, with a suitable adhesive backing to be affixed to a package or product, the outer surface of a container or other article, and upon which the optically readable information

DK 175743 B1 I

mation. is printed in accordance with the present H

invention. H

"Optically readable data set" or "data set" means you

in this specification a pattern of juxtaposed H

5 hexagons or other polygonal cells with two or more j I

optical properties such that in a reversible manner H

can be encoded a collection of data from the individual optical properties I

creates of, as well as the spatial relations between the hexagons I

or whatever other polygonal cell shape now used. Sex- H

10, the edges or polygons printed so that they are in I

contains revocable information hereinafter referred to as H

as "information-encoded" hexagons or polygons, on H

because of the way in which the information is encoded in eti- H

decal. IN

15 The pattern of hexagonally positioned with the maximum number of transitions between the hexagons for optimum

reading and for maximum information storage density are referred to as I

a "honeycomb pattern".

The contrasting reflective properties used by H

20 by printing the individual hexagons or cells in H

the data set can be widely varied within it-> I

the spirit of invention. In the present writing, H means

"printing" placement of material with predetermined optical H

properties of a substrate, or alteration of the optical properties

25, as is the case with "thermal" printing. "Pressure-H

"also includes failure to secure a material H

having a predetermined optical property on a portion of the substrate, H

wherein the substrate itself has a designated optical property. Eg. H

, when printing hexagonal cells in black and white, H

30 only the black cells are actually printed if sub- I

the layer is white. As used herein, the white hexagonal I

cells thus also fall within the definition of the term 'I

"printing" or "printing". IN

"Optical Properties" as used herein means

Properties such as light absorption, reflection and / or refraction I

of the cells which are printed on different media. If the cells I

19 DK 175743 B1 is printing in black (black high density black), gray (black tones) and white (no printing on a white substrate), as is the case in a preferred embodiment of the invention, the material is said to be provided according to the invention with three optical properties.

"A plurality of concentric rings" or "concentric rings" 10 means herein and referring to FIG. 1 shows two or more concentric rings 12, one of which is constituted by the inner circular region 15, which is fixed 10 at the smallest radius "r" in the rings.

FIG. 2 shows part of an electro-optically scannable label according to the present invention. As shown in FIG.

2, the label includes a number of adjacent printed hexagonal cells arranged in a honeycomb pattern.

Each of the hexagons is denoted by the number 20, and includes six equal sides 22. The inner angles "a" of the hexagon are also equal, each of which is 120 °. In the embodiment shown, the hexagons are provided with a long vertical axis y-y and a horizontal axis 20 x-x. The size x-x in hexagon 20 is slightly smaller than the size y-y in hexagon 20 due to a regular hexagon's geometry.

In FIG. 3, a label 30 having dimensions of approximately 1 x 1 inch (about 2.5 x 2.5 cm) is shown, and approximately 888 hexagons or cells 20 will be provided (taking into account the fact that the middle part of the label in the preferred embodiment is seized by a capture tag 35 which consists of a number of concentric rings). These adjacent hexagons 20 naturally form horizontal rows of "R" indicated by dashed lines 31, and vertical bars "C" indicated by dashed lines 33. In this example, a label of size lxl a total of 33 horizontal rows "R" and 30 vertical 35 columns "C" of hexagon 20 are provided. Each hexagon is provided with a "diameter" of approx. 0.8 mm. There are more

DK 175743 B1 I

rows "R" than columns "C" in an area of square boundary I

in a honeycomb pattern of hexagons as a result of the up I

Hexagonal geometric gasket placed against each other. IN

; Referring now to FIG. 2 hexagons I

5 it can be seen that the hexagons are arranged in staggered I

and mutually overlapping vertical columns with alternating H

Hexagonally spaced vertically with coincident I

y-y axes, y-y The axes in the spaced-apart H

hexagons 20 are aligned with an outer vertical side 22, H

10 on an intermediate, offset hexagon, y-y The axes in hex- H

the edges 20 are parallel to the two vertical edges 32 and H

34 on the label, as shown in FIG. 3. Horizontal rows "R" I

is measured at the x-x axes through the center of the hexagon 20. H

As explained in more detail later, H is produced

15 the hex edges 20 by a printing process whereby the hex edges 20 H

printed with two or more different optical properties, H

eg. in contrasting colors. These colors may be white H

25, variety 26 and also, by choice, however preferred, H

gray 27, as shown in FIG. 3, though other contrasting

20 colors can be used. It is possible to use only two contra- H

dying colors, such as white 25 and black 26, as shown in FIG. H

2. In the preferred embodiment of the invention there is H

used three contrasting colors, white 25, black 26 and gray H

27, as shown in FIG. 3. The special shades of white, black and H

2 gray is selected to obtain maximum contrast so that identi- H

the fixation by an electro-optic sensor is made easier. Gray- H

The vault is so designated that its properties are approximately H

lies between the optical properties of white and black, thus H

as these are used in producing the label. H

30 The label 30 of FIG. 3 can be designed as a single H

label with, in a preferred embodiment, an area of 1 H

square inch (approx. 6 cm2) or, if a rear H is used

because of a suitable color (preferably white), the label H

be pressure directly on the surface of a gasket without the H

35 must be provided with a separate label. Due to the significance- H

by providing a background with a controlled I

21 DK 175743 B1 optical property as one of the contrasting colors, it is preferable to use a separate label as it is easier to control the background color of the label.

It is important that the hexagons printed on the label are aligned with the sides of the label because of the subsequent determination of the label's main axis, as explained later. The label is printed so that the y-y axes of the hexagons constituting the honeycomb will be parallel to the vertical sides of the label, 32 and 34, as shown in FIG. Third

By "reading" the hexagonal data set for decoding the information contained in each hexagon, it is essential that a sharp color contrast is provided between adjacent hexagons. For reasons explained later, the scanning equipment and the necessary software for decoding the hexagons will be simpler, the fewer optical properties used in encoding the hexagons. However, fewer optical properties will also reduce the data density on the label. In a compromise between the 20 amount of decoded information that can be stored on the label and the cost of scanning labels with many optical properties, it has been desirable to print the encoded hexagons with three different optical properties, namely fair, black, gray and white. . If the substrate or label has a good white background, the white hexagons can be produced in the absence of ink, and only black or gray hexagons must be printed.

In a preferred embodiment of the invention, the gray hexagonal cells are provided by printing the black ink cells, but only every 15 pixels of the pixel grid of a dot matrix printer is printed as explained herein. This is done using a halftone algorithm in a manner known in the art. This causes a printer to print a predetermined portion of pixels so as to produce a designated gray hexagon, while a black hexagon requires printing of

I DK 175743 B1 I

I 22 I

H each pixel within the hexagon. The special halftone algo- I

In rhythm used to print labels in the preferred! IN

fl embodiment is listed in the list of source codes I

In the mark "LABEL" in the program supplement page 29, lines 39-48. IN

fl 5 The black hexagonal cells can be formed by printing I

In with a standard black ink. As explained below, you are exercised

H, which is associated with the decoding process associated with the decoding process

In light software a rough distinction between the reflections I

I from black, gray and white, so that the exact color defi

In 10 nition is not necessary. On the other hand, if you

Colors other than black, gray and white are used or if you

Different shades of gray are used to create I

In four or five color data sets, a more careful styling occurs H

In the ring of contrast between the ink shades so that you

In it, it is ensured that measurable optical properties are provided

In cabinet differences between the individual colors. It will be able to

It can be seen that the use of black ink is the simplest and I

easiest way to provide a honeycomb pattern with hexagon H

cells with three different optical properties, and the I

fl 20 is preferred. H

Since the preferred embodiment of the invention H

is to provide a square label relative to the H

B hexagonal cells, the edges of the honeycomb pattern I

fl include incomplete hexagons 56. As shown in FIG. 3 uses

fl 25, these incomplete hexagons are not for transfer of application

more information. fl

fl The label also includes an intercept mark. IN

fl Initial marking 35, as shown in FIG. 3, I include

B a number of concentric rings in contrasting colors (shown as fl fl 0 0 black and white). The black rings are designated respectively. 42, 4 6 and fl B 48, and the white rings are designated respectively. 44, 50 and 52. It is preferred that fl B be placed in the geometric center of the label fl B so that it is less exposed

B is for total or partial damage or destruction, B

B 35 as if the circumference of the label is torn, soiled or fl

B is damaged. In addition, the size of the image buffer- I

23 DK 175743 B1 storage (as explained below), which is to be used for storing data from the label before the label's capture tag is identified, becomes as small as possible when the capture tag is located in the label's center.

5 The number of concentric rings used in the capture tag may be different, but a number of six concentric rings 42, 44, 46, 48, 50 and 52 and the interfaces provided by the rings vary from white to black to white, etc. proved to be convenient and j 10 desirable.

A pattern correlation technique is used when comparing a calculated pattern for what could be read from the concentric rings with what is actually read.

When the comparison fits, the capture marking has been located 15, as explained in more detail later. The particular filter provided and used in connection with the preferred embodiment of the invention is set forth in the program supplement page 41, lines 51-52, page 42 lines 1-8 and page 40 lines 19-41 under the file name "FIND.C.".

The intercept mark may assume any diameter smaller than the data set to provide an area which may be 25% and preferably approx. 7% of the data set area. It is preferable that the capture marking is designed as small as possible since the area recorded on the label cannot carry encoded information. In the preferred embodiment, the diameter of the printed rings is designated such that the outer boundary of the outer ring 52 is approx. 7.45 mm. That is, the area of the marking mark 35 in FIG. 3 records approx. 7% of the surface area of a label 30 on a square inch (about 6 cm2). In this way, a suitable capture tag 35 can be printed on a label 30 having an area of 1 square inch, without unduly affecting the amount of information encoded in the hexagonal area surrounding the capture tag 35. As is the case with the incomplete hexagons along the outer edges of the label 55, is used

I DK 175743 B1 I

I I

B the cut hexagons which lie against the outer constraint B

Opening the capture marking 56 not for encoding B

In information. It is preferred that the width of each ring B

approximately the same size as the size of the distance B

In 5 between two sides of the hexagon (x-x axis of Fig. 1), whereby B

The solution is made easier. Six rings are convenient. Six rings j fl

B is a reasonable number to place on the least possible label- B

B area with the least probability of erroneous reading- B

B strings from "foreign" labels on the label and other "strangers" B

10 labels that are not on the label, such as labels on a trans-B

port band. B

The intercept mark may be formed on second B

I I

wise, than with concentric rings. Eg. can be used! B

In squares, spirals or hexagons to provide B

15 transitions between contrasting concentric shapes, so that B

as long as a linear section through the intercept mark you will

provide uniform, predetermined and identifiable B

color transitions suitable for registration at B

B an electro-optic sensor and measured by a suitable filter. That B

20 it should be noted that although a spiral is not a collection con

B centric circles, depending on size and B

B radius in the spiral, a close approximation to I is provided

concentric circles. A marking with concentric rings I

B is preferred since the signal provided by an I

B 25 scanning through their center, has a frequency which is B

B the same as if cut in other directions through I

B the center of the concentric rings. This makes identification I

B of the center simpler, as it is more detailed I

B is explained below and enables identification of the location I

B 30 of the intercept mark on a one-dimensional search with B

B the analogue or digital output signal from the scanning organ- B

B, although in the B provided by the invention

B method alternatively or subsequently will be able to B

B is a two-dimensional digital search used to provide B

B 35 watch for increased accuracy when analyzing a digital signal. B

B As the term "concentric rings" is used, 'B

In this specification, the term shall include complete rings, partial rings in the form of semicircles, sections of concentric rings occupying between 180 ° and 360 °, and concentric spirals approximating concentric rings.

Since each hexagon can be encoded with three different optical properties, in the preferred embodiment, 1585 "bits" of information can be encoded in each hexagon {log 23) It is obvious that if fewer or more optical properties are used than three, the number of 10 encoded bits in each hexagon will be changed accordingly. The encoding algorithm is. so constructed that a density so close to the maximum data density is obtained, and so that the number of cell-to-cell transitions with different optical properties is increased, to support the two-dimensional clock repetition process, which is explained later.

