An image processing section of an image processing device is constructed by plural image processing modules being connected in a pipeline form, such that a buffer module is connected at at least one of preceding and following stages of each module. A buffer control section of the buffer module: when image data is outputted from the preceding image processing module, causes the module to write, immediately or after completion of reading, based on weather the following image processing module is reading data from the buffer; and when image data is requested from the following image processing module, causes the module to read, immediately or after completion of writing, based on weather the preceding image processing module is writing data to the buffer.