Title of Invention	A METHOD AND SYSTEM FOR PREVENTING THE PRODUCTION OF ILLEGAL HARD COPIES OF A DIGITAL DOCUMENT MARKED WITH A PREDETERMINED SECURITY TAG
Abstract	The present invention proposes a method for the detection of security tag in a document using a combination of text and image processing so as to ascertain whether the data being duplicated is permitted to be copied. It is alos provided that the reference security tag can be updated or a new one can be added in the system. When an illegal attempt is detected the suspected digital data will not be printed and the breach will be notified to the administrators through E-mail, Paging, SMS etc. Also a copy of the suspected didgital data will be stored for further investigation.

Title of Invention

A METHOD AND SYSTEM FOR PREVENTING THE PRODUCTION OF ILLEGAL HARD COPIES OF A DIGITAL DOCUMENT MARKED WITH A PREDETERMINED SECURITY TAG

Abstract

The present invention proposes a method for the detection of security tag in a document using a combination of text and image processing so as to ascertain whether the data being duplicated is permitted to be copied. It is alos provided that the reference security tag can be updated or a new one can be added in the system. When an illegal attempt is detected the suspected digital data will not be printed and the breach will be notified to the administrators through E-mail, Paging, SMS etc. Also a copy of the suspected didgital data will be stored for further investigation.