In FIG. 4, there is shown a group of 3 x 3 cells with nine hexagonal cells 60, which is the basic encoding unit used in the preferred embodiment of the invention.

Although this is a preferred encoding solution, it is not essential. Other encoding units may be used within the scope of the invention. As explained in more detail later, groups of 3x3 hexagonal cells 60 are arranged to encode 13 bits of information if group 25 contains full nine hexagons, or less than 13 bits if the group is incomplete because there are useless hexagons. In a 1 square inch label with a data set which includes approx. 888 hexagons, and a capture mark which occupies approx. 7% of the label area, approx. 1292 bit information.

By encoding each group, the outer, lower hexagons 62 and 64 of each group 60, as shown in FIG. 4 is limited by the assumption of the optical properties so that they must always be different from the intermediate six-edge edge 66 with which they are in complete contact. Thus, only 1 bit can be encoded per second. hexagon in hexagon 62 and

DK 175743 B1 I

64. In this way it is possible to encode 13 bit information H

in the group 60 by encoding 11 bits in the remaining 7

hexagons. Since alignment of 7 hexagons provides H

yields more possible combinations than used (i.e., 37 = 2187 H

5 combinations against 211 = 2048 combinations) certain H is rejected

combinations such as e.g. all black, all gray and all white

combinations or virtually all black, gray or white H

combinations. The reason why contrasting H is required

colors in hexagons 62 and 64 relative to hexagon 66H

10 is that the necessary transitions for clock H must be ensured

the repeat step and optionally the normalization process step, H

which will be explained later, as well as to help determine H

late of the horizontal device in line with the data set, H

as explained below. In cases where the encoding clusters H

15 is provided with 7 or 8 hexagons, 7 usable H are encoded

hex bits with 11 bits and the 8 hex hex if it is for H

available, encoded with 1 bit. For all, only partially

brought clusters 3, it is true that bits are encoded in each pair of H

hexagons, and 1 bit is encoded in each remaining H

20 single hexagon, as explained later in more detail. H

It can therefore be seen that the label includes H

a highly efficient, easily readable, (by means of suitable scan- H

coding equipment and analytical programs) label for encoding H

of information with very high density at a relatively inexpensive H

25 label where the information is easily printed. As noted apply- H

then, in the preferred embodiment, an arrangement of H

hexagons in 33 rows and 30 columns on a label of 1 kva-H

drum blank, with a catch mark representing H

approximately 7% of the total surface area of the label. In practice H

30 provides 13 bits of information from a group of 9. H

hexagons, so that 1.44 data bits are derived per second. cell. H

This is less than the theoretical number of 1585 pr. six- H

edge, which is due to other constraints on encoding algo- H

the rhythm since all 37 patterns are not used and since H

35 the optically least desirable transitions between the cells exclusively- H

Kes.

27 DK 175743 B1

For reasons explained later, in the preferred embodiment of the invention, it is desirable to include a certain magnitude of error protection in encoding the label so that the actual readable amount of information on the label is reduced in favor of a large degree of data error freedom in the decoding process.

It will be readily appreciated by one of ordinary skill in the art that the foregoing explanation of label embodiments used for hexagonal cells can be directly transferred to optically readable labels using other polygonal cells. Similarly, the explained method of "printing" optical properties in hexagons involves printing the optical properties in other polygonal cells, whether in black, white, gray (through halftoning) or in other colors. Similar limitations and benefits associated with data density apply to labels printed with polygonal cells other than hexagons when the black and white and possibly gray optical properties are used when printing the polygonal cells.

As with labels containing hexagons, labels printed with other polygonal encoding cells can be "read" with scanner equipment of less complexity if only two optical properties are used to encode information in the polygonal cells, especially optical 25 properties such as black and white, since maximum contrast effect is achieved in these colors.

The information encoding procedures explained with hexagon labels and the associated algorithm can be directly applied to labels printed with aberrant polygonal cells. Similarly, as with hexagon labels, incomplete polygonal cells which may appear at the edges of the optically readable label or provided by partial cut-off at the capture marking, including a series of concentric rings, are not used for encoding of information.

A "honeycomb pattern" includes a set of up against each other.

I DK 175743 B1 I

I 28 I

In the second placed hexagons 310 whose geometric centers 311 I

similarly, on the angular tips 311A lie in a "six-I

angled mesh "or" a hexagonal arrangement "312, as shown in FIG

in FIG. 11. Regular hexagons, ie. hexagons with six I

In 5 equal sides and six equal internal angles, you form

In hexagonal arrays, which are also regular in out

the molding, with three equally spaced axes (Al, I

A2 and A3), the axes being positioned at a mutual angle I

distance of 60 °. IN

10 If the hexagons 320 are irregular but symmetrical, I

For example, if the hexagons are extended along two parallel I

In pages 321, 322, the geometric centers 325 of adjacent I will

hexagons describe an irregular hexagonal array 327, I

as shown in FIG. 12. Such an irregular hexagonal arrangement I

I 15 will still be provided with three axes (A1, A2 and A3),

However, the three axes will not be located with the same I

At a distance, that the three axes will not have one

At a distance of 60 °. IN

I Although in FIG. 12 hexagonal arrangement I

20 is not a regular set-up, it is nonetheless an I

In two-dimensional geometric mesh or array with axes I

With predetermined spacing. That is, the location H

and the distance between the geometric centers of the hexagons, I

which are located at the angular tips of each other I

25 cutting axes in the hexagonal arrangement are also preceded by I

I determined. The geometry of the hexagonal arrangement is used

thus in the decoding process, as explained below. Especially you

You are the filtration step that is performed on the transformed digi

In speech data according to that of the optical sensor I

In 30 full-frame image, set to reproduce the predetermined I

et label geometry so that the digital representation I

I for the sensed label can be used to accurately recon

destroying the original grid. In the reproduction process I

You further provide the missing points from the six

I 35 edged the net. The missing grid points are due to the transition I

In between the optical properties does not take place between polygons

DK 175743 B1; 29 with uniform optical properties.

With irregular hexagonal grids of the one shown in FIG. 12 it will be desirable to adjust the step for determining the major axis, step (3) {e) of FIG. 7 in the decoding process performed after the Fourier transformation step in determining the principal axis of the optically readable label.

The main axis of the label will be positioned so that the geometric centers of the polygons lie along this axis with distances that deviate from the distances of the other two axes.

It is possible to make designs of labels according to the invention which are approximated to the preferred hexagonal cells embodiment, as explained above, using certain polygonal cells. In FIG. 13 shows a label design using polygonal cells 330, 15 which are essentially hexagonal, but which are branched into polygons instead of hexagons. Similarly, 1 polygons with more or less sides than 20 can also be printed. The polygons 330 lie only partially against each other in contrast to the imaginary hexagonal cells 331 within 20 whose boundaries the polygons 330 are shown.

The space 332 of the one shown in FIG. 13 may be printed with an optical property which differs from the optical properties of the encoded polygons, but this may also be omitted. The spaces do not carry encoded information, so their presence results in a smaller data density for a given optical resolution and a given execution level. Further, if the gaps located between the polygons are of a different optical property than the adjacent polygons, more than 30 transitions between the optical properties of the polygons and in the gaps of the optical sensor may be sensed, therefore a higher clock signal energy level will be provided. in the transformation region of the decoding process described in more detail below.

35 Since the polygons of the embodiment shown in FIG. 13 is located in a hexagonal mesh with three axes of uniform

I DK 175743 B1 I

IN

spaced apart, the geometric centers 333 lie in the I

In polygonal cells 330 at the angular tips of a hexagonal I

In position 335. Distance, location and spatial orientation I

I of the centers of the polygons are predetermined and detectable

5 in the decoding process transformation area. IN

In the embodiment shown in FIG. 13, polygons of I are used

In largely hexagonal shape. Since they are closely approximated to I

a hexagon, a medium resolution optical sensor will be able to

In "these" are read as hexagons. However, the geometric centers 333 of the I polygons 330 lie at the angular points of the

In three equally spaced axes (A1, A2 and A3) located in I

In the hexagonal arrangement 335. I

In FIG. 14 illustrates one relative to the polygon 330 I

In FIG. 13 similarly formed polygonal figure 340 which is I

In 15 so arranged that they touch each other completely. These H

In polygons 340 can be approximated to an imaginary hexagon 341, I

As in FIG. 13, but there is no space (332 in Fig. I)

I 13) between the current polygons. Such an arrangement with I

In complete contact between the polygons, one is desirable

In 20 to simplify the decoding process, but it is not an I

In absolute terms when practicing the invention. Polygons 340 H

You are shown with their geometric centers 342 lying on the angle I

At the tips of a hexagonal arrangement 345. As with the polygons I

In 330 of FIG. 13, the polygons 340 are substantially hexagonal, and I

25, at moderate optical resolution, they will appear as hexagons. IN

In FIG. 15 is a large-scale reproduction of a label, H

Thus, as this one will appear, if pressed with an H

dot matrix printer, which prints 200 pixels per inch (about H

2.54 cm). The polygons 360 in FIG. 15 illustrates the shape of H

30 the geometric figure which will in fact be printed

instead of a hexagon with such a dot matrix printer, I

In because of the printer's pixel density. Printers with larger I

pixel density would provide a greater approximation to H

a hexagon than the polygon 360 of FIG. 15. Polygons 340 in I

In FIG. 14 and 360 in FIG. 15 are thus likely to result

In designs due to the accompanying limitations of I

31 DK 175743 B1 certain printers, in connection with the printing process with hexagonal cells, or as a result of deliberate attempts to print such polygons in the first instance, mainly shaped as hexagons. The design of such polygons 5 mainly in hexagonal form ensures that in practice they act as equivalents to juxtaposed hexagonal encoding cells.

As was the case in FIG. 3 contains the optically readable label of FIG. 15 also includes an intercept mark 370, 10 which includes a series of concentric rings 371 to 376.

As in connection with the hexagons of the FIG. 3, they are essentially hexagonally shaped polygons 360 in FIG. 15 arranged in columns "C" and rows "R", as defined by the dotted lines 361 and 362, 15 respectively. 363 and 364. As was the case with the hexagons of Figs. 3, the polygons of FIG. 15 with their geometric centers placed at the angular points in a hexagonal arrangement, as determined by the axes A1, A2 and A3, which are spaced apart. Labels according to the embodiment shown in FIG. 15 is thus encoded and decoded according to the processes explained below.

If another label geometry is used, such as a set of squares or rectangles, or similar figures, adjustments must be made in the two-dimensional two-dimensional clock development process explained below. Different geometries in the predetermined arrangement require that changes be made to the filters used in the filtration step of the two-dimensional clock recall process. The filters operate with transformed digital data corresponding to the optical properties of the polygons sensed by the sensor in the image area. Such minor adjustments to the filtration scheme can be easily performed by one of ordinary skill in the art. In cases where the predetermined two-dimensional array is provided with axes of differing distances, 35 or is irregular in shape, it may be preferable to identify the major axis of the label prior to exercise.

I DK 175743 B1 I

I 32 I

I of a Fourier transformation of the digital data which represents

You present the optically sensed image. This is because they are

In geometric centers of the polygons do not have the same distance I

along the axes. IN

5 Polygons which are not completely opposite to each other

it can also be used to produce an optically readable I

In the label of the present invention. IN

It will be appreciated that it is possible to provide I

many variations of the label. H

For example. the label need not be a square of H

In a side of 1 inch (about 2.54 cm). This size was designated H

as a reasonable size for a label to obtain an I

In acceptable data density of 100 alphanumeric information boxes H

protects with a high degree of failure protection without advancing H

In 15 bring very large labels. It is desirable to provide- I

You bring a label with a 1 inch page to reduce

In paper and other printing related costs, I

In shipping and handling such labels. Known dashes

In code labels of similar size will exhibit a strong H

In 20 reducing the data density. Using 4, 5 or I

In several optical properties or colors to indicate six- I

the edges will be able to pack considerably more information H

into a given area of hexagons of predetermined size I

but it will require an increase in the complexity of I

In the software and the sensitivity of the scanning system, in order to H

This information can be recalled. Therefore, it is in high H

It is desirable, for practical purposes, to use an encoder H

In optical system with three optical properties, black, gray and white.

