AU601707B2 - Method and device for storing and reproducing graphical patterns or signatures - Google Patents

Description

COMMOIIWE -L TH OF A -S RA A PATENVf ACT 1952 COMPLETE SPECIFICAT (original) FOR- OFFICE USE class Int- Class Application Number: Lodged: 6 qg Z186 Complete Specification Lodged: Accepted: Published: Priority: Related Art: This do umn;nt ccn- aiiis tile amendments made under Section 49 and is correct for printing 0 Namne of Applicant: Address of Applican~t: MAURER ELECTRONICS GmbH and LEIGH-MARD-ON PTY. LIMITED Nymphenburger Strasse 154, D-8000 Munichl9, FEDERAL REPUBLIC OF GERMANY; and 71-79 Macquarie Street, Sydney, New South Wales 2000, AUSTRALIA respectively Thomas MAURER Actual Inenor(s), Address for Serv~ice: 0 DAVIE~S COLLISON, Patent Attorneys, I Little Collins Street, Melbourne, 3000.

Comiplete Specification for the invention' entitled: METHOD AND DEVICE FOR STORING AND REPRODUCING GRAPHICAL PATTERNS OR SIGNATURE S" The following statement is a full description of this invention, including. the best method of performing it known to us ~ffi 4 41 I *4 44l.

4 4 14 44, 4.

SPECIFICATION

The invention relates to electronic storage of graphic patterns, and finds particular application in the storage of written characters.

It has already been proposed for the storage of a graphic pattern or signature that the pattern should be stored by means of an input device in an image storage in the form of pattern data which are associated with image areas disposed in the form of a matrix and which are called up from the image storage by means of a central control device and can be passed to a repeat input device.

In the case of the storage of the pattern data associated with the image areas disposed in the form of a matrix, however, a relatively large amount of storage space is needed, so that the image storage L77 YL r 0 i. 1.

2 must have a large capacity if a large number of patterns or signatures are to be stored in it.

The invention is based on the problem of electroric storage of graphic patterns, such that they can be reproduced, and in particular of written characters, in which the storage required per graphic pattern or per written character is significantly reduced.

According to a first aspect of the present invention, there is provided a method of electronic o 0 o0 0 storage of a graphic pattern in an image memory, said Ca o° 0 pattern comprising a first region having a first o° o image characteristic and a second region, adjoining a o0ao oO margin of the first region and having a second image characteristic, said method comprising the steps of: i) converting the pattern into a series of 0 elements of data representative of an array o aQ of image areas of the pattern, taken from 00 both said regions, said data elements o o comprising information with regard to said first and second image characteristics; ii) storing the elements of data in a temporary memory, arranged in a matrix corresponding to said array; iii) scanning said matrix with reference to said information to select marginal elements of data which represent image areas at the margin of the first region; V. 2a iv) generating position data with respect to the position of the selected marginal elements of data; and v) storing said position data in said image memory.

Methods according to embodiments of the present invention are characterised by the fact that the sample data of the sample are first kept in an o o intermediate storage, only the positions of limit 0 image areas which lie immediately at and along the entire margin of sample structures belonging in each S case to the sample are determined by means of the 0 intermediately stored sample data and stored, and oO that for the reproduction of the pattern the positions of the marginal image areas are called up and the sample structures associated with them in each case which correspond to the sample data of the Ioo, sample structures are filled in with data and oO, depicted.

4' 4( tThus only the positions of the marginal image areas of sample structures are determined by means of the sample initially temporarily stored, the sample data of which are associated with image elements disposed in matrix form and stored, so that the storage of the sample requires much less storage space than in the conventional method. On reproducing the pattern these limit image areas are again called up by means of the central control device and stored temporarily true to position, so that image areas lying between the marginal image areas and associated with the sample structures which 'i ul coincide with the sample data of the original sample structures can be filled in with data and depicted.

The sample data of the sample structures may, for example, be selected so that the pattern structures appear black on a monitor, while the sample data outside the sample struct- S00 0 00 0 0s 0000 0 0 0 0000 0 0 000 04I 00 0 0 4* *0*t ii I ures may be selected so that this area appears white on a monitor.

