1. Apparatus for generating an overview image of a plurality of images, the apparatus comprising: a storage unit configured to store a plurality of processed images of the overview image, wherein each processed image of the plurality of processed images is assigned to a position of the overview image, wherein the storage unit is configured to provide the overview image comprising the plurality of processed images at their assigned positions for displaying; and an image processor configured to determine feature points of a new image and configured to compare the determined feature points of the new image with feature points of a stored processed image to identify common feature points and to acquire 3-dimensional positions of the common feature points, wherein the image processor is configured to determine common feature points located within a predefined maximum distance of relevance to a reference plane based on the 3-dimensional positions of the common feature points to identify relevant common feature points, wherein the image processor is configured to process the new image by assigning the new image to a position in the overview image based on a comparison of an image information of each relevant common feature point of the new image with an image information of each corresponding relevant common feature point of the stored processed image without considering common feature points located beyond the predefined maximum distance of relevance to the reference plane, wherein the storage unit is configured to add the processed new image with the assigned position to the plurality of processed images of the overview image; wherein the image processor is configured to determine the reference plane by fitting a horizontal plane to the 3-dimensional positions of the common feature points, so that a maximal number of common feature points are located within a predefined maximum fitting distance to the reference plane or so that the reference plane is as far away as possible from a camera position, the new image was taken from, with at least one common feature point located within the predefined maximum fitting distance to the reference plane.