In addition, the sizes of the hexagons and the interceptor I

The 30 marking changes within wide limits. H

Although a "grouping" of hexagons into groups with H

In 3x3 cells have been explained, other H can be used

In patterns of grouping, or the grouping can be completely avoided, H

I and the encoding algorithm can be directed to an individual six- H

In 35 border pattern. Furthermore, the relative size of the H

In encoded information in the message in relation to error correction- H

DK 175743 B1 33 in the deed varies within wide limits.

The process can be started with a predetermined set of data that is desired to be encoded on a label. In a preferred embodiment, the label is a shipping label and data 5 is divided into two fields, identified as "high priority messages" and "low priority messages". It will be understood that the invention is not limited to two different messages or priority levels. Many messages and priority levels can be provided within the quantitative limits of a label of a given size and number of cells.

For example, where the label is to be used as a shipping label, the "high priority message" may include nine characters representing the postal code of the recipient of the package or letter. Nine numbers are referred to because in nine-digit zip codes, although many single people and fours have five-digit zip codes, because nine-digit ZIP codes are used more frequently and more frequently. When processing packages for delivery, the postal code is the most important information. Hereby, 20 determines the main destination of the package, and different scanning and packaging control systems can be used so that the package is taken to the correct destination on trucks, aircraft, transport systems, etc.

The low priority message can e.g. include name 25 and shipping address with the zip code of the recipient of the package, as well as payment information.

The reason that a high priority message is provided and a low priority message is that the high priority message must be protected with a special error correction, so that the high priority message is placed (encoded) in! a more central area of the label, where the message is less likely to be damaged or destroyed, while at the same time providing opportunities for high priority; the rite message is repeated and distributed in the low priority message, so that even if the high priority message only j is destroyed, there will be a great possibility that the high priority message! in

I DK 175743 B1 I

The message can be obtained again from the low priority forge

delelsen. By placing the high priority message in a centered area, it will only be necessary to decode the high priority message.

for certain purposes, so that only part I

5 of the label must be treated, which reduces the treatment I

the time. This will e.g. be the case when a package is in you

located on a transport system and you only need the postal code

to be determined to designate it out of several transport I

paths that the package should use during the treatment process. IN

10 The low priority message does not have to be- I

weighed twice on the label. However, as below I

explained, both the high priority message and the low priority I

the message includes various error protection codes and I

correction possibilities such that the probability that you

15 both messages will be provided accurately, max

meres. IN

The use of fault protection characters as part I

of the encoded information can in the preferred embodiment I

form of the invention together with a suitable stored program and I

20 an associated computer cause the system to correct I

an error during the decoding process on the one explained below

View. The use of error protection codes is known in the art

the field is within the scope of the knowledge of one skilled in the art

in the field is in possession of. IN

In practicing the invention, an operator who

generates a label, manually loading data into a suitable data I

matter terminal, which, as explained below, is designed thus, I

that it activates a printer for printing a label with I

the high priority message and the low priority message encoded I

3 0 appropriately in the hexagons of the label. It is not of you

essential to the invention is to provide I

a high priority message and a low priority message, I

but it is desirable to maximize the probability of, I

that the most important data to be encoded can be recalled. IN

In the preferred embodiment, the label is also printed with a centrally located capture marking consisting of a number of concentric rings with two contrasting colors arranged alternately, the colors being preferably two of the colors used to print the individual hexagons, and in particular, the colors should be black and white to provide maximum contrast.

At the operator's manually entered data, a suitably programmed computer will be caused to encode each character in the loaded message and use suitable range indications to provide in the activated computer a binary bit in stream representing the characters in the message, which j bit stream is thus encoded by the region, the high priority message and the low priority message are specified, and the relative location of them is stated. The operation is carried out by the program "TEXTIN.C" listed in the program supplement, 15 page 1, lines 8-54, page 2, lines 1-54 and page 3 lines 1-36, and as indicated in 110 in fig. 9. A computer with the required capabilities can be Compaq Deskpro 386 (with a 16-MHz clock and an Intel 80387 math coprocessor chip).

Alternatively, the process may begin with the information to be encoded already located in a binary bit stream, e.g. the information is received from a data storage medium or otherwise provided. Therefore, the message to be encoded may be provided in a form which is manually (by electronic means) converted to a binary bit stream or which begins as a binary bit stream.

Once the binary bitstream has been provided, or an error-protected bitstream is provided at the steps explained in detail later, the bitstream must be arranged in accordance with a predetermined array pattern for encoding the hexagonal honeycomb of the present invention. FIG. Figure 5 shows a group arrangement indicating the individual groups of 3x3 hexagonal cells in each placed in a grid or honeycomb with 33 rows and 30 columns with hexagons. Each row is numbered 35 and each column is numbered. The row numbers go from 1 to 33 and the column numbers go from 1 to 30. It can be seen that some

I DK 175743 B1 I

I 36 I

I of the hexagons along the upper boundary and the right

In defining the layout and within the geometric I of the grid

The center area is indicated by X. This indicates that these hexagonal I

You do not contain bit information, this is because, I

In that the outer hexagons denoted by X represent partial hexagon I

You are along the edge of the label, causing each of you to

These rows are provided with fewer hexagons. The inner I

In hexagons, indicated by X, represent areas, I

You are either occupied by the capture mark or where you are

In 10, there are incomplete hexagons along the outer boundary I

I of the intercept mark, so that these inner hexagons- 'I

The utes indicated by X are not bitwise. All the I

Hexagonals that are not marked with X can register I

In information. According to the preferred embodiment of the invention

In each case, each of the areas will be occupied by a black <B), I

white (W), or gray (G) hexagon. As noted above, will

that in the practice of the present invention, although I

various grouping and arrangement techniques may be used, I

groups of 9 hexagons are used in 3 rows of 3 I

20 hexagons in each for defining designated information I

By bit, it is preferable that 13 information j be encoded

bit in each group of 9 hexagons. IN

I In a data set with 33 rows and 30 columns of up I

positioned opposite each other there is provided a net I

In 25 with 11 rows and 10 columns of hexagonal groups, I

each group includes an array of 3x3 cells of I

Hexagonally positioned against each other, which can be clearly seen

made in connection with FIG. 5. However, you will

It will be appreciated that each row of groups of 3 x 3 cells within the network of 11 x 10 groups will include a group of either I 7 or 8 hexagons due to the geometric arrangement of hexagons and the number will change from row to row .

Thus, in this arrangement, six groups I are provided

with 8 hexagons and five groups with 7 hexagons. Furthermore, I

35 is provided at the centrally located interceptor I

In labeling additional incomplete groups. FIG. 5 vividly- I

in DK 175743 B1 37! thus making a graphical representation of usable hexagonal groups available for encoding information bits in a 33-row data set and 30 columns of juxtaposed hexagons.

5 Groups of nine usable hexagons, as shown in FIG. 4, is encoded using the following algorithm:

Take eleven pieces of information and place them in a set of 7 hexagons, identified as a, b, c, d, 10 e, f and h.

The hexagons g and i are each used to represent 1 bit in such a way as to ensure that each of them differs from the hexagon h.

Thus, the thirteen information bits are encoded in a total group of 3 x 3 cells ie. nine hexagonally positioned one another.

20 For subgroups of 7 or 8 hexagons usable:

Take eleven pieces of information and place them in the set of the first seven usable hexagons.

2 5 The eighth hexagon, if available, is used to represent one bit.

For all subcells: 30 Place three pieces of information in as many hexagon pairs as possible.

Any remaining single hexagon is used to represent one bit.

Since placement of seven hexagons provides more 35

I DK 175743 B1 I

fl I

fl combinations eleven bits (i.e. 37 = 2187 vs. 211 = 2048), I

fl, certain hexagonal compositions must be rejected. They for- I

fledged compositions are designated from among the compositions I

fl thereby providing the fewest number of transitions. In order that you

fl 5 introducing this, look-up tables are provided for place-I

ring of the groups according to FIG. 5. Providing- I

Comparison and use of these look-up tables may be possible

fl is taken by any professionally trained programmer. IN

fl Referring to FIG. 9 it should be stated that the

B 10. For providing lookup tables "BINHEX.LUT" 132 and I

fl "HEXBIN.LUT" 134 can be found in the appendix page 4, li-I

lines 3-52, page 5, lines 1-53 and page 6, lines 1- I

fl 34, identified as "MK HEX LUT" 130. I

fl Using this bit placement scheme allows fl B 15 to encode 1292 information bits in a data array fl fl with 33 rows and 30 columns of adjacent fl hex edges. fl fl The order in which the high priority information and the fl fl the low priority information are placed in the group statement fl fl 20 is predetermined, depending on: fl fl (a) the size of the high priority message, fl

fl (b) the size of the low priority message, B

B (c) the most suitable location of high priority med- B

B sharing in a protected area. B

B 25 In the embodiment shown in FIG. 5 group summary is used as B

B a template is determined in advance through a stored benefit B

Calling program "MKMAPS.C" 140, which works with the digital B

B data contained in a data storage medium, how to inform B

The B mation must be distributed, which applies to both high priority B

B 30 the message as the low priority message, as the low priority B

B the message, over the entire group lineup, as for- B

B clarified in more detail later. This distribution program is in B

B the enclosed source code list identified as "MKMAPS.C" B

fl 140, and it can be found in the program supplement. B

B 3 5 To reduce the probability of error, and for I

B to be able to correct errors, it is preferred that the preferred embodiment of the invention include a wide range of error protection and correction capability. Eg. it is desirable, as in a preferred embodiment with 1292 information bits, which can be encoded within 1 square inch of a hex array of 33 rows and 30 columns and with a capture mark occupying 7% of the area of the label, it is desirable to use 36 bits with high priority message for encoding a nine-digit zip code plus an additional alphanumeric character that may represent a shipping code. In this example, it would also be desirable to use 120 check bits for the high priority message. This is determined by the desired magnitude of error correction capability.

Similarly, in the embodiment disclosed herein, 560 bits of low priority message are included. This set contains 15 bits of high priority message which is inserted into the low priority message. In the example, 576 check bits will be added to the low priority message to maintain security and to support the retrieval of the low priority message. This example illustrates the widespread use of check bits to preserve and enable retrieval of the high priority message over the low priority message. It is to be understood that the foregoing is to be construed only by way of example, and that the high priority message may be both longer and shorter and that the low priority message may be longer or shorter and that the number of check bits may be greater or less depending on the particular application of the invention.

In a "systematic code", a special message sequence is extracted and a delimited error check frequency is added.

30 In a "non-systematic" code, a special message sequence is extracted and inserted into the error check sequence so that the message is no longer delimited but can of course be recalled. It is within the scope of the present invention to use both systematic and non-systematic coding for error protection. In the following discussion a systematic code is used.

I I

I DK 175743 B1 in I

I i

As used herein, the "insertion I" step includes

I of the error detection symbols "systematic and / or not

In systematic coding systems. i

Various systematic I are known in the art

In 5 linear cyclic error protection codes, e.g. BCH codes, I

In Reed-Solomon codes and Hamming codes. In a preferred embodiment

In reed form, the Reed-Solomon codes are inserted separately for use

In protecting the flawlessness of high priority messages and

In low priority messages. The Reed-Solomon codes are very good

I 10 effective and very useful when multibit grades I

You checked out. The Reed-Solomon codes are well known and so are you

It is understood that this is simply a preferred embodiment.

