DE102015106730A1 - Color-angle-based symbol transmission and symbol failure compensation - Google Patents

Abstract

Disclosed is, inter alia, a method (100, 300) comprising converting (306) a sequence of symbols into a first sequence of color angles, and displaying (104) or effecting displaying (103) at least a partial representation of a temporal sequence of Representation elements on a display unit (35), wherein each display element of the temporal sequence of display elements, a respective color angle of the first sequence of color angles is assigned, which determines the color value of at least a portion of the presentation element. Further disclosed is a method (100, 400, 500, 900), comprising detecting (401, 402) a sequence of samples, each comprising color angle information or from each of which color angle information can be obtained, from at least one displayed on a display unit (35) partial representation of a temporal sequence of display elements, or obtaining a sequence of samples recorded in this way, wherein each display element of the temporal sequence of display elements is associated with a respective color angle of a first sequence of color angles which defines the color value of at least a portion of the presentation element, and wherein first sequence of color angles based on conversion from a first sequence of symbols, at least a portion of which represents a first sequence of information elements, and determining (403, 405-410) a representation of the first sequence of information elements based at least on the detected Fo length of samples. Also disclosed are corresponding apparatuses (2, 4) and computer programs for implementing each of these methods, and a system (3) comprising such apparatuses (2, 4).

Description

Field of the invention

The present invention relates, among other things, to methods, apparatuses, programs and a system in the field of optical transmission of information, in particular the optical transmission of information by means of different color angles.

Background of the invention

Optical transmission is used in many fields. For example, display units such as computer monitors or displays of mobile phones can be used to display information that is then captured with an optical sensor positioned near the display unit. The information can be coded, for example, in a barcode or QR code, which can be displayed on the display unit and with an optical sensor, such as a camera of a mobile phone, detected and then evaluated by the mobile phone. In this way, for example, information that is used in the context of an authentication process, for. B. in online banking, transferred.

General description of some embodiments of the invention

It is an object of the present invention to provide an improved optical transmission of information over the prior art in various aspects.

According to a first exemplary aspect of the invention, a method is disclosed that is performed by at least one device and includes: converting a first sequence of symbols into a first sequence of color angles, and displaying or effecting an at least partial representation of a temporal sequence of Display elements on a display unit, wherein each display element of the temporal sequence of display elements, a respective color angle of the first sequence of color angles is assigned, which determines the color value of at least a part of the display element.

According to a second exemplary aspect of the invention, there is disclosed a method performed by at least one device comprising: detecting a sequence of samples each comprising color angle information or from each of which color angle information is obtainable from an at least partial representation displayed on a display unit a temporal sequence of display elements, or receiving a thus detected sequence of samples, wherein each display element of the temporal sequence of display elements associated with a respective color angle of a first sequence of color angles, which determines the color value of at least a portion of the display element, and wherein the first sequence of Color angles based on a conversion of a first sequence of symbols, of which at least a part represents a first sequence of information elements, and determining a representation of the first sequence of information at least based on the detected sequence of samples.

• – Ein Computerprogramm, umfassend Programmanweisungen, die einen Prozessor zur Ausführung und/oder Steuerung des Verfahrens gemäß dem jeweiligen Aspekt der Erfindung veranlassen, wenn das Computerprogramm auf dem Prozessor läuft. Unter einem Prozessor sollen in dieser Spezifikation unter anderem Kontrolleinheiten, Mikroprozessoren, Mikrokontrolleinheiten wie Mikrocontroller, digitale Signalprozessoren (DSP), Anwendungsspezifische Integrierte Schaltungen (ASICs) oder Field Programmable Gate Arrays (FPGAs) verstanden werden. Dabei können entweder alle Schritte des Verfahrens gesteuert werden, oder alle Schritte des Verfahrens ausgeführt werden, oder ein oder mehrere Schritte gesteuert und ein oder mehrere Schritte ausgeführt werden. Das Computerprogramm kann beispielsweise über ein Netzwerk wie das Internet, ein Telefon- oder Mobilfunknetz und/oder ein lokales Netzwerk verteilbar sein. Das Computerprogramm kann zumindest teilweise Software und/oder Firmware eines Prozessors sein. Es kann gleichermaßen zumindest teilweise als Hardware implementiert sein. Das Computerprogramm kann beispielsweise auf einem computerlesbaren Speichermedium gespeichert sein, z. B. einem magnetischen, elektrischen, elektro-magnetischen, optischen und/oder andersartigen Speichermedium. Das Speichermedium kann beispielsweise Teil des Prozessors sein, beispielsweise ein (nicht-flüchtiger oder flüchtiger) Programmspeicher des Prozessors oder ein Teil davon.
• – Eine Vorrichtung, eingerichtet zur Ausführung und/oder Steuerung des Verfahrens gemäß dem jeweiligen Aspekt der Erfindung oder umfassend jeweilige Mittel zur Ausführung der Schritte des Verfahrens gemäß dem jeweiligen Aspekt der Erfindung. Dabei können entweder alle Schritte des Verfahrens gesteuert werden, oder alle Schritte des Verfahrens ausgeführt werden, oder ein oder mehrere Schritte gesteuert und ein oder mehrere Schritte ausgeführt werden. Ein oder mehrere der Mittel können auch durch die gleiche Einheit ausgeführt und/oder gesteuert werden. Beispielsweise können ein oder mehrere der Mittel durch einen oder mehrere Prozessoren gebildet sein.
• – Eine Vorrichtung, die zumindest einen Prozessor und zumindest einen Speicher, der Programmcode beinhaltet, umfasst, wobei der Speicher und der Programmcode eingerichtet sind, die Vorrichtung mit dem zumindest einen Prozessor dazu zu veranlassen, zumindest das Verfahren gemäß dem jeweiligen Aspekt der Erfindung auszuführen und/oder zu steuern. Dabei können entweder alle Schritte des Verfahrens gesteuert werden, oder alle Schritte des Verfahrens ausgeführt werden, oder ein oder mehrere Schritte gesteuert und ein oder mehrere Schritte ausgeführt werden.

In each of these aspects of the invention, the following are further disclosed:

• A computer program comprising program instructions that cause a processor to execute and / or control the method according to the particular aspect of the invention when the computer program is running on the processor. A processor is to be understood in this specification to include control units, microprocessors, microcontroller units such as microcontrollers, digital signal processors (DSP), application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In this case, either all steps of the method can be controlled, or all steps of the method can be executed, or one or more steps can be controlled and one or more steps can be executed. The computer program can be distributed, for example, via a network such as the Internet, a telephone or mobile network and / or a local network. The computer program may be at least partially software and / or firmware of a processor. It may equally be at least partially implemented as hardware. The computer program may for example be stored on a computer-readable storage medium, eg. B. a magnetic, electrical, electro-magnetic, optical and / or other storage medium. The storage medium may for example be part of the processor, for example a (non-volatile or volatile) program memory of the processor or a part thereof.
• A device arranged to carry out and / or control the method according to the respective aspect of the invention or comprising respective means for carrying out the steps of the method according to the respective aspect of the invention. In this case, either all steps of the method can be controlled, or all steps of the method can be executed, or one or more steps can be controlled and one or more steps can be executed. One or more of the means may also be executed and / or controlled by the same unit. For example, one or more of the means may be formed by one or more processors.
• A device comprising at least one processor and at least one memory containing program code, the memory and the program code being arranged to cause the device with the at least one processor to perform at least the method according to the respective aspect of the invention and / or to control. In this case, either all steps of the method can be controlled, or all steps of the method can be executed, or one or more steps can be controlled and one or more steps can be executed.

According to a third exemplary aspect of the invention, there is disclosed a system comprising a device according to the first aspect of the invention and a device according to the second aspect of the invention. For example, the system may further comprise a device with the display unit if that display unit is not part of the device according to the first aspect of the invention.

In the following, exemplary features of the aspects of the invention will be described, each of which is to be understood as being equally disclosed for the methods, apparatus, programs according to the first and second aspects of the invention and the system according to the third aspect of the invention.

According to the first aspect of the invention, a first sequence of symbols is converted into a first sequence of color angles. This can be done, for example, according to an assignment rule that can be predefined or predefined according to a predefined rule, for example. For example, the assignment rule can assign each symbol a respective color angle, for example such that each symbol of a set of different symbols is assigned a different color angle to a set of color angles. Alternatively, the assignment rule can also assign a respective color angle difference to each symbol, for example such that each symbol of a set of different symbols is assigned a different color angle difference to a set of different color angle differences. The symbols of the first sequence of symbols are then assigned sequentially to respective color angles or color angle differences to obtain either the first sequence of color angles or to obtain a sequence of color angle differences from which the first sequence of color angles is then obtained, for example by from a starting color angle, which may for example be predefined and which may, for example, form the first color angle of the sequence of color angles, is added to this starting color angle the first color angle difference of the sequence of color angle differences by the second color angle of the sequence of color angles and proceed accordingly for the further color angle differences to obtain the entire first sequence of color angles.

The symbols are represented, for example, by tuples of m bits (as m-bit symbols, where m denotes a natural number, for example m = 1, 2, 4 or 8, to name just a few non-limiting examples the m bits may then 2 ^m different symbols are illustrated. In particular, a first sequence of symbols designates a plurality of successive symbols. the first sequence of symbols, for example, represent at least a part of a sequence of information elements (eg., bits). for example, the first sequence of symbols may be a sequence of bits or may be obtained by means of a mapping rule associating m bits of the sequence of bits each with a symbol.

The color angles determine the respective color value in a color space, in particular the HSV color space, the HSL color space, the HSB color space, the HSI color space or the CIE-LCh color space. The HSV color space is the color space of several color models, where one defines the color with the help of the color value (English: Hue), the color saturation (English: Saturation) and the light value (or the dark level) (English: Value). Similar definitions lead to an HSL color space with the relative brightness (English: lightness), an HSB color space with the absolute brightness (English: brightness) and a HSI color space with the light intensity (intensity).

• – Farbwert als Farbwinkel H auf dem Farbkreis (etwa 0° für Rot, 120° für Grün, 240° für Blau),
• – Sättigung S in Prozent (0% = Neutralgrau, 50% = wenig gesättigte Farbe, 100% = gesättigte, reine Farbe), oder in einem Intervall von Null bis Eins
• – Hellwert V als Prozentsatz (0% = keine Helligkeit, 100% = volle Helligkeit), oder in einem Intervall von Null bis Eins, auch Dunkelstufe genannt.

The following parameters are used for the description of the color location in the HSV color space (correspondingly similar for the other color spaces mentioned):

• Color value as color angle H on the color wheel (about 0 ° for red, 120 ° for green, 240 ° for blue),
• - Saturation S in percent (0% = neutral gray, 50% = low saturated color, 100% = saturated, pure color), or in an interval from zero to one
• - Brightness V as a percentage (0% = no brightness, 100% = full brightness), or in an interval from zero to one, also called darkness.

Color angles can therefore be in a range of 0 ° -360 °, for example. As a consequence of color angles, in particular a multiplicity of successive color angles is understood.

