Abstract: An image processing apparatus that processes image data consecutively in the column and row directions has an image memory, a reading unit, a temporary memory and an operative unit. The image memory stores image data consecutively in column and row directions on a pixel unit basis. The reading unit reads from the image memory a series of pixels within one column at one row and at least one pixel adjacent to the one row in the column direction. The temporary memory sequentially stores a number of groups of pixels read from the reading unit as is necessary for image processing. The operation unit reads the values of an objective pixel and pixels necessary for a neighborhood operation of the objective pixel from the temporary memory, and subjects the values to a neighborhood operation to determine the output value of the objective pixel.