In form, though many other error correction codes could be used

I in connection with the present invention. IN

In 15 Reed-Solomon and other code cysts are mentioned in e.g. Richard I

E. Blahut, "The Theory and Practice of Error Control Codes", I

In 1983, Addison & Wesley, pages 174 and 175. I

H Just as an example is certain essential information I

In about the Reed-Solomon code listed below. Specific characteristics

I 20 for the Reed-Solomon code can be specified by the following parameters: H

In m = the number of bits in each symbol I

I n = number of symbols in the block = 2m-l I

I k = the number of message symbols (the number of I

I. message bit = km) I

25 t = correction ability in number of symbols = (n - k) / 2 I

A nine-digit zip code and a single alphanumeric I

In character for further identification purposes, 36 I require

In bit without error protection in the example given below. IN

I 30 A Reed-Solomon code with the following parameters was designated I

to the high priority message. IN

I m = 6 (6 bit symbols) I

I n = 26-l = 63 I

I I

I 35 Why: k = n-2t = 43 I

41 DK 175743 B1

Since only six 6-bit symbols are required to represent in the 36-bit message, the other 37 symbols (43-6) are fill symbols that are inserted between the encoding means and the decoding means and are not to be placed on the label. Ie that the total number of bits needed for the high priority message label is (63 - 37) x 6, or 156 bits.

This error code scheme will be able to correct a maximum of 60 (10 x 6) bit errors, which represents 38.5% of the bits used.

10 As a result of the large number of completed fill symbols, the high error detection capability of this Reed-Solomon encoding makes it highly unlikely that the high priority message will be read incorrectly.

The low priority message was encoded with a Reed-15 Solomon error protection code with deviating parameters, namely: m = 8 (8 bit symbols) n = 28 - 1 = 255 t = 36 k o n - 2t = 183 20

Since 1292 bits are available for encoding on the label of this example, a total amount of 1136 bits (1292 - 156 high priority message bits and check bits) are available for encoding and check bits for the low priority message. Thus, the remaining 904 bits (255 x 8-1136) would have to include fill bits. This provides options for 560 bits (183 x 8 - 904) for the information content of the low priority message and 576 check bits.

To further ensure the retrieval of the high priority message, this is also included in the low priority message. By the Reed-Solomon error protection code used for the low priority message, this encoding enables an additional 86 6-bit alphanumeric characters with a maximum error correction capability of approx. 25.4%.

35 Using the aforementioned Reed-Solomon error protection encoding, the total number is distributed

I DK 175743 B1 I

I I

I 1292 Information bit available, on the visible- I

made the label as follows: I

In 36 high priority information bits I

In 120 high priority check bits I

5,560 low priority information bits (including

I 4 0 bits of the high priority message inserted

in the low priority message) I

576 low priority check bit I

- 10 Databit stream which includes the associated check I

bit to protect the information is transmitted to the individual I

six hexagons in the FIG. 5. The ten

It will be appreciated that many different I can be used

In distribution patterns, emphasizing that the essential I

The 15 criteria to be determined are:

I (1) secure location of the high priority message close I

I at the capture mark (if such is provided

I in the data set), I

(2) providing a pattern from which it is

In 20 reasonably easy to make a re-read reading. IN

The special error coding program used in it I

The example given here is included in the program supplement under I

H program "ERRCODE.C" on page 15, lines 1-52 and page 16, I

lines 1-50. IN

25 Reed-Solomon code encoding requires I

multiplying the message code vector by a generator I

matrix. The matrix multiplication is performed using I

In Galois field arithmetic. Adding two elements to field I

You are provided by the performance of an exclusive operation or operation

H 30 between the two elements. Multiplication is performed via a "log" - I

H operation in the Galois field. log and antilog are provided

using lookup tables generated from I

primary polynomials, especially for the high priority message: 1 + I

x6, and for the low priority message: 1 + χ2 + χ3 + x4 + x8

35 Referring to FIG. 9, an auxiliary device is provided

H program "GF.C" 126 to produce those for Galois field- I

43 DK 175743 B1 arithmetic required lookup tables. The utility '· "GF.C" is listed in the program supplement page 8, lines 1-53 and page 9, lines 1-32. The lookup tables are calculated and stored in the file "GF.LUT" 127 for use during encoding and decoding. The generator polynomial g (x) for the Reed-Solomon code is determined by the following equation: g (x) = (x + a) (x + a2) ....... (x + a2t), where a is the primitive element of Galois field.

10 Generator matrix for the Reed-Solomon code is provided by executing a long divison of each row in the generator matrix.

The known row in the generator matrix is obtained from the others by the exercise of a long division of χη _ ^ _ ϊ with g (x).

The calculation of the generator polynomials g (x), as well as the generator matrices for both high-priority messages and low-priority messages is implemented according to the utility "MKRSLUT.C" 125, which is listed in the program in page 10, line 1-52, page 11, line 1-53, page 12, line 1-54, page 13, line 1-52, and page 14, line 1-4. The lookup tables for the 20 generator matrices are generated and stored in the file "RS.LUT" 128.

In a preferred embodiment of the invention, hexagon labels are printed with standard printing equipment which is generally available and inexpensive. A printer with a 300 x 300 dot matrix per square inch (approx. 6 cm2) will provide satisfactory results in printing three-color labels (black, gray, white) with 888 hexagons plus a centrally located capture mark. A printer with such performance is the Hewlett Packard Laser Jet Series II 30 with 0.5 megabytes of data storage and a graphic resolution of 300 dots per minute. inch (about 2.54 cm). A 300 x 300 pixel grid with a density of 90,000 pixels per square inch produces approx. 90 pixels per hexagon in the preferred embodiment.

. Each pixel is assigned a value of 0 or 1, which is represented by a black or white pixel. This printer is used to print data sets in two colors with black and white hexagons.

I DK 175743 B1 I

I 44 I

It can also be used to print data sets in three colors I

I with black, white and gray hexagons if using an I

In halftoning algorithm for generating gray hexagons, I

In as previously explained. IN

5 Referring to FIG. 9 there is by means of an I

In stored program "MKMAPS.C", 140 provided an area lookup I

In table "REGIONS.LUT" 141 with 34 rows and 30 columns, which you

You are analogous to what is shown in FIG. 5, but adapted I

I for the designation of black or white for the rings in the capture | IN

In the 10 mark. The individual hexagons are encoded in black, I

In white or gray or are unusable. A special reference I

Bel "HEX MAP. LUT" 142 is provided by a stored subrule

In the thaw of the program "MKMAPS.C" which specifies the connection I

In the ratio of each of the 300 x 300 pixels in the pixel grid to I

In 15 special areas of "REGIONS.LUT" 141, ie. ca. 90 pixels per IN

Hexagonal. Pixel's which are associated with capture marking I

the rings are encoded either black or white. Capture I

the marking rings are printed by first generating an I

hexagonal pattern in each row, followed by rings

I 20 is generated. Areas partially or completely covered

You with the intercept marking rings are rendered unusable by I

In "REGIONS.LUT" 141. The program previously mentioned "MKMAPS.C" I

and the subroutines are listed in the Appendix, pages 19 to 22. I

The error protection encoding bitstream is placed in I

25 relative to a predetermined order in the 11 x 10 large I

grouping of hexagons. While still referring to you

to FIG. 9, this order is indicated by a lookup table I

"ORDER.LUT" 151 provided by a stored auxiliary I

In program "ORDER.C" 150, which is specified in the program extension I

30 page 101, lines 1-47 and page 102, lines 1-3. A stored pro- I

grams "PRLABEL.C" 160, listed in the Schedule, are I

I used to assign the values 0, 1 or 2 to those to I

Available areas for label printing while I

In areas with a value of 3 are left unchanged. Gray levels for I

Each of the hexagons in a group of 3x3 cells is assigned I

in connection with the stored program named "CELL I

45 DK 175743 B1 CODE.C "170, which is listed in the program supplement.

A priority for placing the high priority message in an area close to the capture mark where the message will be less susceptible to label destruction.

The program "LABEL.C" 180 is therefore used to generate a bit stream suitable for input signal to the laser printer. The program "LABEL.C" 180 is listed in the program supplement.

It will be appreciated that the use of black, gray and white enables a simple method of printing the label, 10 since black ink is only needed when a standard halftone algorithm is used in a known manner. Of course, if other color compositions are used (which is possible), the need for printing in other colors will provide considerable complexity over a solution using only three colors, black, gray and white, or compared to a solution with only two colors, black and white.

Thus, when each pixel of the printer has been assigned a black or white value, the label can be printed to produce an encoded format, as shown in FIG. 3, wherein certain 20 hexagons are white, some are gray and some are black, and wherein a capture mark, preferably provided with black and white concentric rings, is located in the geometric middle portion of the label.

After explaining how data is encoded and printed on the label, it is necessary to explain the subsequent translation or decoding process of the label. It will be appreciated that it is desirable to practice the label translation function at very high rates, on the order of a fraction of a second, to increase the efficiency of handling the package (or other handling or label reading).

There are two different basic solutions that can be used in conjunction with capturing the image when reading the label. The label can be replaced at 35 relatively low speeds using a manual, static, fixed focus scanning device. Alternatively,

I DK 175743 B1 I

I I

It is desirable to achieve high operating speed that you

An electro-optic sensor with a power-controlled I is used

In focusing mechanism to enable dynamic scanning- I

In ring of fast-forwarding packages of various sizes and I

At 5 altitude. The decoding process and the equipment explained I

In later, have been used in connection with a scanning I

fixed focus device. A process with the ones herein explained

In ordinary options compared to a static scan I

In fixed focus device can be adapted to a dynamic I

H 10 scanning system with certain modifications in the optical I

In system, as noted later. When treating packages with I

at high speeds it is desirable to have a high speed I

scanning mechanism that can read labels that are being fed I

with a linear velocity of approx. 100 inches (about 250 cm) per IN

For 15 seconds or more and carried under the place where the fixed I

scanning device is located. Imaging Function- I

thus includes the steps in the following steps, I

the steps of the decoding process being shown in FIG. 7. I

When a package or letter is conveyed on a high-speed I

20 heat transport system, the illuminated area will be pretty I

In large, since the size of the packages to be forwarded

in the feed system, can be very large and is variable. IN

H For example. it is not unusual for an I to be provided

conveyor with a width of 42 inches (about 105 cm), by which I

25 packs with a width of only a few inches and up to 3 l

feet (approx. 90 cm) (and corresponding height) must be transported. IN

Therefore, a label of 1 square inch (about 6 cm2) may be I

located anywhere in the width of the carrier. The packages I

may also be located at oblique angles relative to the trans- I

H 30 axis of movement of the conveyor belt. Packages, letters and similar gen- I

stands will be provided with mutually different elevations.

there, so that the labels to be scanned, e.g. IN

may be placed 1 inch (about 2.5 cm2) or less above I

above the conveyor belt, and up to 36 inches (about 90 cm) or I

35 more above the conveyor belt, taking into account the I

maximum height of the packages that the plant can carry. IN

in 47 DK 175743 B1

In order to properly illustrate the labels provided by the present invention, and especially taking into account the wide variation in the width, height and the angle at which the labels are displayed, it is desirable to use a high intensity light source. so that the light can be reflected well from the designated two or more optical properties of the label.

The light may be infrared light, ultraviolet light or visible light, and the light spectrum of the applicable visible light may vary. The technique of sensing the light preferably includes sensing the light reflected from the black, white and gray hexagons on the label.

The light source must produce light so that sufficient light is reflected to the light sensor (eg, a 15 CCD device, as explained later), so that the light sensor can reliably distinguish between black, gray and white, or any other optical properties the hexagons are assigned. In a dynamic scanning system, a set of light-emitting diodes could be used to produce a light level 20 of approx. 10 mW / cm2 in the area of the label to be illuminated, I

in line with the label. Such light-emitting diodes may be located over a certain area without the use of focusing lenses, or they may be arranged linearly with a cylindrical focusing lens. A laser light source guided through a suitable optical system to produce a linear illumination source could also be used in the practice of the present invention.

