1. A method for identifying objects, the method comprising: receiving pixels for an image of an object; selecting a plurality of pixels from the pixels a plurality of times to form groups of sample pixels, wherein locations in the image for the plurality of pixels in a group of sample pixels are randomly selected for each group in the groups of sample pixels; forming a vector having a plurality of elements using the groups of sample pixels, wherein each element in the plurality of elements in the vector corresponds to a group from the groups of sample pixels; and identifying the object using the vector.