A very advantageous further development of/the invention is characterized by the fact that for the determination of marginal image areas the sample data are in each case compared in pairs in the direction of the lines or columns of the sample continuously until, by determining the difference between two sample data a structural image area lying within one sample structure has been determined on the basis of a sample data difference of a predetermined value, the position of the marginal image area lying before this structural image area is stored, starting from this first marginal image area and proceeding in a clockwise or counter-clockwise direction and beginning with the structural image area which was last used for comparison, the sample data of the adjacent image or structural image areas 0* 0 a and of the first marginal image area are in each case compared with each other until a second marginal image area with the same data value as the first marginal image area is determined, the position of the second marginal image area is stored and that proceeding from the second marginal image area the comparison described and the storage of the positions of further marginal image areas is continued until the first marginal image area is again reached.

The marginal image areas of the pattern structures can be determined very rapidly in this way, by, after finding a first marginal image area of a pattern structure, practically passing round this pattern structure. In the course of this various marginal image areas are determined in succession by comparison and then stored.

According to another advantageous embodiment of the invention, after the first marginal image area has again been obtained, comparison of the sample data by pairs is continued along the same line or column, excluding the area between known positions of structural image areas until a structural image area of a new pattern structure is found, when, after working off the lines or columns mentioned, the process is correspondingly repeated for an adjacent line or column.

If, therefore, after the determination of a first structural image area, a first pattern has been outlined for the determination of its marginal image areas, and if this first pattern structure is not at the end of a line or column, the search or scanning process is continued in the same line or column until a further first structural image area of another pattern structure has been found. This is again scanned round to determine the marginal image areas of it until the further first marginal image area has been determined. On scanning an adjacent line or column structural image areas of structures already scanned are suppressed, which is possible since the positions of them are already known. In this way the covering of sample structures more than once is avoided.

According to another advantageous embodiment of the invention, a check is made in the region between known positions of outer marginal image areas along one line or column to ascertain whether all image areas are structural image areas, in which case, if at least one further image area located within this region is present which is not a structural image area, this further image area is used as a first marginal image area for the determination of inner marginal image areas, in which case only those image areas with pattern data are filled in which lie between the outer marginal image areas and the inner marginal areas.

Through this, areas lying within pattern structures which are not structural image areas can satisfactorily be determined as such and reproduced. Closed linear structures can therefore be precisely reproduced without the inner areas of them being filled in and, for example, appearing, like the lines, black on a monitor.

A further and very advantageous improvement/of the method according to the invention lies in the fact that the position storage of the marginal image areas by storing the coordinates of t~e first marginal image area and an indication of direction by the one of eight directions in which the next marginal image area of the eight marginal image areas adjacent to the preceding marginal image area lies in each case.

In the case of image areas disposed in the form of a matrix eight further image areas are adjacent to each marginal image area, and through these the directions in relation to the one marginal image area in question can be defined. These eight directions may be designated by eight different numbers, so that the direction from the first marginal image area to the next marginal image area needs to be indicated only by one of these numbers. It is therefore no longer necessary to store pairs of coordinates for all marginal image areas, but only for the first one. The positions of all further marginal image 14 0 areas are in each case determined by the aforementioned 0 s directional data in relation to the preceding marginal image.

0 A pattern structure can therefore be described with even fewer data, so that through this storage requirements are still S further reduced.

According to another advantageous embodiment of the invention, for directional information, starting from the direction in which the second marginal image area lies in relation to the first marginal image area, it is possible to determine that number of angular intervals between the eight directions wich 0 must be passed through in a given direction of rotation from the old direction to the new direction.

If there is a change in the direction between two successive marginal image areas, it is simply a matter of counting, taking into account the direction of rotation in question, how many more of the total of eight directions still lie between these two directions in question. The corresponding number of angular intervals is then used to indicate the direction in which the new marginal image area lies in relation to the old marginal image area.

00 4 0I o t i p 4' 0 44 o

S

0(t 0 4 04 4 4 i A determination value as an indicator of direction can conveniently be given to predetermined sequences of numbers of angular intervals. In this way the the extent of the data for the description of a pattern structure can be even further reduced, so that the storage space required for storing a graphic pattern or a signature is even further reduced.

