A two-dimensional code 1 consists of three positioning symbols 2, a data region 3, timing cells 4 and an apex detecting cell 5. The shape of the whole code 1 is a square having the same number of vertical and lateral cells. A scanning line passing through the center of each positioning symbols 2 always gives a constant frequency component ratio--dark:light:dark:light:dark=1:1:3:1:1, irrespective of the scanning direction. For this reason, even if a rotational angle of the two-dimensional code is not certain, the specific frequency component ratio of each positioning symbol 2 can be easily detected by executing only one scanning operation in a predetermined direction. Hence, the coordinates of the center of each positioning symbols 2 can be easily found. Thus, the position of the two-dimensional code 1 is quickly identified.

Optically readable two-dimensional code and method and apparatus using the same

A method of formatting digital data and a method of decoding the formatted digital data. User selectable format parameters (201) vary the dimensions and other attributes of spots and the cells containing those spots as well as other features which the formatting process formats into a pattern. Computer files or files are selected to be printed as spots on paper (202). Compression and error correction processings (203, 204) are used to increase capacity and produce an error-free stream of data. The degree of redundancy selected is information conveyed in the metasector (802), which contains information about the encoding process used to encode the main body of data (803), which the decoding process decodes to recover the original data. Further embodiments include encryption, transmission by facsimile, inclusion of human readable information, and automatic launches of computer files.

Variable formatting of digital data into a pattern

A method and apparatus for capturing information encoded within a surface, such as location information or document metadata, and associating the information with a document is described. The captured information may be obtained by a camera associated with a pointing or writing device having a camera, such as an image-capturing pen.

Stroke localization and binding to electronic document

A bar code (10) has primary information (46, 48, 50, 51) encoded in one direction (e.g., horizontally) and secondary information (13,21,36) encoded in another direction (e.g., vertically) in single (11) or multiple tracks (35) in selected ones of the vertical bars (11) of a bar code (10). Using a non-linear, variable amplitude scanner, all of the primary bars are scanned in the one direction to obtain all of the primary information and all of those vertical bars having secondary information are scanned in the other direction to obtain all of the secondary information. The one direction which is perpendicular to the vertical primary bars (11), is determined by first rotating the scan path axis (86,87) until both start (46) and end (48) code bars are read thereby placing the scan path entirely within the total bar code, and, then, further rotating the scan path (88,89) to determine the direction of the minimum crossing width (Lsc 80) of the total bar code (10). Secondary information is scanned in planes orthogonal to the one direction after those vertical bars (11) having such information are first identified and selected. In a preferred embodiment, the decoded secondary information may be used to control selected station process operations for selected products in a continuous manufacturing assembly line.

Method and apparatus for encoding and decoding bar codes with primary and secondary information and method of using such bar codes

A two-dimensional code reading apparatus uses the image of a reference pattern of a known shape in the two-dimensional code to compute areas, shapes and positions of cells in the image of the two-dimensional code and corrects these computed values using correction values obtained by identifying cells isolated from cells of the same type in at least one direction whenever they appear and extracting their actual boundary coordinates directly from the image data. As a result, even if there is distortion in the image of the two-dimensional a reading scope for each cell to be read is set to a suitable area and the reading position of each cell is determined accurately in correspondence with the distortion and the content of the two-dimensional code is thereby read correctly.

Two-dimensional code reading apparatus

An optically readable matrix (100) has four intersecting sides of approximately equal length defining a perimeter and includes a binary code formed from light and dark squares of substantially equal sizes located within the perimeter. The matrix (100) comprises first and second orientation squares (105, 110) included in the light and dark squares and located in opposite corners of the matrix (100). Each of the orientation squares (105, 110) preferably includes a contrasting circular area (115, 120) located in a predetermined position within the orientation square (105, 110) and having a predetermined size relationship with the orientation square (105, 110). Such a matrix (100) may be formed on a printed circuit board (505) for use in an electronic device (500) to convey information about the printed circuit board (505). An apparatus (600) for decoding the matrix (100) includes an optical scanner (610) for scanning the matrix (100) and for locating the orientation squares (105, 110). Determination circuitry (710) coupled to the scanner ( 610) determines the size and distance between the circular areas (115, 120) relays the information to computing circuitry (715), which computes the size, orientation, and density of the matrix (100). A controller (705) thereafter translates the binary code.

German Gonzalez

Papers

Binary code matrix having data and parity bits