Abstract:
A method for providing an indication of authenticity of an electronic image of a document comprises generating a signal corresponding to a profile of at least one of a number of surfaces of the document, converting the signal into a profile signature, and correlating the profile signature with the electronic image of the document. A method for authenticating an electronic image of a document comprises receiving the electronic image of the document and a profile tracing signature of a surface of the document that is associated with the electronic image, and comparing the profile tracing signature with an exemplar profile tracing signature associated with the document. A document processing system comprises a pickup, a signal processing circuit, and a scanning module and is used for producing a profile tracing signature and electronic image of a document and for correlating the profile tracing signature with the electronic image.

Description:
BACKGROUND  
       [0001]     The invention disclosed herein relates generally to verification systems, and in particular, to a system and method for authenticating a document or other item from indicia included thereon.  
         [0002]     Traditionally, businesses have deposited checks received from, for example, customers by physically taking them to a branch of their bank and depositing them over the counter with a teller or dropping them into a night deposit box. The actual physical presentation of the checks to be deposited was necessary because, under prior banking laws, the depository bank had to present the original of each check to the corresponding paying bank in order to clear the check. This changed in October of 2004 with the enactment of The Check Clearing for the 21 st  Century Act, commonly referred to Check 21. Check 21 removed the legal requirement that an original paper check had to be presented to obtain payment. Instead, digital images can now be used to transport check data, for example, from a customer to the bank of first deposit and/or from the bank of first deposit to the paying bank. If a bank cannot process a check image, the image can be printed, according to certain specifications, to create what is known as a substitute check, which is the legal equivalent of the original paper check. Check 21 has thus opened the door for remote check deposit solutions wherein check images, rather than original paper checks, are used to make deposits, thereby enabling businesses to eliminate trips to the bank. In addition, the use of check images also reduces check transportation costs among banks and improves funds availability.  
         [0003]     For obvious reasons, such as to prevent fraud, it is important to be able to authenticate checks at various points in the banking system. Many checks incorporate sophisticated anti-counterfeiting measures such as engraved printing, specialized color patterns, embossed markings, holograms, and embedded security strips. Furthermore, the handwritten signature on a check is another feature that enhances security. Not only is the written pattern of the signature difficult to manually reproduce, but the pressure of the pen against the paper during the process of writing the signature creates a relief pattern (i.e., a depression in the paper). Prior to Check 21, presentation of the original check provided the depository bank and/or the paying bank an opportunity to examine whether the submitted check included one or more of these anti-counterfeiting measures and whether the handwritten signature was original. By examining the original check, the bank was more readily able to detect a forgery, unauthorized alterations (e.g., adding a “0” to increase the amount of a check from $10 dollars to $100 dollars), etc.  
         [0004]     Although providing several benefits (e.g., eliminating trips to the bank, reducing check transportation costs, and improving funds availability), the implementation of Check 21 magnifies many security challenges because the original check, in most instances, is not available for examination. More specifically, most if not all of the anti-counterfeiting measures mentioned above are rendered ineffectual when a check is converted to a relatively low resolution digital image. Embossed markings and the relief pattern of the handwritten signature, for example, reproduce very poorly in photographs and/or scanned images because lighting in such systems is typically designed to be diffuse in order to avoid reflections. As a result, embossed markings and the relief pattern of the handwritten signature completely disappear in scanned images unless side lighting is employed. As another example, the pattern of interference which produces a hologram&#39;s three-dimensional image is not reproduced in a scanned image. Thus, the usefulness of holograms as an anti-counterfeiting measure is eliminated.  
         [0005]     Elimination of the effectiveness of these anti-counterfeiting measures alone causes serious problems for banks. Compounding this problem is the fact that technology has become so advanced that even standard commercial devices, such as photocopiers and printers, are capable of producing credible copies of documents. Accordingly, a thief may utilize these devices to produce counterfeit documents, which when converted to a digital image, may be nearly impossible to detect as being counterfeit.  
         [0006]     Thus, there exists a need for a system and method for authenticating a document or other item from indicia included thereon.  
       SUMMARY  
       [0007]     One aspect of the present invention relates to a method for providing an indication of authenticity of an electronic image of a document. The method comprises generating a signal corresponding to a profile of at least one of a number of surfaces of the document, converting the signal into a profile signature, and correlating the profile signature with the electronic image of the document.  