For example, two series of equal numbers of angular intervals are associated with one determination value. Two series of equal numbers of angular intervals occur relatively often, so that it is logical to described the two series by only a single determination value as a direction indication.

The pattern data can be determined before the determination of the marginal image areas, for example by determining a mean value from the pattern data of four image areas lying opposite to each other. In this way it is possible to obtain a lower-noise and sharper pattern image which is used to determine the positions of the marginal image areas of the pattern structures.

It is also of advantage to subject the pattern data to digital filtering, since in this way the contrast of the pattern image is improved and the/=a=6 is standardized.

According to another advantageous further development of/ the invention the entire pattern of pattern data which represent the pattern background is framed. If, for example, the pattern structures that appear on a monitor are black, a white image frame is placed round the entire pattern. Through this white frame it is assured that pattern structures can in each case be completely outlined to determine the marginal image areas.

The graphical pattern or the signature can to advantage be optically scanned and temporarily stored to produce the pattern data. The pattern can be reproduced by means of a laser beam on a radiation-sensitive chart or by means of a i Y' suitable printing device.

According to a second apsect of the present invention, there is provided apparatus for electrically storing a graphic pattern, said pattern comprising a first region having a first image characteristic and a second region having a second image characteristic, said second region adjoining a margin of said first region, the apparatus comprising: Si) pattern conversion means which is sensitive to said first and second image no 0° Ocharacteristics, for converting the graphic S* pattern into a series of elements of data 0 representative of an array of image areas of 00 the pattern, elements of data representing image areas having said first and second image characteristics being distinguished respectively; Sii) a temporary memory for storing said elements of data in a matrix corresponding to said array; iii) scanning means for scanning said matrix so as to select marginal elements of data from said matrix, which marginal elements represent image areas of said first region which lie adjacent its margin; iv) position data generating means for generating position data with respect to the position of the selected marginal elements of data; and 11- i i_.i v) an image memory for storing said position data.

A device for the application of embodiments of the method has an input device to receive a pattern in digital form, a storage device for storing data of the pattern, a central control device for calling up the sample data from the storage device and a reproduction device for reproducing the pattern, the control device containing a computing oo stage for calculating the marginal image area positions of the pattern structures and being oo connected to a further storage device in which only 0 0 the marginal image area positions or positional data o* oderived from these can be stored.

o oo A preferred embodiment of the present invention is described hereafter, by way of example only, with reference to the accompanying drawings wherein: 441 402 r Fig. 1 shows a pattern M stored in an image storage with image elements disposed in the form of a matrix, this pattern comprising two pattern structures M 1 and M'1; Fig. 2 shows a graphical representation for the definition of eight directions in which eight image elements adjacent to an image element lie; Fig. 3 shows a part of the pattern structure

M

1 as in Fig. 1 to explain the determination of the marginal image areas of it; 0; P, L /,I NS N-I 7b Fig. 4 shows an annular pattern structure

M

2 temporarily stored in the image storage; and Fig. 5 shows a suitable device for storing and reproduction of pattern structures or signatures.

Fig. 1 shows an extract from an image storage B with image areas or image elements disposed in matrix form, with which are associated pattern data D, D 0 and D' The pattern M stored in the image storage B has two pattern structures M 1 and .s M' which are described by pattern data D O and D' The image areas associated with the pattern all structures M 1 and M'1 will subsequently be described as structural image areas WS and W'S, while the image areas lying outside the pattern structures M 1 and M' are labelled W.

1 a V o IJ I The pattern structure M1 is described completely by its marginal image areas W W 15 and the pattern data D o while the pattern structure M' I is described by its marginal image areas W' 0

W'

6 and its pattern data D' 0 The pattern data

D

0 and D' have a value such that, for example, the corresponding pattern structures M and M' appear black on a monitor, wh \e the pattern data D of the image areas W lying outside the pattern Ctructures M1 and M'1 have values which cause the area lying outside the pattern structures to appear white on the monitor.

The black and white areas inside the pattern M are obviously interchangeable.

