GB2283850A

GB2283850A - Method and apparatus for coding and decoding information

Info

Publication number: GB2283850A
Application number: GB9323186A
Authority: GB
Inventors: William Alexander Courtney
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-11-10
Filing date: 1993-11-10
Publication date: 1995-05-17
Anticipated expiration: 2013-11-10
Also published as: GB2283850B; GB9323186D0

Abstract

An apparatus and method for coding and decoding information, enabling the user, especially visually impaired people, to hear a message which has been coded as a bar code, which is read by an optical scanner and reproduced as a synthesized, spoken message. The original information may be in different languages and output in different languages. The information may also be given out on a visual display unit or on a tactile display unit which allows the decoded information to be output in Braille. <IMAGE>

Description

Method and Apparatus for Coding and Decoding Information This invention relates to an apparatus and method for coding and decoding information. Its applications include enabling the user to hear a message which has been coded as a bar code.

Innovative features of the apparatus allow visually impaired people to detect the location of publicly displayed message boards which include bar codes, use a bar code scanner to read the code and listen to the message using a portable computer which emits an audio message related to the specific bar code.

The hand held apparatus includes a transmitterlreceiver which emits and detects electromagnetic or acoustic radiation. This acts as a ranging and direction sensing device.

The message board includes retro-reflectors which can deviate an incident beam of radiation back along its original path, giving a strong reflected signal. An audio output signal from the hand held apparatus increases in intensity and/or pitch as the user homes in more accurately on the direction of the message board. The ranging device can compute the distance to the message board and trans!ate this into an audio distance statement.

On reaching the message board the user guides the scanner over the board. The board has guiding rails which ensure that the whole of the board is scanned in the correct sequence.

The bar codes relate to digits which are addresses for information stored in the portable computer. Each address may store data relating to a phrase, word, alphanumeric character or character from the Internatic;nal Phonetic Alphabet. Because the bar codes represent addresses rather than spoken language information the phrases or words stored at an address may be varied. This allows different computers or different software programmes to store equivalent messages in different spoken languages or dialects for a given bar code. Where possible, phrases rather than words are stored in order to minimise the problem of different spoken languages having different rules of grammar.

The method and apparatus can be used to read bar coded public notices, restaurant menus, lists of symptoms for medical or car mechanical diagnoses etc which are completely independent of any spoken language, offering information communication benefits for all international travel srs, irrespective of their language skills, visual or reading abilities.

The bar codes on public notice boards may also include position coordinate information. This can be integrated with direction finding instruction software stored in the computer which will allow the computer to emit audio instructions, written instructions or direction finding maps relating to a preferred route to a pre specified location.

The apparatus, combined with suitable software may be used to read product label bar codes at retaii outlets. This has several purchaser benefits, including offering an audio description of the essential product features for visually impaired shoppers.

Tne invention will now be illustrated by reference to a specific example.

Figure 1 shows the apparatus.

1 is a lightweight, hand held component which incorporates a ranging device and optical scanner. This is linked to a small portable computer, 2. The computer produces an an audio output which may be heard through an earphone, 3. 4 is a public notice board which includes retro-reflectors, allowing the position of the board to be detected by 1.

The portable apparatus may be used in conjunction with optical character recognition software to read ordinary type faces. However the apparatus is preferably used to output information coded as bar codes. Bar codes are preferred because they are less prone to reading errors and offer pronunciation quality and language translation benefits which will be explained later in this application.

Figure 2 shows the notice board in greater detail.

1 is a retro-reflector, used for example, to reflect infra-red radiation transmitted by a hand held infra-red signal generator and detector. Retro-reflectors which consist of a multiplicity of cones are already known. They have the property that after the incoming beam is reflected at a multiplicity of surfaces on the interior of the cones the emergent beam is deviated by one hundred and eighty degrees compared with the incoming beam. This deviation takes place for an incoming beam which can be at a range of angles to the normal of the retro-reflector surface. 1 is preferably convex in shape increasing the range of angles of incidence for the incoming beam for which the beam is strongly reflected.

