1. A method comprising: determining a ratio of pixels having a first attribute in a first region of an image to generate a first determination result; determining a ratio of pixels having a second attribute in a second region of the image to generate a second determination result, wherein the second region is arranged inside the first region, and the first and second regions are rotationally symmetric figures having coincident centers; determining whether human face images can exist in the vicinity of the first region based on the first determination result and the second determination result; and detecting a human face image in the vicinity of the first region when it is determined that the human face image can exist.