A more detailed explanation is given below, by means of figs. 1 to 3, of how the marginal image areas W 0

W

1 and W' 0 W W' of the pattern structures M and M' are 6 1 1 2 determined. It should be pointed out that before any such determination the pattern data of the pattern M stored in the image storage B can be subjected to a suitable mean value determination in order, for example, to obtained a lower-noise and 0, sharper pattern M. For contrast improvement and background standardization of the pattern, this can be further subjected to a digital filtering, so that a contrast intensification occurs, especially in the region of the margins.

The pattern M stored in the image storage B, which repres- L ents, for example, a signature or the like, and has been transi t ferred into the image storage B by optical scanning and digitization, may be scanned by lines or by columns. It will be assumed Shereinafter that the scanning is effected by columns. As can be Sseen, neither of the two patterns M 1 or M' extends into the first column which runs ve-Halfy along the left margin of the image storage B, so that on scanning this first column no structural image area W S can be determined. It is not until the scanning of the second column that a structural image area W S is detected which lies in the fifth line from the top. The scanning in this case takes place along the columns from top to bottom in fig. 1. It is effected by comparing in each case the pattern "T4 data of two adjacent image elements lying in the direction of S 7i <F .tl t- -9of the column. If the difference between the two image elements compared reaches a predetermined value, it is assumed that the last image area is a structural image area W s The image area lying before this structural image area W S in the direction of scanning is defined as the first marginal image area W 0 The coordinates of it are then stored. To determine the position of the second marginal image area W I the pattern data D, D of the first marginal image area W 0 and further image areas directly surrounding it are compared with each other. The comparison begins with that structural image area W S which has last been used for a comparison, that is in this case with the the sructural image area which is located below the first marginal image area W 0 This structural image area W S is located in a direction a 3 in relation to the first marginal image area W0, as can be st-n from fig. 2. The other image areas adjacent to the first marginal image area W 0 are located here, viewed in the direction of rotation B, at the angles a 4 a 5 a 6 a 7 a 0 a 1 and a 2 in o0 relation to the first marginal image area W 0 It is surrounded althogether by eight image areas which lie in eight different o directions.

o f rr The aforementioned comparison of the pattern data between the first marginal image area W and the image areas surrounding it is continued in the direction of rotation 3 (counter-clockwise) until it is established that equal pattern data D, D 0 occur between the image areas in question. In this case the next area to be found is therefore the marginal image area W 1 the coordinates of which are also stored. Starting from this second marginal image area W 1 the comparison previously mentioned is repeated, beginning with the structural image area WS, which lies in the third line from the top and in the third column from the left in the image storage B. Equality between the pattern data x obtained for the first time in the direction of rotation l when the area W 2 is compared with the second marginal image area W 1 The coordinates of the image area W 2 are therefore also stored. It represents the third marginal image area. By continuing this scanning process the pattern structure M1 is outlined, so that subsequently the coordinates of the further marginal image areas v 4 eb -1-

W

3

W

4

W

5

W

15 can also be determined and stored. If the first marginal image area W 0 is then again reached, the comparison in question is completed.

Fig. 3 shows once more the principle of the scanning in question for determining the marginal image areas in general representation. Starting from an image area W (first marginal n image area, the coordinates of which are stored), a comparison of image data is made between this and the structural image area

W

S lying beneath it in the direction a 3 which has last been used for a comparison. Corresponding comparisons are made with the structural image areas in the direction c 4 5 and a 6 and with the further image area in the direction a 7 if the rotation takes place in the direction 3. A comparison could obviously also be made in the opposite direction. It must remain constant only in one cycle of a pattern structure. If it is found in the case of a comparison of the image data of the image areas W and n o° Wn+I that they coincide, the image area Wn+I is defined as the S second marginal image area, the coordinates of which are also stored. A corresponding comparison of the image data now begins with the regions W and W Viewed in the 3 direction, n+1 s+l the image area W is therefore then obtained, which is a third n+2 marginal image area, the coordinates of which are also stored, and so on.