Full Text	FIELD OF THE INVENTION This invention in general relates to document reproduction and security in networked printers. This invention further relates to digital document security based on watermarking, keyword detection etc. more particularly, this invention relates to a method and system for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag. DESCRIPTION OF RELATED ART Document security is a key area of concern in the digital technology domain. The progress in recent years in digital technology, coupled with that in colour image recording technology has made it possible to output a copy image, which is similar to the image of an original. It is a fact that the use of essential and necessary devices such as computers and digital copiers cannot be avoided as we live in the digital era. At the same time, there should be measures for the protection of copyrighted works as we are living in a world where intellectual property is valued as one of the most important assets of an individual/organisation. Therefore, protection against duplication of any digital image/document with a nature of confidentiality is very much essential in order to secure the privacy and to prevent the piracy of such documents. A considerable amount of research and work has been done in this field since document security is vital in these times, which heavily depends on digital technology. The US granted Patent Kashioka 4,334,241 provides a pattern position detecting system which picks up the image of an object having a target pattern to be detected and compares it with a standard pattern having the same feature as that of the target pattern so as to assess the degree of coincidence between the patterns. This technology is very useful in the detection of a watermark, logo, etc. Now according to the embodiments of US Patent Philibert 4,908,873, it is possible to selectively effect the operation of a copying machine or facsimile machine in accordance with the textual content of a scanned document. The system according to the above said patent comprises an operation central circuit responsive to central signals applied thereto for actuating the copying apparatus, an optical character reader (OCR), memory means for storing indicia of at least one correlation criterion in respect of the portion of text read by the OCR means and a processor for generating Central Signals to the central circuit and thereby enabling the copying apparatus in accordance with a correlation of the said criterion with said portion of text. It is a generic system that can detect textual data by OCR and use the same from preventing the reproduction machine from making copies of secure documents. For achieving this purpose, it uses a predefined number of scan lines and also predefined number of characters per line to determine whether a piece of text is present in the document or not. They use pre-determined patterns stored in PROM to perform the detection. In order to compensate the misalignment, it proposes changing of 0/P code reader (e. g: -CCD device) in comparison with multiple images stored in PROM which are copies of same character with different alignment. The advancement of technology in this field further resulted in image processing apparatus which can permit colour copying of an original but at the same time protecting against the scanning of secure images such as currencies. Granted US Patent Hasuo 5,321,470 describes an image processing apparatus of the said type which permits colour copying of an original, and makes it possible to discriminate a specific original for the sake of prevention of forgery of a banknote, a negotiable instrument or the like. In its operation, the specific original is provided with a process of copying which is different from that provided for an ordinary original. The apparatus according to the said patent comprises a scanning device, means for determining whether the original represented by the scanned image is an original having a specific pattern, printing means and controlling means for controlling the processed image and processing means. The arrangement and working herein is such that both the determining and processing are performed in parallel. Very sophisticated and powerful image processing methods are now available to detect a specific pattern in an image. Document 59825105, NLPR, China illustrates digital watermarking for forgery detection in printed material and therefore has been incorporated herein by reference. In order to have a general idea about the architecture of the copying machine employed in this invention, a description of the similar system known from US Patent 4,908,873 is made with reference to Figure 1. As it is apparent to a person of ordinary skill in the art that it has a scanner (50), optical code reader (12), misalignment indicator (32), a micro processor (16), memory means (18, 20, 40), Interface means (14, 22), coin meter (42) and a Remote alarm (26) as major components. The aforementioned device operates as follows. First, the sheet of paper for which an electrical scanned copy is required, is placed on the scanner. The scanner then mechanically moves the optical code reader mechanism along the length of the sheet. As the reader progresses, it uses the photo diodes to convert the image on the paper It is apparent from the foregoing discussion that the teachings of the prior art use an image processing mechanism to detect an image with another image/text present in it. Once such a pre-known image/text is found as part of the bigger image under consideration alerting means are activated. In one typical embodiment an alarm is sounded and a count is incremented. LIMITATIONS Even though the techniques applied in the above described arts achieve their purpose there are a number of drawbacks. The related art is more concerned about digitizing an existing document and printing them and not on the proper analysis of the details when an offence is detected. It is understood from the prior art that only fixed lines have been used for optical character reorganization (OCR) and the number is kept as a constant. This will not 1 ' work in case of printers when a page is printed with different resolutions. Also in the absence of a code reader (which consists of a CCD device) the misalignment in the codes (e. g.:- detecting an inverted document) cannot be determined and hence the system will remain unaware of the misalignment and therefore it will be very simple to deceive the system using some software which can change the alignment of the document. It is also not practicable to store all the expected alignments in a PROM as generation of bit-maps on the fly by changing the co-ordinate system associated with the bit-map. Yet another problem with the teachings of the prior art is that they have only predefined text/image and it is apparent that in a drastically changing world single time programmable PROM will not be able to store all information sufficient to evaluate plurality of documents submitted for copying. Another disadvantage of the prior art is that it uses a remote alarm to alert the authorities and also requires the authorities to be present to watch and wait for the alarm. It is also a drawback of the existing technology that the digital data given to the copier is not stored at a safe location especially when an illegal attempt is detected. If the data is so stored it can be used as evidence against the offender. It is also possible to examine the document later to confirm whether the machine raised a genuine alert or made a false alarm. There is also a disadvantage according to the method in the prior art that it always resorts to image processing for finding a piece of text also and therefore is not efficient. There can be situations when the printed file uses device fonts or when the printed file is of the kind PS-1 etc. and hence possible to have simple and efficient detection. OBJECTS OF THE INVENTION The primary object of the present invention is to provide a method for the detection of a security tag in digital documents to be copied using a combination of text and image processing so as to ascertain whether the data being duplicated is permitted to be copied. It is another object of the invention to provide a method and system that allows the user to add any new pattern that needs to be matched with the document to be processed and to update the set of the patterns from time to time. It is yet another object of the invention to provide a method and system that employs paging, SMS or E-mail to notify the authorities about the breach. It is also an object of the present invention to provide a back-up of the suspected digital data in a secured location for further investigation which can prove the innocence/guilt of a user. It is a further object of the invention to provide an option of a network server from where the printer can collect security information in addition to the update in the PROM. It is again an object of the present invention to create all the image orientations by redefining the co-ordinate axis associated with the patterns to be searched to create such scenarios rather than storing all the possible image orientations as suggested by the prior art. SUMMARY OF THE INVENTION Therefore in light of the foregoing