1. An apparatus comprising: a computer processor; a non-transitory computer-readable medium having instructions executable by the computer processor to cause the computer processor to: access a digital image; determine a largest patch size to traverse the digital image, the largest patch size having a dimension set to approximately the minimum of the digital image's width and height dimensions; analyze the digital image to detect whether the digital image includes a one or more first objects of a size approximately the same as the largest patch size; discontinue analyzing the digital image when the one or more first objects are detected; if the one or more first objects are not detected at the largest patch size, progressively decrement the patch size and analyze the digital image to detect the one or more first objects of a size approximately the same as one of the smaller patch sizes until the one or more first objects are detected or the patch size is decremented below a minimum patch size.