If the first marginal image area W is again reached after passing round the pattern structure M 1 the aforementioned downward scanning in the direction of the column in fig. 1 is continued. In this case the area between the known marginal Simage regions W and W14 is ignored. By further comparison of the pattern data D and D' a following structural image area 0 W' of a next pattern structure M'1 is detected. The image area S1 lying in the scanning direction before this structural image area W'S is again regarded as the first marginal image area W' 0 for the second pattern structure M' The coordinates of it 1" are stored. The second pattern structure M' 1 is then traced to determine the further marginal image areas of it W' 1

W'

2

W'

6 a corresponding comparison to that in the case of the

"Y

1-3 '4'

'~NT

-1I I pattern structure M1 being undertaken. The coordinates of these further marginal image areas W' 1 W 6 are also stored.

After the completion of the sca.nning of the second column, the third column from the left in fig. 1 is then scanned from top to bottom, the areas between known marginal image areas

W

2 W13 and W' 1

W'

3 again being ignored in order to avoid a renewed passage round the pattern structures M1 and M' I This procedure is continued until all columns have been scanned. The columns can obviously also be scanned in the opposite direction.

In order to determine whether the pattern structures M1 and M' in question are those that are not completely filled in and enclose a free area, as is shown in fig. 4, a check is made in the area between known positions of outer marginal image areas between the marginal image areas W 2 and W 1 4 in 0 0 fig. 4) as to whether all image areas are structural image 0 areas W

S

The verification is also effected by comparison in pairs of the image data, in each case in the column direction, 0 0 4 S of adjacent image areas or by finding the difference between o 0 oo the corresponding image data. When at least one further image o a area W lying within this area is present which is not a struct- 0004 ural image area, this further image area W is used as the first marginal image area for the determination of inner marginal image areas. These marginal image areas are labelled W 0 Wi, 0 W7 in fig. 4. The coordinates of the inner marginal image 7 areas are also determined like the coordinates of the outer marginal image areas of the pattern structures M1 and M' 1 as is shown by figs. 1 to 3. They are also stored separately.

If, after complete scanning of the pattern, all outer and inner marginal image areas have been determined and stored, the pattern itself can be deleted in the image storage or overprinted by a new pattern. If the previously stored pattern is to be reconstructed, onlyLe separately stored outer and inner marginal image areas are called up by a control device, so that the areas between the outer and possibly inner marginal image -12areas can be filled out with data which correspond to the original pattern data Do, D' 0 of the pattern structures M i M'I and M 2 The filling in of the areas in question by means of the outer and inner marginal image areas is effected by conventional methods, which will not be described here, and which are common knowledge to the average specialist.

As already mentioned, the outer marginal image areas W0,

W

1 5

W'

0

W'

6

W

0

W

20 and the inner marginal image areas W 0 W7 can be kept by storing the coordinates of them. For example, for the storage of the marginal image areas W 0

W

15 of the pattern structure M1 in fig. 1, sixteen pairs of coordinates can be stored, which nteans a storage requirement of 32 bytes 64 half-bytes). By using the eight basic vectors or directions shown in fig. 2, the storage space required to store the marginal image areas in question

W

0 W15 can be reduced. For example, only the coordinates °o (02, 04) of the first marginal image area W 0 are stored, while for all following marginal image areas W 1

W

2

W

3 only directional data in relation to the immediately preceding otc S marginal image area are stored. The margin of the pattern structure M can thus be completely described by the pair of coordinates (02, 04) for W and 15 basic vectors 7 6 5 4 3 5 4 2 2 2 0 1 0 0, which are associated with the directions a0 to a 7 in each case. For example, the second marginal image area W of the pattern structure M lies in a direction 7 in relation to the first marginal image area W 0 so that this direction a can be described by a basic vector 7. Accordingly, a basic vector 3 corresponding to the direction 3 could be associated with the outer marginal image areas W 4 and W 5 the marginal image area W 5 lying in this direction in relation to the marginal image area W 4 etc.

The directions and basic vectors mentioned can also be translated into rotations or numbers of angular intervals which lied between the directions concerned. As already mentioned, thk,:second marginal image area W1 lies in a direction a7 in relation to the first marginal image area W 0 so that the basic A 4.

_I II-LII~_IIX---I~L I) I 11.CI~-- -13vector 7 is associated with this pair of marginal image areas.

