PURPOSE: To promptly activate an entire picture processor even when the number of job tasks is large by deciding a range capable of processing jobs based on the result of detection whether or not the job task is in a state capable of processing the job.

CONSTITUTION: The respective job tasks transmit a message 'taskavailable' to a job task management task 15g at the point of time when the processing of a printing job becomes possible in the respective job tasks. After activating the respective job tasks, the job task management task 15g updates a task management table by the message transmitted by the respective job tasks corresponding to the state and decides the range capable of performing processings corresponding to the set state of the table. Thus, for instance, a LAN reception task 15b and a parallel reception task 15c can receive the printing job from a work station N being a host without waiting for the activation of a printing part management task 15f and a job analysis/expansion task 15e and activation time as the entire processor is shortened.