1. A method for displaying a three-dimensional image, comprising: receiving a left-eye gray level image array and a right-eye gray level image array; converting the left-eye gray level image array and the right-eye gray level image array into a left-eye luminance image array and a right-eye luminance image array respectively; receiving a compensation array; adjusting the right-eye luminance image array according to the left-eye luminance image array and the compensation array; converting the adjusted right-eye luminance image array into an adjusted right-eye gray level image array; adjusting the adjusted right-eye luminance image array according to the right-eye luminance image array and the compensation array; and displaying the adjusted right-eye gray level image array on a display platform; wherein adjusting the right-eye luminance image array according to the left-eye luminance image array and the compensation array is subtracting each right-eye element of the right-eye luminance image array by a product of a corresponding element of the left-eye luminance image array and a corresponding element of the compensation array, for generating the adjusted right-eye luminance image array; wherein adjusting the adjusted right-eye luminance image array according to the right-eye luminance image array and the compensation array is adding each right-eye element of the adjusted right-eye luminance image array with a product of the right-eye element and a square of the corresponding element of the compensation array, for adjusting the adjusted right-eye luminance image array.