6. An image processing method, comprising: performing, using a plurality of processor cores, analysis processing of analyzing data of page description language form to generate intermediate language data and rendering processing of generating rendering data based on the intermediate language data generated by the analysis processing, wherein each of the processor cores is capable of performing and switching between the analysis processing and the rendering processing, and performs the analysis processing or the rendering processing in parallel with the analysis processing or the rendering processing performed by the other processor cores; storing the intermediate language data and the rendering data in a memory; obtaining information with regard to a vacant capacity of the memory by at least one of the plurality of processor cores performing the analysis processing; discontinuing the analysis processing being performed by the at least one processor core and performing the rendering processing with the at least one processor core based on the information with regard to the vacant capacity of the memory and a predetermined set value, wherein the data of page description language form includes data of a plurality of pages, each of the plurality of processor cores performs the analysis processing of a page different from each other, at least one of the plurality of processor cores performing the analysis processing obtains page numbers of the analysis processing performed by the plurality of processor cores, and if any of the processor cores is performing the analysis processing of a page other than a forefront page number among the obtained page numbers, the processor core performing the analysis processing of the page other than the forefront page number discontinues the analysis processing and performs the rendering processing based on the information with regard to the vacant capacity of the memory and the predetermined set value, the plurality of processor cores comprises a first processor core corresponding to the processor core that discontinued the analysis processing, the first processor core performs, after discontinuing the analysis processing, the rendering processing of a first page corresponding to the forefront page number among the obtained page numbers, the plurality of processor cores further comprises a second processor core corresponding to a processor core that was performing the analysis processing of the first page when the first processor core discontinued the analysis processing, and the first processor core performs the rendering processing of the first page in parallel with the second processor core performing the analysis processing of the first page.
14. The image processing method of claim 6 , wherein after the first processor core completes the rendering processing of the intermediate language data stored in the memory by the second processor core performing the analysis processing of the first page, the first processor core resumes the analysis processing of a second page that was being performed at the time the analysis processing was discontinued, the second page corresponding to a page other than the forefront page number, and the first processor core performs the analysis processing of the second page in parallel with the second processor core performing the analysis processing of the first page.