Each color angle of the first sequence of color angles is a respective display element of a temporal sequence of display elements assigned and sets the color value of at least a part of the respective presentation element. For example, for all n from 1 to N, the nth color angle in the first sequence of color angles is assigned to the nth display element of the temporal sequence of display elements, where N is the number of color angles in the sequence of color angles.

A display element is an optical, in particular on a display unit, representable element, in particular an image, an image area or a picture element such as a letter, a symbol or a figure. The color value of at least one part (but also, for example, of the entire display element) is determined by the respective color angle of the first sequence of color angles. In the temporal sequence of display elements, for example, only one display element of the sequence of display elements is simultaneously displayed (although on a display unit on which the sequence of display elements is displayed, other contents can also be displayed simultaneously, for example a background, text, etc. ). The presentation elements of the sequence of presentation elements thus follow one another temporally, for example. For example, the presentation elements of the sequence of presentation elements are all displayed at the same position of the display unit. Alternatively, for example, at least one display element of the sequence of display elements is displayed at a different position on the display unit than another display element of the sequence of display elements.

An at least partial representation of the temporal sequence of presentation elements is displayed on a display unit or the display of the temporal sequence of display elements on a display unit is effected. For example, the display unit may be a monitor connected to, for example, an electronic device, such as a computer, or part of the electronic device, such as a laptop, tablet, or phablet computer, or a mobile phone (especially a smartphone).

The at least partial representation may be, for example, a complete representation of the temporal sequence of presentation elements, for example the temporal sequence of presentation elements themselves, or a partial representation of the temporal sequence of presentation elements, in which, for example, one or more presentation elements of the temporal Sequence of presentation elements are not included. The fact that one or more presentation elements of the temporal sequence of presentation elements are not contained in the partial representation of the temporal sequence of presentation elements may, for example, be due to an asynchronicity between a processor and a graphics card and / or an asynchronicity between a graphics card and a display unit Process of displaying the timing of display elements on the display unit, and / or transmission errors on a transmission channel between a first device, of which a second device connected to the display unit contains information (eg, control commands) for displaying the time sequence retrieves or receives from presentation elements. This can lead, for example, to the fact that display elements that are actually intended to be displayed on the display unit are not displayed there and, for example, instead the respective display element preceding each non-displayed display element is displayed longer. The first device may be, for example, a computer or server that provides control commands, for example via a website, which are called up or received by a program running on a processor of the second device, in particular a browser. The control commands may represent, for example, direct or at least indirect instructions to a graphics card of the second device to display the temporal sequence of presentation elements on a display unit of the second device, which then leads to the display of the at least partial representation of the temporal sequence of presentation elements. The computer or server thus causes the display of the at least partial representation of the temporal sequence of presentation elements on the display unit.

According to the first aspect of the invention, a first sequence of symbols is optically transmitted by assigning a sequence of color angles to the first sequence of symbols and displaying a temporal sequence of display elements each associated with a color angle of the sequence of color angles on a display unit becomes. The symbols are thus transmitted using color angles. This procedure is based on the knowledge that, in particular, the color angle, in particular in comparison to other optical parameters (such as, for example, the saturation or the brightness), can be detected relatively robustly. In addition, sensors for detecting the color angle are structurally simple and thus inexpensive, in particular in comparison to camera sensors, which are required for the detection of more complex optical information elements, such as bar codes or QR codes. Such color angle sensors are used, for example, for calibrating monitors and are available at low cost as a mass product. Furthermore, the transfer of symbols through color angles opens up Possibilities for more visually appealing design than barcodes or QR codes. For example, instead of the bar codes or QR codes, any display element, for example a logo of a company (or the background of the logo) may be used and its color angle (and thus the color value) adjusted according to the sequence of color angles (in the temporal sequence of display elements then in each case basically the same display element displayed, but with an appropriate color value according to the respective color angle of the sequence of color angles).

For example, at least a portion of the first sequence of symbols (or, for example, the entire first sequence of symbols) may be an encoded representation of a first sequence of information elements. The coding may, for example, be an encoding according to an error-correcting code. Error correcting codes are, for example, fixed length codes (so-called block codes) or convolutional codes which allow variable block lengths. Examples of error-correcting codes, in particular block codes, are the Hamming code, the Bose-Chaudhuri-Hocquenghem code (BCH code) or the Reed-Solomon code (RS code). The first sequence of information elements may include payload and CRC thereon.

For example, at least a portion of the first sequence of symbols may represent information (eg, a sequence of informational elements) that, by displaying the at least partial representation of the temporal sequence of presentation elements on the display unit, optically to a device that is from the at least one device is transferred to be recovered there.

For example, at least a portion of the first sequence of symbols may represent information (eg, a first sequence of information items) that may be used as part of an authentication, such as an entity such as an entity. A person or device, or an operation (e.g., a transaction or login). The information may include, for example, information about the identity of the entity, information about the process, a password, and / or a transaction number.

In one embodiment of all aspects of the invention, converting the first sequence of symbols into the first sequence of color angles comprises assigning a respective color angle to each symbol of the first sequence of symbols according to an assignment rule to obtain a second sequence of color angles; Color angles is the second sequence of color angles or is generated using the second sequence of color angles. The order of the color angles in the second sequence of color angles corresponds, for example, to the order of the symbols to which the color angles are respectively assigned, in the first sequence of symbols. The first sequence of color angles may be generated, for example, by applying a mask to the second series of color angles or to a portion thereof, as will be explained in greater detail below.

In an exemplary alternative embodiment of all aspects of the invention, converting the first sequence of symbols into the first sequence of color angles comprises assigning a respective color angle difference to each symbol of the first sequence of symbols according to an assignment rule to obtain a sequence of color angle differences, and generating one third sequence of color angles such that the difference between a respective color angle of the third sequence of color angles to a preceding (or immediately) succeeding color angle corresponds to a respective color angle difference of the sequence of color angle differences, wherein the first sequence of color angles is the third sequence of color angles or is generated using the third sequence of color angles. The first sequence of color angles may be generated, for example, by applying a mask to the third series of color angles or to a portion thereof, as will be explained in greater detail below. For example, the order of the color angle differences in the sequence of color angle differences corresponds to the order of the symbols to which the color angle differences are respectively associated in the first sequence of symbols.

The first color angle difference of the sequence of color angle differences then exists, for example, between the first and second color angle of the third sequence of color angles, the second color angle difference of the sequence of color angle differences then exists between the second and third color angle of the third series of color angles, etc. Thus, for example nth color angle difference of the sequence of color angle differences between the nth and the (n + 1) th color angle of the third sequence of color angles, this being true at least for all n from 1 to N-1, where N is the number of color angle differences in is the result of color angle differences and the Nth color angle difference between the Nth color angle of the third series of color angles and a color angle subsequent thereto that does not form part of the third series of color angles. Alternatively, this applies to all n from 2 to N, where the first color angle difference between the first color angle of the third sequence of color angles and a color sequence of the third preceding color angle which is not part of the third series of color angles.

The transmission of symbols on the basis of color angle differences is advantageous, for example, if the disturbances (eg noise, interference or distortions) in the display and / or detection of color angles are at least partially correlated, since such correlations are reduced by subtraction of the color angles or eliminate before assigning symbols to the color angle differences thus obtained.

In one embodiment of all aspects of the invention, one or more of the symbols of the first sequence of symbols are predetermined or determinable according to a predetermined rule, whereby it is possible to determine the assignment rule from the displayed at least partial representation of the temporal sequence of the presentation elements. For example, if the predetermined or determinable according to a predetermined rule symbols are transmitted optically as color angle or color angle differences, (to a receiver of this information) can be used to determine the assignment rule symbol to color angle or to determine the assignment rule symbol to color angle difference. Additionally or alternatively, the knowledge that predetermined or determinable according to a predetermined rule symbols are transmitted, used to calibrate an optical sensor, with which the at least partial representation of the temporal sequence of display elements is detected. For example, the predetermined or determinable symbols include all those symbols to which different color angles are assigned according to the assignment rule. For example, if the symbols of the first sequence of symbols are from an alphabet of K different symbols (for example, K = 16 symbols for 4-bit symbols), for example, each symbol k with k = 1 through K has the color angle α _k = according to the assignment rule (360 ° / K) · (k - 1) assigned. For example, then of the predetermined or determinable symbols at least the K different symbols are included. The predetermined or determinable symbols then act as a translation table (look-up table) for the assignment rule. In this case, the assignment rule can be the same in each case for the optical transmission of a multiplicity of different first sequences of symbols (ie be static, for example), or different in at least two optically transmitted different first sequences of symbols (ie, be dynamic, for example in a rolling form according to a predetermined rule), whereby the spying of the optically transmitted information by third parties who do not know the assignment rule (and for example also the predetermined rule) is made more difficult.

In one embodiment of all aspects of the invention, a respective color angle to each symbol is assigned to a second sequence of symbols according to an assignment rule to obtain a fourth sequence of color angles, wherein the symbols of the second series of symbols are predetermined or determinable according to a predetermined rule; at least partial representation of a second temporal sequence of presentation elements is displayed or their display is effected, each color angle of the fourth sequence of color angles defining a respective color value of at least a portion of the color angle respectively associated representation element of the second temporal sequence of presentation elements.

Thus, in addition to the at least partial representation of the temporal sequence of presentation elements associated with the first sequence of symbols, an at least partial representation of a second temporal sequence of presentation elements associated with a second sequence of symbols is displayed or displayed , wherein the symbols of the second sequence are predetermined or determinable according to a predetermined rule. For example, the symbols of the first sequence may be represented in the temporal sequence of display elements by means of color angle differences, while the symbols of the second sequence in the second temporal sequence of display elements are represented by color angles. The second temporal sequence of presentation elements can be displayed, for example, before, after or within the temporal sequence of presentation elements.

In one embodiment of all aspects of the invention, converting the first sequence of symbols into the first sequence of color angles includes applying a mask to at least a portion of a fifth sequence of color angles (or even the entire fifth series of color angles) based on an assignment rule is obtained from the first sequence of symbols to obtain at least a portion of the first sequence of color angles (or even the entire first sequence of color angles), wherein by applying the mask one or more color angles of the part of the fifth sequence of color angles. The fifth sequence of color angles may, for example, be the second series of color angles already described above or the third series of color angles.

The mask, for example, each cause different rotations of the color angle of at least the part of the fifth sequence of color angles. For example, the mask contains as many elements as the fifth sequence of color angles, and is added elementally to the fifth sequence of color angles by adding the first element of the mask to the first color angle of the fifth sequence of color angles, the second element of the mask to the second color angle of the fifth sequence of color angles, etc. The elements of the mask may, for example, be chosen randomly, for example from a set of predefined elements. For example, the elements of the mask can assume the same values as the color angles. The mask may be, for example, a mask of a plurality of different masks whose elements are determined, for example, randomly or pseudo-randomly (eg from a limited set of elements) or according to a prescription. Each mask of the plurality of masks may then be associated, for example, with a respective identifier with which the mask can be identified. Information about the identifier of the mask used may, for example, be included in the first sequence of symbols or transmitted together with them.