The selection of the light source and the designation of characteristics 1 of the light source for the application herein can be carried out by one skilled in the art. It should be remembered that since the label to be located has only a maximum size of 1 square inch (about 6 cm2) and that it is located at heights up to 36 inches (about 90 cm) on a conveyor belt which is 42 inches (about 100 cm) wide and conveyed at speeds 35 of e.g. up to 100 inches (about 250 cm) per second, it is very important to be able to illuminate the label,

I DK 175743 B1 in I

I 48 I

In a suitable way for surrounding identification and location. IN

In connection with the static focus fixed sensor,

As used in the example illustrated, it has

found that an illumination level of approx. 2 milliwatts / cm 2 is 1

Suitable for carrying out the invention. Such an illumination became you

provided by a fluorescent light source. IN

The second step in the recognition part of the decoding pro- I

the cess is the optical sensing of the illuminated region with an I

electronically driven sensor. The camera / light sensor used I

10 of the example illustrated here is a static scan I

fixed focus system includes a color CCD television I

more of industrial quality, such as model No. WV-CD 130, which I

marketed by Panasonic Industrial Company, One Panasonic I

In Way, Secaucus, New Jersey 07094 and provided with I

H 15 a 50 mm f: 1.3 C-mounted TV lens with a 5 mm pull-out I

In tubes marketed by D.O. Industries, Inc. (Japan), 317 I

H East Chestnut Street, East Rochester, New York 14445, and as I

You market under the trade name NAVITRON ™. The camera I

H was connected to an image capture card called I

20 Model No. DT-2803-60 marketed by Data Translation I

I Inc., 100 Locke Drive, Marlboro, Massachusetts 01752. I

Optical sensing may include an image transmission signal

applying the entire label using an area sensor;

such as the camera and image capture described above

Or it may alternatively be provided with an I

linear scanning sensor with a chip with a charge coupled I

device ("CCD"), the scanning of the second label of the label

dimension is exerted by movement of the package (and label) .An I

suitable CCD chip for this purpose is a linear CCD image sensor I

At a high speed, called Thomson-CSF THX 31510 00Z, 4096, I

which is marketed by Thomson-CSF, Division Tubes Electron! - I

ques, 38 rue Vautheir B.P. 305 92102 Boulogne-Billancourt I

. Cedex, France. IN

In dynamic systems which include movement of I

35 the label carrying package in a transport system, it will be you

advantageous to have a long optical path between the labels I

49 DK 175743 B1 to be sensed and the light sensor. The main reason for producing a long optical path is that it reduces the change in the apparent size or magnification of the label as sensed by a light sensor located at a distance 5. For example, the optical path is 4 feet (approx. 120 cm), the image size of the label will be 1 inch (approx.

2.5 cm) across the conveyor belt has been very different, from the size of the labels 3 feet (about 90 cm) across the conveyor belt. If a long optical path is used on e.g. 20 10 feet (about 6 feet), the image sizes of the same labels will be approximately the same. This ensures that the area being sensed, regardless of its height, performs or nearly performs the entire range of the light sensor so as to provide a consistently high image resolution. If an area sensor 15 is used instead of a linear sensor, the same principle can also be used. This can be provided by a long optical path as illustrated in FIG. 6th

In order to focus on labels on packages of different heights, it is necessary to provide a height-20 sensor. For this an ultrasonic sensor can be used or the package can break a set of light rays. Any of these systems is usable and the system can then activate a suitable adjustable focusing mechanism with an open or closed loop mechanism for sensing and adjusting the position of the optical sensing element (e.g., lenses and sensor) in mutual relationship on a continuous basis. base, as shown in FIG. 6th

FIG. 6 is a schematic representation of a camera focusing and adjusting system operated in accordance with the invention for adjusting the position of the camera light sensor according to the height of the package being sensed.

In FIG. 6 shows a suitable lens 196, coil drive, height sensor and feedback loop according to the invention. In FIG.

6, the height sensor 206 may be an ultrasonic height sensor, or it may e.g. be a ray of light that breaks at each

I DK 175743 B1 I

I 50 I

In package conveyed by the carrier. The height sensor out- I

Input signal is transmitted to microprocessor 204, which in turn I

You activate coil drive 202 for moving coil 200, on I

In which CCD 198 or other suitable light sensor is mounted. IN

I 5 An axis location sensor 208 senses the location of the coil I

I 200, and the output signal from here to the microprocessor 204 I

You complete a feedback loop to, of sensor and I

In setting the coil 200's location. IN

The Sensor must be able to sense the reflected light that you

I 10 comes from the illuminated label and it must also produce I

In an analog signal according to the intensity of I

In the reflection properties of the label, such as these I-

Resected at the individual pixels of the electro-optic sensor. IN

I A suitable light source, as explained above, may be

15 located on a mounting surface above a conveyor for I

illumination of an area extending across the transport island

In the entire width of the cleaning with light of a predetermined quality and

intensity. The reflected light from the label may become you

deflect one by a number of reflectors and then be sensed by I

In 20 electro-optic sensor. IN

The purpose of a deflected optical path is to produce

In a compact and therefore more rigid system. IN

H Filter the analog output of the sensor I

hereinafter. The analog electrical signal is used for i-I

25 to connect to an analog bandpass filter to detect time

the absence of a capture mark in the data set. The ten

analog signal is then converted to digital signal I

Using a known analog-to-digital converter, I

H which is included in the image capture card, as below

H 30 below explained, or by others known in the art

bodies. Instead of an analog bandpass filter it is possible I

To insert a digital filter circuit to determine I

In the presence of the capture mark by comparison I

Of the digital data representing such a mark,

35 with the digital output signal from analog-to-digital con- I

the host, as explained later. IN

51 DK 175743 B1

An example of a range sensor with a CCD chip having a plurality of detectors used in connection with the present invention is the previously mentioned Panasonic WV-CD 130 color CCD television camera. The analog output signal from the sensor is transmitted to the previously mentioned data environment. phrase DT 2803-60 image capture card, which includes a 6-bit monochrome video with A / D conversion for digitization and subsequent processing. By means of a suitable stored subroutine, the digitally output digital signal from the image capture card is stored in a data storage device as an exact copy of the image recorded by the optical sensor.

The most important part of the invention is the processing of the optically sensed image so that the original label structure can be recreated and oriented with accuracy and so that the color (optical property) of each hexagon is reproduced. This is accomplished by using the steps mentioned below, according to which the known pattern by which the label was initially encoded and the bits set up can be used to decode the information contained in the label.

Prior to using the above-mentioned CCD television camera and image capture card, as shown in FIG. 10, an introductory program "DTINIT.C" 250 is run such that the image capture table is placed in a known clear state, and so that the output color lookup tables followed by the program "DTLIVE.C" 255 are advanced, thereby activating the image capture card. The program "DTGRAB.C" then causes the image capture card to digitize the image for transfer to a 30 image data store of 240 rows and 256 columns, with samples stored as 6-bit sizes divided by bytes. The mentioned program is listed in the program supplement on page 31, lines 1-53, page 32, lines 1-39, page 33, lines 1-22 and page 34, lines 1-19. Two utilities, "DTSAVE.C" and "DTLOAD.C" 35, establish the transfer of screens to and from a storage medium. Source code lists for the mentioned programs are listed

I DK 175743 B1 I

I 52 I

in the Appendix. IN

In the first recording of the label image, you can

You use a known analog bandpass filter for identification

I of two or more optical characteristics of intercept mark I

5 concentric rings. It is preferable that these two I

Optical properties are the colors black and white since it I

greatest contrast will produce the greatest signal energy. In order that you

You find a fixed pattern with transitions from black to I

white to black, etc., it is preferable that I

In a linear scan over the capture mark, which I

scanning must be carried through the center of the marking, where- I

You obtain a uniform frequency response independent of I

the orientation of the label. That is, the marking rings give you

In optimum effect when provided as contrasting I

15 concentric rings. The output of the sensor is divided into I

then and passed through two detection paths. Along one road

H, the total energy is detected in the output signal, and along I

the other measures the energy of the ring frequency. By comparison I

with the two output signals, the energy of the ring detector I

I 20 is closest to the energy of the detector for the total energy I

give / when a scan through the capture marking center I

You have been sacked. The capture marking center is located

right when this closest approximation occurs. Source Code Listing I

In connection with the creation of a digital bandpass file I

25 and the filtering process is listed in the program supplement under I

In the file name "FIND.C" on pages 39 to 43. However, you must

it is preferred that the first filter step of the preferred dyna I

physical embodiment of the invention is practiced during use I

of an analog bandpass filter, or an exemplary analog I

30 bandpass filters, although a digital filter is applicable. IN

It should be noted that the step of locating I

the intercept mark, designated "FIND.C" 280 in FIG. 1 I

10 is indicated as an optional step in FIG. 7, since a manual I

scanning device may be used in that of the invention I

35, in which case the operator of suitable I

may position the scanning device to secure the card

in 53 DK 175743 B1 j right position on the sensor line. This is of course a much slower method than that provided by the use of an automatic sensor, and the use of the automatic sensor must be preferred in high speed operation. If an automatic sensor (not manual) is used, the location of the capture tag will be a necessary step in the process.

As an alternative to the analog filter explained above, a digital bandpass filter can be built using the Parks-McClellan algorithm provided with the "Digital Filter Designs Software for the IBM PC" program (Taylor and Stouraitis, Marcel Dekker, Inc., New York, NY 1987).

A one-dimensional digital bandpass filter was used in the present invention to filter a normalized digital bit stream, as explained later, through the filtration subroutines hereinafter referred to. The band that is filtered corresponds to the expected ringing frequency.

The one-dimensional digital bandpass filter is sized 20 to a sample size of 400 pixels per second. inch (about 2.5 cm) and to a length of 125 pixels (or 0.3125 inches - about 8 mm), being designed based on the size of the printed capture marking rings, as shown in FIG. 3. The frequency was 300/16 line pairs per second. inch (about 2.5 cm), thereby providing a normalized frequency (where 400 line pairs per inch = 1) of 300/16 x 400 or 0.046875. A filter with a bandpass range extending 5% below this frequency and 15% above was designated because distortions of the label typically result in image shrinkage and, as a result, an increased frequency. Stop bands from 15% below the frequency down to 0 and from 25% above the ring frequency to 0.5 (Nyquist's limit) were provided. The filter coefficients were stored in the file "IMPULSE.LUT" 275, cf. 10 for later use, omitting the first 62 coefficients since the filter is symmetrical. A flow chart is shown in FIG. 8th

In addition, refer to the source code lists in the Appendix below

I DK 175743 B1! IN

I I

In the file name "FIND.C", 280. I

A 25 pixel length filter was provided

I by sampling the bandpass filter at output intervals I

Corresponding to the measured horizontal magnification. Eg. would, I

I 5 if the horizontal magnification of the image is 80 pixels I

per. inch (about 2.5 cm), every fifth sample of the filter I

You are used (400/80 = 5 pixels). For non integer steps, I

linear interpolation of adjacent filter sample was used

calling. IN

H 10 Another two-dimensional filter of 25 x 25 pixels became I

also used. Sample values for this two-dimensional in I

The filter was based on the Euclidean distance of each point I

from the center of the filter, which was scaled to fit horizontal I

In and vertical magnification. Linear interpolation was used

15 thereafter for non-integer sample intervals. IN

The output of the one-dimensional I mentioned above

filter was squared and smoothed by a first order I

recursive low-pass filter, thereby providing an exponent I

tilt window. When the smoothed output of the filter I

20 exceeded a predetermined threshold, used one of choice I

designated two-dimensional filtering step for the verification I

of the presence of the mark and to determine precisely- I

giving its location as explained later. The first one

part of the two-dimensional filtration worked with a reduced I

In 25 filter size of 10 pixels x 10 pixels to reduce computation

up the volume. This filter scans a rectangular area I

around the location detected by the one-dimensional filter

tion. If the maximum two-dimensional correlation over- I

exceeding a predetermined threshold, the end I was used

30 straight steps in the two-dimensional filtration with a full 25 x I

25 pixel filter for a narrow square window around the max

simum. If the best result from this filter exceeded I

a predetermined threshold, the center was detected. IN

If any of the threshold values were not reached

H 35 exceeded, the program would partially postpone smoothing file I

and return to one-dimensional scanning. If you

55 DK 175743 B1 the one-dimensional scan was completed without detecting the presence of the capture mark, the program would issue an error mark. For further explanation of the filtration process used in the example given herein, reference is made to the source code lists in the Appendix.

