To improve speed and precision by limiting the detecting range of a reference second scanning image block at the time of detecting movement to a small range in accordance with a moving quantity in a detected reference first scanning image block to reduce an arithmetic quantity of the reference second scanning image block at the time of the detecting movement to reduce erroneous detection.

A movement detecting part 1 calculates the moving quantity and its matching error quantity (the total value of the absolute difference of each pixel) by pattern matching in a detecting range designated by inputting image data. An arithmetic part 2 calculates a reference point in the detecting range based on the obtained moving quantity and a memory 4 stores the matching error quantity. A switch SW switches a prescribed threshold value and the matching error quantity stored in the memory 4; a comparing part 3 compares the matching error quantity with the value selected by the switch SW; a selection part 5 selects the moving quantity by this comparing result. Thus, the arithmetic quantity of movement detection is reduced to improve the speed.