For example, applying the mask to the portion of the fifth sequence of color angles may serve to increase the distinctness of at least some successive color angles of the portion of the first sequence of color angles. For example, the mask may be used to reduce the frequency of occurrence of the same contiguous color angles (or contiguous color angles whose difference is below a predefined threshold) in the first sequence of color angles, for example at least in a predefined portion of the first sequence of color angles , A measure of the distinctness of two color angles can be, for example, the smaller angular distance (of the two possible angular distances) between the two color angles on the color wheel. This smaller angular separation of the two color angles can be determined, for example, by subtracting the signed difference of the two color angles from 360 ° if it is greater than 180 ° and adding them to 360 ° if it is smaller than -180 °.

For example, a plurality of different masks (for example, as described above) are applied to the fifth sequence of color angles, and the mask selected from those masks having an extreme value (eg, maximum or minimum) on the distinctness compared to the other masks based criterion or (eg exceeds a predefined threshold) as the first of the masks.

High distinctness of successive color angles may, for example, facilitate or facilitate the recovery of a symbol clock and / or the detection of color angles in an oversampled signal from a sensor which detects the timing of presentation elements.

For example, applying the mask to the portion of the fifth sequence of color angles may result in the smaller angular distances on the color wheel between every two successive color angles for at least a portion of the portion of the first sequence of color angles being greater than the smaller angular spacings on the latter Color circle between each two successive color angles for a corresponding part of the part of the fifth sequence of color angles, and / or that the smaller angular distances on the color wheel between (for example all) each two consecutive color angles for at least a part of the part of the first sequence of color angles predefined or below a predefined rule determinable threshold.

In one embodiment of the first aspect of the invention, causing the display of the at least partial representation of the timing of the presentation elements on the display unit includes generating control commands to execute when displaying the timing of the presentation elements and outputting the control commands. The control commands are, for example, generated by the device according to the first aspect of the invention, for example a computer or server, and output for transmission to a second device, for example an electronic device, which comprises or is connected to the display unit. The electronic device, in particular a processor thereof, executes the control commands, which leads to the display of the at least partial representation of the temporal sequence of presentation elements.

In one embodiment of the first aspect of the invention, causing the display of the at least partial representation of the temporal sequence of the presentation elements on the display unit comprises generating a representation of the temporal sequence of the presentation elements at least as part of a sequence of images or a video, and outputting at least the representation of chronological sequence of the presentation elements.

According to the second aspect of the invention, the displayed or displayed according to the first aspect of the invention at least partially representation of a temporal sequence of display elements as a result of samples and obtains a representation of the first sequence of information elements based at least on the detected sequence of samples. Therefore, as in the first aspect of the invention, each representation element of the temporal sequence of presentation elements is associated with a respective color angle of a first sequence of color angles that defines the color value of at least a portion of the presentation element, and the first sequence of color angles is based on a conversion from a first sequence of symbols, at least a part of which represents the first sequence of information elements. The symbols of the first sequence of symbols are represented, for example, by a respective color angle of the first sequence of color angles or by a respective difference between a respective color angle of the first sequence of color angles to an immediately preceding or immediately following color angle, as already explained above.

The sequence of samples is detected, for example, by a sensor, for example a color angle sensor, which can be part of the apparatus according to the second aspect of the invention or at least temporarily connected to this apparatus for receiving at least the sequence of samples. The display of the at least partial representation of the temporal sequence of presentation elements takes place, for example, with another device, in particular a display unit which, for example, can be connected to an electronic device at least temporarily electrically (in particular for data transmission). The device according to the second aspect of the invention can be, for example, an electronic device comprising the sensor, a processor and a display unit, for example to display at least part of the first sequence of information elements. The electronic device may be portable, for example. For example, it is not part of the display unit on which the at least partial representation of the first sequence of presentation elements is displayed.

The samples each include color angle information. Alternatively, color angle information can be obtained from the samples. For example, a respective sample of the sequence of samples may be a single value, e.g. A color angle, or may be a value tuple, for example a tuple (R, G, B) with the color signals red, green and blue or a tuple (L, A, B) according to the L * a * b color space. From the value tuples, color angles can be obtained, for example, by color space transformations.

In one embodiment of the second aspect of the invention, determining the representation of the first sequence of information elements comprises determining a candidate sequence of samples based on the sequence of samples.

For example, the number of samples of the candidate sequence of samples may be less than the number of samples of the sequence of samples. Compared with a clock with which the display elements of the first sequence of display elements (and thus also the color angles of the first sequence of color angles and also the samples of the candidate sequence of samples) follow one another, the sequence of samples is thus overscanned, for example by a factor of 2 , 4, 8, 16 or 32, just to name a few examples.

Determining the candidate sequence of samples may include, for example, selecting samples from the sequence of samples to obtain the samples of at least a portion of the candidate sequence of samples (or the entire candidate sequence of samples), or selecting samples, each by interpolation and / or extrapolating at least two respective samples from the sequence of samples to obtain the samples of the candidate sequence of samples. For example, those samples of the sequence of samples most likely to be associated with color angles of a sequence of color angles, in particular color angles of a sequence of color angles having only a few pairs of consecutive equal color angles, are selected. This property can be generated for example by the use of masks on an optically transmitted sequence of color angles, as already explained above.

In the selection, for example, samples of the sequence of samples, each substantially in the middle (eg, as the nearest sample to the center) of respective regions of a curve in which the curve is substantially horizontal, may be as the samples the candidate sequence of samples is selected, the curve being formed by the samples of the sequence of samples or formed by samples obtained by interpolation and / or extrapolation of at least two respective samples from the sequence of samples. The curve runs in the jeweligen areas, for example, then substantially horizontally, if the slope (for example, determined by the first derivative) of the curve in each of these areas below a predefined or determinable according to a predefined rule threshold.

The regions then represent, for example, local plateaus in which several successive samples resemble each other, so that if the samples represent the samples of a color angle signal of a sensor with which the at least partial representation of the temporal sequence of presentation elements is detected, it can be assumed that these samples all belong to the same color angle of the first sequence of color angles. Display unit and sensor have then settled in these areas to the respective color angle.

However, this approach is only conditionally suitable without further measures to identify corresponding samples for the candidate sequence of samples for a plurality of immediately following identical color angles of the first sequence of color angles. For if the selection of the samples of the sequence of samples is based on a particular region in which the curve is substantially horizontal, for example, two or three equal immediately successive color angles of the first sequence of color angles each form about twice or three times as long is like just one color angle that occurs between two different color angles in the first sequence of color angles. However, since the range twice or three times as long is only recognized as a single area, this area will only result in one sample for the candidate sequence of samples. This may result in the candidate sequence of samples for one or more color angles of the first sequence of color angles containing no samples. However, apart from these omitted detections of color angles of the first sequence of color angles, one or more display elements may not even be included in the at least partial representation of the temporal sequence of display elements, so that the associated color angles of the first sequence of color angles are not detected by the sensor and can not be included in the candidate sequence of samples (color angles).

In one embodiment of the second aspect of the invention, determining the representation of the first sequence of information elements further comprises determining whether one or more elements are missing in a sequence of elements that is or has been extracted from the candidate sequence of samples, wherein the determining based at least on the elements of the sequence of elements respectively associated sampling times.

The sequence of elements may be, for example, a sequence of symbols obtained from the candidate sequence of samples according to an assignment rule that assigns color symbols to respective symbols and corresponds to an assignment rule according to which the first sequence of symbols has been converted into the first sequence of color angles. The sequence of elements may also be the candidate sequence of samples.

As a result of elements, one or more elements may be absent, for example for the reasons explained above, in particular due to the erroneous evaluation of the oversampled signal of a color angle sensor due to two or more equal successive color angles.

For example, determining whether one or more elements are missing in the sequence of elements may include: determining time distances between elements of the sequence of elements based on the sample times associated with the elements, assigning labels to the respective temporal distances, one Sequence of identifiers, and recognizing, in the sequence of identifiers, one or more identity patterns from one or more of the identifiers, wherein at least some of the identity patterns are associated with a respective default pattern indicating how many missing elements produce such an identity pattern and how these missing elements are time-aligned with respect to non-missing elements. The time distances result, for example, as differences of sampling times.

For example, the time distances are each determined between an element and its pre-predecessor in the sequence of elements. This definition is particularly suitable for detecting possible failures of elements in the sequence of elements.

For example, the identifiers indicate or may be determined from them (for example, by adding a predefined number), how many integral multiples of mean time distance between immediately consecutive elements of the sequence of elements between the element to which the identifier (over the time distance ) and its predecessor.

For example, respective value ranges are assigned to the identifiers, and a time interval is assigned in each case that identifier in whose value range the time interval lies. The limits of the value ranges are determined, for example, using an average or median of the time distances between respectively directly consecutive elements of at least part of the sequence of elements. For example, this mean or median provides a first indication of the average time interval with which the color angles of the first sequence of color angles follow one another, and can therefore be used to define the boundaries of the value ranges.

An identifier pattern is, for example, a sequence of one or more identifiers, or a sequence of at least two identifiers. For example, an identifier pattern is never part of the beginning of another identifier pattern.

For example, a failure pattern is a sequence of information elements (eg, bits), each information element, for example, may take only two values, and a first value of the two values indicates that an element is missing at the position of the information element, and a second value the two values indicate that an item exists at the location of the information item.

The identification patterns and the default patterns are predefined, for example. The identification patterns and the respectively associated default patterns can be calculated and / or determined, for example, in advance and / or once.

The determination of the representation of the first sequence of information elements may further include, for example: generating first failure information indicating for which positions in the sequence of elements each has been determined to be missing an element (eg, based on the dropout patterns comprising the recognized identity patterns are assigned); or inserting respective elements or wildcards into the sequence of elements at those positions in the sequence of elements that have been determined to be missing an element (eg, based on the dropout patterns associated with the recognized identity patterns), to a modified one Obtaining sequence of elements, and generating second failure information indicating at which positions in the modified sequence of elements the inserted elements or wildcards are located.

The inserted elements can be, for example, predefined elements. The placeholders may be, for example, predefined elements or otherwise symbolize a missing element, for example as a blank.

For example, if it is determined that not all the missing elements have yet been located in the sequence of elements, the following steps may be performed: select from one or more identity patterns that are from the set of recognized identity patterns and to which no corresponding default pattern is associated ( and comprising, for example, at least two identifiers), the identifier pattern having the identifier with the highest assigned value range, and either: noting, in the first failure information, that at a position in the sequence of elements, which position is associated with the selected identifier pattern an element is missing, or inserting an element or wildcard in the modified sequence of elements at a position associated with the selected identifier pattern, and noting in the second failure information that there is an inserted element or inserted wildcard at that position t.

For example, the selected identifier pattern is thereby marked in each case, and the step of selecting and either the step of memorizing or the step of inserting and memorizing are as long as for the unmarked recognized identifier patterns, which no respective default pattern is assigned (and which, for example, at least two Include tags) until all identified tag patterns that do not have a respective fail pattern associated with them (and include, for example, at least two tags) have been tagged or found to have all missing items located in the sequence of tags.