deficiencies in the prior art, the applicant's invention is herein presented. Due to the limitations in the existing art, there is a need to provide a copying/printer device which is less prone to misuse and suitable for the present digital technology scenario. The present invention proposes a method of detection of security tag or tags in digital documents to be copied, using a combination of text and image processing, so as to ascertain whether the data being duplicated is permitted to be copied and allows the user to add any new pattern that needs to be matched with the document to be processed and to update the set of the patterns from time to time, employs paging, SMS or E-mail to notify the authorities about the breach, provides a back-up of the suspected digital data in a secured location for further investigation which can prove the innocence/guilt of a user. Further, the proposed invention provides an option of a network server from where the printer can collect security information in addition to the update in the PROM and can create all the image orientations by redefining the co-ordinate axis associated with the patterns to be searched to create such scenarios rather than storing all the possible image orientations as suggested by the prior art. The present invention also proposes to update the number of scan lines stored as reference to a new number when it is detected that a certain number of lines for a number of cases crosses the threshold set earlier. These and other objects and advantages of the present invention are accomplished by sophisticated image processing techniques and self learning mechanism to support the detection of watermark/text pattern. Accordingly, the present invention comprises a method for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag, the method comprising the steps of: (a) checking for a security tag that matches with the one stored in a storage device; (b) blocking the printing process when the said security tag is matched; (c) alerting the administrators about the security breach; and (d) providing a backup of the document for further investigation. wherein it permits the operator to update security tags in the storing means. Accordingly, the present invention further comprises a system for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag, the said system comprising: (a) an image forming apparatus for supplying electrical image data representing the original; (b) a firmware for determining whether the said electrical image data contains the said security tag; (c) memory for updating and storing the said security tags; (d) a firmware for processing the electrical image data supplied by the said image forming apparatus and for outputting a processed image when required or for blocking the printing; (e) backup apparatus for enabling the production of backup of the document; and (f) memory for storing the backup of the said document; where the administrator is alerted of the status of the document. Other advantages and features of the invention will become more clearly apparent from the following description of the embodiments of the invention given as non-restrictive example only and represented in the accompanying drawings. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figurel shows the architecture of a copying apparatus according to the prior art as available in the US patent document no. 4,908,873 as sheet 1 of drawings. Figure 2 shows a flow chart, which explains the operation of the copying apparatus in Figure 1 as available in the US patent document no. 4,908,873 as sheet 2 of drawings. Figure 3 is a pictorial representation of the system according to the present invention. Figure 4 represents the method of performing the present invention. DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings and the features of the invention will become more readily apparent from the reading of this detailed description. Numerous specific details are described to provide a thorough understanding of the present invention. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention. In order to have a general idea about the architecture of the copying machine employed in this invention, a description of the similar system known from US Patent 4,908,873 is made with reference to Figure 1. As it is apparent to a person of ordinary skill in the art that it has a scanner (50), optical code reader (12), misalignment indicator (32), a micro processor (16), memory means (18, 20, 40), Interface means (14, 22), coin meter (42) and a Remote alarm (26) as major components. The aforementioned device operates as follows. First, the sheet of paper for which an electrical scanned copy is required, is placed on the scanner. The scanner then mechanically moves the optical code reader mechanism along the length of the sheet. As the reader progresses, it uses the photo diodes to convert the image on the paper The operation of the above system will now be described with reference to Figure 2. 1. Checking received file type The received file type is checked to determine the type of the document. Traditional auto emulation detection methods can be used with a little variation. The determination is based on the presence or absence of a signature which will serve as the indicator of a particular type. It can also be based on the trial and error method if necessary. The main aim is to distinguish if the document is text alone/mixed or photo (Binary) in type. 2. Direct text search After the first step, if the document is found to be text alone, then this module is used to determine the presence of any secure tags in the document. It could be any appropriate text search algorithm. The secure tags are obtained from a reliable source which might be local or network oriented storage locations. 3. Searching through an image (Binary data) In case of binary data, which will correspond to a particular emulation, the job is allowed to proceed till the final printable image is formed. This bit map is then subjected to various image processing techniques such as OCR and other pattern reorganisation processes to detect the presence of any secure tags. The text data obtained by OCR can be processed by the algorithm used for direct text search. The image part is matched using a combination of techniques such as SSD (Sum-of-Squares differences), salient or surface feature study etc. The source for the tags is secured and updatable if necessary. Since this involves complex image processing, optionally the printer can upload a part/whole of printable image to the secure server for this analysis. 4. Locations for secure tags Secure tags can be placed on a Read Only Memory, Programmable Read Only Memory, or a secure server in the network. If a secure server is used, the network parameters of the same should be present in the ROM or PROM. This information is accessible only to the administrator and he/she alone can modify the same. The access to these storage locations is restricted using a password or similar mechanisms. 5. Actions on detection of a secure tag On detection of secure tag, the device will try to alert the system administrator using e-mail, pager, telephone or other forms of messages. Most of the current multifunctional devices do have interfaces that connect to the above mentioned networks. The device will also write the data sent to it for making hard copy onto a secured storage device. This will enable the administrator to manually analyze the data and know more about the breach. The most important difference in the system according to the present invention from that of the prior art is that the present invention makes it possible to employ multiple methods for detecting the breach and also in informing them to administrators. The system employs OCR and watermark detection as the conventional part to it. But they are used in a very innovative manner by providing them in the printer firmware so as to assure maximum security. Hence it does not allow the user to tamper with the software unlike when it is installed as an application program running on a computer where the user can easily manipulate such programs. A system according to the present invention is represented in Figure 3. The printer communicates with a plurality of devices including a network server, pager, mobile etc. The printing device according to the present invention can be realized using a multifunction device having a general purpose processor, a connection to an external network such as the internet and a modem for connecting to the networks. The alerting and backing up job can be easily performed using the system as described above. Whenever the system detects a violation it saves a copy of the digital document acquired to a hard disk which is accessible only to service personnel/administrator or to a trusted network server from where the administrator can retrieve the document later. The above system also confers the user with a facility to add his own security patterns to be searched with the help of a trusted network server or an OTP that can be added separately to the printer in a tamper proof manner. This OTP can be a part of PROM that saves the printer code completely/partly so that tampering the same will render the system unusable. It is also possible to store