An image processing apparatus and a method are proposed to control the disparity and rate of disparity change in a 3D image. The method includes the following steps: inputting a maximum negative disparity threshold value and/or a maximum rate threshold value of disparity change by a viewer; receiving data of a 3D image; decoding the data into left eye image data and right eye image data; determining a maximum negative disparity and a rate of disparity change of the decoded 3D image data; determining and image movement value based on the determined maximum negative disparity and rate of disparity change and at least one threshold value; adjusting the left eye image and the right eye image using the image movement value; and displaying the adjusted left eye image and right eye image to a viewer on a 3D display device. The apparatus comprises image receiver, image decoder maximum disparity analyzer disparity control value determiner, user interface, disparity adjuster, and stereo display.