In an illustrative system, a point-of-sale scanner is equipped to respond to multiple different symbologies printed on a single product. The scanner captures many frames per second, as products are swiped through a viewing volume. Each frame is decoded, yielding one or more payloads. A reconciliation module compares each newly-decoded payload against a list of payloads previously output by the module, to determine if the current payload is semantically-equivalent to a previously-output payload. If so, the previously-output payload is output again, in lieu of the just-decoded payload. If no equivalent is found, the current payload is output and added to the list for comparison against future payloads. A great number of other features and arrangements are also detailed.

A secure indicator includes a substrate, a barcode symbol that has a plurality of barcode modules provided on the substrate, and a security material positioned proximate the barcode symbol on the substrate. The security material is configured to be activated by irradiation at one or more predetermined activation wavelengths. Additionally, the barcode symbol is configured to be read (i) before the security material is activated and (ii) while the security material is activated.

Technology for generating, reading, and using machine-readable codes is disclosed. There is a method, performed by an image capture device, for reading and using the codes. The method includes obtaining an image, identifying an area in the image having a machine-readable code. The method also includes, within the image area, finding a predefined start marker defining a start point and a predefined stop marker defining a stop point, an axis being defined there between. A plurality of axis points can be defined along the axis. For each axis point, a first distance within the image area to a mark is determined. The distance can be measured from the axis point in a first direction which is orthogonal to the axis. The first distances can be converted to a binary code using Gray code such that each first distance encodes at least one bit of data in the code.

Methods, systems, and apparatus for combining preprinted information together with coded sensor information within a two-dimensional barcode. The sensor information may be of an environmental, physical or biological nature, and records a cumulative change in status of the environmental or biological condition to which the labeled product has been exposed. A sensor dye chemistry is employed that undergoes a continuous chemical or physical state change in response to the occurrence of the environmental condition. The continuous change is between an initial state and an end state causing a change in the color state of the sensor dye embedded within the sensor-augmented two-dimensional barcode, encoding sensor digital information. Sensor information is recovered utilizing the error-correction feature during barcode decoding.

A method for securely marking an object, comprising: a step of determining a maximum cell size (302) of a two-dimensional barcode (301), the cell size being defined by an area containing a number of dots (304, 305), a step of estimating a minimum number of dots of a predetermined colour referred to as the “main colour” in a cell such that the cell is detected as being said colour by a predetermined reader, a step of encoding a message in cells of a two-dimensional barcode by defining the main colour of each cell, said message representing at least one instance of access to a remote resource, for at least one cell, a step of defining an image (306) to be represented in the cell, the number of dots in the colour image defining the cell being greater than the estimated minimum number and a step of marking the object with the secure two-dimensional barcode.

A secure indicator includes a substrate, a barcode symbol that has a plurality of barcode modules provided on the substrate, and a security material positioned proximate the barcode symbol on the substrate. The security material is configured to be activated by irradiation at one or more predetermined activation wavelengths. Additionally, the barcode symbol is configured to be read (i) before the security material is activated and (ii) while the security material is activated.

Various implementations disclosed herein include devices, systems, and methods for verifying that an image includes a complete code of a time-varying visual marker that displays codes sequentially on a display. In some implementations, the verification determines that the image include a complete code rather than combinations of sequentially-displayed codes that may be included in an image based on use of a rolling shutter (e.g., in a camera of a detecting electronic device). In some implementations, the verification involves comparing a first verification portion of an image to a second opposing verification portion of an image. Various implementations disclosed herein include devices, systems, and methods for modifying image capture parameters (e.g., frame rate) to ensure capture of all codes of a time-varying visual marker.

Sheet-like product and method for authenticating a security tag including a section of the sheet-like product. The sheet-like product includes at least one security feature having optical properties that change with the viewing angle and, and at least one marker, wherein each marker is uniquely attributable to a position on the sheet-like product. The position of the at least one security feature on the sheet-like product is predetermined relative to the position of the at least one marker on the sheet-like product.

Technology for generating, reading, and using machine-readable codes is disclosed. There is a method, performed by an image capture device, for reading and using the codes. The method includes obtaining an image, identifying an area in the image having a machine-readable code. The method also includes, within the image area, finding a predefined start marker defining a start point and a predefined stop marker defining a stop point, an axis being defined there between. A plurality of axis points can be defined along the axis. For each axis point, a first distance within the image area to a mark is determined. The distance can be measured from the axis point in a first direction which is orthogonal to the axis. The first distances can be converted to a binary code using Gray code such that each first distance encodes at least one bit of data in the code.

The invention protects a content of a digital or physical document against forgery. It allows automatic detection of any modification in an arrangement of graphical symbols (e.g. a text) provided on a support (e.g. printed or displayed) with respect to an original arrangement by providing on the support reproducible verifiable data including a verification barcode, while eliminating redundancy between data inside the barcode and the graphical symbols, and resolving the problem of the size of the barcode when the size of the data for these graphical symbols is large.