A 3-dimensional image is generated from an input 2-dimensional image based upon illuminative characteristics of the input image by filtering the 2-dimensional input image with filters of different orientations, outputting base shading images corresponding to the filters, extracting positive pixel values for each base shading image, calculating a difference between the pixel values of the input image and the extracted positive pixel values, calculating a median value of the calculated difference, selecting the filter to output a base shading image of smallest median, outputting a shading image by filtering the input image with the selected filter, combining the input image with the shading image and outputting the 3-dimensional image based upon the combined image. A previously selected filter for a preceding image can be considered when selecting a filter for a current image, enabling generation of 3-dimensional moving pictures.