         [0008]     Another aspect of the present invention relates to a method for authenticating an electronic image of a document. The method comprises receiving the electronic image of the document and a profile tracing signature of a surface of the document that is associated with the electronic image, and comparing the profile tracing signature with an exemplar profile tracing signature associated with the document.  
         [0009]     Another aspect of the present invention relates to a document processing system comprising a pickup structured to sense contour variations on a surface of a document and to generate a signal based on the contour variations in response to relative movement between the pickup and the surface of the document, a signal processing circuit for converting the signal into a profile tracing signature, and a scanning module for generating an electronic image of the document, wherein the profile tracing signature is correlated with the electronic image of the document.  
         [0010]     Therefore, it should now be apparent that the invention substantially achieves all the above aspects and advantages. Additional aspects and advantages of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. Moreover, the aspects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The accompanying drawings illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the principles of the invention. As shown throughout the drawings, like reference numerals designate like or corresponding parts.  
         [0012]      FIG. 1  is an isometric view of a check processing system according to one embodiment of the present invention.  
         [0013]      FIG. 2  is a simplified block diagram of the check processing system of  FIG. 1 .  
         [0014]      FIG. 3  is block diagram of a profile scanning module according to one embodiment of the present invention.  
         [0015]      FIG. 4  illustrates an example of the profile scanning module of  FIG. 3  in use.  
         [0016]      FIG. 5  is a profile tracing signature from the profile scanning module of  FIG. 3  for an authentic check having perforations on the top edge thereof.  
         [0017]      FIG. 6  is a profile tracing signature from the profile scanning module of  FIG. 3  for a forged check having a non-perforated top edge thereof.  
         [0018]      FIG. 7  illustrates an example of the profile scanning module of  FIG. 3  in use with a cancelled check.  
         [0019]      FIG. 8  illustrates an example of the profile scanning module in use with a credit card reader. 
     
    
     DETAILED DESCRIPTION  
       [0020]     Each printing technology used to create a secured document has a number of distinctive characteristics and/or indicia. For example (and without limitation), some printing technologies decrease the elevation of a portion of the document surface by causing indentations in the document (e.g., writing with a ballpoint pen), some add material to a portion of the document surface and thus raise that portion&#39;s elevation relative to a portion of the document surface that does not have printing thereon (e.g., laser printing), some do not alter the elevation of the document surface because the ink used simply soaks into the document (e.g., ink jet printing), and some alter the surface texture of the document (e.g., dye sublimation printers may make the surface waxy). These distinctive characteristics may be utilized to ascertain the authenticity of a document and/or to distinguish a secured document from a counterfeit copy. Furthermore, many secured documents incorporated anti-counterfeiting measures.  
         [0021]     As employed herein, the terms “document”, “secured document”, and variations thereof, refer to an item, for example and without limitation, currency, checks, certificate of deposits, stock certificates, postage, credit cards, etc. which include a distinctive printing characteristic and/or incorporate a number of anti-counterfeiting measures such as engraved printing, specialized color patterns, embossed markings, holograms, and embedded security strips (among others). The expression “a number of” and variations thereof, as employed herein, shall refer broadly to any quantity, including a quantity of one.  
         [0022]     Other characteristics and/or indicia may be used to distinguish documents from each other and to ascertain the authenticity of a document. For instance, another helpful indicator of check authenticity is the presence of perforations on the top edge (or left edge) of the check. The presence of perforations indicates that a check was likely removed from a checkbook printed by a security printer, thereby increasing the likelihood that the check is authentic. Thus, the ability to detect perforations on a check would be advantageous for banking systems, as the presence of perforations suggests that the check is authentic; as opposed to a fraudulent check (e.g., made using a copier) which would not have the perforations because the fraudulent check would not have been torn from a checkbook issued by the bank.  