If it is then determined that not all the missing elements have yet been located in the sequence of elements, and all identified identifier patterns to which no respective default pattern has been assigned (and which, for example, comprise more than two identifiers) have been marked, then the following can be carried out: Selecting, from the recognized identifier patterns which are not associated with a respective default pattern (and which include, for example, more than two identifiers), the identifier pattern having the identifier with the highest assigned value range and either noting, in the first failure information, that at a position in the sequence of elements which position is associated with the selected identifier pattern, an element is missing, or inserting an element or wildcard into the modified sequence of elements at a position which position is associated with the selected identifier pattern, and remarking in the second failure Inform At this position, there is an inserted element or an inserted placeholder.

The representation of the first sequence of information elements may be determined, for example, based on: the first failure information and either the sequence of elements or a sequence of symbols obtained from the sequence of elements; or the second Failure information and either the modified sequence of elements or a sequence of symbols derived from the modified sequence of elements.

When the representation of the first sequence of information elements is determined based on the first outage information and a sequence of symbols obtained from the sequence of elements, the sequence of symbols in the case where the sequence of elements represents a sequence of color angles may be, for example, by conversion the sequence of color angles can be obtained in the sequence of symbols according to an assignment rule or by applying a mask to the sequence of color angles to obtain a masked sequence of color angles and the conversion of the masked sequence of color angles into the sequence of symbols according to an assignment rule. How such a mask according to the first aspect of the invention is applied (on the transmitter side of the optical transmission path) has already been explained above. The application of the mask according to the second aspect of the invention (on the receiver side of the optical transmission path) serves to cancel the influence of the mask. For example, on the transmitter side, the mask is added and subtracted on the receiver side, or vice versa.

If the representation of the first sequence of information elements is determined based on the second failure information and a sequence of symbols obtained from the modified sequence of elements, the sequence of symbols may be the case for the modified sequence of elements representing a sequence of color angles, for example by converting the sequence of color angles into the sequence of symbols according to an assignment rule, or by applying a mask to the sequence of color angles to obtain a masked sequence of color angles and converting the masked sequence of color angles to the sequence of symbols according to an assignment rule become.

The assignment rule, for example, assigns color angles or color angle differences to respective symbols and corresponds to an assignment rule according to which the first sequence of symbols has been converted into the first sequence of color angles.

For example, the first sequence of symbols may represent a representation of the first sequence of information elements encoded according to a code having error-correcting properties, and determining the representation of the first sequence of information elements may further include: decoding the acquired sequence of symbols taking into account the first failure information or the second failure information for obtaining the representation of the first sequence of information items. Examples of codes with error-correcting properties have already been mentioned above. By taking into account the first or second failure information, for example, the quality of the error correction and / or the number of errors that can be corrected by the error correction (due to the missing elements / color angles / symbols) can be increased.

The first sequence of symbols may, for example, represent a section of a sequence of symbols arranged in frames, the sequence of the symbols repeating in each of the frames, and the first sequence of symbols representing a rear portion of a frame and the front portion of one Frame contains the following framework. The processing (the acquisition of the sequence of samples and the determination of a representation of the first sequence of information elements at least based on the acquired sequence of samples) thus takes place, for example, for the symbols of a frame, although processing does not necessarily have to start at the beginning of the frame , This makes it possible to allow the fastest possible processing, since the next frame start does not have to be awaited, but the processing can be started immediately upon the start of the acquisition of sample values.

Further advantageous exemplary embodiments of the invention can be found in the following detailed description of some embodiments of the present invention, in particular in conjunction with the figures. However, the figures should only serve the purpose of clarification, but not to determine the scope of the invention. The figures are not to scale and are merely intended to exemplify the general concept of the present invention. In particular, features included in the figures should by no means be considered as a necessary part of the present invention.

Brief description of the drawings

In the figures show:

1 Fig. 3 is a flow chart of embodiments of methods according to the first and second aspects of the invention;

2 : a schematic representation of a system according to the third aspect of the invention;

3 FIG. 3 is a flow chart of an embodiment of part of a method according to the first aspect of the invention; FIG.

4 a flowchart of an embodiment of a method according to the second aspect of the invention;

5 FIG. 3 is a flowchart of an embodiment of part of a method according to the second aspect of the invention. FIG

6 (split into the 6A and 6B ): schematic representations of sequences of color angles with existing and missing color angles and the associated identification patterns, according to an embodiment of the invention;

7 FIG. 2: an exemplary assignment of identification patterns to outage patterns according to an embodiment of the invention; FIG.

8th : a schematic representation of a sequence of color angles with existing and missing color angles, the associated identification patterns and a modified sequence of color angles with inserted color angles in accordance with the identity patterns associated default patterns according to an embodiment of the invention;

9 FIG. 3 is a flow chart of another embodiment of part of a method according to the second aspect of the invention; FIG.

10 : a schematic representation of a frame to be optically transmitted according to an embodiment of the invention.

Detailed description of some embodiments of the invention

The 1 and 2 show a flowchart 100 of exemplary embodiments of methods according to the first aspect (steps 101 - 103 or 101 - 104 ) and second aspect (steps 105 - 107 ) of the invention and a schematic representation of a system 1 according to the third aspect of the invention. The dashed lines show in each case which steps of the method exemplify which device of the system 1 be executed. In particular, the steps become 101 - 103 from the device 2 For example, a computer or server, the step 104 from the device 3 , For example, an electronic device with a display unit, and the steps 105 - 107 from the device 4 , For example, an electronic device with an optical sensor and a processor executed.

Embodiments of the invention are used in particular for the optical transmission of information, in particular via display units, on which a representation of the information is displayed and then detected by an optical sensor and then further processed.

This is done in one step 101 initially generates payload. This can be, for example, payload that is used as part of an authentication or authorization. An example of such information is a transaction number required to make and / or confirm a transaction, such as a financial transaction (for example, in the context of online banking). The payload may be encrypted, for example, and only using one in the device 4 be decrypted stored key.

In step 102 For example, based on the payload, a frame is generated as a sequence of color angles, as described in more detail below with reference to FIG 3 is described. For example, a frame is created as a sequence of symbols and then converted into a sequence of color angles. This conversion can be done either directly or via the detour, where symbols are first converted into a sequence of color angle differences according to an assignment rule, and then this sequence of color angle differences is converted into a sequence of color angles, as already explained. In the following description, the variant in which the conversion of the sequence of symbols into the sequence of color angles takes place directly is considered as an example.

The 10 shows an example of such in step 103 of the 1 generated frame 5 which includes a variety of symbols. These may be, for example, symbols of the respective length of 4 bits, so that 16 different symbols are distinguished. Of course, however, any other bit lengths are possible for the symbols. The frame 5 includes a start marker 50 which comprises 7 symbols by way of example and for detecting the beginning of the frame 5 serves. For example, it is chosen so that it is particularly robust to detect. This is followed by a color angle table 51 in the present case, for example, comprises 14 symbols. In the color angle table 51 For example, each of 14 symbols (symbols No. 2, No. 3, etc., No. 15) is assigned a different color angle among a set of color angles used for optical transmission (for example, this set of color angles includes the 16 equidistant color angles of 0 ° ; 22.5 °; 45 °; 67.5 °; ... 315 °; 337.5 °, but other, eg even non-equidistant, sets of color angles are possible). For each of the 16 different At least two different symbols (symbol no. This can be the starting marker 50 and the Color angle table 51 which are either predefined or determinable according to a predefined rule, on the device 4 used to determine the assignment of color angles to all 16 symbols. This may be due to the device 14 for calibration purposes and / or to be used to learn a secret (for example time-variable) assignment of symbols to color angles.

The frame 5 includes a number B of blocks 52-1 to 52-B each with 14 symbols, of which the last 4 symbols each redundancy information (in block 51-1 With 524 and in the block 52-B With 524 ' ) for the first 10 symbols. This redundancy information is generated according to an error-correcting code, for example a reed solomom code. Here, by way of example, a systematic coding is used in which the information of the first 10 symbols of a block is not modified by the coding and the redundancy is contained exclusively in the last 4 symbols of a respective block. In the first block 51-1 For example, 6 symbols of these first 10 symbols contain special control information, in particular the MaskID 520 (2 symbols), the frame length 521 (2 symbols), and a checksum 522 (Cyclic Redundancy Check, CRC, 2 symbols) over the entire payload, that is, over the 4 symbols payload 523 of the block 52-1 and the respective 10 symbols payload of all other blocks 52-2 to 52-B (in the block 52-B when 523 ' designated). With the checksum 522 can the device 4 Check whether the payload (after decoding) is error-free. The frame length 521 gives the length of the entire frame 52 which, for example, may vary depending on the extent of the payload to be transmitted. If the same amount of payload always has to be transmitted, it is alternatively possible to work with a constant frame length and the frame length 521 can be omitted, since it is then known. The MaskID identifies a mask from a set of different masks applied to a sequence of color angles to increase the distinctness of at least some successive color angles. This is for example in step 308 of the 3 made as will be explained in more detail below. Due to the systematic coding, in particular the MaskID 520 and the frame length 521 at the device 4 even before Reed-Solomon decoding usable (but possibly not error-corrected). This is for taking the step 406 of the 4 relevant before the decoding of the step 407 takes place. However, it is also possible that in the Reed-Solomon coding at least the first 2 symbols (MaskID) and / or 4 symbols (MaskID and frame length) are disregarded (ie set to predefined values, for example), since the symbols corresponding to these symbols Information (MaskID or MaskID and frame length) on the device 4 be evaluated anyway before decoding, and also the MaskID on the device 2 only after the coding in the first block 52-1 of the frame is inserted.

After the frame 5 as a result of color angles in the step 102 of the 1 is generated in step 103 the display of an at least partial representation of a temporal sequence of images (as an example of display elements) with respective color angles of the sequence of color angles, and this display takes place in the step 104 accordingly.

The frame 5 is thus optically transmitted by the fact that the symbols of the frame translated into color angles 5 is displayed as a time series of images whose color value is set by a respective color angle of the sequence of color angles. For example, these images are all displayed one after the other at the same position in a page displayed on a display unit (for example, a web page). For example, the images can each have exactly one color value (that is to say monochrome), which is defined by the respective color angle. For example, the images may be square, rectangular, or round, or may be in the shape of a logo, just to name a few examples. For example, the pictures may be displayed against a background. The frame 5 For example, it is repeatedly transmitted identically in succession, for example, until the device 1 from the device 3 or 4 or another device receives feedback that the frame 5 from the device 4 received and in the frame 5 contained useful information could be recovered error-free.

Displaying the at least partial representation of the temporal sequence of images is effected, for example, by the device 2 Control commands, a processor 30 and / or a graphics processor 34 (For example, a graphics card) of the device 3 should cause the temporal sequence of images on a display unit 35 the device 3 to indicate to the device 3 transfers. These control commands can be accessed, for example, via a web page from one on the processor 30 the device 3 running browser from the device 2 is retrieved to the device 3 be transferred, for example according to the HTTP protocol (Hypertext Transfer Protocol). The at least partial representation of the temporal sequence of images can be realized, for example, as embedded video in a web page or by means of Java Script methods. The temporal sequence of images may be from the device 2 also as a video for retrieval (eg for retrieval in whole or streamed) through the device 3 to be provided.

