CCD-based input device was used to convert printing test pattern to digital image. Spatial frequency response characteristics of the printing system were obtained by measurement using spatial frequency response measurement algorithm based on incline edge gradient analysis. The area in spatial frequency response curve obtained from human vision system filtering was normalization processed and the result was used as sharpness quality factor. Experimental results indicated that the sharpness quality factor well reflects the reproduction effect of the prints sharpness, and offers a new way to measure prints sharpness objectively and quantitatively. The purposed was to provide technical support for automatic measurement and evaluation of printing quality.