         [0023]      FIG. 1  and  FIG. 2  are an isometric view and a simplified block diagram, respectively, of a check processing system  10  according to the present invention. Check processing system  10  exploits a number of the distinctive printing characteristics and security features discussed above (without limitation) to authenticate checks. Check processing system  10  comprises a housing, designated generally by the reference numeral  12 , the housing  12  having a check input end, designated generally by the reference numeral  14 , and a check output end, designated generally by the reference numeral  16 . The housing  12  includes a base  20  and a cover  22  mounted on the base  20 . The cover  22  may be removed to expose various operating components and parts for service and/or repair as needed. The cover  22  includes a slot  23 , connecting the check input end  14  to the check output end  16 .  
         [0024]     The check processing system  10  also includes a user interface controller  24  (UIC) which, in the current embodiment, is remotely connected to the housing  12  via a communications/power bus  18 . The UIC  24  may include one or more input/output devices, such as, for example, a keyboard  25  and a display device  26 . The UIC  24  may also include a storage device (not shown), such as a disc drive or memory, and a central processing unit (CPU) (not shown) for executing one or more routines contained on the storage device. Keyboard  25  and display device  26  are structured to provide a user interface to the CPU. In one embodiment the UIC  24  is a personal computer (PC).  
         [0025]     The base  20  carries a number of modules or sub-systems each of which performs a different task on a check  7 . Referring to  FIG. 2 , in the current embodiment, the check processing system  10  includes a transport module  27 , an optical scanning module  28 , a profile scanning module  30 , and a cancellation module  29 , among others.  
         [0026]     The transport module  27  conveys the check  7  within slot  23  to each of the other modules, generally in a downstream path of travel as indicated by arrow A ( FIG. 1 ). As the check  7  is conveyed, it passes by and/or is brought into contact with the other modules prior to exiting the check processing system  10  at the check output end  16 . More specifically, the check passes by and/or is brought into contact with the optical scanning module  28 , the profile scanning module  30 , and the cancellation module  29 .  
         [0027]     The optical scanning module  28  is structured to generate a digitized image of the check  7 . More specifically, the optical scanning module  28  is structured to read the text and/or illustrations on the front and/or rear faces of the check  7  and to capture the information as a digitized image that can be stored, displayed, and manipulated as needed by the check processing system  10  and/or other device. In the current embodiment, for example, the digitized image is transmitted to the UIC  24  via the communications/power bus  18  where it is stored, displayed, and used to authenticate the check  7 .  
         [0028]     The profile scanning module  30 , as will be described in more detail below, is structured to generate a signal corresponding to a profile of one or more of a number of surfaces of the check  7 . In the current embodiment, the signal is transmitted to the UIC  24  via the communications/power bus  18  where the CPU converts the signal into a profile signature which is correlated with the digitized image of a scanned check. More specifically, in the current embodiment, the profile scanning module  30  is structured to detect a number of indicia on at least one of the front face, the rear face, the top edge, the bottom edge, the leading edge, and/or the trailing edge of the check  7  and to generate a profile tracing signature in response thereto. The indicia that are detected by the profile scanning module may include, without limitation, a written signature, a laser copied signature, an engraved marking, an embossed marking, a thinned area, a hologram material, an applied plastic material, a tear pattern, and a perforation pattern.  
         [0029]     The cancellation module  29  is structured to alter the check  7  in such a manner as to indicate that the check  7  has been processed by the check processing system  10 . The cancellation module  29  may be structured, for example, to print a cancellation marking on the rear face and/or front face of the check  7 , emboss the check  7  with a cancellation making, and/or punch a hole through the check  7  to indicate that the check  7  has been cancelled, among others. The cancellation module  29  helps to insure that the check  7  is not submitted for payment multiple times.  
         [0030]     It should be noted that the transport module  27  may be capable effecting bidirectional travel on the check  7  within slot  23 . Bidirectional travel may be employed, for instance, in confirming that the cancellation module  29  properly cancelled the check  7 . For example, after the cancellation module  29  has embossed the check  7  to indicate cancellation, the transport module  27  may reverse the direction of travel of the check  7  within slot  23  such that the check  7  passes by and/or is brought back into contact with the profile scanning module  30 . As a result, the profile scanning module  30  can be used to verify that the check  7  was embossed correctly. As a further example, the cancellation module  29  may print a number of cancellation markings on the check  7 . After the cancellation module  29  prints the cancellation markings, the transport module  27  may reverse the direction of travel of the check  7  within the slot  23  such that the check  7  passes by and/or is brought back into contact with the optical scanning module  28 . As a result, the optical scanning module  28  can generate a second digitized image of the check  7  (the second image including the cancellation markings). The second digitized image may then be compared, for example within the UIC  24 , to the first digitized image to verify that the cancellation markings were correctly applied to the check  7 .  
