Abstract: A calibration element (1) serves for calibrating the magnification ratio of a camera (3). The calibration element (1) has at least one calibration region (4) in which at least one perforation (5) or indentation is provided. The perforation (5) or indentation can be detected by the camera. The calibration element (1) is sufficiently slight in the calibration region (4) that the detection of an upper edge or lower edge of the perforation (5) or indentation produces only negligible differences. In order to determine the dependence of the magnification ratio on the thickness, the calibration element (1) additionally has at least one support foot (8), whose length (9) is selected in such a way as thereby to produce a variation in the measured magnification ratio of the camera image that can be evaluated.

Abstract: A method and camera apparatus touches up a source image to produce a target image. The source image is partitioned into non-overlapping tiles of pixels. Each tile is labeled. A probability distribution of the labels is inferred, in which the probability distribution is a conditional random field. Weights are determined from the conditional random field. Then, each tile of the source image is transformed according to the weights to produce a corresponding tile of a target image. The transforming maximizes a conditional likelihood of the target image given the source image, while marginalizing over all possible labelings of the source image.