In a visual environment，a human face is an important visual object and its luminance distribution usually shows a complex pattern. It is considered that the fractal analysis is effective to estimate the complex luminance distribution of mannequin’s faces. It has been clarified that a vertical angle is one of important factors governing the fractal dimension from the dependence of the fractal dimension of luminance distribution measured by digital still camera photometry method on the vertical angle of lighting source.In this paper，image compression dependence of fractal dimension is studied. It is found that the fractal dimension decreases with increasing compression rate. It is also found that for the narrow image area，the image compression rate influences considerably the fractal dimension. It is clarified that such a result is caused by the elimination of harmonic element.