In order to aid detection of the board its total reflectance may be increased by extending the area covered by retro-reflectors. For example, the scanner guide rails may incorporate retro-reflectors and a multiplicity of retro-reflectors may be added to the perimeter of the board.

Suitable infra-red and/or ultrasonic distance and direction ranging devices as required for the implementation of this invention can be constructed by those skilled in the arts of electronics using existing knowledge. These devices typically emit pulses of radiation and calculate the distance to the target by measuring the time lapse between the transmission and detection of the reflected beam. The distance to the notice board may be output from the computer in imperial or metric units. In addition, if the value for the average length of the users stride is fed into the computer the distance value message may be output in paces. The apparatus may include an electronic tally button. At each stride the user presses the button and an optional audio count-down message is delivered at regular intervals as the user walks towards the notice board.This is of benefit to visually impaired users because it allows them to concentrate their attention on overcoming hazards while walking towards the board without being distracted by having to count paces or estimate distances.

The notice boards are preferably displayed at agreed standard heights and in standard locations with respect to doors and street furniture. They are at heights and locations which are accessible to wheelchair bound members of the public.

The surfaces of the boards are made from appropriately weather-proof and durable materials which allow long term use without degradation of the bar code information.

2 is the first of the bar codes.

The bar codes are sets of black bars and intervening white spaces which are arranged in specific patterns to represent digital data. The digital data is used to locate addresses containing verbal information in the hand held computer memory.

The digital information is contained in the relative widths of the bars and spaces.

Symbology rules for coding information are a known art. One or more symbologies may be used as part of the method for the present invention. For example a spatially compact symbology which stores numerical data only may be used for the display boards but the method and apparatus also needs to be able to read Code EAN 13 for reading consumer product bar codes.

A numerical equivalent of the address represented by the bar code is printed adjacent to the code stripes. This allows the code to be manually keyed into the hand held computer or the related phrase to be read from a phrase book if the user does not have access to a working bar code scanner.

3 is part of a scanner guide rail. These rails are positioned as shown to assist visually impaired users to scan all the codes on the board in the correct order. For the design shown the user places the scanner on the board immediately below the retro-reflector and slides the scanner over the surface of the board so that it is guided in the direction of the arrows. The verbal information accessed as a result of the scanning process is temporarily stored in an erasable memory. The audio output unit is preferably equipped with standard tape recorder style features allowing fast forward access, replay features etc.

The normal form of the output information, for visually impaired users will be a computer simulated voice. Computers with Braille outputs are known and these can be employed if the user suffers from visual and audio impairment.

Users with an adequate level of visual ability may also read the message on a visual display screen.

Computers with suitable central processing units include lap top computers and personal digital assistants. The system software and data can be stored as a card in a Personal Computer Memory Card International Association (PCMCIA) expansion slot.

In order to offer an information coding system which transcends spoken language barriers the relationships between spoken language data and the related bar code addresses need to be internationally agreed.

Phrases are the preferred unit of information stored at addresses. The wording of the phrase stored at a given address relates to the intended message rather than a literal word for word translation.

Thus, for example, for British English software users, the whole of the following instruction would be stored at one address: In case of fire do not use the lift A literal translation into Spanish, made simply by replacing each word with a Spanish equivalent, without any attention being paid to meaning may produce: No emplear el levantar en maleta de fuego This would create a nonsense message because levantar, a direct translation of lift means to lift up rather than a means of vertical transport associated with a building.

Case is translated as maleta which is a suite case and fire is translated as fuego which means fire as in shooting.

In order to convey the intended meaning of the instruction In case of fire do not use the lift the wording of the phrase stored in the Spanish version of the software would be: mn caso de incendio, no usar el ascensor In instances where the spoken language has a multiplicity of commonly used dialects, vocabulary differences can also be allowed for e.g. the American English decoding software would use elevator instead of lift in the above example.