The reflected light intensities recorded by the optical sensor used may vary due to variations in illumination, print density, paper reflectance, camera sensitivity and other causes, including a deterioration of the label, fes. folding, offset, etc. As an optional (but desirable) step, the reflected light sensed by the sensor and transmitted to the data store can be normalized by known procedures.

15 Using prior art, a stored normalization program "NORM.C" 270 was used which is shown in FIG. 10, for analyzing the intensity level of the light reflected from the label, as recorded by pixel blocks in the scanning device, to find the minimum values and maximum values of the reflected light intensity recorded for the data set. The set digital output signal from the scanning device mentioned above and from the image capture card was transmitted from the data store to the computer for further processing with said stored normalization program.

Using the equation y = mx + b, where, by inserting the minimum intensity instead of x, a value of y = 0 will be obtained and where, by inserting the maximum intensity of x, a value of y = 63 will be provided. the recorded intensities of the reflected light were adjusted for each pixel so that the blackest black color and the most white color present in the stored image were established by default and so that other shades of black, white and gray was 35 adjusted based on these standards. The normalization step thus facilitates the processed image. The normalization

I DK 175743 B1 I

I I

The ring was exercised using the stored program I

In "NORM.C" as listed in the Appendix on page 37, line I

B 10-52 and page 38, lines 1-11. It may be realized that others

more sophisticated normalization procedures known in the art

B 5 in the art will be applicable. IN

For the subsequent calculation, the storage I

Prepared, rendered label image so as to provide I

an image with equal horizontal and vertical magnification. IN

B This is again an optional step, but it facilitates the fast I

10 and accurate retrieval of the encoded information

B tion. The rescaling operation was performed to provide I

In an image with uniform horizontal and vertical sample I

resolution of e.g. ISO pixels per inch {approx. 2.5 cm), thus I

I as used in the illustrated static embodiment of I

B 15 the invention with fixed focus. IN

I The rescaling operation is provided by calculation I

B of the split row and column address e.g. Examples I

B 'at 1/150 inch, from the known horizontal and vertical I

B magnification. Each point of the new uniformly scaled I

B 20 image is then extracted from a suitable set of points on the reproduced I

B image in the storage medium. Bilinear interpolation is used for I

B to approximate the value of the points to the sub-addresses. By re-

In the scaling, the center of the label is placed in a known position I

B in the data store. The rescaled image is stored for later

B 25 use in the search step. In all subsequent process steps I

B, then it is assumed that a re-scaled label image is centered

B right in a known location in the network, but it should be noted, I

B that does not indicate the orientation of the label, I

B which label may still be inclined to ratio I

B 30 to the sensor. The rescaling operation is performed under control I

B from a stored subroutine listed in the source code lists I

B of the Appendix. IN

B The next steps in the process are collectively referred to as "two-dimen- I

The steps are performed by a suitable,

35 stored program and subroutines, referred to as "CLOCK.C" 290, I

as shown in FIG. 10 and listed in the program supplement of I

57 DK 175743 B1 pages 44 to 51. This operation is performed in two dimensions on the rescaled image to accurately determine the position of each hexagon in the original dataset. The purpose of clock recall is to determine the sample locations and to correct the effects of shear, curl or slope of the label since the label is not necessarily completely flat. This is an essential part of the process and its use is not limited to six-edge encoded labels. It may also apply to other 10 processes of decoding the encoding label, which includes a regular, two-dimensional grid, such as squares, triangles, etc.

One-dimensional clock gene development is a known process known in the art of signal processing. Two-dimensional beat repetition is an extension of this process and will be appreciated by closer reflection by those of skill in the art. It should be understood that the term "clock induction" seems somewhat confusing to the skilled artisan, since it has nothing to do with the temporal division.

The first step of performing the clock gene induction can be performed by various non-linear positioning operations known in the art to provide signal components with a designated clock frequency which are lacking therein. digitized image output signal from the optical sensor and the image capture card. The purpose of the nonlinear placement operation is to provide the (preferably) normalized and re-scaled image provided at this point in the process and to shape it into a two-dimensional non-linear distribution that improves the transitions between adjacent contrasting hexagons. In the preferred embodiment of the present invention, this is done by standard deviation distribution. This step can also be performed by filtration with an image-differentiation nucleus, which is known in the art, such as LaPlace 35 or Sobel's nuclei, after which an absolute value is determined or a squaring of the results is performed. These processes

I DK 175743 B1 I

I 58 I

In durages are mentioned in Rafael G. Gonzalez and Paul Wintz, Digital I

In Image Processing, 1977, Addison Wesley. j I

At the standard deviation distribution, the image is stored; IN

H with undifferentiated cell-to-cell edges in the data store. I I

H

I A standard deviation distribution is then provided for i 'I

location of the edges of adjacent, contrasting hexagonal | IN

Iter when determining the standard deviation of 3x3 pixels | IN

H

groups (not identical to the 3 x 3 cell groups)

In cells), to determine the standard deviation of pixel lines

10 the tensities. The standard deviation calculations are performed to I

determining the pixel areas, with a solid color (with I

lowest standard deviation) representing the interior of I

a hexagon or representing the transition between two I

monochromatic hexagons, unlike the pixel groups I

H 15 which is provided with larger standard deviations which represent

lateral transitions from a hexagon with a color to an incidental I

going hexagon with a contrasting color. Since an- I

In receding hexagons often have the same color, standard deviation- I

the hexagonal distribution does not completely delineate each hexagon. IN

Missing edges between the hexagons will be provided

by the fact that in the standard deviation process I

cannot be distinguished by transitions between hexagons with I

same color. By further features of the beat gene induction pro- I

the cess needs to restore these missing transitions. IN

The decoding process of the present invention I

may be used in conjunction with any of the I

previously mentioned label designs, as shown in the I

FIG. Encoders of different geometry I

can be easily processed and such optically encoded polygonal I

Thirty cells can be set up with the geometric centers of auxiliary I

polygonal cells located at the angular tips of an I

known, predetermined two-dimensional arrangement. IN

H When the optically readable labels provided I

of the present invention, "read" with optical sensors

35 of the kind mentioned, the particular geometry I is determined

H or design of the individual encoding units or I

59 DK 175743 B1 polygonal cells not at the optical sensor. Instead, the sensor simply exemplifies the optically readable label with a known number of samples per and records the intensity of the reflected light corresponding to the optical property of the particular sample area that has been imaged. These sizes are then stored in a storage medium for later processing. In other words, the electro-optic sensor detects the average light intensity sample area by sample area over the entire surface of the label, regardless of whether or not something is printed on the label. This is what is meant by storing the image with undifferentiated cell-by-cell edges in the data store. For this reason, the decoding process can be easily adapted to read optically readable labels! 15 of very different design, as long as the centers of the polygonal encoding units are at a predetermined distance and direction in a two-dimensional arrangement.

In practice, it has been found that alterations of the hexagonal encoding cell-based system, as is the case with label designs, employing substantially hexagonal polygons, as illustrated in FIG. 15, result in negligible reductions in system performance. The use of polygonal shapes with poorer packing properties, or sets of partially opposed, or not at all opposed polygons, instead of a pack of opposite polygons, will thus result in a poorer but nonetheless useful system performance in many applications. However, at certain points, due to the optical; 30 non-soluble high frequency components in polygonal encoding! lower order cell cells, ineffective cell packing and; predetermined two-dimensional arrays, large gaps j between the polygons, and therefore system performance will fall to an unacceptably low capacity for information storage and retrieval | 35. j

Whether the system is acceptable depends on the quality of j i j i

I DK 175743 B1 I

I I

In the signal provided by the electro-optic sensor. IN

I When changing the sensor system, e.g. by increasing the number I

of samples per area unit above label surface, I

You can improve the signal detected by the sensor

I 5 whereby the characteristics of information storage and re- I

provision for such label arrangements where polygons- I

You are partly in touch or not at all

'in mutual touch improves. Such adjustments to

make less desirable label designs usable

I 10 are within the knowledge of any professional within you

the area is in possession of. IN

In the process, therefore, opportunities are created for large I

differences in the label article, bodies for providing I

optical signals and the signal processing. Polygonal Cells I

15 of a regular or irregular form can be used as encoder

optical readable labels according to the invention. IN

In addition, as long as it is spaced apart and you

direction between the centers of the polygons is known in association I

to adjacent polygonal cells, the polygonal encoded I

In 20 cells cells could be in a predetermined pattern, such as I

differs from the hexagonal arrangement and the polygons can be

You are placed so that they are opposite each other so that you

H is partially opposite each other or they are not at all

up against each other on the optically readable label. IN

25 As explained in more detail later, it does not facilitate you

In linear distribution techniques, especially those associated with I

the preferred embodiment referred to as standard deviation

In sharing technology, the reconstruction of the missing transitions I

or edges between polygonal cells with the same optical I

In 30 properties. In addition, you may want the same features

could overcome the lack of transition between polygons and I

spaces between the polygons with the same optical properties. IN

This is the case when the label structure used

includes polygons which are in partial contact with each other

35 or who are not in contact with each other at all. This; IN

features are provided through the subsequent steps of rapid I

61 DK 175743 B1

Fourier transformation, filtration and reverse fast Fourier transformation.

In an optional technique used in the preferred embodiment of the invention, the range of calculation necessary to produce the standard deviation distribution is reduced. Usually, for the calculation of the sum of 9 pixels in each pixel group of 3x3 pixels, 8 addition operations would be used. This can be cut in half by replacing each pixel in the image with the sum of the 10 pixels in question and those pixels that are immediately to the left and right of that pixel. This requires two additions per pixel. After that, the same operation is performed on the new image, except that the sum is calculated for pixels immediately above and below that pixel. Hereby 15 additional two additions are required, a total of four. It can now be seen that at the end of these steps, each pixel has been replaced by the sum of that pixel plus its eight immediate neighbors.

The standard deviation distribution is the preferred technique 20 in providing this distribution of hexagons similar to the original data set, but with missing transitions between original hexagons of the same color. The particular standard deviation distribution technique used in conjunction with the illustrated embodiment is set forth in the source code lists 25 of the Appendix.

