No flickering. No noise. No artifacts. No hard lights that cast shadows. No fog, clouds, trees, or buildings. No conditions of slow-moving or stopped people for long periods. No moving objects whose appearance is similar to the target in the areas of interest. No waving objects that cause the continuous modification of the image in the area of interest, for example a meadow with tall grass. The target must have a minimum height of 30 pixels, which is at least 1/10 of the image height. The body of the target must be visible for at least 3/4 of its height. The target must have a minimum area of 100 pixels and stay in the interested area for a time of at least 1 second. The target must also maintain a sufficient dissimilarity from the background, which means at least a color difference of 5% or a brightness difference of 10%. The image must have a resolution of 640x360, 640x480, 320x180, or 320x240 pixels and must be in landscape orientation with 16:9 aspect ratio.