Spoken language is made more vivid and powerful by the use of similes and metaphors. These are culturally based and can only be translated in sentiment from one language to another by a speaker experienced in both languages. For example a warm, sunny spell of weather in early autumn in Great Britain is often referred to as an Indian summer. The same meteorological phenomenon in Russia is referred to as a grannies summer. Grammar checking software and single word dictionaries would not be able to translate the sentiment inherent in these phrases.

The present invention overcomes this type of language problem without difficuity.

The address in the British English version of the software which stores Indian summer stores grannies summer in the Russian version of the software. For languages which offer no equivalent image based phrase the phrase stored could, for example, be late summer warm, sunny spell.

Thus, provided that the verbal data is added to the decoding software by an author articulate in the spoken language used for the output then decoding of stored phrases can be done rapidly and unambiguously in any chosen language without processing the data using grammar checking software.

The computer output may be an audio message or a visual displayed message.

For a visual display the user requires a correctly spelt message. Spelling may vary between dialects of a spoken language and this can be taken into account. For example, the address storing the ASCII equivalent of the written word jail in the British English version of the software would store the ASCII equivalent of the word goal in the American English software.

In many languages the written version of a word does not correspond to the way that the word sounds when spoken unless complex rules of pronunciation are adhered to. This can be overcome with the present apparatus and method by storing two versions of the word or phrase at two different addresses. One address stores a written version, the other a spoken version. The spoken version is stored using computer code which relates to the sound of the word or phrase expressed using the International Phonetic Alphabet. Information identifying two addresses can be stored as one bar code by allowing the final binary digit of the bar code to be ignored for one address but recognised as a digit in the second address.

By careful choice of the agreed translations of words and phrases the system is capable of offering an unambiguous multilingual word and phrase reading system.

Complex verbal communications which require the combination of stored words and phrases can cause difficulties. If the input and output data are in the same spoken language then no problems arise, but if the languages differ then problems may arise because each spoken language has its own rules of grammar. Grammar checking programmes are already known and decoded information can be fed into them before being output in order to reduce translation errors. These checking programmes require processing time and are prone to produce ambiguous results because of the subtleties of spoken languages.

Reconstruction times can be minimised and ambiguities reduced by carefully addressing the data at the input stage.

The principles behind a typical computer programme for appropriately addressing data are outlined below.

Figure 3 is a flow chart relating to a programme and apparatus for translating spoken or written information into a string of bar code data with associated computer memory addresses.

This example relates to the coding of data input in English with a view to allowing the data to be read in a number of other spoken languages.

The desired communication is input using for example a keyboard or computer writing pad capable of recognising the operators hand writing.

After inputting the data the operator is required to identify or highlight all real names. This is essential because real names are normally expected to retain their pronunciation irrespective of the spoken language used. For example, if the input data includes the sentence I have been reading about the British city of Reading then the verb reading will have code stored at an address which will generate the appropriate equivalent of the English word reading for the spoken language required by the data outputter scanning the bar coded version of the sentence.

The real name Reading .will be stored as a spelling, using a separate address for each character in the name and as a sound equivalent using a coded equivalent of the International Phonetic Alphabet spelling. The computer makes a best guess at the phonetic spelling of Reading. The best guess can be modified by the data inputter, if necessary, by selecting different sounds from an audio menu of phonemes.

The spelling checker checks all words input into the computer in a similar manner to existing spelling check programmes but its stored list of valid spellings is limited to words for which there exists an agreed bar code and associated memory address. A word for which a correction can not be found is deemed to be either a proper noun, not in the dictionary or a word which is not recognised by the current version of the valid bar codes. New proper nouns may be added to the dictionary but other words must be replaced by valid words. The thesaurus is used to assist in this task. The thesaurus is similar to existing thesauruses but, in common with the spelling checker, will only pass words on to the next stage if they have valid codes.

The information is preferably stored as phrases. The phrase coder searches the input data, attempting to identify valid phrases. If a long multi-word phrase which can be broken down into a number of smaller phrases is identified then the longer phrase is preferably stored. The phrase coder sends potentially valid phrases to a grammar checker. If the juxtaposition of adjacent nouns, verbs or other parts of speech appears to be inconsistent with the use of the phrase the operator is required to approve the coding of the phrase. Stored examples of valid uses of the phrase with appropriate adjacent parts of speech may be displayed for inspection by the operator in order to assist judgement.