The next subroutine, called creating a window, is optional. In practice, this subroutine is used in the invention to reduce the intensity of edges that are not attached to the hexagon's outline. These edges appear at two locations, at the marking rings, and the unmanaged image surrounding the label. A weighting function is used to reduce the intensity of these areas. The details of how the provision of a window acts as a precursor to a fast Fourier transformation are within the skill of the art. The window procedure used is listed in the source code lists in the Appendix on page 121, line

I DK 175743 B1 I

IN

I 'il

I 6-22. IN

I A two-dimensional fast Fourier transform of the I

In digital sizes that correspond to it (optional) with wine

The standard deviation distribution treated in the pigeon procedure is exercised

I 5 then under the control of a commercially available stored I

In program. During the operation, a computer exercises a fast I

Fourier transformation of the image provided I

You know the preceding step to produce a two-dimensional I

In the representation of distance, direction and intensity of transition I

10 genes between contrasting hexagons identified I

I at the standard deviation distribution step. In short, you are

the fast Fourier transformation a measure of distance, right- I

and intensity of the edges between the hexagons, where

H these are known. That is, the regular distance I

15 and the direction of the delimitation of the hexagon will cause you to

certain points in the transformation area have high energy

At gin level. The brightest point will be 0.0 in transforma- I

the plane of the plane corresponding to the DC component of the image. The I

six points surrounding the central point represent I

20 distance, direction and intensity of the edges between hexagons I

i

It will be appreciated by those skilled in the art that you

As for hexagons, a two-dimensional representation of I

In the distance, direction and intensity of the transitions between the contra- I

H 25 dying polygons identified in the foregoing

standard deviation distribution steps, also calculated by Exercise I

of a fast Fourier transformation of the digital data, I

which corresponds to the non-linearly distributed sensed label car I

missing. Thus, the distance and direction of the polygon boundary will

30 would like to cause certain points in the transformation area I

has high energy. The number of points of higher energy that I

surrounds the central point with the coordinates 0.0 in the transform I

the plane of the plane, will depend on the geometry of the particular I

polygonal encoding cells used for generation I

35 of the optically readable label. As for hexagons, you will

however, such points that surround the center point I-

Time represent the distance, direction and intensity of the edges between the polygons or the edges between polygons and spaces, if the label structure is such that the polygons are in partial contact with each other or not in contact at all with each other. j i

Since the image is assigned real values and not 'complex values, the transformation area is point symmetrical around the starting point. As a result, it is only necessary to calculate the half-plane in the transformation region, thereby providing a saving of a factor of about two during the computation time. Removing these calculations also reduces the work required in the subsequent steps of image filtering and reverse fast Fourier transformation. The fast Fourier transformation program used in conjunction with the illustrated embodiment of a fixed focus static system was the commercially available subroutine R2DFFT from the 87 FFT-2 package from Microway,

Inc. in Kingston, Massachusetts.

A filtering process is now required to reconstruct the total external constraint of all the hexagons in the image area, using the transformed digital data. This is done by eliminating all transformation area points that do not correspond to the designated spacing and direction of the hexagonal boundaries, as identified in the standard deviation distribution step. Six prominent points are made in the transformation area as a result of the label's hexagonal honeycomb structure. In fact, only three points are defined in the transformation area, since the image is point symmetrical about the starting point and the other three points can be inserted from the first three. In the preferred embodiment, the filtration is performed in three steps to remove the transitions from the standard deviation distribution step which are too spaced apart, too close together, and / or 35 are in the wrong direction.

First, high pass filtering is performed by assigning

I DK 175743 B1: I

I I

In all points within a predetermined value around I

At the starting point in the transformation area the value is zero, since they I

You are at a distance of eight from the starting point, except I

In six designated points which are arranged in a hexagonal shape I

I 5 in the graphical transformation area. These points correspond to I

At distances greater than the hexagonal distances and bear sole

H

In this information, which is linked to the missing transitions I

in the label image. To recreate the missing transitions in I

In the label image it is necessary to remove information about I

In 10 the missing transitions in the Fourier transform area. IN

Herein, all points outside a designated I are assigned

In the radius around the six prominent points of the transforma- I

tion range value zero. These correspond to foreign transitions, I

You who are too close together. This operation is combined with I

15 so that a ring of residual I is formed

points. The production of this ring corresponds to the practice of I

In gap band pass filtering. The inner and outer radii of I

The ring is determined based on the expected distance between six

In the perimeters of the edges. Since the "diameter" of the hexagon extends

20 to represent 5 pixels in the example explained here should you

the hexagonal angles for a transformation length of 256 l

. pixels lie 256/5 = 51.2 pixels away from the center. As a result I

of which, a ring having an inner radius of 45 l was used

pixels and an outer radius of 80 pixels, corresponding to six- I

25 border diameters of 3.2 to 5.69 pixels. A filter which allows I

passage of higher frequencies was used because the deformerin I

of the label, such as shear and inclination causes

image shrinkage. IN

After the practice of the interspace bandpass I

Filtration, as explained above, provides an I

ring with six prominent points, each point having

the same angular distance with respect to the center (point I

H 0.0) in the transformation region. To complete the task I

H to remove unwanted information in the transformation area I

35, a directional filtering step is used. Any point that you

lies at too great an angular distance from the prominent circum- I

65 DK 175743 B1 prevails in the transformation area the value is assigned zero. This! has the effect in the image area that any edge which is not in one of the three directions determined by the hexagonal honeycomb pattern is removed.

5 In order to perform directional filtering, it is necessary to find the most prominent point remaining after the gap band pass filtering. This point is believed to be one of the six prominent points in the transformation area which correspond to the angular tips of a hexagon. Five other forward-10 points in the same radius from the center and at angular distances, such as. constituting multiples of 60 °, are also prominent in the transformation area. Therefore, all other points with an angle of stand greater than 10 ° are removed from any of these points. Six wedges of the 15 ring are left. In this directional filtering step, any information containing incorrect distance or direction in the image area is removed. The removal of incorrect distance information allows the recovery of a complete perimeter of each hexagon in the image area.

The aforementioned filtering steps are performed under the control of the stored subroutines contained in the source code lists in the Appendix.

The foregoing explanation of the filtration methods used in conjunction with the preferred label embodiment with closely adjacent hexagons requires modification when using different predetermined two-dimensional arrangements for the optically readable label. However, it will be appreciated by one of ordinary skill in the art that only minor modifications are required in the filtration process to adapt to the divergent label arrangements previously explained in the present disclosure, as illustrated in the accompanying drawing.

Once the individual polygonal encoding cell is determined, it is also predetermined that its delimitations will occur at certain angular distances,

I DK 175743 B1 1 I

I 66 I

You just have a designated number of pages of a specified length. IN

Herein, it is necessary to determine the relationship between I

adjacent polygons, such as whether to bump into you

In complete adherence to one another, only partially adjacent to one another

For 5 or no contact at all. Also the geo- I

metric arrangement, according to which the geometric I of the polygons

H centers must be set up, must be established. When the above mentioned I

In the field of label geometry, one skilled in the art can

build the appropriate filtration scheme for filtering energy I

10 points in the transformation area, so that only those I

brightest points corresponding to the appropriate distance and direction I

I of the boundaries of the polygons, are treated with the inverse I

H fast Fourier transformation. IN

As for the mentioned built-in filters, you will

Figure 15 recognizes the need to build a suitable dimension

rather space bandpass filter, which is based on the preceding I

determined the distance between the polygonal encoding cells. IN

In addition, it is desirable to build a directional filter for I

H filtering out energy points other than the most prominent I

20 points corresponding to the axes of the predetermined two-dimen- I

zonal arrangement of the polygonal encoding cells. This I

removes any information associated with incorrect distance or I

direction of the polygonal encoding cells in the image area I

and in the spaces, if any. By knowing that

25 eliminating such incorrect information, a complete I

positioning the centers of the polygonal encoding cells I

be reconstructed in the image area by the inverse fast I

Fourier transformation according to the one below

H explained the process steps. IN

30 To return to the image area I currently

and in conjunction with that, restore the outline image of the full I

hexagonally positioned against each other in data set I

It is desirable to have a two-dimensional inverse

fast Fourier transformation (2D-IFFT) on the filtered I

35 transformation domain data. The reverse transformation in progress

is set by a standard two-dimensional inverse Fourier trans-I

67 DK 175743 B1 formation subroutine (R2DIFT) available in the package | 87FFT-2 from Microway, Inc., Kingston, Massachusetts. Upon completion of the inverse transformation step, the perimeter of each hexagon is restored in the auxiliary domain. In the new 5 image, the centers of the hexagons are provided with large size. The actual size of the points in the hexagon centers depends on how many edges were provided in the neighboring area. Many edges generate greater energy at the allowed frequencies and thus points of large magnitude. Fewer edges provide smaller size points. Size of the points is a good measure of the confidence level of the clock generation at any point.

The hexagonal image has now been recreated, but its orientation must be determined.

The hexagonal honeycomb pattern provided by the invention has three "axes" with an angular spacing of 60 °. The direction of these axes is determined by the brightest points of the transformation domain after the space-band pass filtering. It is now possible to assess which of these three axes is the main axis. This step is optional. If the step is not performed, the label must be decoded three times, using each of the three axes and only one of the axes providing a meaningful message. The principal axis is arbitrarily selected as the axis running parallel to two sides of the label, as previously explained and illustrated in FIG. 2nd

If the boundaries of the square label are determined from the knowledge of the principal axis, most of the 30 energy placed in the recovered hexagonal pattern will be within the boundaries of that square.

To determine the main axis, each of the three axes is assumed to be the main axis. The resulting square label demarcation is determined for each of the three axes, and the total clock generation pattern of energy within the square is recorded from the digital energy data output.

J

I DK 175743 B1 I 68 In signal from the inverted transformation subroutine.

In the correct outcome, it is the outcome with the greatest energy.

In the Angle of this main axis is stored for the launch step and other search operations. In this situation, it is not yet known whether the recorded angle lies in the correct direction or is 180 ° away from the correct direction.

The source code lists associated with this determination of the main axis are listed in the Appendix. It will be appreciated that all three label areas need not be fully defined.

10 constantly since the energy in the area common to · J

B all three squares need not be determined.

In a stored program called "SEARCH.C" 300, which is illustrated in FIG. 10, the information about the B transformed and retrieved center of the hexagon combines with B 15 the stored intensity levels in the original image, B such that the gray level value for each hexagon can be determined.

B The search is carried out in such a way that the possibility of "getting lost" during the search is as small as possible. At the final B result, a matrix must be provided

B 20 the gray level value for each hexagon in the data set. Source Code- I

The B lists for "SEARCH.C" are listed in the Appendix. You are building

B four important information sets in the first part of SEARCH.C- I

B program. The CVAL (beat value) set stores a measure of quality

The magnitude of the provided rate signal for each hexagon, I

B 25 while the set GVAL stores the gray level values (0-63) for I

B each center in each hexagon. The other data sets IVAL and I

B JVAL stores the row and column locations for each center in I

B each hexagon. IN

B From the main axis angle defined in step (e) and I

B 30 the known distance for the hexagons (5 pixels) present

By way of example, the expected horizontal and ver- tical are calculated

B tical displacement from the center of a hexagon to the centers I

B in the surrounding six hexagons. IN

B After these calculations, the SEARCH.C program I works

B 35 on the clock repetition signal generated from I

B the data store, and the rescaled label image, which also I

69 DK 175743 B1 is pulled forward of the data store. The basic purpose of this implementation routine, as set out in the Appendix, is to mix and contract the information from these two sources, and to generate a data matrix with the gray scale value 5 for each hexagon.

The implementation step of the search is defined by a square around the center of the label of approx. 1/3 inch (about 0.8 cm). Within this range, a good starting point is found, such as the point with the largest size in the 10 bar signal array provided. Next, the location of the starting point is determined relative to the center of the label. This starting point is a point where the beat signal is strong and clear, and also a point which is relatively close by! the center of the label. A strong, clear signal is desirable to ensure that the search begins with an approved hexagonal center, and it is desirable that this point be close to the center of the label so that its absolute location can be determined without seriously affecting the displacement or slope. A measure of the quality of the dot in the clock repetition pattern is the dot size minus the size of the eight surrounding dots. The coordinates of the starting point of the right-angled coordinate system are converted into polar form, and the polar coordinates are adjusted relative to the predetermined principal axis angle, and this result is converted back to coordinates in a right-angled coordinate system. These coordinates are scaled according to the expected row spacing (4.5 pixels) and column spacing (5 pixels) so as to find the insertion location in the hexagonal matrix. Rate quality, gray levels and positions corresponding to the initial hexagon are then inserted into the relevant sets of CVAL, GVÅL, IVAL and JVAL.

