Abstract: An image processing unit of an image switching apparatus includes main circuit blocks (5a), (5b) and (6) and sub circuit blocks (5d), (5e) and (7). An operation unit in the image switching apparatus includes a unit for designating one of or both of the main circuit blocks and the sub circuit blocks. When the main circuit block is designated, the operation unit transmits a signal to designate the operation of the main circuit block. When the sub circuit block is designated, the operation unit transmits a signal to designate the operation of the sub circuit block. When both of the main circuit block and the sub circuit block are designated, the operation unit transmits a signal to designate operations of the main circuit block and the sub circuit block. The image switching apparatus can be constructed by a few circuits and such circuits can be efficiently used without waste in response to the change of purposes.

Abstract: A main operation unit (2) is connected to a control unit (4) which controls image processing units (5) to (9), the main control unit (2) includes a setting means for setting the image processing units (5) to (9) to which a sub operation means (3) is connected to the standard mode or the half-divide mode, the control unit (4) controls the image processing units (5) to (9) in response to instruction from the main operation unit (2) upon the standard mode, the control unit (4) controls the image processing units (5) to (9) in response to instruction from the main operation unit (2) upon the half-divided mode and the control unit (4) controls sub circuit blocks (5d) to (5f) within the image processing units (5) to (9) in response to instruction from the sub operation unit (3). Thus, the image switching apparatus can be composed of lesser circuits and such circuits can be used separately without waste as their uses are changed.