1. An apparatus for classifying an image, comprising: an image divider for dividing an input image into blocks, wherein each block includes a plurality of pixels; and an image type determiner for calculating a hue value and a chroma value for each of the blocks, determining, for each one of the blocks, whether the one of the blocks is a color-changed block by calculating differences between the hue value and chroma value calculated for all blocks adjacent to the one of the blocks and the hue value and chroma value calculated for the one of the blocks, calculating a hue variance and a chroma variance for the entire input image if a number of determined color-changed blocks is greater than or equal to a first preset threshold, and determining that the input image is a non-monochromatic image if the hue variance is greater than or equal to a second preset threshold or the chroma variance is greater than or equal to a third preset threshold.