The complete text now passes to the grammar checker. The grammar checker next inspects words outside of the identified phrases to examine where they slot into sentences. This is necessary to separate nouns from verbs which have the same spelling. For example, in the following sentences The fiv landed on the meat.

Aeroplanes fly to New York.

the word fly appears first as a noun and then as a verb. The computer is likely to recognise whether the word is being used as a noun or verb from where it slots into the sentence. If there is any doubt the computer displays specimen demonstration sentences with the best guessed status of the word included, in order to assist the operator in validating the status of the word.

There are cases where written or spoken British English uses one word in a range of communications but other languages use two different words depending on the context of the communication. The grammar checker can allow for this without the operator having any knowledge of these other languages.

For example, the word you in English may be replaced by the word tu or vos in Latin depending on the context. Several European and Indian languages retain two different words for you with one version being used for intimate conversations or conversations between equals and the second version being used for non intimate communications.

The grammar checker can display two demonstration sentences in English one of which, if translated would require tu the other requiring vos.

Depending on the choice of demonstration sentence which offers closest agreement with the intended use of the word the computer will allocate the word you to a store for tu or vos. For languages where the distinction is not relevant both addresses store the same ASCII translation of the word you.

Spoken languages can be split into configurational and non-configurational languages.

For configurational languages word order is important, non-configurational languages rely on word endings or inflections to indicate the relationship between words. Grammar checkers combined with demonstration sentence techniques are used to eliminate coding ambiguities thrown up by differences between configurational and non-configurational languages.

Intormation coded as described above may be be communicated via radio links.

This could be exploited in order to create simple specific spoken language free radio transmissions. Provided that the receiver is coupled to a suitable code reading device as described above this would allow the listener to hear a spoken conversation in any desired language, read television sub-titles in any language and offer basic specific spoken language free conferencing facilities. A degree of emotion and character can be added to the audio delivery by adding bits to the code which control the loudness, pitch and speed of deiivery of the spoken message.

Bar codes are currently used by retail outlets for identifying stock at the point of sale. The computer stored data used to read product information from a bar code label on the product can be down loaded on to a PCMCIA memory card which can be slotted into the hand held computer. This will enable visually impaired shoppers to use the currently described method and apparatus to identify the name, size and price of products that they may wish to purchase.

This product feature reading facility of the invention will also be of use to other shoppers. Details of the products purchased may be entered into the computer memory using the scanner and a running total of expenditure produced. The data may be transferred to a central computer at the point of sale in order to facilitate the purchasing transaction.

In order to check that purchasers have entered data relating to all goods placed in the collection basket or trolley the goods and container may be weighed and the weight of the container subtracted. This true weight can be compared with the expected weight predicted from the stored bar code data in order to reduce fraud.

In order to allow people with good eyesight and a Knowledge of the native language to read the same information, on the same display as the equipment user the bar codes and written alpha-numeric information may be superimposed so that they occupy he same area of space on a notice board, menu etc. This is only acceptable for normal reading purposes if the printed bar code is not visible to the human eye. According to the present invention this can be overcome in three ways: a) The hand held scanner operates at at infra-red wavelengths. The ink or dye used to print the bar codes has low electromagnetic radiation absorption properties in the visible part of the spectrum but high absorption in the infra red. Consequentially the bar codes are almost invisible to the unaided eye.

b) An infra-red scanner can be used to read bar codes which are printed on the lower layer of a laminate. The upper layer of the laminate is opaque to visible light and has the alpha-numeric information printed on its surface.

c) The bar code information can be printed using a fluorescent dye, The dye is not substantially visible when illuminated by visible light but emits visible light when illuminated by ultra-violet radiation. The scanner used for this option includes a suitable ultra-violet light source in its reading head. The scanner detects the contrast between the fluorescing stripes and the undyed spaces between them.

With all of these options the alpha-numeric data and any other visible markings such as illustrations act as noise, reducing the contrast between the bar code stripes.