In order to move from the direction a 7 to the next'direction a 6 in which the third marginal image area W 2 lies in relation to the second marginal image area W 1 taking into account the direction of rotation 3 in fig. 2, it is necessary to pass through seven angular intervals. This number of angular intervals may also be used to describe the position of the margrial image areas. In order then to reach the fourth marginal image area W 3 which lies in a direction a 5 in relation to the third marginal image area W 2 seven angular intervals in the direction 3 in fig. 2 must also be covered in relation to the original distance between W1 and W 2 and so on. Consequently, the margin of the pattern structure M 1 can be completely described by the pair of coordinates (02, 04) for the first marginal image area W01 the vector 7 between the first marginal image area W 0 and the second marginal image area W1 and the following rotations and numbers of angular intervals 7 7 7 7 2 0 7 6 0 0 6 1 7 0.

S' By the compression table given below the description is further reduced to the coordinate data (02, 04) for W 0 the use of the first basic vector 7 for the direction in which W 1 lies in relation to W 0 and the use of the rotation sequences or sequences of angular intervals 14 14 2 9 6 8 6 1 7 11. Hence an even smaller storage space is required to store those data by which the pattern structure M is completely described. The same applies to the other pattern structures M' and M 2 The rotations in question can be produced by addition module 8.

4$ 4r -14- Half-byte Rotation sequence or sequence of numbers of angular intervals 0 0 1 1 2 2 3 3 4 4 6 6 7 7 8 0-0 9 0-7 0-1 11 12 13 1-1 14 7-7 0-0-0 Fig. 5 shows a device for applying the method described by means of figs. 1 to 4. This device has an optical input means 1 for scanning a document 3 lying on a document-receiving plate 2, the document bearing a signature or a graphical pattern.

o The optical input means 1 transforms the image of the pattern Sor signature into digital signals and passes these signals to a central control means 4 which contains a computing stage o The central control means 4 may in addition be connected to other input means 6, for example to a recording plate, by means of which a signature, when acted on by pressure, is transformed into corresponding electrical signals. Also connected to the o t, Scentral control means 4 are a ROM 7 for storing operating S programmes, a first memory 8 with random access (RAM 1 a second memory 9 with random access (ram 2 and a plurality of reproduction means 10 and 11. A reproduction means may comp- &P 9%t rise, for example, a monitor 10 or a laser printer 11 which creates a pattern corresponding to the input signature on a '1 light-sensitive plot 12 which is disposed on a substrate 13.

The memory 8 (RAM 1 is used for temporary storage of a graphical pattern recorded by the input means 1 or 6, so that the said outer and inner marginal image areas of this pattern can be determined. The marginal image areas themselves or their coordinates are stored in the second memory 9 (RAM 2 A new pattern can then be stored in the memory 8, the old pattern

I;

ii ij then being deleted or overprinted. The corresponding new marginal image areas are also stored in the memory 9, without, however, the marginal image areas of the preceding pattern being deleted. ALtogether the memory 8 requires only one storage capacity which is sufficient to store a single pattern.

It can therefore be relatively small. The storage capacity of the memory R, however:, is much larger, since a large number of marginal image areas associated with different patterns are to be stored in it. By means of the central control means 4 the marginal image areas of a pattern stored in the memory 9 can be called up and the associated pattern structures M 1

M'

1 and M 2 can be reconstructed by common methods in the memory 8. The reconstructed pattern structures are then read out of the memory 8 and passed to the monitor 10 or the laser printer 11 4 46

II'

44 -6P o.

VT0 r ~L~r~n

Claims (19)

1. A method of electronic storage of a graphic pattern in an image memory, said pattern comprising a first region having a first image characteristic and a second region, adjoining a margin of the first region and having a second image characteristic, said method comprising the steps of: 0 i) converting the pattern into a series of elements of data representative of an array of image areas of the pattern, taken from Boo oo both said regions, said data elements *of comprising information with regard to said a o first and second image characteristics; o 14 ii) storing the elements of data in a temporary memory, arranged in a matrix corresponding or to said array; o04 o iii) scanning said matrix with reference to said ,I information to select marginal elements of 04a4 data which represent image areas at the margin of the first region; 4t44 iv) generating position data with respect to the position of the selected marginal elements of data; and v) storing said position data in said image memory. I- .L ;I~1_I~F-I iUI~.Y I-L1.- CL 17

