MXPA97004692A - A method to identify and authenticate tickets as well as the device to carry out this met - Google Patents

Abstract

To identify and authenticate notes (1), the latter is illuminated by a radiation source (4) when a black and white photograph is taken that has at least 32 levels of gray detected by a digital camera (3). The signal of the digital camera (3) is fed into a computer (7) to evaluate the number, frequency and / or spatial distribution of the detected gray levels.

Description

A Method for Identifying and Authenticating Tickets as well as the Device for Carrying Out This Method The invention relates to a method of identifying and authenticating banknotes with the aid of a source of electromagnetic radiation, as well as the device for identifying and authenticating banknotes, in which a note is inserted into a source of electromagnetic radiation, such as a light source. The known devices are those in which the bills are illuminated from below, such as, for example, with the help of an ultraviolet light source in order to allow the visual evaluation thereof. The evaluation in these cases is done by the experience of the evaluator, his attention is directed to certain characteristic points of the ticket that are suitable for the evaluation as a function of the ticket. To evaluate tickets automatically, a number of devices are known which the ticket is passed under an analyzer or scanner. As a rule, a special evaluation in these cases comprises a number of criteria directed to certain bills and is made according to the predetermined scheme that a separate preset is required for each bill. These devices, as a rule, apply only to a small number of different different bills, unless the expenses involved in the evaluation are very high. The invention seeks to provide a method and a device of the initially defined class, to which the simple adaptation of the identification of different bills is facilitated. Taking into account that for reasons of security, the intervals between the reintroduction of bills are increasingly smaller, the invention seeks to minimize the costs of identification by simple procedures so that they are made without the need for complex computers and thus be feasible the rapid and safe evaluation of a large number of different bills from each other. To solve this objective, the method according to the , invention of the identification and authentication of banknotes is essentially characterized in that a black and white photograph of the illuminated bill is taken and this photograph is subjected to an evaluation of the number, frequency and / or special distribution of at least 32 levels of gray detected . Because the black-and-white photograph is taken from an illuminated bill, both the information on the front and the back of the bill can be evaluated in the form of an accumulated recapitulation signal; This minimizes computing expenses by limiting the black and white photo that has a predetermined number of at least 32 levels of gray detected. However, at the same time, the accuracy of the evaluation can easily be increased by detecting 32 different levels of grays mutually so that almost all notes can be easily differentiated from each other and the required security criterion can be achieved for each ticket in order to define its authenticity. It is true that the evaluation of black and white photography involves large computing expenses, but this evaluation can be achieved with today's computers at favorable cost-performance averages such that the method according to the present invention is You can perform safely even with non-specialized computers. The device according to the invention for identifying and authenticating banknotes, in which a banknote is inserted into a source of electromagnetic radiation, such as for example a light source, is essentially characterized in that the banknote is conducted and detected between a digital camera and a light source, the video signal of the camera taking the picture is fed into a computer, at least 32 levels of grays undergo an evaluation in relation to their relative arrangement, the frequency and / or spatial portion in the photography, and the authenticity evaluation signal that is transmitted to a screen or a control to pass the ticket. When detecting the ticket that is driven between the digital camera and the light source, a still photograph of the bill is taken with a video signal from the camera that is optionally subjected to a conventional data compression, in particular, video data compression, before the additional process. Subsequently, the signals that are used contain at least 32 levels of gray on the side of the photograph taken, where the video signal can be subjected to an appropriate computerized operation that can increase the meaning of the evaluation, with an equipment expense. of relatively small computations. The evaluation of the number of gray levels in this case can also be done starting from the compressed signals with the additional option of additionally evaluating the respectively coded signals, for example the recapitulation signals of each point of each individual video point information. By the fact that both the relative array or the frequency or the spatial portion of the gray levels in the photo are subjected to an evaluation in the original form of the video signal or in the appropriately modified encoded or compressed form, it can be transmitting an authenticity evaluation signal to a screen and / or a control to pass the ticket, within an extremely short period of time. In order to ensure the optimum degree of reproducibility of the detected data, an advantageous configuration is planned, so that the bill remains immobile on an illuminated sheet while photographing. This still photography allows any desired compression and encoder prior to processing, reproducibility is independent of the speed of feed transportation or other mechanical parameters in any event.

