1. An image processing method configured to be executed by a plurality of processing blocks, which are connected in series within an image processing apparatus, each of the plurality of processing blocks respectively comprising a processor, the image processing method comprising the steps of: employing a data that is inputted into the processing block to perform an image processing thereupon by way of the processor of the processing block; performing a process upon the processor of the processing block in response to a command that is inputted into the processing block; and causing an output that corresponds to the command that is inputted after the data to wait until an output of the processor that employed the data that is inputted into the processing block prior to the command to perform the process is finished, such that the output of the processor that employed the data to perform the image processing and the output that corresponds to the command is outputted from the processing block in an order whereby the data and the command are inputted into the processing block.