Abstract: A method (1000) of measuring performance parameters of an imaging device (120, 160) is disclosed. The method (1000) maintains a test pattern image (1005), the test pattern image (1005) comprising alignment features and image analysis features. A test chart (110, 170) containing a representation of the test pattern image is next imaged using the imaging device (120, 160) to form a second image (1010). The test pattern image (1005) and the second image (1010) are then registered using region based matching (1035) operating on the alignment features. Finally, the performance parameters are measured by analysing (1060) the image analysis features.

Abstract: A method (200) of determining at least rotation and scale parameters of a transformation relating two images is disclosed. The method (200) starts by forming a spatial domain representation of each of the images that is invariant to translation of the images. A correlation in the log-polar domain is next performed between the representations. After detecting a magnitude peak in the correlation, the method (200) determines the rotation and scale parameters from the position of the magnitude peak.

Abstract: A method (400) is disclosed for estimating an affine relation between a first image and a second image. The first and second images each have at least 4 non-parallel lines therein. The method (400) starts by identifying (406) sets of intersection points of the lines appearing in each of the images. The method (400) then determines (412) whether a relation between intersection points exists. If the relation exists then the first and second images are affine related and the affine distortion may be inverted (418).

Abstract: A method, apparatus and computer program for generating a barcode (200) representing one or more portions of data is disclosed. A block-based correlatable pattern of data is generated and the generated data patterns are arranged according to a predetermined arrangement. The one or more portions of data are interdispersed with the arranged data patterns to generate the barcode (200).

Abstract: A method (100) of demodulating a real two-dimensional pattern (110) is disclosed. The method (100) estimates (120, 130) a quadrature two-dimensional pattern from the real two-dimensional pattern (110) using a smooth phase only transform having an anti-symmetric phase, such as a spiral phase filter (140). A demodulated image is created by combining (180) the real two-dimensional pattern (110) and the estimated quadrature two-dimensional pattern.

Abstract: A method (500) of generating a matching key (599) for an image (501) is disclosed. The matching key (599) is substantially invariant to rotation, scale and translation. The method (500) starts by forming a spatial domain representation of the image (501) that is substantially invariant to translation of the image (501). Rotation and/or scaling in the spatial domain representation is next transformed (580) into translation to form a transformed image. A representation of the transformed image is then formed that is substantially invariant to translation of the transformed image. The representation of the transformed image is the matching key (599) for the image (501).

Abstract: A method (200) of enhanced peak detection in a correlation signal (g(x)) is disclosed. The method (200) comprises identifying (215) in the correlation signal (g(x)) positions where the modulus value of the correlation signal is above a first predetermined value. Each of the identified positions is then processed by forming (220) a sub-signal from the correlation signal by isolating a region of samples, the region comprising substantially equal numbers of samples on opposite sides of the identified position. The sub-signal is then up-sampled (221, 222, 225) to a higher resolution using Fourier interpolation. The up-sampled sub-signal is searched (230) for a peak value, and when the peak value is greater than a second predetermined value, parameters associated with the peak value is stored (236).