Nokia Corporation

Nokia Technologies Oy

Adrian Burian

Radu Ciprian Bilcu

Markku Kalevi Vehvilainen

Jari T Kangas

Markku Vehviläinen

Martin Schrader

Ville-Markus Sipinen

An apparatus that calibrates a parametric mapping that maps between object points and image points. The apparatus captures an image of a calibration pattern including features defining object points. The apparatus determines, from the image, measured image points that correspond to the object points. The apparatus determines, from the mapping, putative image points that correspond to the object points. The apparatus minimizes a cumulative cost function dependent upon differences between the measured image points and putative image points to determine parameters of the parametric mapping. The mapping uses a parametric function to specify points where light rays travelling from object points to image points cross the optical axis.

Camera calibration and/or use of a calibrated camera

An apparatus for providing a camera barcode reader includes a processing element configured to process an input image for an attempt to decode the input image using a current barcode reading method, to determine whether the processing of the input image is successful, to switch to one of a different barcode reading method or processing a new frame of the input image using the current barcode reading method in response to the processing of the input image being unsuccessful, to attempt a decode of the input image using the current barcode reading method in response to the processing of the input image being successful, and to perform a switch to the different barcode reading method in response to a failure of the attempt to decode the input image using the first barcode reading method.

Method, apparatus, and computer program product for providing a camera barcode reader

For binarizing an image, which is composed of pixels, the image is split into two semi-images. Local parameters are initialized based on values of pixels that lie in an area adjacent to a boundary separating the semi-images. A binarization is then performed separately for each of the semi-images using an adaptive threshold, wherein the adaptive threshold is calculated for each of the semi-images proceeding from the initialized local parameters.

Binarization of an image

The present invention relates to an image pre-processing method for a pattern detection system, such as a bar code detection system. The method comprises the steps of: detecting a start point and an end point of a pattern on the basis of image data of at least a portion of a captured image, estimating a point spread function from the image data or a modified image data on the basis of the detected start point and the end point, and restoring the image data or the modified image data using the estimated point spread function.

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Tampere, Finland

Adrian Burian