the incidents of breach in a non-volatile memory and indicate the same at the time of restarting the peripheral if it is not connected to the network. The preferred embodiment of the working of the invention is herein described with reference to Figure 4. The working of the invention is based on the fact that the data stored in the confidential document possesses certain distinguishing features that can be recognized when the job is submitted for reproducing at a printer or multi function device (MFP). The system according to the present invention stores certain default security tags within itself that will be checked while printing the document. Since each organization will have its own security tags/watermarks, a provision is provided for updating the same in PROM, which cannot be erased later, or on a trusted server, which will be polled by the printer at constant intervals. These details are already explained in the above system description. It can be seen from Figure 4 that the system first checks whether searching of text strings provided is possible. If it is possible then it resorts to such simple methods first before trying complex image processing methods. When it is found that text search is not possible the system employs powerful forgery detection methods to find the presence of a string/watermark. One such digital processing method is known from the Document 5982 5105, NLPR, China which describes digital watermarking for forgery detection in printed material. In order to perform the above step, the data which comes in the form of a PDL is converted into bit-map and the bit-map file is used for the evaluation. If no security tag is found, the system allows the hardcopy reproduction. But on detecting a secure tag in the image, the system blocks the printing and alerts the administrator in a plurality of methods which can be pre-configured in the system. This alerting method includes paging, SMS and E-mail. Also, the copying device makes a backup of the submitted job for further investigation. If the system is not connected to a network, this data can be written into Its non-volatile memory using which it can produce recognizable error messages on a local user Interface which attracts the attention of the user. The system described herein also has an advantage in terms of minimum average processing power as the said system does not use image processing always to detect the security tag. The system for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag involves the following components. An image forming apparatus is provided for supplying electrical image data representing the original. A firmware is placed in the rendering device for determining whether the said electrical image data contains the said security tag. The system has a memory for updating and storing the security tags and the said firmware is used for processing the electrical image data supplied by the said image forming apparatus and for outputting a processed image when required or for blocking the printing. Also a backup apparatus is also provided for enabling the production of backup of the document and an associated memory for storing the backup of the said document. The same concept of the above-described mode of the invention is also incorporated into several alternate embodiments and the foregoing functional description applies generally to all the other embodiments of the invention set forth herein after. Each subsequently described alternative embodiment is to be interpreted in the light of the foregoing description. WORKING OF THE SYSTEM When a printer or multifunction device receives the data to be printed, it first determines the type of the document that it needs to print. Based on the type of the document, the printer employs a predetermined method to check for the presence of any security related tags in the document meant to be copied. These tags are stored in a secured storage medium accessible only to the system administrator. A direct text search or an OCR followed by a text search is done to detect the presence of any text based security tags in the document. Other watermark detection or pattern comparison methods are employed to detect any picture based security tags. If any such tags are found, the system admin can be alerted using an IP, Telephony or other network. The action of tag detection can optionally be performed by another computing device that is connected to the printer via a network or other interfacing mechanisms. In this embodiment of the present invention, the printer exports the document or a part of it to the trusted server which performs the necessary tag detection actions on the document. All sensitive information is stored in a secure storage device which might be encrypted if the administrator wishes to. They can also be present on a one time programmable memory to reduce the chances of un-authorized alterations to the database. However, this will reduce the flexibility of the device to handle multiple tags and sources for them. In an alternate embodiment of the present invention, the security tag is implemented with text only on text+OCR based tests. The first system herein will not be as good as the second one in detecting the breaches, but will be simple and cheap. In a yet another embodiment of the invention a separate hardware having ports on either side is used for performing the invention. The copying/image forming apparatus can be connected to one side of it and the computer can be connected to the other side. This device can monitor the data passing through the same and take necessary action. In a further embodiment of the present invention the invention is performed in the host side i.e. computer instead storing the means in the printer firmware. It is hereby stated for clarity that the examples of storage medium to which the particular aspects of the present invention can be applied include but are not limited to ROM, PROM, EPROM and flash memory. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a computer, printer or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. WE CLAIM 1. A method for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag, the method comprising the steps of: a. checking for a security tag that matches with the one stored in a storage device; b. blocking the printing process when the said security tag is matched; c. alerting the administrators about the security breach; and d. providing a backup of the document for further investigation wherein it permits the operator to update security tags in the storing means. 2. The method according to claim 1 wherein the check for security tag includes the step of searching a text if the document is found to be text first and searching through an image when direct text search is not possible. 3. The method according to claim 2 wherein the hardcopy reproduction is permitted when no security tag is found. 4. The method according to claim 1 wherein the security tags are stored to a PROM or a secure network server. 5. The method according to claim 1 wherein the alerting the administrators via various means include E-mail, paging and SMS. 6. The method according to any of the preceding claims wherein the security tags includes watermark and string. 7. The method according to any of the preceding claims wherein all the image orientations of the security tag image is created by redefining the co-ordinate axis associated with the pattern. 8. A system for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag, the said system comprising: a. an image forming apparatus for supplying electrical image data representing the original; b. a firmware for determining whether the said electrical image data contains the said security tag; c. memory for updating and storing the said security tags; d. a firmware for processing the electrical image data supplied by the said image forming apparatus and for outputting a processed image when required or for blocking the printing ; e. backup apparatus for enabling the production of backup of the document; and f. memory for storing the backup of the said document; where the administrator is alerted of the status of the document. 9. A system according to claim 8 wherein the determining of tags and processing of the image are done by firmware embedded in the rendering device's.. 10. A system according to claim 8 wherein the processing and determining are operated in a computer. 11. A system according to claim 8 wherein the security tag is implemented by text. 12. The system according to claim 8 wherein the security tag is implemented by a combination of text and OCR based tests. 13. The system according to claim 8 wherein all the means are implemented into a separate hardware having ports on either side and in which image forming apparatus can be connected to one side of it and the computer can be connected to other side. 14. The system according to any of the claims 8 to 13 wherein it is not in network. 15. A method for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag, substantially as herein above described particularly with reference to the accompanying drawings. 16. A system for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag, substantially as herein above described particularly with reference to the accompanying drawings.