As already explained, the at least partial representation of the temporal sequence of images may be a complete representation of the temporal sequence of images, or an only partial representation of the temporal sequence of images in which at least some images are missing, for example because of information losses on the transmission path between device 2 and device 3 (For example, a transmission link, which includes a transmission over the Internet at least as a partial path), or due to an asynchronicity between a processor 30 and / or a graphics processor 34 and / or a display unit 35 the device 3 ,

In step 105 becomes the at least partial representation of the temporal sequence of images by means of a sensor 43 the device 4 from the display unit 35 the device 3 receive. This is accomplished, for example, by having a user the sensor 43 the device 4 near a portion of the display unit 35 the device 3 holds in which the at least partial representation of the temporal sequence of images is presented.

In step 106 becomes from the received at least partial representation of the temporal succession of pictures in the step 101 recovered generated information. For this purpose, the color angle information of the temporal sequence of images is evaluated and the possible absence of color angle information is at least partially (or completely) recognized and compensated, as described below with reference to 4 - 9 will be explained in more detail.

In step 107 then the processing of the payload takes place. This may, for example, their decryption, modification and / or display on a display unit 44 the device 4 include, allowing a user of the device 4 use this information, for example, to authenticate the user or to authorize a transaction. For example, the device provides 4 a factor "ownership" of a two-factor authentication / authorization process, wherein the second factor is a "knowledge" of the user, such as a PIN or other secret code, entering the device 4 or by means of the device 3 must be entered into a web page on which the at least partial representation of the temporal sequence of images is displayed. For example, the device 4 able in step 101 to generate generated payload, for example, to decrypt and / or in the context of a challenge-response method using secret information (for example, a key) to create a correct expected response to the payload (containing, for example, the challenge), and at least the result of the processing (and possibly further information, eg about a transaction to be authorized) on the display unit 44 the device 4 display, allowing a user of the device 4 the result for example by means of the device 3 can enter into a web page on which the at least partial representation of the temporal sequence of images is displayed (and, if necessary, can check the correctness of the transaction based on the further information).

In the 2 illustrated device 2 For example, a computer or a server includes a processor 20 containing one or more programs from program memory 22 executes while doing a memory 21 uses. processor 20 is used to control the functions of the device 2 and in particular the implementation and / or control of the steps 101 - 103 of the 1 , The device 2 furthermore has a communication interface 23 For example, for connecting the device 2 to a network such as the Internet. The communication interface 23 allows the device 2 at least the communication with the device 3 , The device 2 illustrates an example of a device according to the first aspect of the invention. An in program memory 22 the device 2 stored program containing the processor 20 causes the steps 101 - 103 of the 1 illustrates an example of a program according to the first aspect of the invention.

The device 3 For example, a computer (eg, a desktop computer, laptop computer, tablet computer, phablet computer) or mobile phone (eg, a smartphone) includes a processor 30 containing one or more programs from program memory 32 executes while doing a memory 31 uses. processor 30 is used to control the functions of the device 3 and in particular the implementation and / or control of the step 104 of the 1 , The device 3 furthermore has a communication interface 33 For example, for connecting the device 3 to a network such as the Internet. The communication interface 33 allows the device 3 at least the communication with the device 2 , The device 3 further includes a graphics processor (eg, a graphics card of the device 3 ), for driving a display unit 35 For example, as an external monitor (for a desktop PC), z. In the form of an LCD TFT or LED monitor, or internal monitor (e.g., a laptop, tablet, phablet or mobile phone), e.g. As a LED, OLED or AMOLED display, may be formed. The graphics processor 34 However, it can also be part of the processor 30 or it can not be a dedicated graphics processor 34 to be available. The device 3 finally includes a user input interface 36 , z. As a keyboard (for example, in the form of a keyboard formed by a touch-sensitive display unit) and / or a pointing device control device such. As a mouse, a trackball, a track pin or a trackpad.

The device 4 is for example a portable electronic device, such as battery powered. For example, it may be a dedicated device for the purpose of detecting and retrieving information transmitted by color angles, but may alternatively be incorporated into a mobile phone (eg, a smartphone) or any other portable user device, such as a smartphone. As a music player, navigation device, game device, etc. may be integrated. contraption 4 includes a processor 40 containing one or more programs from program memory 42 executes while doing a memory 41 uses. processor 40 is used to control the functions of the device 4 and in particular the implementation and / or control of the steps 105 - 107 of the 1 , contraption 4 includes a sensor 43 , with the color angle or color information from which, for example, by transformation - color angles can be calculated, can be detected. Such sensors are used, for example, for calibrating monitors and are already partially installed in monitors for this purpose. contraption 4 further comprises a display unit 44 , which is designed for example as an LCD display. contraption 4 optionally includes a crypto chip 45 with which security-relevant functions or calculations are carried out, for example the processing of the payload according to step 107 of the 1 , Alternatively, the functionality of the crypto chip 45 from processor 40 be implemented. contraption 4 may also have a user input interface (not shown), for example to turn the device on and off 4 and / or to start detection / processing by the device 4 , The device 4 illustrates an example of a device according to the second aspect of the invention. An in program memory 42 the device 4 stored program containing the processor 40 causes the steps 105 - 106 (and, if necessary, also 107 ) of the 1 is an example of a program according to the second aspect of the invention.

One or more of the processors 20 . 30 and 40 of the devices 2 . 3 and 4 For example, each as a control unit, microprocessor, microcontroller such. As a microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC) or Field Programmable Gate Array (FPGA) be realized. The processors may each include one or more processor cores. The processors may also each be formed by a plurality of processors. The processors may be implemented as system-on-a-chip processors. For example, the main memory and / or the communication unit can each be integrated with the respective processor on a chip.

One or more of the program memories 22 . 32 and 42 of the devices 2 . 3 and 4 For example, each may be a persistent storage such as a read only memory (ROM). The respective program memory can be designed, for example, as a flash memory. The respective program memory, for example, fixed to the respective processor 20 . 30 or 40 connected, but can alternatively be solved with the respective processor 20 . 30 or 40 be connected, for example, as a memory card, floppy disk or optical disk media (eg, a CD or DVD). The respective program memory 22 or 42 and the program stored therein may be arranged to communicate with the respective processor 20 or 40 the respective device 2 or 4 at least to cause the above-described embodiments of the method according to the first or second aspect of the invention to be executed when the program is on the respective processor 20 or 40 is performed.

One or more of the memory 21 . 31 and 41 are for example used for storing temporary results during execution of the program instructions, this is, for example, a volatile memory, such as a random access memory (RAM) memory.

It should be emphasized that in 2 by way of example it was assumed that device 2 also the step 101 of generating the payload. However, this can also be done by another device, such as a computer or server, and the payload then corresponding to the device 2 be transmitted.

Likewise was in 2 by way of example, assume that displaying the at least partial representation of the temporal sequence of images by the device 3 is performed. However, this can alternatively also by a display unit of the device 2 be performed (for example, when the device 2 a terminal, for example a self-service machine (eg an ATM) or a terminal for making transactions).

3 is a flowchart of an embodiment of a part 300 a method according to the first aspect of the invention, the for example, from the device 2 of the 2 is executed and, for example, the step 102 of the 1 equivalent.

In a first step 301 is payload obtained, for example, in step 101 of the 1 was generated. The payload is in the form of bits, for example. In one step 302 a checksum CRC is generated for the payload. This checksum will later be called the checksum CRC 522 in the frame 5 embedded.

In step 303 is made of the payload, the CRC and the frame length a bit-to-symbol mapping, that is, for example, each assigned 4 bits to each one symbol.

In step 304 a Reed-Solomon coding is carried out such that in each case 4 symbols redundancy to 10 symbols payload are generated. As explained, the MaskID and possibly also the frame length can be excluded from the Reed-Solomon coding.

In step 305 the symbols are like in 10 exemplified in the frame 5 arranged. In this case, for example, the symbols of the start marker 50 and the color angle table 51 added.

In step 306 become the symbols of the frame 5 Assigned color angle, for example on the basis of an assignment rule that assigns each symbol a respective color angle. As described, for example, 16 different symbols are distinguished, to each of which 16 different color angles are distributed equidistantly on the color wheel. This gives an unmasked sequence of color angles, the number of which, for example, is the number of symbols in the frame 5 equivalent.

In step 307 a MaskID is set to 1, and in step 308 For example, color angles are added to the unmasked sequence of color angles that represent this MaskID.

In step 309 For example, a mask identified by this MaskID is applied to at least a portion of the unmasked sequence of color angles (or even the whole) (e.g., by adding individual angles contained in the mask to the unmasked sequence of color angles). The aim of the masking is, as explained, to increase the distinctness of at least some directly successive color angles in the sequence of color angles. In particular, it may be desirable that in the area of the start marker 50 , the color angle table 51 , the MaskID 520 , the frame length 521 and / or the CRC 522 of the frame 5 there are no equal contiguous color angles (or the color angle difference between immediately adjacent color angles is below a predefined threshold) to minimize errors in the recovery of this particularly relevant control information. In addition, however, it is also in the remaining areas of the frame 5 it is desirable that as few (or none) as possible immediately following color angles (or contiguous color angles with a difference below a predefined threshold) occur, since these may only be recognized as one color angle (see step 403 of the 4 ).

In step 310 the distinctness of the sequence of color angles is checked. This can also be understood, for example, as checking the sequence of color angles for good clock recovery properties.

In step 311 is then checked, according to the test in step 310 the sequence of color angles obtained by the masking has good distinctness of successive color angles. Good distinctness is assumed, for example, if at least in a predefined area of the frame 5 (For example, at least in the areas listed above, control information) no pairs of contiguous color angles occur in which both color angles are equal, or in which both color angles have a difference that is below a predefined threshold (larger color angle differences can occur in the detection of For example, color angles may be beneficial).

If it is determined that there is no good distinctness, it will be in step 312 the MaskID increases by one, in the step 308 This new MaskID corresponding color angle is inserted in the unmasked sequence of color angles and in step 309 treats the unmasked sequence of color angles with a correspondingly different mask identified by the enhanced MaskID to obtain a different sequence of color angles.

This process is repeated until an obtained sequence of color angles has good distinctness. This is in the device 2 a plurality of different masks, each with associated MaskIDs stored or determinable according to a predefined rule. This also applies to the device 4 which must undo the masking accordingly. For example, the masks represent a series of angles that are added to the color angles of the unmasked sequence of color angles. For example, the angles of the masks come from the same For example, alphabets such as the color angles are multiples of 360 ° / N (where N represents the number of color angles used, for example 16). However, it may also be sufficient that the angles in the mask are obtained from the alphabet containing only two values {-360 ° / N, + 360 ° / N} or from the two-value alphabet {0, 360 ° / N} or { 0, -360 ° / N}. Of course, other choices of masks are possible, especially if the color angles are not distributed equidistantly. In areas of the frame 5 that do not change, for example in the area of the start marker 50 and / or the color angle table 51 For example, the different masks may match and / or may include optimized angles for those areas. For example, no masking can take place in these areas, ie the angles of the mask in these areas are, for example, 0 °. The masks associated with the respective MaskIDs are additionally or alternatively in the area where the MaskID 520 as part of 5 is arranged so optimized that also the color angles associated with the symbols of the MaskID have good distinctness. This is possible because MaskID is known for each mask.