2. A method according to claim 1 wherein said matrix comprises rows and columns and said scanning is carried out firstly in a linear fashion by comparing the elements of data in the matrix in pairs consecutively in the line or column direction of the matrix until a difference in said information with regard to the first and second image characteristics between the elements of data in a pair is detected, a first element of data being selected as a marginal element of data in accordance with detection of said o0 o difference, and secondly in a rotary fashion by 60 oC° comparing the elements of data in the matrix which o o lie adjacent said first element, with said first element, to detect and select a marginal element of o r data, scanning in a rotary fashion then being C66b a oo repeated with respect to the second marginal element, and each subsequently detected marginal element, so as to detect and select a series of consecutive marginal elements representing image areas at the o ~margin of said first region of the graphic pattern. .0.0 4 0 0, 3. A method according to claim 2 wherein said 6004 first element of data selected is the last element of data in a line or column direction for which no difference is detected with respect to the preceding element of data in that direction, and wherein i scanning in a rotary fashion is started in each case '4 with respect to the pair of elements of data most recently compared, the second and series of marginal elements then each comprising the first element of data in a rotary scanning step which shows no difference with respect to the previously selected marginal element. a' 18

4. A method according to any one of the preceding claims wherein said pattern comprises a plurality of second regions, and steps iii), iv) and v) are carried out to generate position data with respect to all the marginal elements of data corresponding to image areas of said first region which lie adjacent to a second region, and then steps iii), iv) and v) are repeated to generate position 0°0 0. data with respect to all the marginal elements of S0 data corresponding to image areas of said first o e region which lie adjacent a further second region. 0 h0 00 0 o 5. A method according to any one of claims 2, 3 or 4 wherein said scanning in a linear fashion is carried out along a first line or column of the matrix, and continued along consecutively adjacent lines or columns until said difference is detected.

6. A method according to any one of claims 2 to wherein a second region of said pattern may be annular, having an outer margin and an inner margin, and wherein said scanning is carried out to select all the marginal elements of data which represent image areas of the first region adjacent the outer ,j margin of the second region, the method further comprising the steps of: scanning in a linear fashion only elements of data which represent image areas within said outer margin of the second region, so as to locate any ,c7. L .IL 19 inner margin said second region may have; and, subsequent to locating an inner margin, scanning in a rotary fashion so as to detect inner marginal elements of data which represent image areas of the first region adjacent said inner margin of the second region.

7. A method according to claim 6 wherein said oOo p inner marginal elements of data represent image areas o" of the first region within and adjacent said inner Sno margin of the second region. 0 0 so o o oo a6 8. A method according to any one of the preceding claims wherein said pattern comprises more than one second region, the first region having margins adjacent each of said second regions, and allo said method comprises carrying out steps i) to v) 0oo Cinclusive with reference to a first one of the second regions, and further comprises repeating steps iii) 1 oto v) inclusive with reference to a second one of the second regions, marginal elements of data already located with respect to the first one of the second regions being excluded from said repeated steps. tit

9. A method according to claim 8 wherein elements of data lying between the excluded marginal elements of data, in the matrix, are also excluded from said repeated steps. ~i I "A 7rda A method according to any one of claims 2 to 9, wherein the storage of said position data is effected by storing the matrix coordinates of the first element of data detected with respect to a region and an cindi ation of the one direction selected from a pi-determined plurality of potential directions in which the second and each subsequent marginal element of data of a region lies in relation o to the preceding marginal element of data detected in o000 respect of the region. 0 0 oa 11. A method according to claim 10, wherein said o indication of the one direction is derived by starting from a reference direction, and counting that number of angular intervals between the potential directions which have to be passed through 0ooo0 to progress from said reference direction to the 0°0O direction in which each subsequent marginal element of data lies in relation to the preceding marginal So"« element of data detected in respect of the region, so ooo as to generate an angular interval number. 00000: 12. A method according to claim 11 wherein said reference direction comprises the direction, selected from said plurality of potential directions, in which the second marginal element of data lies in relation j to the first marginal element of data detected in respect of the region.

13. A method according to claim 11 wherein said reference direction comprises the direction, selected i- Icrm~--u 21 from said plurality of potential directions, in which the preceding marginal element of data detected in respect of the region lies with respect to the marginal element of data detected immediately prior to said preceding marginal element of data.

14. A method according to any one of claims 11, o 12 or 13, wherein a predetermined sequence of angular 0o interval numbers is assigned a determination value °0 for use in said position data. 0 ID .0 0 0 0 Q o a oo 0 o° 15. Method as in claim 14, wherein two sequences of angular interval numbers are assigned determination values for use in said position data. ot

16. Method as in any one of the preceding claims, wherein the elements of data undergo an image processing step before the selection of the marginal elements of data.

17. Method as in claim 16, wherein said image processing step comprises obtaining a mean value from the elements of data relating to four mutually adjacent image areas in each case.

18. Method as in either one of claims 16 or 17, wherein the elements of data are subjected to digital filtering before the selection of the marginal elements of data. U 0 A I--

19. Method as in any one of the preceding claims, wherein the entire matrix of elements of data which represent a background of the pattern is framed. Method as in any one of the preceding °o claims, wherein the graphic pattern is optically 9 09 o0o scanned for the conversion into elements of data. 0 9 00o 21. A method according to any one of the o preceding claims, further comprising the step of reproducing the graphic pattern, by reproducing image areas of said array, using the position data to identify a margin of the first region, and allocating a predetermined visual characteristic to zeproduced 0"OO* image areas of said pattern lying along said margin. G ti 0 4I

22. A method according to claims 21, wherein reproduction of the pattern is carried out by means f' of a laser beam directed on a radiation-sensitive plotter.

23. A method according to either one of claims. 21 to 22, wherein reproduction of the pattern is effected by printing out the elements of data.

24. Apparatus for electrically storing a graphic pattern, said pattern comprising a first region _.ri-pL O *i *I 23 having a first image characteristic and a second region having a second image characteristic, said second region adjoining a margin of said first region, the apparatus comprising: i) pattern conversion means which is sensitive to said first and second image characteristics, for converting the graphic 0o O pattern into a series of elements of data 0 0 o representative of an array of image areas of the pattern, elements of data representing 0o00 0."0 image areas having said first and second o image characteristics being distinguished 11 respectively; .000 ii) a temporary memory for storing said elements of data in a matrix corresponding to said .090 o°°array; 0000 o 0f iii) scanning means for scanning said matrix so 0o as to select marginal elements of data from Oott said matrix, which marginal elements represent image areas of .did first region which lie adjacent its margin; iv) position data generating means for generating position data with respect to the position of the selected marginal elements of data; and v) an image memory for storing said position data. Apparatus according to claim 24 which 4* h a r i 24 further comprises reproducing means for reproducing image areas of said array, said reproducing means selecting image areas which lie in the second region of the pattern, with reference to said marginal elements of data, and reproducing the selected image areas with a predetermined image characterisic. S 26. Apparatus according to claim 25 wherein siad reproducing means reproduces image areas of the pattern which lie in the first region of the pattern with a further, different predetermined image characteristic.

27. Apparatus according to any one of claims 24 to 26 wherein said pattern conversion means comprises San optoelectrical device.

28. Apparatus according to any one of claims to 27 wherein said reproducing means comprises a laser printer.

29. A method of electronic storage of graphic patterns substantially as hereinbefore described with reference to the drawings. A method of reproducing a graphic pattern substantially as hereinbefore described with reference to the accompanying drawings. ^^hI o O oa 0o 0 0 090 S0 0 0 600 0 090 0ooa o Qo oo o 00 0 000 0 0 00 0 0000 0009 o 4 0 604 0 ft4 a0 4 t a

31. Apparatus for electronic storage of a graphical pattern, substantially as hereinbefore described with reference to the accompanying drawings. DATED this 25th day of May, 1990 MAURER ELECTRONICS GmbH and LEIGH-MARDON PTY. LIMITED By their Patent Attorneys DAVIES COLLISON i YW--