An image processing apparatus in which a time base corrector and an image coding apparatus are integrated so as to use a common memory, thereby realizing a simple circuit arrangement. The apparatus performs control of writing each line of input image data to an image memory in turn while reading image data from the image memory in predetermined coding units, in the following manner: when a picture of the image data has been written, if the number of data units, each corresponding to the coding unit, is equal to or below a first threshold, then a picture is skipped in the image data writing operation; and when a picture of the image data has been read, if the number of written lines is equal to or below a second threshold, then the same picture is again read in the image data reading operation.
