The present technology relates to an image processing apparatus and method and a program that enable natural representation of light in an image in accordance with a viewpoint. The image processing apparatus calculates information indicating a change in a light source region between an input image and a viewpoint-converted image that is obtained by performing viewpoint conversion on the input image on the basis of a specified viewpoint, and causes a change in representation of light in the viewpoint-converted image on the basis of the calculated information indicating a change in the light source region. The present technology can be applied to an image display system that generates a pseudo stereoscopic image with motion parallax from one image.