There are two methods of overcoming this problem according to the present invention: a) By using a read head which includes a multiplicity of sensors for detecting the bar codes. The sensors are mounted in a direction at right angles to the scan direction so that the multiplicity of sensors reads similar portions of the code almost simultaneously. Data is only accepted from individual sensors on occasions when the contrast patterns are identical from two or more sensors over one block of code. This can be guaranteed for bar codes with superimposed alpha-numerical data if the height of the bar code stripes exceeds the height of the alpha-numeric characters so that at least two reading sensors examine the blank space above and below the characters.

This condition can only be met if the direction of scan of the reading head is parallel to the lines of print. Visually impaired users can achieve this alignment easier on documents which include scanner guides. For example semi-rigid documents such as menus printed on card can include narrow flaps along their vertical sides. These can be raised up and pressed against the side of the scanner to help control torsional movement.

b) Using a single read head which scans across the bar code but only recognises signals as valid if the same pattern is registered by the scanner on two occasions separated by a short interval of time.

For example, figure 4a is a short alpha-numeric phrase. 4b is its bar code equivalent, assumed to be almost invisible to the unaided eye according to one of the above methods. 4c shows the two items superimposed. Numbers 1 to 11 in figure 4c represent successive lines scanned by the read head.

Inspection of the diagram indicates that only lines 1 and 7 represent identical patterns

Claims

Claims 1 A method and apparatus for coding and decoding verbal information which allows the information to be coded as one or more bar codes, allows the bar codes to be read using an optical scanner then decoded and reproduced as a synthesized, spoken message.

2 As for claim one but with the additional feature that the original information and decoded information are different spoken languages.

3 As for claim one but with the additional feature that the decoded information may be output in a multiplicity of different spoken languages.

4 As for any of the above claims but with the inclusion of a visual display unit which also allows the decoded information to be output as a written message on a visual display unit.

5 As for any of the above claims but with the inclusion of a tactile display unit which also allows the decoded information to be output in Braille.

6 As for any of the above claims but with the inclusive feature that the method and apparatus used includes a direction finding device which allows visually impaired apparatus users to determine the direction of a relevant bar code display at a distance beyond their immediate reach.

7 As for any of the above claims but with the inclusive feature that the method and apparatus used includes a ranging and direction finding device which allows visually impaired apparatus users to determine the direction and distance of a relevant bar code display at a distance beyond their immediate reach.

8 As for any of the above claims but with the ranging or direction seeking system specifically including an infra-red radiation transmitter and receiver.

9 As for any of the above claims but with the ranging or direction seeking system specifically including an ultra sonic acoustic wave transmitter and receiver.

10 As for any of the above claims but with the inclusion of a tally counter which gives an audio message, estimating the distance to the bar code display as the operator moves towards the display.

11 As for any of the above claims but with the inclusion of a bar code display board which includes one or more reflecting components which deviate the incoming radiation beam from a detector through one hundred and eighty degrees, for a range of angles of incidence so that a substantial fraction of the beam intensity is returned along its incoming path.

12 As for any of the above claims but with the inclusion of a bar code display board which includes guiding rails which assist the user to scan the bar codes in a preferred sequence.

13 As for any of the above claims but with the inclusion of apparatus which can store the digital data obtained by scanning the bar codes and allow the decoded, equivalent verbal information or selections of the information to be output on a multiplicity of occasions.

14 As for any of the above claims but with the coded verbal data being transferable between different parts of the apparatus or between different sets of apparatus using radio signals.

15 As for any of the above claims but with the portable apparatus including optical character recognition software which allows the apparatus to be used for reading alpha-numeric characters and words.

16 As for any of the above claims but for a system with the apparatus being specifically able to store information relating to the weight or mass of a number of items following a scanning of the items and the system including a weighing device which is capable of comparing the weight or mass of a container holding a number of items with the predicted weight or mass of the container and items obtained by the scanning operation.

17 As for any of the above claims but for a system which includes a bar code scanner which includes an ultra-violet source of illumination and has one or more data reading sensors which can detect electromagnetic radiation of a longer wavelength than that emitted by the ultra-violet light source.

