Image processing apparatus with memory area management portion

摘要

In an image processing apparatus, a memory area management portion generates a descriptor for a block storage area allocated in each of a first work memory and a second work memory, and generates sub-band management data associated with the descriptor for the block storage area in which compressed sub-band data is stored, sequentially according to arrangement of the sub-band data in the primary scanning direction and the secondary scanning direction in image data. A data loading portion changes, according to a rotation angle, the association between the sub-band management data and the descriptor after the compressed sub-band data is stored in the second work memory. A decompression processing portion performs rotating process in the sub-band data according to the rotation angle.

主权项

1. An image processing apparatus comprising:
a memory; a compression processing portion configured to compress image data in units of sub-band data, and store each piece of the sub-band data having been compressed in a first work memory of the memory; a data storing portion configured to read, from the first work memory, the sub-band data obtained by compressing the image data, and store the sub-band data having been compressed in a data storage area; a data loading portion configured to read the compressed sub-band data from the data storage area, and store each piece of the compressed sub-band data in a second work memory of the memory; a decompression processing portion configured to decompress the compressed sub-band data stored in the second work memory; and a memory area management portion configured to allocate the first work memory in the memory, and transfer, from the first work memory, the sub-band data having been compressed and store, in the data storage area, the sub-band data having been compressed, and to thereafter deallocate the first work memory, and allocate the second work memory in the memory, wherein the memory area management portion (a) physically allocates one or plural block storage areas in the memory, allocates to the first work memory the one or plural block storage areas that have been physically allocated, and generates first block management data with which the one or plural block storage areas are associated, (b) physically allocates one or plural block storage areas in the memory, allocates to the second work memory the one or plural block storage areas that have been physically allocated, and generates second block management data with which the one or plural block storage areas are associated, and (c) generates, for each piece of the compressed sub-band data, sub-band management data associated with the block management data for the block storage area in which the compressed sub-band data is stored, sequentially according to an arrangement of the sub-band data in a primary scanning direction and a secondary scanning direction in the image data, the data loading portion changes, according to a rotation angle, an association between the sub-band management data and the block management data after the compressed sub-band data is stored in the second work memory, the decompression processing portion performs a rotating process in the sub-band data according to the rotation angle, the sub-band data is data obtained by dividing band data of the image data in the primary scanning direction, the memory area management portion allocates the first work memory and the second work memory for the band data such that one first work memory and one second work memory are allocated to one piece of the band data, the sub-band management data includes offset information that represents an offset, from a head of the block storage area, of a start location of the compressed sub-band data corresponding to the sub-band management data, the data loading portion changes the offset information so as to indicate a value of an offset from a head of the block storage area associated with the second work memory when the association between the sub-band management data and the block management data is changed, the sub-band management data represents a size of the compressed sub-band data corresponding to the sub-band management data, and the memory area management portion identifies, for one piece of the band data, a total size of the compressed sub-band data corresponding to the one piece of the band data, based on the sub-band management data, and allocates a storage area having a size based on the total size as the one second work memory.