Comparison method for CCD camera accuracy in photography measurement

Digital photography measurement is widely used in the fields of reverse engineering and 3D inspection. CCD camera measurement accuracy in the photography measurement is discussed. A calculation method based on the mathematical statistics is put forward. The distance of coded points or uncoded points was calculated with several groups of photographs taken by a camera with software XJTUDP, and then their average value was acquired. The individual error of each measurement was obtained by subtraction of the average value from the measured individual value of each group. The measuring accuracy of every group and the concept of standard accuracy were acquired by deriving the absolute value of ratio between the individual error and average value. The standard accuracy can be taken as the criteria for judging the accuracy of CCD cameras. The Cannon400D fixedfocus camera and zoom camera were analyzed in combination with the method and experiment data. The scientific basis for selection of zoom cameras and fixed-focus camera was provided.