Two-dimensional code reading apparatus, two-dimensional code reading process, two-dimensional code reading program and recording medium for said program, portable terminal and digital camera

摘要

When a two-dimensional code having data cells (referred to as DC) comprising two-dimensional data, positioning finder patterns (referred to as FP) and an alignment pattern (referred to as AP) is input, the positions of FP are detected by evaluating the proximity from patterns in three horizontal, vertical and inclined directions. The position of AP is detected by conducting the template matching after the rotation correction of part of the input image. The version of the code is determined by calculation of the number of cells from the widths and positions of FP. Coordinate conversion expressions for converting the positions of DC into their coordinate positions based upon the positions of FP and AP and the version are determined and DC are cut out. The array of the cut out DC is decoded for reading the two-dimensional code.