A further increase in the accuracy of the evaluation and in the security differentiation of a large number of different banknotes can be achieved with an evaluation comprising at least 64, preferably 128 gray levels, when the gray levels of the signal are compared with the reference signals in order to obtain adequate results in rapid succession. With this arrangement, the reference signals can externally feed the respective computer in the form of data. Still, as another alternative, the arrangement can advantageously be planned so that the computer comprises an adapted learning circuit, in particular an iteration circuit for calibrating the given note, therefore, it allows the formation of reference signals by iteration. In order to reduce the evaluation time and the number of data processed, the arrangement can advantageously be planned in such a way that a differential signal of the video signal and the reference signal are fed into the evaluation circuit. In a particularly advantageous form, the configuration is planned in such a way that the source of electromagnetic radiation is constituted by a radiation source that includes a short wave light, an ultraviolet light or an X-ray source, where it is ensured that a Maximum signals evaluated will still be obtained with tickets with relatively tight prints. In addition to the option of the simple evaluation of the statistical data related to the levels of gray detected in each case, a more complex evaluation can also be carried out with slightly higher computer equipment costs, in this case, the preferred configuration is plan in such a way that the black and white photograph of the ticket is subjected to an evaluation of the element of the photograph, such as, for example, a recognition pattern, the photography evaluation programs of this class are used as, for example, in relation to with the evaluation of satellite photographs, where high degrees of fault tolerance are achieved in these cases due to the possibility of error data or faults that can be compensated by the computer as the photograph is taken. The method according to the invention will be explained in more detail by the exemplary embodiment of a desired arrangement illustrated schematically in the drawing. In this drawing a ticket 1 placed on a transparent support 2 is seen, the bill remains immobile as the photograph is taken by a digital camera 3. The bill l is illuminated by a radiation source 4 constituted by a light source . The signal from the digital camera via data lines 5 and a data compressor or data concentrator 6 arrive at the computer 7, in which the respective evaluation is carried out. The digital camera 3 detects at least 32 levels of grays, where the appropriate signal 8 can be triggered to indicate authenticity if the latter has been confirmed for evaluation. As an alternative, an appropriate conduit or an additional transport mechanism may be operated in such a way as to allow the bill recognized as authentic to be deposited in a suitable place to receive this bill. The light source can be adapted to a respective type of ticket 1 to be investigated. In principle, sources of electromagnetic radiation rich in energy are particularly advantageous with bills printed very tightly. For fast and secure detection, the digital camera 3 is capable of taking at least five photos per second at a desired resolution. The transparent platform 2 can be repositioned with a perforated platform and this makes it possible to secure the immobilization of the bill by suction of air through two suitable holes in the sheet, in particular with the aim of fixing the bill while the photograph is taken.

Claims (10)

1. CLAIMS 1. A method for identifying and authenticating notes with the help of a source of electromagnetic radiation, characterized in that a black and white film is taken from the illuminated bill (1) and that the film is subjected to an evaluation of the number, frequency and / or special distribution of at least 32 levels of gray detected.
2. 2. A device for identifying and authenticating banknotes, in which the bill (1) is inserted into a source of electromagnetic radiation, such as a light source (4), characterized in that the bill (1) is conducted and detects between a digital camera (3) and a light source (4), the video signal of the camera taking the picture (3) is fed to a computer (7), at least 32 levels of grays that undergo evaluation in relation to the relative arrangement, the frequency and / or the special portion in the photograph, and the authenticity evaluation signal that is transmitted to a screen and / or a control to pass the ticket.
3. 3. A device according to claim 2, characterized in that the video signal is fed to the computer (7) via a data compression (6).
4. 4. A device according to claim 2 or 3, characterized in that the bill (1) is held immobile in an illuminated sheet (2) while the photograph is taken.
5. 5. A device according to any of claims 2 to 4, characterized in that the evaluation comprises at least 64, preferably 128 gray levels.
6. 6. A device according to any of claims 1 to 5, characterized in that the signal of gray levels is compared with reference signals. A device according to any of claims 2 to 6, characterized in that the differential signal of the video signal and the reference signal are fed into the evaluation circuit. 8. A device according to any of claims 2 to 7, characterized in that the computer (7) comprises a adapted learning circuit, in particular an iteration circuit for calibrating the given bill. A device according to any of claims 2 to 8, characterized in that the source of electromagnetic radiation (4) is constituted by a radiation source that includes a short wave light, ultraviolet light or an X-ray source 10. A device according to any of claims 2 to 9, characterized in that the black and white photograph of the bill (1) is subjected to an evaluation of the element of photographs, such as, for example, a recognition pattern.