The main search loop continues to locate the centers of the other hexagons. The loop ends when the expected number of hexagons has been located. The 35 order in which the search for the centers of the hexagons is carried out is extremely important. The increased reliability in decode I I 175743 B1

I 70 I

In the process of etiquette destruction, I originate

You use this particular search technique, such as below

In for explained. IN

Each iteration of the search loop begins with the repeat I

5 provides the location of the rate-evoked spot I

of the largest size whose neighbors have not been sub- I

In the cast search for their largest sizes. From this I

In the known point, the search will be extended in the distance answer

they to one hexagon in each of the hexagons. In this way I

In 10 there is a search pattern along a path from the best to the r £ n- I

Better quality of beat quality. Thus, if there is an I

In a re-created rate range of inferior quality, for example I

in the middle of a label with a broken area, the search algorithm- I

You move around this area instead of searching

15 through it. By delineating such weak areas and reserves

if they are for the last treatment, the probability of you

In getting lost in the net be substantially reduced. Since it, I

Getting lost is just as wrong as reading a gray level I

Incorrectly, this property of the search algorithm is very important

20 light. IN

A subroutine specified in the Appendix is responsible

Searching for neighbors with best quality clock values,

which is found at the head size. The subroutine is looped six I

H times, one for each neighboring hexagon to the hexagon which sub- I

25 searches. First, the location of a neighbor is calculated. If this I

In the neighbor is outside the label boundary, the loop ends

feiterationen. If not, check the neighbor to see if you

It has already been subjected to search by another

direction. The loop iteration will be terminated if the neighbor I

30 has been searched since the algorithm places I

earlier searches being more reliable than later searches

searches. If the neighbor is accepted in this test,

You calculate the expected location of the neighbor's center in rate I

gentilvejebringelsesmønsteret. At this point in the program I

In 35, a gradient search for the clock signal with the largest I is performed

size. The eight pixels surrounding the retrieved I

71 DK 175743 B1 location, is sought to provide a possible higher clock value. If one is found, the eight neighbors are examined for the best neighboring point to see if there is an even better size. This gradient search provides a degree of 5 matching which is necessary if displaced and inclined labels are to be read. After that, the subroutine moves on to the next neighbor, or it returns when all neighbors have been examined.

As mentioned in step (d), the retrieved network, as a result of the data transformation processes, carries information about the geometric centers of the polygonal encoding cells. This grid has greater energy in areas where initially several contrasting transitions were located. The centers will be in the predetermined two-dimensional alignment with a predetermined number of axes with uniform or non-uniform distance, whichever is the case. The information about the spatial interrelationship of the axes in the predetermined two-dimensional arrangement would be advantageous to use in the main axis orientation step.

However, it will be appreciated that this algorithm could be suitably modified such that the decoding process determines the current geometry of the two-dimensional array and proceeds from this determination to determine the filtering scheme, the so-called principal axis of the label (i.e., the axis of the label). the two-dimensional array parallel to two sides of a square optical readable label, as previously explained) and providing the necessary coordinates for the search subroutine.

Whether the label geometry is determined by such an optional step as explained above, or simply loaded into the decoding process by appropriate modifications to the two-dimensional clock gene development process, the various label structures discussed and explained herein can be readily adapted by one of ordinary skill in the art. It will be appreciated that the number of axes on which the centers of the individual adjacent polygonal encoding cells are located, and in their respective angular orientation, may be inserted in the step of determining the principal axis instead of the three axes of the the preferred embodiment used a six-in edge arrangement. Therefore, the principal axis of the predetermined 5-dimensional array can be determined without performing the experimental analysis explained above in step (e). As to the hexagonal arrangement in the preferred embodiment, the information from the step of determining the principal axis and the known distance of the polygons can be used to calculate the expected horizontal and vertical displacements from the center of one of the polygons to the centers of the surrounding polygons. . After these calculations and after the necessary adjustments have been made to the search subroutine, the search, including the preamble step and the main search loop step, can -

15 fins, continue for this particular label design, which I

is used. It will be appreciated that such minor adjustments to the SEARCH.C. 300 in the enclosed source code list may be exercised by one of ordinary skill in the art.

Upon completion of the subroutine, the location of the present center is marked so that it is not searched.

The intention is to exclude this point from being a point H whose neighbors should be sought. For loop iteration, add from

0 to 6 new candidates and 1 candidate are removed. By an effect I

For the best use, a data structure could be used, I

25 in which the candidates are placed on the order of magnitude

H as insertion and deletion operations are performed. Such an I

H structure is called priority queue, cf. Aho, · Hopcroft and Ullman, I

"The Design and Analysis of Computer Algorithms", 1974, Ad- I

dison Wesley. It is known that a linear search algorithm requires you

30 operations in the order n2, while an efficiently used priori I

density queue using a balanced data structure where pos- I

the terns are organized in a hierarchical system that can remind you

whether a tree with branches or in an accumulation, requires only opera- I

H tions of size n log n. A search algorithm of the order η I

35 based on so-called "bucket" search can also be used if I

the obtained rate values are scaled and reduced to 1

73 DK 175743 B1 a small number of whole numbers. j

After completion of the main search loop, the locations of the centers for all hexagons have been determined and the gray levels for the centers of all hexagons that have been stored are completely set up. The next step is to set the digitized gray level values in order! 0-63 for determining the discrete levels for e.g. in black, gray, and white (for a black, white, and gray label). This is done by constructing a histogram for the intensity magnitudes <10 in the label image of the hexagonal centers. Level sections can be determined by looking at decreases in the histogram. The particular subroutine used for histogram structure and level section determination is listed in the enclosed source code list in the Appendix on page 130, lines 16-52 and page 15 131, lines 1-15.

After dividing into discrete levels, two distortions may still be present. First, the set-up may be fault-centered. This can happen if the initial search step has not correctly determined the location of the 20 beat signal for the best quality relative to the label center.

The other option is that the entire label has been read in reverse, with the main axis angle having an 180 ° ambiguity.

A stored subroutine listed in the Appendix performs the function of determining whether the label is off-center. If the label is positioned correctly, the center row coordinates must pass the row through the center of the label. To determine whether a vertical placement error has occurred, the rows above 30 are examined above the hypothetical center to see which of these forms a line that passes closest to the label center.

If a row above or below is closer than the row with the hypothetical center, suitable exercises are exercised! alternating up or down. If the left setting of 35 short rows is incorrectly adjusted, this is adjusted by shifting the short rows one position to the right.

I DK 175743 B1 74 I Horizontal positioning errors and reading of the label In the wrong way we investigate using the information

Iion which is embedded in the label and referred to as coarse I

In network information. The information is divided into hexagonal groups 5 with 3x3 cells, as previously explained. For example, since the label may be provided with a grid of 33 rows I and 30 columns, these groups constitute a grid of 11 x 10. The lower middle hexagon of each complete group of 3x3 cells has a particular property provided 10 during encoding. A transition on each side I of this hexagon is assured, as previously explained in connection I to FIG. 4. For example, if the lower middle hexagon is

black, the lower left and the lower right hexagon I

be either gray or white. A stored subroutine listed in

15 of the Appendix, utilizes this transitional property to remove I

they completed two possible distortions. First, you provide

there is a set where each element of the set indicates whether I

a transition has taken place between two horizontally towards I

hexagonally placed. Next, the set I is examined

20 for each of the nine hypothetical sections in the coarse grid

as a 3 x 3 pattern around the expected cut at 0. One I

of these sections will show a better fit between the current I

or the expected transition, and this cut position

maintained. Next, the same hypothesis under I

25 the assumption that the label was read the other way around. You will

occur if the main shaft angle is currently pointing from the right I

on the left relative to how the label was printed,

instead of left to right. IN

If the label is simply the reverse, i.e. that they

30 higher rows are interchanged with the lower rows and that they

higher columns are interchanged with lower columns, the result I

of the incision placement also be an inversion. However, I

one significant transformation must be performed in order to correct I

show to invert the label. While reading the short (length I

35 29) rows are determined on the left. Thus, when the label is I

inverted, these labels must be adjusted to the right. Just- I

It is this procedure that will cause the results from the incision hypotheses to be anything but a simple inversion. In fact, the best results from the cross-sectional test will be better than any earlier mentioned test if the label is actually read the other way around.

After determining whether or not the label is read inversely and whether there is a cut in the absolute location, the label's matrix can now be decoded.

10 With a correct image and cut, the image processing functions are completed and the data decoding processes are started.

With a stored program "RD.LABEL.C" 182 in FIG. 9, which is listed in Appendix page 61, lines 1-52 and page 62, 15 lines 1-28, reads the file provided by the search program and generates a bit stream file of, in the preferred embodiment, 1292 bits. A stored subroutine, CELL DEC.C 183 in FIG. 9, as set out in the Appendix on pages 63 to 66, for masking out useless hexagons 20, and for decoding, which is the reverse of the coding program.

The first step of the decoding process is to generate a bit stream from the hex edge information, using a hex-to-bit distribution process, which is the inverse of the bit-to-hex distribution process used in the encoding operation.

The bit (information) stream is then divided by the program into a bit stream with a high priority message and a bit stream with a low priority message, or in as many as 30 bit streams used in encoding the label.

It is then necessary to apply error correction to each bit stream using error coding techniques used in the label encoding process. For example, using Reed-Solomon encoding, error correction on the bitstream generated by the search program will produce an output signal set up in the same _

I DK 175743 B1 I

I 76 I

format previously explained in conjunction with encoding I

In the Load Load File. Error correction can be performed in the after- I

In the following sequence (see the "Theory and Practice I" mentioned above)

Error Control Codes ")

I 5 1. Calculate Syndromes I

I 2. Calculate the mislocation polynomial using I

In part Berlekamp-Massey algorithm I

I 3. Calculate misplacement using Chien- I

search I

I 10 4. Calculate error sizes using Forney's I

algorithm. IN

The last step is performed only if detected. IN

In a number of correctable errors in steps 2 and 3. The number of I

errors detected are also calculated. If detected I

In 15 an irrecoverable number of errors or if there are loca- I

correct a mistake in the fill used (as explained above- I

In court), a flag is inserted. The special error coding procedure, I

As used in the present illustrative example,

You are listed in the Appendix and are designated ERRDEC.C 184 in FIG. 9. I

I - 20 When managing the package (by identifying its package I)

the high priority message, I

indicating the postal code number of the package's destination, I

to activate suitable control arms or transport systems

I for routing the package for the right truck, airplane I

25 or package transport truck which carries the package to its destination

tion. IN

Although the invention may be applicable to a trans I

gate / diversion system, it will be obvious that it also · I

can be applied in a wide range of information

30 collection, handling of packages and producing - I

operations in which it is desirable to read a label on I

a package, a letter, a production part, a machine or the like

devices and cause the system to perform packaging

learning operations or production operations e.g. with I

35 the object on which the label is placed. In the invention I

is it possible that these operations can take place with I

B1 high speed, high accuracy, since a considerable amount of label information can be processed and even there are *; provided protection for a great deal of information from being lost due to label damage and similar phenomena.

Referring to FIG. 9 it can be seen that the decoded message can alternatively be displayed on a computer terminal using the program TEXTOUT.C 185. This program is listed in the Appendix.

10

Claims (8)

1. Optically readable article for storing encoded information including a plurality of information encoded I polygons of the same shape and more than six pages, which I 5 polygons are provided with one of at least two different I optical properties, characterized in that the polygons are located with the geometrical midpoints of neighboring polygons lying at the angular tips of a predetermined two-dimensional grid, and that each polygon is substantially 10 shaped as a hexagon. An object according to claim 1, characterized in that the net is a hexagonal set. Object according to claim 2, characterized in that the hexagonal set has three axes spaced 60 ° apart. Object according to claim 1, characterized in that the optical properties are the colors black, white and gray. An object according to claim 1, characterized in that the polygons are irregular polygons. IN 6. An article according to claim 1 or 2, characterized in that it further includes a capturing mark I! in the form of a number of concentric rings (372, 373, 374, 375, I · 376) which occupy an area of the object separated from the area occupied by the information-encoded I 25 polygons, each concentric ring having one of at least two mutually different optical properties in alternating order. IN An article according to claim 6, characterized in that the concentric rings are located centrally on the article. IN Object according to any one of the preceding claims, characterized in that the polygons (340) I are completely adjacent to each other. IN