Modifying wavelet division level before transmitting data stream

• US 7,386,175 B2
• Filed: 10/24/2003
• Issued: 06/10/2008
• Est. Priority Date: 10/25/2002
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Nishimura, Takayuki, Sakuyama, Hiroyuki, Yano, Takanori, Hara, Junichi, Miyazawa, Toshio, Matsuura, Nekka, Kodama, Taku, Nomizu, Yasuyuki, Shinkai, Yasuyuki
• Primary Examiner(s): Bella; Matthew C.
• Assistant Examiner(s): WANG, CLAIRE X
• Application Number:
  US10/691,623
• Publication Number:
  US 20040141651A1
• Time in Patent Office: 1,691 Days
• Field of Search: 382/232, 382/240, 382/305, 382/299, 709/209, 709/203, 375/240.18, 375/240.19, 375/240.09
• US Class Current: 382/232
• CPC Class Codes: H04N 19/1883 the unit relating to sub-band structure, e.g. hierarchical level, directional tree, e.g. low-high [LH], high-low [HL], high-high [HH]
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards

Abstract

An image processing apparatus includes a memory which stores a code stream having a wavelet division level, an interface unit which transmits the code stream to another apparatus, and a processing unit which changes the wavelet division level of the code stream before the transmission of the code stream to such another apparatus by acquiring a target division level that is a wavelet division level of such another apparatus, checking a difference between the target division level and the wavelet division level of the code stream, generating data that compensates for the difference, and embedding the generated data into the code stream.

Claims

1. An image processing apparatus that transmits image data from a second device to a first device, comprising:

acquisition means for acquiring a target division level that is a wavelet division level supported by the first device;

checking means for checking a difference between the target division level and a wavelet division level in an original code stream of the second device, wherein said original code stream is compressed and encoded according to a JPEG 2000 algorithm;

reading means for reading coded data responsive to a check result of the checking means from the original code stream;

decoding means for decoding wavelet coefficients from the coded data read by the reading means;

generating means for generating LL component data of the target division level by performing a wavelet transform or an inverse wavelet transform on the wavelet coefficients decoded by the decoding means;

coding means for coding the LL component data generated by the generating means;

changing means for changing the wavelet division level of the original code stream by embedding, in the original code stream of the second device, the LL component data coded by the coding means for transmission to the first device; and

coding condition changing means for changing coding conditions in the original code stream based on the wavelet division level changed by the changing means.

2. The image processing apparatus as claimed in claim 1, wherein if the target division level is low, the reading means reads coded data of levels higher than the target division level from the original code stream.

3. The image processing apparatus as claimed in claim 1, wherein if the target division level is high, the reading means reads coded data of an LL component of a level lower than the target division level from the original code stream.

4. The image processing apparatus as claimed in claim 1, wherein the coding conditions are a decomposition level number in a parameter regarding a coding style of components included in a default coding style marker (COD) in a start marker (SOC) of the original code stream.

5. The image processing apparatus as claimed in claim 2, wherein the coding conditions are a decomposition level number in a parameter regarding a coding style of components included in a default coding style marker (COD) in a start marker (SOC) of the original code stream.

6. A method for transmitting image data from a second device to a first device, said method comprising the steps of:

acquiring a target division level that is a wavelet division level supported by the first device;

checking a difference between the target division level and a wavelet division level in an original code stream of the second device, wherein said original code stream is compressed and encoded according to a JPEG 2000 algorithm;

reading coded data responsive to a check result of the checking step from the original code stream;

decoding wavelet coefficients from the read coded data;

generating LL component data of the target division level by performing a wavelet transform or an inverse wavelet transform on the decoded wavelet coefficients;

coding the generated LL component data;

changing the wavelet division level of the original code stream by embedding, in the original code stream of the second device, the coded LL component data for transmission to the first device; and

changing coding conditions in the original code stream based on the changed wavelet division level.

7. The method as claimed in claim 6, wherein if the target division level is low, the step of reading coded data includes reading coded data of levels higher than the target division level from the original code stream.

8. The method as claimed in claim 6, wherein if the target division level is high, the step of reading coded data includes reading coded data of an LL component of a level lower than the target division level from the original code stream.

9. The method as claimed in claim 6, wherein the coding conditions are a decomposition level number in a parameter regarding a coding style of components included in a default coding style marker (COD) in a start marker (SOC) of the original code stream.

10. The method as claimed in claim 7, wherein the coding conditions are a decomposition level number in a parameter regarding a coding style of components included in a default coding style marker (COD) in a start marker (SOC) of the original code stream.