In case there are other people on the images, the “right to one's own picture“ is not to be violated. It says that images of other people can only be used with their respective approval, unless the person displayed only appears as an accessory in the background or in any other place (§§ 22, 23, sub-section 2 of the German law concerning works of fine arts and photography). For instance, you take a picture of a landscape and there are pedestrians walking on a path. The landscape is the focal point and not the people.
In few cases when publishing pictures of objects, the copyright can be violated. For instance, private objects or in countries where the copyright is regulated differently and where objects can be protected, e.g. the Eiffel tower at night.