Image processing
AssigneeTeleonaktiebolaget L M Ericsson (publ)
InventorsJacob Ström, Per Wennersten
Life of this patent
Estimating the term…
Abstract
An image (1) is decomposed into multiple superblocks (20, 22), each encompassing multiple pixel blocks (30A-30D, 32A-32D) having multiple pixels (40). The property values of a superblock (20) is fixed rate compressed to get a compressed block having a target bit length. The compressed block is stored in the memory locations (310, 320) assigned to the multiple pixel blocks (30A-30D) encompassed by the superblock (20) to thereby get multiple copies of the compressed block in the memory (300). The multiple copies collectively constitute a compressed representation of the superblock (20). When accessing a compressed block in a memory location (310) using random access during decoding, property values for neighboring pixel blocks (30B-30D) are obtained for free
Claims20
A method of compressing an image comprising multiple pixels having property values, said method comprising the steps of:
- decomposing said image into multiple superblocks, where a superblock encompasses N pixel blocks (30A-30D, 32A-32D) of multiple pixels and N is an integer equal to or larger than two;
- for at least a superblock (20) of said multiple superblocks:
- fixed rate compressing property values of said superblock to get a compressed block having a target bit length;
- assigning said compressed block to memory locations assigned for said N pixel blocks (30A-30D) encompassed by said superblock to get N copies of said compressed block in said memory locations, wherein said N copies of said compressed block collectively constitute a compressed representation of said superblock.
A method of decoding an image represented by multiple compressed blocks stored in a memory, said method comprising the steps of:
- fetching a compressed block from said memory (300);
- decompressing said compressed block to get multiple property values;
- assigning said multiple property values to a pixel block (30A) and at least one other pixel block (30B-30D) being encompassed together with said pixel block (30A) in a superblock;
- decoding said image based on at least one property value of said pixel block (30A) and at least one property value of said other pixel block (30B-30D).
An image compressor for compressing an image comprising multiple pixels having property values, said image compressor comprises:
- an image decomposer for decomposing said image into multiple superblocks, where a superblock encompasses N pixel blocks (30A-30D, 32A-32D) of multiple pixels and N is an integer equal to or larger than two;
- a fixed rate compressor for fixed rate compressing, for at least a superblock of said multiple superblocks, property values of said superblock to get a compressed block having a target bit length;
- and
- a memory assigner for assigning said compressed block to memory locations of a memory and being assigned for said N pixel blocks (30A-30D) encompassed by said superblock to get N copies of said compressed block in said memory locations, wherein said N copies of said compressed block collectively constitute a compressed representation of said superblock.
An image decoder for decoding an image, said image decoder comprises:
- a memory accessor for fetching a compressed block from a memory storing multiple compressed blocks representing said image;
- a decompressor for decompressing said compressed block to get multiple property values;
- a value assigner for assigning said multiple property values to a pixel block (30A) and at least one other pixel block (30B-30D) being encompassed together with said pixel block (30A) in a superblock;
- a pixel decoder for decoding said image based on at least one property value of said pixel block (30A) and at least one property value of said other pixel block (30B-30D).
Dependencies are inferred from the claim text.