1. A method for determining a navigation image configured to display features of a region of interest of a patient, the method comprising: recording a first X-ray image and a mask image with an X-ray device; determining a first subtraction image by subtracting the mask image from the recorded first X-ray image; recording a second X-ray image with the X-ray device; determining a second subtraction image by subtracting the mask image or a further mask image from the recorded second X-ray image; and determining the navigation image by superimposing the first subtraction image and the second subtraction image, wherein at least one of the subtraction images is preprocessed before the superimposition by transfer from a gray-value space into a color space that is different from a color space of the other subtraction image, and wherein the navigation image is determined in color and/or dynamics of at least one of the subtraction images is compressed.