18 As for any of the above claims but for a system which includes a bar code reading device which has a multiplicity of bar code reading sensors which operate in parallel and has a data retrieving computer which is programmed so that it only accepts as valid, readings from two or more sensors, reading the same bar code, if the contrast patterns detected by the two or more sensors are substantially the same in pattern.

Amendments to the claims have been filed as follows A method and apparatus for coding and decoding verbal information which allows the information to be coded as one or more bar codes relating to computer memory addresses, allows the bar codes to be read using an optical scanner then decoded and reproduced as a synthesized, spoken message with the apparatus including a memory which stores the component parts of spoken language information in a range of different degrees of detail including alpha-numeric characters, words and phrases and includes a computer programme which assists in coding input verbal information for the preparation of bar codes by comparing the input information with permanently stored characters, words and phrases such that a complex verbal statement can be recorded using the minimum number of codes by first allocating codes for phrases if this is possible, then as a second choice allocating codes for words and only where necessary allocating codes for individual characters.
2 As for claim one but with the additional feature that the original information and decoded information are different spoken languages.
3 As for claim one but with the additional feature that the decoded information may be output in a multiplicity of different spoken languages.
4 As for any of the above claims but with the inclusion of a visual display unit which also allows the decoded information to be output as a written message on a visual display unit.
5 As for any of the above claims but with the inclusion of a tactile display unit which also allows the decoded information to be output in Braille.
6 As for any of the above claims but with the inclusive feature that the method and apparatus used includes a direction finding device which allows visually impaired apparatus users to determine the direction of a relevant bar code display at a distance beyond their immediate reach.
7 As for any of the above claims but with the inclusive feature that the method and apparatus used includes a ranging and direction finding device which allows visually impaired apparatus users to determine the direction and distance of a relevant bar code display at a distance beyond their immediate reach.
8 As for any of the above claims but with the ranging or direction seeking system specifically including an infra-red radiation transmitter and receiver.
9 As for any of the above claims but with the ranging or direction seeking system specifically including an ultra sonic acoustic wave transmitter and receiver.
10 As for any of the above claims but with the inclusion of a tally counter which gives an audio message, estimating the distance to the bar code display as the operator moves towards the display.
11 As for any of the above claims but with the inclusion of a bar code display board which includes one or more reflecting components which deviate the incoming radiation beam from a detector through one hundred and eighty degrees, for a range of angles of incidence so that a substantial fraction of the beam intensity is returned along its incoming path.
12 As for any of the above claims but with the inclusion of a bar code display board which includes guiding rails which assist the user to scan the bar codes in a preferred sequence.
13 As for any of the above claims but with the inclusion of apparatus which can store the digital data obtained by scanning the bar codes and allow the decoded, equivalent verbal information or selections of the information to be output on a multiplicity of occasions.
14 As for any of the above claims but with the coded verbal data being transferable between different parts of the apparatus or between different sets of apparatus using radio signals.
15 As for any of the above claims but with the portable apparatus including optical character recognition software which allows the apparatus to be used for reading alpha-numeric characters and words.
16 As for any of the above claims but for a system with the apparatus being specifically able to store information relating to the weight or mass of a number of items following a scanning of the items and the system including a weighing device which is capable of comparing the weight or mass of a container holding a number of items with the predicted weight or mass of the container and items obtained by the scanning operation.
17 As for any of the above claims but for a system which includes a bar code scanner which includes an ultra-violet source of illumination and has one or more data reading sensors which can detect electromagnetic radiation of a longer wavelength than that emitted by the ultra-violet light source.
18 As for any of the above claims but for a system which includes a bar code reading device which has a multiplicity of bar code reading sensors which operate in parallel and has a data retrieving computer which is programmed so that it only accepts as valid, readings from two or more sensors, reading the same bar code, if the contrast patterns detected by the two or more sensors are substantially the same in pattern.
19 Information coding and decoding equipment substantially as described or substantially as illustrated in the current patent application.