In step 313 then the sequence of color angles is output.

4 shows a flowchart 400 an embodiment of a method according to the second aspect of the invention, therefore, relates to the processing on the device 4 by the steps 105 - 107 of the 1 has been roughly circumscribed and now based on the 4 is further specified by way of example.

In step 401 becomes a representation of the temporal sequence of images with the color sensor 43 the device 4 received, for example, from the display unit 35 the device 3 , The related output of the color sensor, for example, a color angle signal (eg, an H signal) or a color signal (eg, an RGB signal) from which color angle information can be obtained, is determined in step 402 in terms of the rate of images in the temporal sequence of images oversampled, for example by a factor of 2, 4, 8, 16 or 32.

In step 403 is obtained on the basis of the sampled output signal of the color sensor, a candidate sequence of samples with their respective sampling times and thereby also the clock of the images in the temporal sequence of images recovered. In the following, it is assumed by way of example that the sampled values are color angles, and that the further processing takes place on the basis of these color angles, and not, as far as possible, the symbols associated with these color angles. The candidate sequence of color angles is hereinafter referred to as "sequence of color angles".

In step 404 Optionally, a calibration / color angle correction of the color sensor 43 the device 4 respectively. This is for example based on the received color angle from those areas of the frame 5 possible, which are already known on the device, for example, the start marker 50 and / or the color angle table 51 ,

In step 405 who is based on the 5 will be explained in more detail, failures (missing color angles) in the sequence of color angles are detected on the basis of the sampling times and filling information (eg placeholders or predefined color angles) is inserted in the sequence of color angles, whereby a modified sequence of color angles and failure information which indicates at which positions in the modified sequence of color angles filling information has been inserted (ie, defaulted).

While the steps 401 - 404 For example, can be carried out continuously over several frames away, for example, from step 405 the processing for the sequence of color angles of exactly one frame 5 take place, for example, recognized by the fact that its start marker 50 and the start marker 50 of the subsequent frame 5 was detected. The start marker, for example, can not be masked and therefore also be recognizable independently of the knowledge of the MaskID. Such a procedure will be described later on the basis of 9 explained in more detail.

Alternatively, however, the processing from step 405 not for the sequence of color angles from a completely received frame 5 but based on a sequence of color angles that a rear part of a first frame 5 and a front part of a subsequent second frame 5 (which contains the same information as the first frame 5 ) correspond. This makes it, for example, when the detection of the representation of the temporal sequence of images in the middle of the first frame 5 is started (for example, the fact that the user at a time, this middle of the first frame 5 corresponds to the device 4 in front of the display unit 35 the device 3 holding the representation of the temporal sequence of images displayed), it is possible to start processing already and to recover the payload before the second frame 5 was completely received. It exploits that information in the first frame 5 and in the second frame 5 are the same.

In step 406 of the 4 becomes an inverse masking of the modified sequence of color angles based on the mask identified by the MaskID. For this, the color angles corresponding to the MaskID are extracted from the modified sequence of color angles and evaluated. If at the device 2 the masking was done, for example, by adding up angles to the sequence of color angles, is applied to the device 4 in step 406 A subtraction with these angles is made accordingly.

In step 407 the color angles are converted back to symbols (analogous to the step 306 of the 3 ) and then Reed-Solomon decoding using the failure information. The failure information indicates to the Reed-Solomon decoder at which positions of the sequence of symbols to be decoded errors have occurred. Methods for Reed-Solomon decoding using failure information (also referred to as "erasure code") are known to those skilled in the art. By knowing the failure information, the number of correctable errors compared to a scenario in which no failure information is present, for example, be doubled. For example, in the case of a Reed-Solomon code with a code word length of 14 for 10 useful symbols, four errors at known positions (known here that the failure information indicates these positions) or two errors at unknown locations, or an error at an unknown location, for example and simultaneously correct one to two errors at known locations. It is therefore also possible in principle to correct symbol failures with the Reed-Solomon code, which are described in step 405 were not detected (both in the event that at least some symbol failures were detected, so even in the event that no symbol failures were detected).

In step 408 it is checked if the Reed-Solomon decoding was successful. If this is not the case, in step 413 error handling is executed, for example, an error message is issued and / or causes the next frame to be attempted 5 , to process. This is particularly useful if the same (ie same content) frame 5 is transmitted several times in succession.

Otherwise, in step 409 a conversion of symbols into bits (analogous to step 303 of the 3 ) and in the step 410 from the result obtained a received representation of the payload.

For this payload is then in step 411 checks whether the checksum CRC calculated above with the received representation of the checksum CRC 522 matches. If this is the case, the processing of the payload is in step 414 made, as already to step 107 of the 1 has been described. Otherwise, an error handling according to step 413 carried out.

5 shows a flowchart 500 an embodiment of a part of a method according to the second aspect of the invention, in particular the step 405 of the 4 ,

First, in one step 501 temporal distances between color angles of the sequence of color angles determined by the. The temporal distances are determined, for example, by forming the difference of the sampling times of one color angle and its predecessor in the sequence of color angles and, for example, associated with the respective later of the two color angles. The time distances can be referred to as L2 distances, for example.

In one step 502 Identification values are assigned to the respective temporal distances that can be specified or determined (for example by adding the number 2 ) how many integer multiples of the mean time distance between immediately successive color angles of the sequence of color angles (hereinafter referred to as d ') between the color angle to which the label value (over the time distance) is associated and its predecessor. An identifier value of "2" indicates, for example, that the time distance between a color angle and its predecessor is 2 * d '.

In the following, a definition of the identifier values is used in which the value 2 is deducted from the number of integer multiples of d 'between the color angle to which the identifier value is assigned and its predecessor. If, for example, there are 2 multiples of d 'between the color angle and its predecessor, the associated identifier value is "0", if 3 multiples of d' corresponding to "1", if 4 multiples of d 'corresponding to "2" etc The selected identification value directly expresses how many multiples of d 'actually lie between the color angle and its predecessor, in addition to the two multiples of d' to be expected between a color angle and its precursors (ie according to the determined sequence of color angles). If the label value is "0", this indicates that no color angle is missing between the color angle and its predecessor (a missing color angle would, especially if it is based on the fact that according to step 403 of the 4 in the oversampled sensor signal, the same or similar successive color angles could not be identified, leading to an increase in the time distance between the color angle and its predecessor). If the label value is "1", this indicates that at least one color angle between the color angle and its predecessor is missing, and so on.

The identifiers are assigned, for example, respective value ranges with respective upper and lower limits. The boundaries are calculated, for example, based on the average value d 'of the time distances between immediately successive color angles of the sequence of color angles, for example for each on the device 4 received frame 5 , A value range for an identifier "0" is, for example, [1.5 · d '; 2.49 · d '], a value range for an identifier "1" is, for example, [2.5 · d'; 3.49 · d '], a value range for an identifier "2" is, for example, [3.5 · d'; 4,49 · d '] etc.

In one step 503 then one or more identity patterns are detected. The identification patterns comprise one or more (or alternatively at least two) of the previously described identifiers in a defined sequence. Each identification pattern is assigned a respective failure pattern which indicates how many failed color angles (that is to say lacking color angles) produce such an identification pattern and how they are temporally positioned with respect to unequaled (that is to say existing color angles).

For a better understanding of the identity patterns, let us first look at the 6 directed. There are 16 different actual sequences of color angles 601 to 616 shown. For example, these actual sequences of color angles correspond to the temporal sequence of images displayed on the display unit 35 the device 3 was displayed and that with the sensor 43 the device 4 was recorded. As already described in the device 4 in determining the (candidate) sequence of color angles in the step 403 of the 4 However, under certain circumstances, one or more color angles are not recognized as such, for example because they are the same or too similar to temporally adjacent color angles. The actual consequences of color angles 601 to 616 may alternatively be understood as those sequences of color angles, their corresponding sequence of images actually on the display unit 35 the device 3 should be displayed. However, as already explained, this can lead to failures (images / color angles, not shown) due to asynchonities between processor, graphics card and / or display unit 35 come here, and it may also, for example, additionally occur the effect that one or more color angle from the sensor 43 not be recognized as such (and thus "fail") because they are, for example, the same or too similar to temporally adjacent color angles.

Such dropout color angles are in the actual consequences of color angles 601 - 616 of the 6 represented as "X", the existing color angles are symbolized by a "0". The temporal distance between immediately successive color angles in the actual sequences of color angles 601 - 616 is in each case marked with "d" and idealized as assumed in each case the same between successive color angles, but in reality, significant fluctuations may result here.

The (candidate) consequences of color angles, the processing in step 405 of the 4 and thus the processing in 5 are based on the actual consequences of color angles 601 - 616 by the color angles marked with "X" from the respective actual sequences of color angles 601 - 616 be taken out. In these (candidate) sequences of color angles, the distance between immediately adjacent color angles is also not nearly equal, but varies depending on which sample was selected from the oversampled sensor signal for the color angle (this depends, inter alia, on how fast the display unit 35 the device 3 converts a new color angle, how fast the sensor 43 this may be and / or how large are the differences to previous and subsequent color angles) and also depending on whether color angles between two color angles of the (candidate) sequence of color angles are missing. An average of the temporal distances of immediately successive color angles of the (candidate) sequence of color angles is d 'as explained above.

The actual consequences of color angles 601 - 616 or the associated (candidate) sequences of color angles are in 6 also associated with the respective identifiers on the color angles, these identifiers are also grouped by pairs of square brackets to identity patterns.

For example, in the sequence of color angles 601 no color angle has failed, so that the identifiers (for the first time calculable for the third color angle, since the time distance to the predecessor, so the first color angle of the sequence, must be determined) are always "0", so it is found for any color angle, that the is so great a distance from the previous predecessor that there is reason to believe that a color angle might have failed. In total, the identifier pattern "[0]" is detected 11 times.

As a result of color angles 602 However, the fourth color angle has failed. The calculation of the identifier for the fifth color angle of the actual sequence of color angles 602 (or for the fourth color angle of the (candidate) sequence of Color angles) results in a "1" indicating that the time distance to the predecessor lies in an area that suggests that a color angle has dropped between the color angle and its predecessor. For example, assuming for example that d 'is approximately equal to d and approximately equal between the color angles of the (candidate) sequence of color angles, the time distance between the color angle and its predecessor is 3 * d', which is in the range [2 , 5 x d '; 3.49 · d '], which is assigned to the identifier "1".

This also applies to the sixth color angle of the actual sequence of color angles 602 (or for the fifth color angle of the (candidate) sequence of color angles).