         [0031]     By supporting bidirectional travel, the check processing system  10  may prevent a user having less than honorable intentions from attempting to process the same check  7  multiple times. Assume for example that the cancellation module  29  prints cancellation markings on processed checks. A user may cover the check  7  with a clear film (e.g., a Mylar® sheath) prior to inserting the check  7  into the check input end  14  of the check processing system  10 . Because the film is clear, the optical scanning module  28  will be able to generate a “normal” digital image of the check  7 . However, the cancellation module  29  applies the cancellation markings to the clear film, not to the check  7 . As a result, the user can merely remove the clear film and submit the same check  7  for processing multiple times.  
         [0032]      FIG. 3  is a simplified block diagram of a profile scanning module  30  according to one embodiment. The profile scanning module  30  includes a pickup  32  and a recording device  34 . The profile scanning module  30  may also include other components, such as amplifier  33 , while remaining within the scope of the present invention.  
         [0033]     Generally speaking, the pickup  32  comes into contact with a surface of the check  7  as the check is transported within slot  23  of the check processing system  10 . Contour variations on one or more surfaces of the check  7  are sensed by the pickup  32 . For example, a pickup  32  may be structured within slot  23  to come into contact with the front face of check  7 . Contour variations present on the profile of the front face of check  7  cause the pickup  32  to move. This movement is converted by the pickup  32  into an electrical signal. The pickup  32  may be, for example, a piezoelectric transducer, a modified microphone, or a photograph magnetic cartridge, among others.  
         [0034]     In the current embodiment, the signal generated by the pickup  32  is amplified by amplifier  33 . The amplified signal is then sent to the recording device  34 . The recording device  34  may include a signal processing circuit  35  and a storage device  36  (e.g., disc drive, memory, buffer, etc.), among others. The signal processing circuit  35  may include, for example, an analog-to-digital converter, a digital-to-analog converter, a filter, etc. The signal processing circuit  35  conditions the signal as needed to produce a “profile tracing signature”. The profile tracing signature is stored on the storage device  36 . The profile tracing signature is also communicated to the UIC  24  which correlates the profile tracing signature with the image of the check  7  produced by the optical scanning module  28 . The profile tracing signature may also be used by other components of the check processing system  10  as needed.  
         [0035]     It should be apparent that one or more components of the profile scanning module  30  may be incorporated into, or combined with, another component of the check processing system  10  while remaining within the scope of the present invention. For example, the signal processing circuitry  35  and/or the storage device  36  may be incorporated within the UIC  24 .  
         [0036]     The amount of movement encountered by the pickup  32  can easily be reduced or increased through the use of a lever (not shown). A pickup  32  used to scan the perforations on the top edge of the check  7 , for example, may experience a gross (i.e., large) amount of movement. This gross movement may be too large and prevent the use of, for example, a piezoelectric transducer pickup. Likewise a pickup  32  used to scan the front face of the check  7  may experience only fine (i.e., small) amounts of movement. This movement may be too small to be adequately sensed by, for example, a piezoelectric transducer. By using a lever, the amount of movement encountered by each pickup  32  can easily be decreased (scaled down) or increased (scaled up) as needed, thus allowing the same type of pickup  32  (e.g., piezoelectric transducer) to be used in both instances, reducing the complexity of the profile scanning module  30 .  
         [0037]     Although the profile scanning module  30  has been generally discussed in conjunction with scanning a single surface, it should be apparent that multiple profile scanning modules  30  may be employed, each scanning a different surface and/or a different portion of the same surface of the check  7 , while remaining within the scope of the present invention. Additionally, a single profile scanning module  30  having multiple pickups  32  for scanning multiple surfaces and/or a different portion of the same surface of the check  7  is also contemplated.  
