An image processing apparatus is provided for enhancing the image processing function without having to increase the circuit scale. The image processing apparatus includes an image divider, a pixel processor, and an image coupler. If the number of horizontal pixels on the width of an input image is larger than a size of a line buffer, the image divider equally divides the input image in the vertical direction so that the resulting divided area is smaller than the number of horizontal pixels on the width of the line buffer. Then, the image divider controls an input data transfer circuit so that the pixel data of the input image may be sequentially transferred to the line buffer for each of the equally divided areas. The image processor sequentially processes the pixel data of the input image temporarily stored in the line buffer and then sends out the output pixel data. The image coupler controls the output data transfer circuit so that the output pixel data sequentially outputted for one divided area may be coupled with the output pixel for another divided area, for generating the output image.