For the seventh color angle of the actual sequence of color angles 602 (or for the sixth color angle of the (candidate) sequence of color angles) and the subsequent color angle, the identifier is then again "0".

The following identification patterns are thus recognized successively: "[0]", "[1 1]", "[0]", "[0]", "[0]", "[0]", "[0]" , "[0]".

The other actual consequences of color angles 603 - 616 illustrate further examples of what identifiers are recognized at different numbers of failed color angles and also different distributions of failed color angles and how they are grouped into feature patterns.

7 shows on the left a list of different identification patterns 701 - 716 as they are in 6 in each case in square bracket pairs were shown, and on the right of these identification patterns respectively assigned default pattern. A failure pattern indicates in each case how many color angles have failed (symbolized here by a "0", for example) and where color angles that are not unusual are located (symbolized here by a "1", for example).

It can be seen directly that no failure pattern is assigned to the identification pattern [0], since in this case no color angle loss has taken place.

On the other hand, the flag pattern [1 1] discussed above has the associated dropout pattern "1 0 0" indicating that a color angle has failed, and then two color angles have not failed. The failure pattern can therefore be used to fill the (candidate) sequence of color angles at those locations with fill information where one or more color angles have failed.

In the 7 shown identification pattern 701 - 716 (And possibly further) and their respective assigned pattern failure are calculated, for example, once and then in the device 4 stored many times in the respective processing of the samples of different received frames 5 to be consulted.

Accordingly sees the step 504 of the 5 for each detected feature pattern associated with a defect pattern, fill information is inserted in the sequence of color angles at those positions of the sequence of color angles at which one or more color angles have failed according to the default pattern associated with the recognized feature pattern, a modified sequence to get from color angles. Furthermore, failure information is stored, which indicates at which time positions in the modified sequence of color angles in each case filling information was inserted.

This will be exemplified in the following 8th clarified, in similar to the 6 an actual sequence of color angles is shown, consisting of existing (symbol "0") and failed color angles (symbol "X"), and from which in turn, by omitting the failed symbols, the (candidate) sequence of color angles can be obtained. In square brackets are again the identification patterns 801 - 806 specified.

Again, it can be seen that the first fancy color angle becomes a feature pattern "[1 1]" 802 leads, according to 7 the failure pattern "1 0 0" is assigned. This pattern of failure can thereby be applied to the (candidate) sequence of color angles that precede the two color angles to which the label pattern 802 heard filling information (a placeholder or a predefined color angle, which is unlikely to coincide with the failed, on the device 4 generally unknown color angle) is inserted, as in the modified sequence of color angles 81 in 8th is shown. There, the inserted filling information is symbolized as a filled circle. The filled circle with the subsequent two symbolized by the symbol "0" nonexistent color angles corresponds to the default pattern and is denoted by the reference numeral 812 Mistake. Accordingly, the identification pattern "[2 2]" leads 803 for insertion of two fill information according to defect pattern 813 and the identification pattern "[3 3]" 806 for inserting three fill information according to defect pattern 816 ,

If you compare now the actual sequence of color angles 80 with the modified sequence of color angles 81 , you notice that in all places where color angles in the sequence 80 have failed, in the modified sequence 81 fill information was inserted. If now stored as failure information, at which positions in the modified sequence of color angles 81 When filling information has been inserted, this failure information can be used to decode a sequence of symbols corresponding to the modified sequence of color angles 81 corresponds to indicating the positions where errors have occurred and thus increasing the number of correctable errors.

The 9 finally shows a flow chart 900 a further embodiment of a part of a method according to the second aspect of the invention, in particular of the step 405 of the 4 , It is, as already to step 405 of the 4 By way of example, it has been assumed that the processing takes place for a sequence of color angles that occur between two detected start markers 50 but this is not mandatory. While in the previous description of the method according to step 405 of the 4 If it has been assumed that all missing color angles can be identified on the basis of identity patterns and a suitably corrected modified sequence of color angles can be generated using the default patterns assigned to the identity patterns, the flow chart of FIG 9 now also handles the different case that identification patterns occur for which no default pattern exists (for example, because only the most frequently occurring identification pattern with associated default pattern in the device 4 or that the recognition pattern-based processing does not result in a modified sequence of color angles having an expected length (according to the expected frame length).

In a first step 900 Color angles are collected (for example, based on the results of the steps 401 - 404 of the 4 ), up to two start markers 50 were detected. These color angles are then as a result of color angles of a frame 5 processed.

In step 902 then becomes the expected number of color angles for the frame 5 determined or estimated. This can be done, for example, by determining the frame duration based on the time between the two start frames, dividing this frame duration by the duration of a block, multiplying the rounded result by the known number of color angles per block, and counting the number of the start marker 50 and the color angle table 51 required color angle is added. The size of a block of Reed-Solomon coding is fixed (for example, given a length specification of 14 symbols by the Reed-Solomon code, a block may only be 14 symbols long). If, for example, 27 symbols were detected between two start markers, this may not be correct, so a 28th symbol is missing. The number of missing / failed symbols can thus be estimated from the distance of the start markers. It is also possible, for example, the number of required characters from the length field 521 to calculate if no second start marker has yet been detected.

In step 903 Then temporal distances (in particular L2 distances) between the color angles of the sequence of color angles are calculated and assigned to the time distances respective identifiers, as already to the steps 501 and 502 of the 5 was explained.

In step 904 Identification patterns are then recognized, the sequence of color angles corresponding to the pattern of defects associated with the pattern of identification filled with information fill to obtain a modified sequence of color angles, and stored corresponding failure information. This has already become the steps 503 and 504 of the 5 explained.

In step 905 is then checked if the in step 902 calculated expected number of color angles corresponds to the number of color angles in the modified sequence of color angles (ie, all missing color angles have been located and filled with fill information).

If so, the procedure jumps 900 to the end. Otherwise, in one step 906 check if there are identity patterns (eg, identity patterns other than [0] and / or identity patterns containing at least two identifiers) to which no default pattern is assigned and due to which (with respect to the currently received / processed frame 5 ) no filling with filling information has taken place.

If this is not the case, the procedure jumps 900 to the step 908 , Otherwise, the step becomes 907 executed. In step 907 Fill information is inserted into the modified sequence of color angles in an area (eg, at the end, but this choice is arbitrary since there is no default pattern) associated with the identifier pattern of the identifier pattern referred to in the previous paragraph, which has the highest assigned identifier Range of values (as described above), and corresponding failure information is stored. This approach is based on the assumption that the identity pattern with the identifier, which is assigned the highest value range (and thus the highest time L2 distance), is the best candidate for filling information, since there is, with very high probability, actually at least one color angle has failed. Then the process jumps 900 again to step 905 ,

The step 908 is entered for the first time when fill information is (uniquely) inserted in all areas associated with identity patterns to which no pattern is assigned, yet the expected number of color angles still does not correspond to the number of color angles in the modified sequence of color angles. In step 908 it is checked whether there are identification patterns to which no default pattern is assigned.

If not, the procedure jumps to the step 910 and fill information is added at the end of the modified sequence of color angles.

Otherwise, step will be 909 executed. In step 909 For example, fill information is inserted into the modified sequence of color angles in a region (eg, at the end thereof, which choice is again arbitrary since there is no identity pattern) associated with the identity pattern of the label patterns to which the pattern is not assigned, that is the identifier with the highest assigned value range, and corresponding failure information is stored. Thereafter, the process returns to the step 905 ,

It should be emphasized that the method for detecting missing color angles described in the present application in a sequence of color angles (eg according to step 405 of the 4 or according to the dependent claims 16-25) should also be understood as a method for detecting missing elements in a sequence of elements and should be understood detached from the context of optical transmission of information disclosed by color angles or color angle differences (this corresponds, for example, the The subject matter described in claims 16-25, wherein in claim 16 would then be understood as an independent claim without reference to previous claims). The elements can be recognized, corresponding filling information can be inserted into a modified sequence of elements and corresponding failure information can be stored. Based on the modified sequence of elements and the failure information, then, for example, an error-correcting decoding of the modified sequence of elements or a sequence of symbols that can be obtained from the modified sequence of elements can be undertaken.

The exemplary embodiments of the present invention described in this specification and the respective optional features and properties cited in this context should also be understood to be disclosed in all combinations with one another. In particular, the description of a feature encompassed by an exemplary embodiment is - unless explicitly explained to the contrary - not be understood in this case as meaning that the feature is essential or essential for the function of the exemplary embodiment. The sequence of the method steps described in this specification in the individual flowcharts is not mandatory, alternative sequences of the method steps are conceivable. The method steps can be implemented in various ways, so an implementation in software (by program instructions), hardware, or a combination of both to implement the method steps is conceivable. Terms used in the claims, such as "comprising," "comprising," "including," "containing," and the like, do not exclude other elements or steps. The phrase "at least partially" includes both the "partial" and "full" cases. The expression "and / or" should be understood to mean that both the alternative and the combination should be disclosed, ie "A and / or B" means "(A) or (B) or (A and B)". The use of the indefinite article does not exclude a majority. A single device can perform the functions of several units or devices mentioned in the claims. Reference signs indicated in the claims should not be regarded as limitations on the means and steps employed.

Claims (35)

