PURPOSE: To execute accurate information transmission for a restricted code amount and to efficiently encode/decode a motion vector by outputting the encoded signal of each area from an encoding means together with importance and a motion vector.

CONSTITUTION: A moving vector of each area divided by an area dividing circuit 100 is stored in a motion vector memory 102 for a fixed period. An importance judging circuit 104 judges the importance of motion detected in each area or that of the area while referring to past motion information stored in the memory 102. Then an encoding circuit 105 executes encoding in accordance with the judged importance. In the case of low importance, quantizing step size is increased to execute rough quantization and a code amount is reduced though an quantizing error is large. When the importance is high, the quantizing step size is reduced to execute accurate quantization and a minute image having a large code amount and reduced at its quantizing error can be regenerated.