In the stage of completion of the image analysis of the Nth page (derivation of the toner application amount), the decompressed data of the Nth page stored in the memory for analysis is discarded and the memory for analysis is released. Then, the decompression processing for analysis for the compressed data of the (N+1)th page is performed in parallel to the decompression processing for printing of the Nth page. The decompressed data of the (N+1)th page obtained by the decompression processing for analysis is stored in the memory for analysis, the image analysis is performed for the decompressed data, and the printer 130 is notified of the toner application amount of the (N+1)th page. The same processing is performed also for the (N+2)th page. That is, in the stage of completion of the image analysis for the (N+1)th page, the memory for analysis is released. Then, the decompression processing for analysis for the compressed data of the (N+2)th page is performed in parallel to the decompression processing for printing for the compressed data of the (N+1)th page. Then, the image analysis is performed for the decompressed data obtained by the decompression processing for analysis for the (N+2)th page and the printer 130 is notified of the toner application amount of the (N+2)th page.