Full Text

FIELD OF THE INVENTION
This invention in general relates to document reproduction and security in networked printers. This invention further relates to digital document security based on watermarking, keyword detection etc. more particularly, this invention relates to a method and system for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag.
DESCRIPTION OF RELATED ART
Document security is a key area of concern in the digital technology domain. The progress in recent years in digital technology, coupled with that in colour image recording technology has made it possible to output a copy image, which is similar to the image of an original. It is a fact that the use of essential and necessary devices such as computers and digital copiers cannot be avoided as we live in the digital era. At the same time, there should be measures for the protection of copyrighted works as we are living in a world where intellectual property is valued as one of the most important assets of an individual/organisation. Therefore, protection against duplication of any digital image/document with a nature of confidentiality is very much essential in order to secure the privacy and to prevent the piracy of such documents.
A considerable amount of research and work has been done in this field since document security is vital in these times, which heavily depends on digital technology. The US granted Patent Kashioka 4,334,241 provides a pattern position detecting system which picks up the image of an object having a target pattern to be detected and compares it with a standard pattern having the same feature as that of the target pattern so as to assess the degree of coincidence between the patterns. This technology is very useful in the detection of a watermark, logo, etc. Now according to the embodiments of US Patent Philibert 4,908,873, it is possible to selectively effect the operation of a copying machine or facsimile machine in accordance with the textual content of a scanned document.

The system according to the above said patent comprises an operation central circuit responsive to central signals applied thereto for actuating the copying apparatus, an optical character reader (OCR), memory means for storing indicia of at least one correlation criterion in respect of the portion of text read by the OCR means and a processor for generating Central Signals to the central circuit and thereby enabling the copying apparatus in accordance with a correlation of the said criterion with said portion of text. It is a generic system that can detect textual data by OCR and use the same from preventing the reproduction machine from making copies of secure documents. For achieving this purpose, it uses a predefined number of scan lines and also predefined number of characters per line to determine whether a piece of text is present in the document or not. They use pre-determined patterns stored in PROM to perform the detection. In order to compensate the misalignment, it proposes changing of 0/P code reader (e. g: -CCD device) in comparison with multiple images stored in PROM which are copies of same character with different alignment.
The advancement of technology in this field further resulted in image processing apparatus which can permit colour copying of an original but at the same time protecting against the scanning of secure images such as currencies. Granted US Patent Hasuo 5,321,470 describes an image processing apparatus of the said type which permits colour copying of an original, and makes it possible to discriminate a specific original for the sake of prevention of forgery of a banknote, a negotiable instrument or the like. In its operation, the specific original is provided with a process of copying which is different from that provided for an ordinary original. The apparatus according to the said patent comprises a scanning device, means for determining whether the original represented by the scanned image is an original having a specific pattern, printing means and controlling means for controlling the processed image and processing means. The arrangement and working herein is such that both the determining and processing are performed in parallel. Very sophisticated and powerful image processing methods are now available to detect a specific pattern in an image. Document 59825105, NLPR,

China illustrates digital watermarking for forgery detection in printed material and therefore has been incorporated herein by reference.
In order to have a general idea about the architecture of the copying machine employed in this invention, a description of the similar system known from US Patent 4,908,873 is made with reference to Figure 1. As it is apparent to a person of ordinary skill in the art that it has a scanner (50), optical code reader (12), misalignment indicator (32), a micro processor (16), memory means (18, 20, 40), Interface means (14, 22), coin meter (42) and a Remote alarm (26) as major components.
The aforementioned device operates as follows. First, the sheet of paper for which an electrical scanned copy is required, is placed on the scanner. The scanner then mechanically moves the optical code reader mechanism along the length of the sheet. As the reader progresses, it uses the photo diodes to convert the image on the paper
It is apparent from the foregoing discussion that the teachings of the prior art use an image processing mechanism to detect an image with another image/text present in it. Once such a pre-known image/text is found as part of the bigger image under consideration alerting means are activated. In one typical embodiment an alarm is sounded and a count is incremented.
LIMITATIONS
Even though the techniques applied in the above described arts achieve their purpose there are a number of drawbacks. The related art is more concerned about digitizing an existing document and printing them and not on the proper analysis of the details when an offence is detected.
It is understood from the prior art that only fixed lines have been used for optical character reorganization (OCR) and the number is kept as a constant. This will not

1
' work in case of printers when a page is printed with different resolutions. Also in the absence of a code reader (which consists of a CCD device) the misalignment in the codes (e. g.:- detecting an inverted document) cannot be determined and hence the system will remain unaware of the misalignment and therefore it will be very simple to deceive the system using some software which can change the alignment of the document.
It is also not practicable to store all the expected alignments in a PROM as generation of bit-maps on the fly by changing the co-ordinate system associated with the bit-map.
Yet another problem with the teachings of the prior art is that they have only predefined text/image and it is apparent that in a drastically changing world single time programmable PROM will not be able to store all information sufficient to evaluate plurality of documents submitted for copying.
Another disadvantage of the prior art is that it uses a remote alarm to alert the authorities and also requires the authorities to be present to watch and wait for the alarm.
It is also a drawback of the existing technology that the digital data given to the copier is not stored at a safe location especially when an illegal attempt is detected. If the data is so stored it can be used as evidence against the offender. It is also possible to examine the document later to confirm whether the machine raised a genuine alert or made a false alarm.
There is also a disadvantage according to the method in the prior art that it always resorts to image processing for finding a piece of text also and therefore is not efficient. There can be situations when the printed file uses device fonts or when the printed file is of the kind PS-1 etc. and hence possible to have simple and efficient detection.

OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a method for the detection of a security tag in digital documents to be copied using a combination of text and image processing so as to ascertain whether the data being duplicated is permitted to be copied.
It is another object of the invention to provide a method and system that allows the user to add any new pattern that needs to be matched with the document to be processed and to update the set of the patterns from time to time.
It is yet another object of the invention to provide a method and system that employs paging, SMS or E-mail to notify the authorities about the breach.
It is also an object of the present invention to provide a back-up of the suspected digital data in a secured location for further investigation which can prove the innocence/guilt of a user.
It is a further object of the invention to provide an option of a network server from where the printer can collect security information in addition to the update in the PROM.
It is again an object of the present invention to create all the image orientations by redefining the co-ordinate axis associated with the patterns to be searched to create such scenarios rather than storing all the possible image orientations as suggested by the prior art.
SUMMARY OF THE INVENTION
Therefore in light of the foregoing deficiencies in the prior art, the applicant's invention is herein presented. Due to the limitations in the existing art, there is a

need to provide a copying/printer device which is less prone to misuse and suitable for the present digital technology scenario.
The present invention proposes a method of detection of security tag or tags in digital documents to be copied, using a combination of text and image processing, so as to ascertain whether the data being duplicated is permitted to be copied and allows the user to add any new pattern that needs to be matched with the document to be processed and to update the set of the patterns from time to time, employs paging, SMS or E-mail to notify the authorities about the breach, provides a back-up of the suspected digital data in a secured location for further investigation which can prove the innocence/guilt of a user. Further, the proposed invention provides an option of a network server from where the printer can collect security information in addition to the update in the PROM and can create all the image orientations by redefining the co-ordinate axis associated with the patterns to be searched to create such scenarios rather than storing all the possible image orientations as suggested by the prior art.
The present invention also proposes to update the number of scan lines stored as reference to a new number when it is detected that a certain number of lines for a number of cases crosses the threshold set earlier.
These and other objects and advantages of the present invention are accomplished by sophisticated image processing techniques and self learning mechanism to support the detection of watermark/text pattern.
Accordingly, the present invention comprises a method for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag, the method comprising the steps of:
(a) checking for a security tag that matches with the one stored in a storage device;

(b) blocking the printing process when the said security tag is matched;
(c) alerting the administrators about the security breach; and
(d) providing a backup of the document for further investigation.
wherein it permits the operator to update security tags in the storing means.
Accordingly, the present invention further comprises a system for preventing the production of illegal hard copies of a digital document marked with a predetermined security tag, the said system comprising:
(a) an image forming apparatus for supplying electrical image data representing the original;
(b) a firmware for determining whether the said electrical image data contains the said security tag;
(c) memory for updating and storing the said security tags;
(d) a firmware for processing the electrical image data supplied by the said image forming apparatus and for outputting a processed image when required or for blocking the printing;
(e) backup apparatus for enabling the production of backup of the document; and
(f) memory for storing the backup of the said document;
where the administrator is alerted of the status of the document.
Other advantages and features of the invention will become more clearly apparent from the following description of the embodiments of the invention given as non-restrictive example only and represented in the accompanying drawings.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

Figurel shows the architecture of a copying apparatus according to the prior art as available in the US patent document no. 4,908,873 as sheet 1 of drawings.
Figure 2 shows a flow chart, which explains the operation of the copying apparatus in Figure 1 as available in the US patent document no. 4,908,873 as sheet 2 of drawings.
Figure 3 is a pictorial representation of the system according to the present invention.
Figure 4 represents the method of performing the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings and the features of the invention will become more readily apparent from the reading of this detailed description. Numerous specific details are described to provide a thorough understanding of the present invention. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention.
In order to have a general idea about the architecture of the copying machine employed in this invention, a description of the similar system known from US Patent 4,908,873 is made with reference to Figure 1. As it is apparent to a person of ordinary skill in the art that it has a scanner (50), optical code reader (12), misalignment indicator (32), a micro processor (16), memory means (18, 20, 40), Interface means (14, 22), coin meter (42) and a Remote alarm (26) as major components.
The aforementioned device operates as follows. First, the sheet of paper for which an electrical scanned copy is required, is placed on the scanner. The scanner

then mechanically moves the optical code reader mechanism along the length of the sheet. As the reader progresses, it uses the photo diodes to convert the image on the paper
The operation of the above system will now be described with reference to Figure 2.
1. Checking received file type
The received file type is checked to determine the type of the document. Traditional auto emulation detection methods can be used with a little variation. The determination is based on the presence or absence of a signature which will serve as the indicator of a particular type. It can also be based on the trial and error method if necessary. The main aim is to distinguish if the document is text alone/mixed or photo (Binary) in type.
2. Direct text search
After the first step, if the document is found to be text alone, then this module is used to determine the presence of any secure tags in the document. It could be any appropriate text search algorithm. The secure tags are obtained from a reliable source which might be local or network oriented storage locations.
3. Searching through an image (Binary data)
In case of binary data, which will correspond to a particular emulation, the job is allowed to proceed till the final printable image is formed. This bit map is then subjected to various image processing techniques such as OCR and other pattern reorganisation processes to detect the presence of any secure tags. The text data obtained by OCR can be processed by the algorithm used for direct text search. The image part is matched using a combination of techniques such as SSD (Sum-of-Squares differences), salient or surface feature study etc.

