PURPOSE: To output inputted source picture data by analyzing the data and decomposing the data into a test data section and a graphics data section.

CONSTITUTION: The outline of a white or black area is obtained from an inputted picture by expressing the picture with white and black binary data and detecting pixels at the boundary between the white and black areas, and then tracing the pixels. The shape of the white or black area is obtained by using outline data and whether the object is test data or graphics data is discriminated based on the outline data, and then, the test data and graphics data are separately outputted.