Visual exploration of large image data sets is a common and widely performed task. With the ubiquity of cameras, personal image collections are growing. Even when working with large high-resolution displays, collections are typically too large to display all images. In this work, we present two full-body, hands-free zooming interaction techniques for image exploration on large high-resolution displays that allow users to freely move in front of the display. We compare these techniques with state-of-the-art image browsing, where a large number of images is presented in a static grid. The first technique selects and enlarges whole columns by full-body-tracking of the user. The second technique additionally uses the height of the users head to select a single picture as a focus point. The results show that novel interaction techniques and visualizations for image sets on large high-resolution displays are required and can enhance the advantages of such displays.