The source for the tags is secured and updatable if necessary. Since this involves complex image processing, optionally the printer can upload a part/whole of printable image to the secure server for this analysis.
4. Locations for secure tags
Secure tags can be placed on a Read Only Memory, Programmable Read Only Memory, or a secure server in the network. If a secure server is used, the network parameters of the same should be present in the ROM or PROM. This information is accessible only to the administrator and he/she alone can modify the same. The access to these storage locations is restricted using a password or similar mechanisms.
5. Actions on detection of a secure tag
On detection of secure tag, the device will try to alert the system administrator using e-mail, pager, telephone or other forms of messages. Most of the current multifunctional devices do have interfaces that connect to the above mentioned networks.
The device will also write the data sent to it for making hard copy onto a secured storage device. This will enable the administrator to manually analyze the data and know more about the breach.
The most important difference in the system according to the present invention from that of the prior art is that the present invention makes it possible to employ multiple methods for detecting the breach and also in informing them to administrators. The system employs OCR and watermark detection as the conventional part to it. But they are used in a very innovative manner by providing them in the printer firmware so as to assure maximum security. Hence it does not allow the user to tamper with the software unlike when it is installed as an application program running on a computer where the user can easily manipulate such programs. A system according to the present invention is represented in Figure 3. The printer communicates with a plurality of devices including a network server, pager, mobile etc. The printing device according to the

present invention can be realized using a multifunction device having a general purpose processor, a connection to an external network such as the internet and a modem for connecting to the networks.
The alerting and backing up job can be easily performed using the system as described above. Whenever the system detects a violation it saves a copy of the digital document acquired to a hard disk which is accessible only to service personnel/administrator or to a trusted network server from where the administrator can retrieve the document later. The above system also confers the user with a facility to add his own security patterns to be searched with the help of a trusted network server or an OTP that can be added separately to the printer in a tamper proof manner. This OTP can be a part of PROM that saves the printer code completely/partly so that tampering the same will render the system unusable. It is also possible to store the incidents of breach in a non-volatile memory and indicate the same at the time of restarting the peripheral if it is not connected to the network.
The preferred embodiment of the working of the invention is herein described with reference to Figure 4. The working of the invention is based on the fact that the data stored in the confidential document possesses certain distinguishing features that can be recognized when the job is submitted for reproducing at a printer or multi function device (MFP). The system according to the present invention stores certain default security tags within itself that will be checked while printing the document. Since each organization will have its own security tags/watermarks, a provision is provided for updating the same in PROM, which cannot be erased later, or on a trusted server, which will be polled by the printer at constant intervals. These details are already explained in the above system description.
It can be seen from Figure 4 that the system first checks whether searching of text strings provided is possible. If it is possible then it resorts to such simple methods first before trying complex image processing methods. When it is found that text search is not possible the system employs powerful forgery detection methods to

find the presence of a string/watermark. One such digital processing method is known from the Document 5982 5105, NLPR, China which describes digital watermarking for forgery detection in printed material. In order to perform the above step, the data which comes in the form of a PDL is converted into bit-map and the bit-map file is used for the evaluation. If no security tag is found, the system allows the hardcopy reproduction. But on detecting a secure tag in the image, the system blocks the printing and alerts the administrator in a plurality of methods which can be pre-configured in the system. This alerting method includes paging, SMS and E-mail. Also, the copying device makes a backup of the submitted job for further investigation. If the system is not connected to a network, this data can be written into Its non-volatile memory using which it can produce recognizable error messages on a local user Interface which attracts the attention of the user. The system described herein also has an advantage in terms of minimum average processing power as the said system does not use image processing always to detect the security tag.
The system for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag involves the following components. An image forming apparatus is provided for supplying electrical image data representing the original. A firmware is placed in the rendering device for determining whether the said electrical image data contains the said security tag. The system has a memory for updating and storing the security tags and the said firmware is used for processing the electrical image data supplied by the said image forming apparatus and for outputting a processed image when required or for blocking the printing. Also a backup apparatus is also provided for enabling the production of backup of the document and an associated memory for storing the backup of the said document.
The same concept of the above-described mode of the invention is also incorporated into several alternate embodiments and the foregoing functional description applies generally to all the other embodiments of the invention set

