Abstract: Method, system and calibration marker for calibrating a three-dimensional printer. The method includes the steps of providing an image of a calibration marker to the three-dimensional printer; forming a calibration marker based on the provided image by depositing toner material on a first substrate of the printer, the calibration marker having a feature size and being fully interconnected to impart structural integrity to the calibration marker, and having annular spectral energy concentrated at a radius determined by the feature size of the calibration marker, wherein the interconnectedness and feature size of the calibration marker enables the structural integrity of the calibration marker to be maintained during transfer; transferring the formed calibration marker from the first substrate to a second substrate of the printer; and calibrating the printer from a determination of distortion introduced to the calibration marker during the forming and the transferring of the calibration marker.

Abstract: Disclosed is a method (160) for identifying potential tamper in a candidate document having content affected by noise. A candidate content value for each of a plurality of sub-regions of the candidate document and an original content value for each of a plurality of sub-regions of a corresponding original document are determined. The content values are desirably determined based on at least one characteristic of the content in the corresponding sub-region. The candidate content values (330) are associated with the corresponding original content values and a distribution of the candidate content values based on the corresponding original content values is determined. The method characterizes (340) the noise in the candidate document by determining an expected content value range based on the spread of a selected part of the distribution of candidate content values. The method can then identify (350) candidate content values outside the expected content value range as potential tamper.

Abstract: Disclosed is a method (160) for identifying potential tamper in a candidate document having content affected by noise. A candidate content value for each of a plurality of sub-regions of the candidate document and an original content value for each of a plurality of sub-regions of a corresponding original document are determined. The content values are desirably determined based on at least one characteristic of the content in the corresponding sub-region. The candidate content values (330) are associated with the corresponding original content values and a distribution of the candidate content values based on the corresponding original content values is determined. The method characterises (340) the noise in the candidate document by determining an expected content value range based on the spread of a selected part of the distribution of candidate content values. The method can then identify (350) candidate content values outside the expected content value range as potential tamper.

Abstract: A method of authenticating a first document (270) including content (271) and a barcode (272). The barcode (272) comprising barcode elements each having a predetermined form. A plurality of the barcode elements of the barcode are detected in a representation of the first document (270). A visual difference between each of the detected barcode elements and the predetermined form of the barcode element is determined. The barcode (272) is decoded to determine a second document. The first document (270) and the second document are compared based on the determined visual difference, in order to authenticate the first document (270).

Abstract: A method of authenticating a first document (270) including content (271) and a barcode (272). The barcode (272) comprising barcode elements each having a predetermined form. A plurality of the barcode elements of the barcode are detected in a representation of the first document (270). A visual difference between each of the detected barcode elements and the predetermined form of the barcode element is determined. The barcode (272) is decoded to determine a second document. The first document (270) and the second document are compared based on the determined visual difference, in order to authenticate the first document (270).

Abstract: An authoring system and authoring method to assigning a real geo-spatial position to sensory-effect data representing virtual sensations, including a virtual sound sensation. The system includes an author interface for displaying a representation of a real geo-space, means for accepting the sensory-effect data, and means for an author to assign the virtual sensory effect data to a location within the displayed representation corresponding to a real location within the geo-space, such that a user has the sensation of the virtual sound coming from the location assigned for the sensory-effect data.

Abstract: An authoring system for assigning geo-spatial position to sensory-effect data is disclosed. The sensory-effect data can include one or more of the group of alpha numeric data, image data, sound data, smell data, temperature data, humidity data, wind data, pressure date and light data. The alphanumeric data may comprise computer readable code for, in use, instructing the system to control presentation of the sound, image, smell, humidity, wind, pressure, or light data to an exposee. The authoring system may comprise a user interface on which the geo-space is represented, the interface being arranged in a manner such as to enable, in use, a user to assign the geo-spatial position to the data by placing and manipulating markers on the interface. The authoring system preferably comprises means for defining relationships between markers.