Procedure ( 100 . 300 ) executed by at least one device ( 2 ), comprising the steps: - converting ( 306 ) of a first sequence of symbols into a first sequence of color angles, displays ( 104 ) or effecting the display ( 103 ) an at least partial representation of a temporal sequence of presentation elements on a display unit ( 35 ), wherein each display element of the temporal sequence of display elements is associated with a respective color angle of the first sequence of color angles, which defines the color value of at least a part of the presentation element. Procedure ( 100 . 300 ) according to claim 1, wherein said converting ( 306 ) of the first sequence of symbols into the first sequence of color angles comprises: assigning a respective color angle to each symbol of the first sequence of symbols according to an assignment rule for obtaining a second sequence of color angles, wherein the first sequence of color angles is the second series of color angles or is generated using the second series of color angles. Procedure ( 100 . 300 ) according to claim 1, wherein said converting ( 306 ) of the first sequence of symbols into the first sequence of color angles comprises: assigning a respective color angle difference to each symbol of the first sequence of symbols according to an assignment rule to obtain a sequence of color angle differences, and producing a third series of color angles such that the difference between a respective color angle of the third sequence of color angles to a previous or subsequent color angle corresponds to a respective color angle difference of the sequence of color angle differences, wherein the first series of color angles is the third series of color angles or is generated using the third sequence of color angles. Procedure ( 100 . 300 ) according to any one of claims 2-3, wherein one or more symbols of the first sequence of symbols are predetermined or determinable according to a predetermined rule and thereby it is possible to determine from the displayed at least partial representation of the temporal sequence of the presentation elements the assignment rule. Procedure ( 100 . 300 ) according to any one of claims 2-3, further comprising: - associating a respective color angle to each symbol of a second sequence of symbols according to an assignment rule to obtain a fourth sequence of color angles, wherein the symbols of the second series of symbols are predetermined or according to a predetermined rule are determinable, and - advertisements ( 104 ) or effecting the display ( 103 ) an at least partial representation of a second time sequence of presentation elements, each color angle of the fourth sequence of color angles defining a respective color value of at least a portion of the color angle respectively associated representation element of the second temporal sequence of presentation elements. Procedure ( 100 . 300 ) according to any one of claims 1-5, wherein said converting ( 306 ) of the first sequence of symbols in the first sequence of color angles further comprises: - applying ( 309 ) a mask on at least a portion of a fifth sequence of color angles obtained based on an assignment rule from the first sequence of symbols to obtain at least a portion of the first sequence of color angles, wherein by applying the mask one or more color angles of the portion the fifth sequence of color angles are modified. Procedure ( 100 . 300 ) according to claim 6, wherein said applying ( 309 ) of the mask on the portion of the fifth sequence of color angles serves to increase the distinctness of at least some successive color angles of the portion of the first sequence of color angles. Procedure ( 100 . 300 ) according to any one of claims 6-7, wherein said applying ( 309 ) of the mask on the portion of the fifth sequence of color angles results in that the smaller angular distances on the color wheel between each two successive color angles for at least a portion of the portion of the first sequence of color angles are greater on average than the smaller angular distances on the color circle between each two successive color angles for a corresponding portion of the portion of the fifth sequence of color angles, and / or that the smaller angular distances on the color wheel between each two successive color angles for at least a portion of the portion of the first sequence of color angles is a predefined or determinable threshold according to a predefined rule do not fall short. Procedure ( 100 . 300 ) according to any one of claims 1-8, wherein causing the display ( 103 ) of the at least partial representation of the temporal sequence of the presentation elements on the display unit ( 35 ) comprises: - generating control commands in the execution of which the display of the chronological sequence of the presentation elements is to take place, - issuing the control commands. Procedure ( 100 . 300 ) according to any one of claims 1-8, wherein causing the display ( 103 ) of the at least partial representation of the temporal sequence of the presentation elements on the display unit ( 35 ) comprises: generating a representation of the temporal sequence of the presentation elements at least as part of an image sequence or a video, outputting at least the representation of the temporal sequence of the presentation elements. Procedure ( 100 . 400 . 500 . 900 ) executed by at least one device ( 4 ), comprising the steps of: - detecting ( 401 . 402 ) of a sequence of samples, each comprising color angle information or from each of which color angle information can be obtained, from one on a display unit ( 35 At least partial representation of a temporal sequence of display elements, or receiving a sequence of samples recorded in this way, wherein each representation element of the temporal sequence of presentation elements is associated with a respective color angle of a first sequence of color angles that defines the color value of at least a portion of the presentation element, and wherein the first sequence of color angles is based on a conversion from a first sequence of symbols, of which at least one part represents a first sequence of information elements, and - determining ( 403 . 405 - 410 ) a representation of the first sequence of information elements based at least on the acquired sequence of samples. Procedure ( 100 . 400 . 500 . 900 ) according to claim 11, wherein determining the representation of the first sequence of information elements comprises: - determining ( 403 ) of a candidate sequence of samples based on the sequence of samples. Procedure ( 100 . 400 . 500 . 900 ) according to claim 12, wherein the number of samples of the candidate sequence of samples is less than the number of samples of the sequence of samples. Procedure ( 100 . 400 . 500 . 900 ) according to any one of claims 12-13, wherein said determining ( 403 ) of the candidate sequence of samples comprises: selecting samples from the sequence of samples to obtain the samples of at least a portion of the candidate sequence of samples, or selecting samples each by interpolating and / or extrapolating at least two respective samples from the sequence of samples to obtain the samples of the candidate sequence of samples. Procedure ( 100 . 400 . 500 . 900 ) according to claim 14, wherein, in the selection, samples of the sequence of samples, each lying substantially in the middle of respective regions of a curve in which the curve is substantially horizontal, are selected as the samples of the candidate sequence of samples, wherein the curve is formed by the samples of the sequence of samples or is formed by samples each obtained by interpolation and / or extrapolation of at least two respective samples from the sequence of samples. Procedure ( 100 . 400 . 500 . 900 ) according to any one of claims 12-15, wherein determining the representation of the first sequence of information elements further comprises: - determining ( 405 ), whether one or more elements are missing in a sequence of elements which is or has been obtained from the candidate sequence of samples, the determination being based at least on the values of the elements of elements of respectively associated sampling instants. Procedure ( 100 . 400 . 500 . 900 ) according to claim 16, wherein determining whether one or more elements are missing in the sequence of elements comprises: - determining ( 501 ) time distances between elements of the sequence of elements on the basis of the respective sampling times assigned to the elements, 502 ) of identifiers at the respective time intervals in order to obtain a sequence of identifiers, and - recognition ( 503 ), as a result of identifiers, of one or more identity patterns from one or more of the identifiers, wherein at least some of the identity patterns are associated with a respective default pattern indicating how many missing elements cause such identity pattern and how these missing elements are not missing Elements are temporally positioned. Procedure ( 100 . 400 . 500 . 900 ) according to claim 17, wherein the time distances are each determined between an element and its pre-predecessor in the sequence of elements. Procedure ( 100 . 400 . 500 . 900 ) according to any one of claims 17-18, wherein the identifiers respective ranges of values are assigned and wherein a temporal distance is assigned in each case that identifier in whose value range the time distance lies. Procedure ( 100 . 400 . 500 . 900 ) according to claim 19, wherein the boundaries of the ranges of values are determined using an average or median of the time distances between respective immediately consecutive elements of at least part of the sequence of elements. Procedure ( 100 . 400 . 500 . 900 ) according to one of claims 17-20, wherein the identification patterns and the default patterns are predefined. Procedure ( 100 . 400 . 500 . 900 ) according to any one of claims 16-21, wherein determining the representation of the first sequence of information elements further comprises: - generating ( 405 ; 504 ) first failure information indicating for which positions in the sequence of elements it has been determined in each case that an element is missing there, or - inserting ( 405 ; 504 ) of respective elements or wildcards into the sequence of elements at those positions in the sequence of elements which have been determined to be missing an element to obtain a modified sequence of elements and to generate second failure information indicating which positions in the modified sequence of elements are the inserted elements or placeholders. Procedure ( 100 . 400 . 500 . 900 ) according to claim 22, wherein if it is determined that not all the missing elements have yet been located in the sequence of elements, the following steps are performed: - selecting ( 907 ), one or more identity patterns, which are derived from the set of recognized identity patterns and to which no respective default pattern is associated, of the identity pattern having the identifier with the highest assigned value range, and either - Memorize ( 907 ), in the first breakdown information, that at a position in the sequence of elements, which item is associated with the selected label pattern, an item is missing, or - paste ( 907 ) of an element or wildcard in the modified sequence of elements at a position which position is associated with the selected identifier pattern, and noting in the second failure information that there is an inserted element or an inserted wildcard at that position. Procedure ( 100 . 400 . 500 . 900 ) according to claim 23, wherein the selected identifier pattern is respectively marked, and wherein the step of selecting and either the step of memorizing or the step of inserting and memorizing repeat for the unmarked recognized identifier patterns to which no respective default pattern is assigned until all recognized identity patterns, which do not have a respective default pattern associated with them, are flagged or it is determined that all missing elements have been located in the sequence of elements. Procedure ( 100 . 400 . 500 . 900 ) according to claim 24, wherein, if it is determined that not all the missing elements in the series of elements have yet been located, and all recognized identity patterns to which no respective default pattern is associated have been marked, the following is carried out: 909 ), of the recognized identifier patterns to which no respective default pattern is assigned, of the identifier pattern having the identifier with the highest assigned value range, and either - Memorize ( 909 ), in the first failure information, that at a position in the sequence of elements which position is associated with the selected identity pattern, an element is missing, or - inserting ( 909 ) of an element or wildcard in the modified sequence of elements at a position which position is associated with the selected value pattern and noting, in the second failure information, that there is an inserted element or an inserted wildcard at that position. Procedure ( 100 . 400 . 500 . 900 ) according to one of claims 22-25, wherein the representation of the first sequence of information elements is determined based on the following: the first failure information and either the sequence of elements or a sequence of symbols obtained from the sequence of elements, or the second failure information and either the modified sequence of elements or a sequence of symbols obtained from the modified sequence of elements. Procedure ( 100 . 400 . 500 . 900 ) according to claim 26, wherein the representation of the first sequence of information elements is determined based on the first failure information and a sequence of symbols derived from the sequence of elements, and wherein the sequence of symbols in the event that the sequence of elements is a sequence of Color angles obtained by converting the sequence of color angles into the sequence of symbols according to an assignment rule, or by applying a mask to the sequence of color angles to obtain a masked sequence of color angles and converting the masked sequence of color angles into the sequence of symbols an assignment rule is obtained. Procedure ( 100 . 400 . 500 . 900 ) according to claim 26, wherein the representation of the first sequence of information elements is determined based on the second failure information and a sequence of symbols obtained from the modified sequence of elements, and wherein the sequence of symbols for the case where the modified sequence of elements is a Sequence of color angles, obtained by converting the sequence of color angles into the sequence of symbols according to an assignment rule, or by applying a mask to the sequence of color angles to obtain a masked sequence of color angles and converting the masked sequence of color angles into the sequence of Symbols according to an assignment rule is obtained. Procedure ( 100 . 400 . 500 . 900 ) according to one of claims 27-28, wherein the assignment rule color angles or color angle differences assigns respective symbols and corresponds to an assignment rule, according to which the first sequence of symbols has been converted into the first sequence of color angles. Procedure ( 100 . 400 . 500 . 900 ) according to any one of claims 22-29, wherein the first sequence of symbols represents a representation of the first sequence of information elements encoded according to a code with error-correcting properties, wherein determining the representation of the first sequence of information elements further comprises: decoding ( 407 ) of the obtained sequence of symbols taking into account the first failure information or the second failure information for obtaining the representation of the first sequence of information elements. Procedure ( 100 . 400 . 500 . 900 ) according to any one of claims 11-30, wherein the first sequence of symbols represents a section of a sequence of symbols arranged in frames, wherein in each of the frames the sequence of symbols repeats, and wherein the first sequence of symbols represents a back part of a symbol Frame and the front part of a frame following the frame. Procedure ( 100 . 300 . 400 . 500 . 900 ) according to any one of claims 1-31, wherein the respective color angles specify the respective color values in a color space, in particular the HSV color space, the HSL color space, the HSB color space, the HSI color space or the CIE-LCh color space. Contraption ( 2 . 4 ) arranged for execution or comprising means for carrying out the method ( 100 . 300 . 400 . 500 . 900 ) according to any one of claims 1-32. System ( 3 ) - a device ( 2 ) arranged for execution or comprising means for carrying out the method ( 100 . 300 ) according to any one of claims 1-10, and - a device ( 4 ) arranged for execution or comprising means for carrying out the method ( 100 . 400 . 500 . 900 ) according to any one of claims 11-30. Program comprising - program instructions for carrying out the method according to one of the claims 1-32, when the program is stored on a processor ( 20 . 40 ) is performed.

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