         [0038]      FIG. 4  illustrates the use of the profile scanning module  30 . More specifically, a portion of a signed check  50  is shown being scanned by a profile scanning module  30 . The pickup  32  of the profile scanning module  30  is positioned against the front face  52  of the check  50  at point  53 . As the check  50  is moved (e.g., by the transport module  27 ) generally in the direction of arrow “A”, the pickup  32  travels across the front face of check  50  from point  53  to point  54  along sampling line  55 . As shown in  FIG. 4 , sampling line  55  intersects portions of the handwritten signature  56 . The points of intersection with the handwritten signature  56  are marked by lines  57   a - 57   h.    
         [0039]     As the pickup  32  travels relative to the check  7 , it produces a profile tracing signature associated with the contour of the surface of the front face of the check  7 . The profile tracing signature detected by the pickup  32  moving relative to an original check is represented by line  58 . For an original document, the handwritten signature  56  causes physical indentations in the front face of the check  7 . Thus, at each point where sampling line  55  crosses the signature  56  results in a depression in the profile tracing signature as seen at  58 .  
         [0040]     In contrast, a forged (e.g., copied) check having a laser printed signature (as compared to the handwritten signature) produces a different profile tracing signature. More specifically, the profile tracing signature detected by pickup  32  moving relative to a copied document is represented by line  59 . The pattern of line  59  is inverted (i.e., as compared to line  58 ) because the laser printer and/or copier used to make the forged check adds material (i.e., toner) to the surface of the document making it higher at the points where the sampling line  59  crosses the copied signature. A check that is encased in a clear film (e.g., a Mylar® sheath as discussed above) will produce a different profile (not shown in  FIG. 4 ). Because it is relatively smooth, the clear film covering the check will produce a substantially flat profile.  
         [0041]     In brief, image data obtained by the optical scanning module  28  is correlated with the profile tracing signature (i.e., lines  58 / 59 ) across the front face of check  7  obtained by the profile scanning module  30 . The nature of the genuine print (i.e., pressing down with a pen) determines the expected pattern (i.e., indentations caused by the handwriting) in the profile tracing signature  58 . This expected pattern is difficult to forge using typical copying methods. The profile tracing signature  58  may be compared to an exemplar profile tracing signature. A determination can then be made as to whether the check  7  was original or forged.  
         [0042]     As employed herein, the expression “an exemplar profile tracing signature” and variations thereof shall refer broadly to a typical or standard profile tracing signature for a particular type of item.  FIG. 5  and  FIG. 6 , for example, illustrate profile tracing signatures for an authentic check having perforations on the top edge thereof and a profile tracing signature for a forged check having a non-perforated (i.e., substantially straight) top edge, respectively. The amplitude of the profile tracing signature (i.e., as seen in  FIG. 5 ) for the authentic check has a certain magnitude signifying the presence of perforations, whereas the amplitude of the profile tracing signature (i.e., as seen in  FIG. 6 ) for the forged check has a certain lower magnitude therein signifying the absence of perforations. By comparing the profile tracing signatures shown in  FIGS. 5 and 6  to an exemplar profile tracing signature, it can determined which of the profile tracing signatures was generated from an authentic check and which was generated from a forged check.  
         [0043]      FIG. 7  illustrates that this same approach, at a gross scale, may be utilized to detect a genuine scrape cancellation on a check or a fraudulent image of such a cancelled check. Here a check  60  includes a portion having a scraped hole  61 . The fiber patterns of this scraped hole  61  may be observed, but are difficult to forge. Without the physical check, however, it is not possible to know whether these fiber patterns are an image or the actual fibers torn by the abrasion. This is an issue since the original check will not survive.  
         [0044]     A check that is encased in a clear film when submitted (e.g., a Mylar® sheath as discussed above) may be detected with the image and/or the trace profile. On the image, the gouged film layer looks different than torn paper fibers. The trace profile will also be different because of the different properties of paper and plastic. Subsequent forensic analysis will be able to determine if the clear film protector was in place when the cancelled check was re-read (i.e., if the clear film was stored by the customer and the check was resubmitted with the clear film having the ink jet printed cancellation present on top thereof).  
         [0045]     More specifically, a portion of a signed check  60  is shown being scanned by a profile scanning module  30 . The pickup  32  of the profile scanning module  30  is positioned against the front face  62  of the check  60  at point  63 . As the check  60  is moved (e.g., by the transport module  27 ) generally in the direction of arrow “A”, the pickup  32  travels across the front face  62  of check  60  from point  63  to point  64  along sampling line  65 .  
