PURPOSE: To provide 1a picture data encoding device of a channel division system capable of sufficiently suppressing the decline of picture quality.

CONSTITUTION: This device for dividing picture data into plural channels and performing an encoding processing is provided with a control part 40 for setting data division to the respective channels (areas) by FIFOs 20 and 30 in a form where mutually superimposed parts remain in the boundary parts and ROMs 70 and 80 and the control part 90 as gain control means for controlling the levels of demodulated data in the respective parts where the channels are overlapped in mutual relation among the respective channels. Thus, the transfer of the data at the boundaries of the respective channels appears in a form where the fluctuation of the picture quality continues and thus, the transfer can be obtained even when the difference of the picture quality is present while it is inconspicuous and the decline of the picture quality can be sufficiently suppressed.