A method is provided for a three-dimensional (3D) image processing system including a stereoscopic display device. The method includes providing a stereoscopic image and obtaining a parallax range of the stereoscopic image and a parallax range supported by the stereoscopic display device. The method also includes determining a parallax operation to adjust the parallax range of the stereoscopic image based on the relationship between the parallax range of the stereoscopic image and the parallax range supported by the stereoscopic display device. Further, the method includes determining an offset value and an offset direction of a horizontal coordinate of each pixel of the stereoscopic image, and shifting the horizontal coordinate of each pixel of the stereoscopic image by the offset value and in the offset direction.