         [0046]     As shown in  FIG. 7 , sampling line  65  intersects a portion of the scraped hole  61 . The points where the scraped hole  61  starts and ends are marked by lines  67   a - 67   b . When the profile tracing signature is captured, the scraped hole  61  with sloping walls (i.e., the current example is of an abrasion and not a clean puncture hole) on either side is clearly visible in the profile tracing signature  68 . In contrast, the profile tracing signature  69  of a laser image or photograph, regardless of the resolution used, results in a smooth line. It should be noted that the data gathered in conjunction with the discussion of  FIG. 7  is at a much lower vertical scale than the data gathered in conjunction with  FIG. 4  because the thickness of the document is much greater than the laser print toner thickness. In this instance, therefore, the laser toner is displayed as having no thickness because the profile scanning module  30  is scaled for detection of the entire document thickness being absent in the scraped hole  61  rather than the small variability associated with the embossed or indented text.  
         [0047]     Once again, image data obtained by the optical scanning module  28  is correlated with the profile tracing signature (i.e., lines  68 / 69 ) obtained by scanning the front face  62  of check  60  with the pickup  32  of the profile scanning module  30 . The nature of the genuine print determines the expected pattern in the profile tracing signature which is difficult to forge using typical copying methods. The profile tracing signatures  68  and  69  are compared to an exemplar profile tracing signature. A determination can then be made as to whether the check  60  was original or forged.  
         [0048]     Although described and illustrated in the context of a use within a check processing system  10 , it should be apparent that the teachings of the present invention may be utilized in any application for which the authentication of an item is desirable while remaining within the scope of the present invention. The teachings of the present invention may be employed, for example and without limitation, to verify the authenticity of currency, CD&#39;s, stock certificates, postage, credit cards, etc. which may incorporate anti-counterfeiting measures such as engraved printing, specialized color patterns, embossed markings, holograms, and embedded security strips (among others) to help prevent fraud.  
         [0049]      FIG. 8 , for instance, illustrates the profile scanning module  30  being used in a credit card reader (not shown) to detect the surface features associated with the magnetic strip and the human signature block on the back of a credit card. More specifically, a portion of a credit card  70  is shown being scanned by a profile scanning module  30 . The pickup  32  of the profile scanning module  30  is positioned against the back surface  72  of the credit card  70  at point  73 . As the credit card  70  is moved (e.g., swiped through the credit card reader) generally in the direction of arrow “A”, the pickup  32  travels across the back surface  72  of the credit card  70  from point  73  to point  74  along sampling line  75 .  
         [0050]     The scanned image again shows a profile tracing signature with specific transition point mapping (i.e.,  71   a - 71   f ). The high relief of the original card profile tracing signature trace  78  shows the onset of the edge of the card  70  (i.e., at point  71   f ), the low amplitude rise/fall (i.e., at points  71   e  and  71   d ) associated with the signed text and security printing on the signature block  77  (i.e., at points  71   e  and  71   d ), the rise (i.e., at point  71   c ) and fall (i.e., at point  71   b ) associated with the magnetic strip  76 , and the large step off the far end of the card  70  (i.e., at point  71   a ). In contrast, the profile tracing signature  79  of a laser image or photograph of the credit card  70 , regardless of the resolution used, results in a smooth line. It should be noted that the data being gathered in conjunction with the discussion of  FIG. 8  is at a much lower vertical scale than the data gathered in conjunction with  FIG. 4 . In this instance, therefore, the laser toner is displayed as having no thickness because the profile scanning module  30  is scaled for detection of the relatively large relief changes rather than the small variability associated with, for example, embossed or indented text.  
         [0051]     Again the nature of the real credit card  70  determines the expected pattern in the profile tracing signature which is difficult to forge using typical copying methods. The profile tracing signatures (i.e., lines  78 / 79 ) obtained by scanning the back surface  72  of credit card  70  with the pickup  32  of the profile scanning module  30  can be compared with an exemplar profile tracing signature. A determination can then be made as to whether the credit card  70  is original or forged.  
         [0052]     While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims.