System and method for compressing and rotating image data

• US 20060072147A1
• Filed: 10/06/2004
• Published: 04/06/2006
• Est. Priority Date: 10/06/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Tec Corporation (Toshiba Corporation)
• Inventors: Kanno, Hiroki
• Granted Patent: US 7,742,199 B2
• Time in Patent Office: Days
• US Class Current: 358/1.150
• CPC Class Codes: H04N 1/3877 Image rotation
• CPC Class Codes: H04N 1/41 Bandwidth or redundancy reduction by scanning H04N1/17 ; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence

Abstract

A system and method for reproducing original documents includes scanning an original document to generate image data corresponding to the scanned original document, dividing the image data into a plurality of image data blocks, and compressing the plurality of image data blocks into respective compressed image data blocks, such that data of each compressed image data block is independent of data of each other compressed image data block. Each compressed image data block is stored in a first memory with a respective predetermined beginning address. The first compressed image data block, having a first predetermined beginning address, is accessed from the first memory and decompressed into a first decompressed image data block. At least one image processing function is performed on the decompressed first image data block.

Claims

1. An image processing method, comprising the steps of:

scanning an original document to generate image data corresponding to the scanned original document;

dividing the image data into a plurality of image data blocks;

compressing the plurality of image data blocks into respective compressed image data blocks, such that data of each compressed image data block is independent of data of each other compressed image data block;

storing each compressed image data block in a first memory with a respective predetermined beginning address;

accessing a first compressed image data block, having a first predetermined beginning address, from the first memory and decompressing the first compressed image data block into a first decompressed image data block; and

performing at least one image processing function on the decompressed first image data block.

2. A method according to claim 1, further comprising:

storing the decompressed first image data block in a second memory after performing the at least one image processing function.

3. A method according to claim 2, wherein one of the at least one image processing functions is to rotate the image data.

4. A method according to claim 3, wherein a second compressed image data block is stored in the first memory and has a second predetermined beginning address that is offset by a predetermined amount from the first predetermined address, the method further comprising:

accessing the second compressed image data block from the first memory and decompressing the second compressed image data block into a second decompressed image data block;

performing the at least one image processing functions on the second decompressed image data block; and

storing the decompressed second image data block in the second memory after performing the at least one image processing function.

5. A method according to claim 4, wherein the second decompressed image data block is stored in the second memory in a position adjacent to the first image data block.

6. A method according to claim 4, wherein the first and second decompressed image data blocks are rotated, and

wherein the first decompressed image data block is rotated before the second decompressed image data block is rotated.

7. A method according to claim 2, wherein the first memory is configured to store the compressed image data blocks, and the second memory is a page memory.

8. A method according to claim 7, wherein a size of the page memory is configured to correspond in size to a predetermined number of decompressed image data blocks that is less than the total number of decompressed image data blocks for the document.

9. A method according to claim 7, wherein the size of the page memory corresponds in size to one column of image data of decompressed image data blocks of the image data.

10. A method according to claim 7, wherein the size of the page memory corresponds in size to a multiple of one column of image data of decompressed image data blocks of the image data, the multiple being at least two.

11. A method according to claim 2, further comprising:

accessing and decompressing each of the remaining compressed image data blocks one at a time in a predetermined order;

performing the at least one image processing function on each of the remaining image data blocks after the image data block is decompressed, respectively; and

storing each of the remaining image data blocks in the second memory after performing the at least one image processing function to the image data blocks.

12. A method according to claim 11, wherein each remaining compressed image data block is stored in the first memory at a predetermined beginning address having a respective predetermined offset from the first predetermined beginning address, and

wherein the step of access the compressed image data blocks is performed without reference to an address table.

13. A method according to claim 11, further comprising:

rasterizing all of the image data of the document stored in the second memory; and

printing the rasterized data.

14. A method according to claim 2, wherein the first decompressed image data block is stored at a predetermined beginning address of the second memory.

15. A method according to claim 1, wherein each remaining compressed image data block is stored in the first memory at a predetermined beginning address having a respective predetermined offset from the first predetermined beginning address.

16. A method according to claim 1, wherein, after storing the compressed first image data block, the first memory includes unused memory addresses between an end of the first compressed image data block and a second predetermined address corresponding to a beginning address of a second compressed image data block.

17. A method according to claim 2, further comprising:

rasterizing the image data in the second memory before all of the compressed image data blocks have been decompressed; and

printing the rasterized image data.

18. A method according to claim 1, wherein the step of decompressing includes decompressing at least two compressed image data blocks at a time.

19. A method according to claim 1, wherein the size of each image data block is one of 256×

256 pixels and 512×

512 pixels.

35. An image forming apparatus according to claim 1, wherein the first memory includes unused memory addresses between an end of the first compressed image data block and a second predetermined address corresponding to a beginning address of a second compressed image data block.

37. An image forming apparatus according to claim 1, wherein the decompressor decompresses at least two compressed image data blocks at a time.

38. An image forming apparatus according to claim 1, wherein the size of each image data block is one of 256×

256 pixels and 512×

512 pixels.

20. An image forming apparatus configured to reproduce original documents, comprising:

a scanner that scans an original document and generates image data corresponding to the scanned original document;

a compressor that compresses a plurality of image data blocks, which correspond to respective portions of the image data generated by the scanner, into respective compressed image data blocks, such that data of each compressed image data block is independent of data of each other compressed image data block;

a first memory that stores each compressed image data block at a respective predetermined beginning address;

a decompressor that accesses a first compressed image data block, having a first predetermined beginning address, from the first memory and decompresses the first compressed image data block into a first decompressed image data block; and

an image processor that performs at least one image processing function on the decompressed first image data block.

21. An image forming apparatus according to claim 20, further comprising:

a second memory that stores the decompressed first image data block after the image processor performs the at least one image processing function.

22. An image forming apparatus according to claim 21, wherein one of the at least one image processing functions is to rotate the image data.

23. An image forming apparatus according to claim 22, wherein the first memory stores a second compressed image data block at a second predetermined beginning address that is offset by a predetermined amount from the first predetermined address, and

wherein the decompressor accesses the second compressed image data block from the first memory and decompresses the second compressed image data block into a second decompressed image data block,

wherein the image processor performs the at least one image processing functions on the second decompressed image data block, and

wherein the second memory stores the decompressed second image data block after the image processor performs the at least one image processing function.

24. An image forming apparatus according to claim 23, wherein the second memory stores the second decompressed image data block in a position adjacent to the first image data block.

25. An image forming apparatus according to claim 23, wherein the image processor rotates first and second decompressed image data blocks, and

wherein the image processor rotates first decompressed image data block before rotating the second decompressed image data block.

26. An image forming apparatus according to claim 21, wherein the first memory is configured to store the compressed image data blocks, and the second memory is a page memory.

27. An image forming apparatus according to claim 26, wherein a size of the page memory is configured to correspond in size to a predetermined number of decompressed image data blocks that is less than the total number of decompressed image data blocks for the document.

28. An image forming apparatus according to claim 26, wherein the size of the page memory corresponds in size to one column of image data of decompressed image data blocks of the image data.

29. An image forming apparatus according to claim 26, wherein the size of the page memory corresponds in size to a multiple of one column of image data of decompressed image data blocks of the image data, the multiple being at least two.

30. An image forming apparatus according to claim 21, wherein the decompressor accesses and decompresses each of the remaining compressed image data blocks one at a time in a predetermined order,

wherein the image processor performs the at least one image processing function on each of the remaining image data blocks after the image data block is decompressed by the decompressor, respectively, and

wherein the second memory stores each of the remaining image data blocks after the image processor performs the at least one image processing function to the image data blocks.

31. An image forming apparatus according to claim 30, wherein the first memory stores each remaining compressed image data block at a predetermined beginning address having a respective predetermined offset from the first predetermined beginning address, and

wherein the decompressor accesses the compressed image data blocks without reference to an address table.

32. An image forming apparatus according to claim 30, further comprising:

a rasterizer that rasterizes all of the image data of the document stored in the second memory; and

a printer that prints the rasterized data.

33. An image forming apparatus according to claim 21, wherein the first decompressed image data block is stored at a predetermined beginning address of the second memory.

34. An image forming apparatus according to claim 20, wherein the first memory stores each remaining compressed image data block at a predetermined beginning address having a respective predetermined offset from the first predetermined beginning address.

36. An image forming apparatus according to claim 21, further comprising:

a rasterizer that rasterizes the image data in the second memory before all of the compressed image data blocks have been decompressed; and

a printer that prints the rasterized image data.