In 3-D profile measurement,when the modulated image by the structure light was processed by low-pass filter,the influence of cut-off frequency on the accuracy of 3-D profile measurement was analyzed in this paper,and the treatment process and results of 3-D profile measurement were presented.The modulated image by the structure light was processed by spatial filtering with different cut-off frequencies and the results were compared.Experimental results show that this method can enhance the accuracy of 3-D p...