An image processing circuit for driving a liquid crystal that encodes and decodes image data to reduce the size of the frame memory that, when it quantizes (45) each block of image data in the current frame and outputs encoded data, selects (44) a mean value on the basis of the dynamic range of each unit block and adjusts the amount by which the image data is reduced (53). This type of control enables it to reduce the amount of image data that must be temporarily stored in the delay circuit (5), so the size of the frame memory constituting the delay circuit can be reduced while minimizing the encoding error that occurs in the encoder (4). Consequently, the image data can be corrected accurately and appropriate voltage corrections can be applied to the liquid crystal without the effects of coding and decoding errors.