Reduction of ringing artifacts in JPEG-2000 | |
| Author | K. C., Nirendra |
| Call Number | AIT Thesis no.TC-02-09 |
| Subject(s) | JPEG (Image coding standard) Image compression |
| Note | A thesis submitted in partial fulfillment of requirements for the Degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. TC-02-09 |
| Abstract | With the increasing use of multimedia technologies, image compression requires higher performance as well as new features. To address this need in the specific area of still image encoding, a new standard is currently emerging which is known as JPEG- 2000. The JPEG-2000 enables decompression of many images products from a single compressed file and offers several opportunities for compressed domain processing. But it suffers from coding artifacts such as ringing artifacts. Since ringing artifacts appear around edges, it is annoying to the eye. We have investigated two techniques for the reduction of ringing artifacts. The first one is the encoding parameter selection technique and the other is postprocessing technique. Four methods have been used for encoding parameter selection technique and Linear Least Square Error Estimation (LLSEE) method has been used for the reduction of ringing artifacts. According to JPEG-2000 standard, we can compress an image with different tiles, codeblock, and precinct and quantizer step sizes. Different tile, precinct, codeblock and quantizer step sizes have been used to investigate the reduction of ringing artifacts. The results show that we can reduce ringing artifacts using a single tile, higher codeblock, and higher precinct sizes both subjectively and objectively. Same is true for different quantizer step size too. The postprocessing LLSEE method has also been used to reduce the ringing artifacts. It does not reduce ringing artifacts. This method requires knowing noise variance for each pixel. Since there is no method available in JPEG-2000 to know noise variance for each pixel, noise variance for a whole image is calculated using robust median filter. Noise variance for the whole image instead for each pixel is responsible for its poor performance. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-02-09 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Fernando, W. A. C. ; |
| Examination Committee(s) | Erke, Tapio ;Teerapat Sanguankotchakorn; |
| Scholarship Donor(s) | The Government of Finland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2002 |