Document printed with graphical symbols which encode information

Abstract

A document is printed with graphical symbols which encode information but are not human readable; the graphical symbols are formed into some or all of a visible element and the shapes of the external borders of several graphical symbols differ from each other in order to achieve a desired appearance for the element. Typically, one or both of the linear dimensions of a graphical symbol can be altered for the appropriate aesthetic effect. Prior art graphical symbols (e.g. glyphs etc.) are generally fixed in shape and hence cannot be modified for aesthetic effect. Instead, they have generally been large and obtrusive blocks which considerably mar the appearance of a printed document. This negative impact on appearance has been one of the major causes inhabiting the uptake of graphical symbol technology for encoding information.

Description

BACKGROUND TO THE INVENTION[0001] 1. Field of the Invention[0002] This invention relates to a document printed with graphical symbols which encode information. The encoded information is not human readable, but is visible, in the same way that a bar code is visible but not human readable. The term `graphical symbol` means any visible mark which encodes information; it therefore includes glyphs, 2D bar codes and other forms of graphical indicia.[0003] 2. Description of the Prior Art[0004] There are many security documents which are communicated between various agencies where the integrity of the documents is a major issue. A prime example is the use of cheques for financial transactions, billions of which are passed between clients and banks and where the risk of fraud is an ever present threat.[0005] Security documents have historically been protected by a considerable range of devices. The actual materials from which they are made are difficult for an outsider to obtain or reproduc...

AI Technical Summary

Problems solved by technology

There are many security documents which are communicated between various agencies where the integrity of the documents is a major issue.

A prime example is the use of cheques for financial transactions, billions of which are passed between clients and banks and where the risk of fraud is an ever present threat.

The actual materials from which they are made are difficult for an outsider to obtain or reproduce.

One system of machine readability from printed documents is the OCR system, and this can achieve a high degree of accuracy from standard fonts but tends to fall well short of practical thresholds for handwritten script.

As a practical matter, it should be noted that the use of a steganographic watermark to embed information with low visual impact in security documents is not a realistic option.

This is because steganographic watermarks typically have a much lower information rate and are difficult to construct in suitable fashion using only the typical laser printer that is available at the time information is embedded into a security document such as a cheque.

There is one major disadvantage with current systems where the information carrier is a pattern of clearly visible graphical symbols feature (i.e. glyphs and 2D bar codes).

It is that the feature may spoil the appearance of the document.

For many situations, particularly cheques, anything which significantly detracts from the overall appearance of the document is commercially very unattractive.

Instead, they have generally been large and obtrusive blocks which considerably mar the appearance of a printed document.

This negative impact on appearance has been one of the major causes inhibiting the uptake of graphical symbol technology for encoding information.

The high density of the encoded data in an implementation make it less easy to reproduce by standard copying and printing methods than a conventional bar code or glyph pattern.

This provides an indication of the occurrence of counterfeiting because any reproduction of a cheque, however skilful, will tend to produce lower quality information.

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