GB2320099A

GB2320099A - Identifying defects on an animal skin

Info

Publication number: GB2320099A
Application number: GB9725536A
Authority: GB
Inventors: Micheal Balluff
Original assignee: Duerkopp Adler AG
Current assignee: Duerkopp Adler AG
Priority date: 1996-12-04
Filing date: 1997-12-02
Publication date: 1998-06-10
Also published as: GB9725536D0; DE19650234C1

Abstract

Markers 8; 9; 10 are used for the identification of a selected area 3; 4; 5 of a workpiece 2, especially an animal skin, wherein selected areas 3; 4; 5 of different quality grades are established in terms of their position relative to the outer edge of the workpiece 2, their size and their quality and are defined with the aid of the markers. The marker 8; 9; 10 is disc-shaped and has a limiting edge within which an identifying marker 15, 16, 18 is arranged. By providing the marker with contrasts it is possible, with the aid of a camera, to capture information on the skin with markers 8; 9; 10 lying on it, irrespective of the tone or colour of the skin 2.

Description

2320099 An object for identifying a selected area on a workpiece,

especially an animal skin The invention relates to an object for identifying a selected area on a workpiece, especially an animal skin.

DE 42 31 222 Cl discloses an object for symbolizing and marking imperfections on natural leather, wherein spheres are laid in varying numbers on zones delimited by cord. Such objects enable the optical capture of zones of differing qualities and their position relative to the outer edge of the workpiece with the aid of a camera and an image processing system arranged in series.

Workpieces such as an animal skin as the starting material for leathers to be cut out for upholstered furniture or car seats are often dyed very different tones or colours so that it is necessary to have the aforementioned objects ready in different tones or colours, and to obtain the necessary contrast these must be chosen/assigned.

The use of such objects has the following disadvantages:

spheres of different tones or colours are required to ensure the necessary tone or colour contrast between the workpiece and the spheres because of the dimensions involved, the number of spheres to be laid on the workpiece is limited so that the quantity of information for different quality grades is also limited the assignment of the number of spheres to specific quality grades necessitates a degree of judgement on the part of the operator, the fact that several spheres need to be laid adjacent to one another means that each individual sphere has to be small, so that the positions of the spheres is not very secure in the event of vibrations despite their flattening, some manual actions are necessary for correct placement of the spheres, so that this approach is time-consuming. In summary, the handling of such objects is not very practicable. To identify faulty areas of smaller dimensions it is conceivable to use an object in the form of a ring, which has an irregular outer border and regions of differing quality zones, for the optical capture of a workpiece. Here too, it would be necessary to assign tones or colours relative to the tone or colour of the workpiece to ensure the necessary contrast for optical recognition by the camera.

US 3,985,293 discloses a machine- readable label in which rings of different configurations are arranged within a ring. Such labels do not provide any impetus for the object in accordance with the present invention.

on the basis of the above considerations, the aim of the present invention is to yield an object which allows work to be carried out whilst avoiding the above -3difficulties.

The aim of the invention is addressed using an object with the characteristics of claim 1. Adjoining areas on the object have different tones or colours, thereby yielding a contrast which is independent of the tone or colour of the workpiece and which can be captured by a camera. The object simplifies the procedure in so far that only a single part has to be laid on the workpiece and only a single set of the objects is used, irrespective of the tone or colour of the workpiece. Further advantages of the object in accordance with the invention are derived from the simple construction, the secure positioning, the low space requirement and the inexpensive manufacturing process. A further advantage is that the tones or colours is yielding the contrast meet along a circular limiting line. This ensures very rapid and certain image capturing and processing in the image processing system arranged in series with the camera.

The further development of the invention provided by claim 2 allows the definition of a region of a faulty area, such as a mosquito bite or a small hole, directly using the object. The further development according to claim 3 enables a specific symbol to be assigned to a specific quality grade. This brings the further advantage that the number of quality grades is solely limited by the number of different symbols. The further development of the object according to claim 4 results in an embodiment which is very safe in terms of operation. The further development of the object according to claim 5 results in simple handling. The remaining subclaims yield further advantageous embodiments.

Details of example embodiments are given in the following description, wherein the object in accordance with the invention, as a marker, is described in three example embodiments.

Figure 1 A f ront view of a workplace with a workpiece laid on a table and a camera arranged over it with an image processing system; Figure 2 An enlarged view of the table with the workpiece laid on it, viewed in accordance with the arrow II in Figure 1; Figs. 3-5 views of different regions on an enlarged scale; and Figure 6 A part of Figure 1 on an enlarged'scale.

A workpiece 2 in the form of a leather item or an animal skin lies on a table 1. The workpiece 2 has selected areas 3, 4 and 5 which are of lower quality compared to the remainder of the workpiece 2 in terms of their appearance or dye uptake.

The selected area 3 is bounded through a limiting cord in the form of a cord 6 and the selected area 4 is bounded through a corresponding cord 7. A marker 8 (example embodiment 1) lies on the selected area 3 and a marker 9 (example embodiment 2) lies on the selected area 4. The selected area 5 is a relatively small area within a circle of maximally 8 millimetres. This may be a small hole or an is insect bite. The selected area 5 is correspondingly delimited directly, without the use of a cord, by a marker (example embodiment 3), the construction of which will be described below.

It is pointed out the markers 8, 9 and 10 are shown in shaded form expressly for graphical representation and in reality are completely filled with the torie or colour black.

Circular discs with a thickness s of approximately 2 millimetres and a diameter D of approximately 35 millimetres are manufactured of a plastics material. From the outer periphery 11, an area, black in tone or colour, extends in the form of a circular ring 12 and has a ring width a of approximately 4 millimetres. The circular ring 12 circumscribes an annular inner region 13 which is white in tone or colour. The tones or colours black and white adjoin one another without an annular limiting line 14 8 has an identifying marker marker 9 has an identifying any intermediate space so that is formed. Further, the marker 15 on its inner region 13 and marker 16 on its inner region 13. The identifying marker 15 is in the form of the letter A, black in tone or colour, and the identifying marker 16 is the number 1,111, black in tone or colour. Here too, the tones or colours black and white are adjacent to each other, without any intermediate space so that a second limiting line 17 is formed. The described arrangement of the identifying markers 15, 16 in the form of the letter A and the number 11111 is such that a distance b of at least 4 millimetres is ensured between the limiting lines 14 and 17. The arrangement of the limiting line 14 in the form of a circle ensures that the markers 8, 9 or 10 can be laid on the workpiece 2 in any chosen rotational position.

The markers 8, 9 are especially easily handled if the identifying markers 15, 16 are used either as only letters or numbers, whereby an alphabetic sequence of letters or ascending sequence of numbers is assigned to a sequence of quality grades.

In contrast. to the above, the marker 10 has an identifying marker 18 in black tone or colour on its inner region 13. This is in the form of an annular ring with a ring width c of approximately 4 millimetres. Here too, the tones or colours black and white are adjacent to one another without any intermediate space so that here too the second limiting line 17 is formed. The identifying marker 18 circumscribes a visual field 19 which is in the form of a through-hole. The visual field 19 could also take the form of a transparent region in the marker 10. The marker

10 is formed such that the annular ring 12, the identifying marker 18 and the visual field 19 are arranged concentrically relative to one another, with the inner region 13 having a ring width d of approximately 4 millimetres.

The above-described arrangement of the markers 8, 9 and 10 is the same in each case on one side 20 and on the opposite side 21, as shown by way of example for marker 10 in Figure 6.

A camera 22 is secured above the table 1 and is a CCD or matrix camera. The camera 22 is connected via a line 23 to an image processing system 24. The relative arrangement of the table 1 and the camera 22 and the sensitivity of the camera 22 and the light conditions enable the optical capture of the workpiece 2 laid on the table 1 and the markers 8, 9 and 10 on it, as well as the cords 6 and 7 and the outer edge 25 of the workpiece 2.

The procedure is as follows:

The workpiece 2 is spread out on the table 1 and is checked visually through inspect ion/viewing by the operator so that the surface of the workpiece 2 is checked for imperfections or other areas of reduced quality. In the process, smaller areas, such as the selected area 5, are directly delimited using the marker 10. Larger areas, for example the selected areas 3 and 4, first need to be delimited with the cords 6 and 7, yielding a quantitative determination of the selected areas 3, 4. This is followed by qualitative determination of the selected areas 3, 4. To facilitate this, the markers 8 and 9 are assigned to the selected areas 3, 4 in accordance with their quality grades and are laid on them. once this work is completed the workpiece 2, together with the cords 6 and 7 and the markers 8, 9 and 10 on it, is captured optically. Because the contrasts are formed at the markers 8, 9 and 10 in each case by the tones or colours black and white, the position of the markers 8, 9 and 10 relative to the outer edge 25 and the identifying markers 15, 16 and 18 can be captured without difficulty by -8 the camera 22 irrespective of the tone or colour of the workpiece 2.

The camera 22 sends information, for instance data, to the image processing system 24, via the line 23. The data for the limiting line 14 is then compared to data already stored by the image processing system. Since the limiting line 14 is circular and can thus assume any desired rotational position, usingtthe appropriate software it is possible within a relatively short period of time to establish the position of the markers 8, 9, 10 relative to the outer edge 25 and to deposit this information in a memory. In addition, the position of the second limiting line 17 is established, followed by the capture and evaluation of the identifying markers 15, 16 and 18. This is allows a statement on the respective assignment of quality grades. The area of the selected areas 3, 4 delimited by the cords is then established. Since the second limiting line 17 for marker 10 has a circular form, there is a correspondingly clear interpretation as marker 10 with the visual field 19.

A data record is thus provided which can be stored and which contains information on the workpiece 2 in terms of the outer edge 25 and the relative positions, sizes and qualities of the selected areas 3, 4 and 5.

9_ is

Claims

Claims:

1 An object for the identification of a selected area of a workpiece, especially an animal skin, with the following features:

the object is of flat material and has a first side and a second side; the object can be laid with its first side on the selected area and its second side can be captured by a camera arranged above the workpiece; the object is provided at least on its second side with an area which has a first tone or colour and which extends around an annular inner region; the inner region has a second tone or colour, whereby the tones or colours form a contrast and have a limiting line between them which can be captured by the camera; the inner region has an identifying marker; the object laid on the selected area can be captured by the camera in terms of its position relative to the outer edge of the workpiece and its identifying marker; information on the relative position and the identifying marker can be transmitted from the camera to an image processing system.

2. An object according to claim 1, in which a visual region for the observation of a part of the workpiece is -10located within the inner region.

3. An object according to claim 1 or 2, in which the identifying marker has a symbol in a third tone or colour, wherein the second and third tones or colours yield a contrast, and with a second limiting line between them which can be captured by the camera.

4. An object according to any preceding claim, in which at least one of the contrasts is formed through the tones or colours.

5. An object according to claim 4, in which the symbol is an annular ring, a letter or a number.

6. An object according to any preceding claim, in which the area is in the form of an annular ring.

7. An object according to any preceding claim, in which is the object is in the form of a disc with an external diameter of approximately 35 millimetres and a thi.ckness of approximately 2 millimetres.

8. An object according to claim 7, in which the first side of the object has a form corresponding to that of the second side.