forth herein after. Each subsequently described alternative embodiment is to be interpreted in the light of the foregoing description.
WORKING OF THE SYSTEM
When a printer or multifunction device receives the data to be printed, it first determines the type of the document that it needs to print. Based on the type of the document, the printer employs a predetermined method to check for the presence of any security related tags in the document meant to be copied. These tags are stored in a secured storage medium accessible only to the system administrator. A direct text search or an OCR followed by a text search is done to detect the presence of any text based security tags in the document. Other watermark detection or pattern comparison methods are employed to detect any picture based security tags. If any such tags are found, the system admin can be alerted using an IP, Telephony or other network.
The action of tag detection can optionally be performed by another computing device that is connected to the printer via a network or other interfacing mechanisms. In this embodiment of the present invention, the printer exports the document or a part of it to the trusted server which performs the necessary tag detection actions on the document.
All sensitive information is stored in a secure storage device which might be encrypted if the administrator wishes to. They can also be present on a one time programmable memory to reduce the chances of un-authorized alterations to the database. However, this will reduce the flexibility of the device to handle multiple tags and sources for them.
In an alternate embodiment of the present invention, the security tag is implemented with text only on text+OCR based tests. The first system herein will not be as good as the second one in detecting the breaches, but will be simple and cheap. In a yet another embodiment of the invention a separate hardware

having ports on either side is used for performing the invention. The copying/image forming apparatus can be connected to one side of it and the computer can be connected to the other side. This device can monitor the data passing through the same and take necessary action.
In a further embodiment of the present invention the invention is performed in the host side i.e. computer instead storing the means in the printer firmware.
It is hereby stated for clarity that the examples of storage medium to which the particular aspects of the present invention can be applied include but are not limited to ROM, PROM, EPROM and flash memory.
It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a computer, printer or a multi function device.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

WE CLAIM
1. A method for preventing the production of illegal hard copies of a digital
document marked with a predetermined security tag, the method comprising
the steps of:
a. checking for a security tag that matches with the one stored in a storage
device;
b. blocking the printing process when the said security tag is matched;
c. alerting the administrators about the security breach; and
d. providing a backup of the document for further investigation
wherein it permits the operator to update security tags in the storing means.
2. The method according to claim 1 wherein the check for security tag includes the step of searching a text if the document is found to be text first and searching through an image when direct text search is not possible.
3. The method according to claim 2 wherein the hardcopy reproduction is permitted when no security tag is found.
4. The method according to claim 1 wherein the security tags are stored to a PROM or a secure network server.
5. The method according to claim 1 wherein the alerting the administrators via various means include E-mail, paging and SMS.
6. The method according to any of the preceding claims wherein the security tags includes watermark and string.
7. The method according to any of the preceding claims wherein all the image orientations of the security tag image is created by redefining the co-ordinate axis associated with the pattern.

8. A system for preventing the production of illegal hard copies of a digital
document marked with a pre-determined security tag, the said system
comprising:
a. an image forming apparatus for supplying electrical image data
representing the original;
b. a firmware for determining whether the said electrical image data
contains the said security tag;
c. memory for updating and storing the said security tags;
d. a firmware for processing the electrical image data supplied by the
said image forming apparatus and for outputting a processed image
when required or for blocking the printing ;
e. backup apparatus for enabling the production of backup of the
document; and
f. memory for storing the backup of the said document;
where the administrator is alerted of the status of the document.
9. A system according to claim 8 wherein the determining of tags and
processing of the image are done by firmware embedded in the rendering
device's..
10. A system according to claim 8 wherein the processing and determining are operated in a computer.
11. A system according to claim 8 wherein the security tag is implemented by text.
12. The system according to claim 8 wherein the security tag is implemented by a combination of text and OCR based tests.
13. The system according to claim 8 wherein all the means are implemented into a separate hardware having ports on either side and in which image forming

apparatus can be connected to one side of it and the computer can be connected to other side.
14. The system according to any of the claims 8 to 13 wherein it is not in network.
15. A method for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag, substantially as herein above described particularly with reference to the accompanying drawings.
16. A system for preventing the production of illegal hard copies of a digital document marked with a pre-determined security tag, substantially as herein above described particularly with reference to the accompanying drawings.

Documents:

0970-che-2004 abstract-duplicate.pdf

0970-che-2004 claims-duplicate.pdf

0970-che-2004 description (complete)-duplicate.pdf

0970-che-2004 drawings-duplicate.pdf

970-che-2004-abstract.pdf

970-che-2004-claims.pdf

970-che-2004-correspondnece-others.pdf

970-che-2004-correspondnece-po.pdf

970-che-2004-description(complete).pdf

970-che-2004-drawings.pdf

970-che-2004-form 1.pdf

970-che-2004-form 13.pdf

970-che-2004-form 26.pdf

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Patent Number

219189

Indian Patent Application Number

970/CHE/2004

PG Journal Number

27/2008

Publication Date

04-Jul-2008

Grant Date

25-Apr-2008

Date of Filing

24-Sep-2004

Name of Patentee

SAMSUNG INDIA SOFTWARE OPERATIONS PRIVATE LIMITED

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	JAIN, SAURABH
2	SARIN, SUSEELAN BHARGAVI

PCT International Classification Number

H03K 19/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA