Block-Adaptive Discrete Cosine Transform with Rate-Distortion Control
碩士 === 國立清華大學 === 資訊工程學系 === 86 === Block-Adaptive Discrete Cosine Transform with Rate-Distortion ControlDiscrete Cosine Transform (DCT) has been used for many image or video coding standards such as JPEG, H.261/3, MPEG-1/2/4, etc. In this...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
1998
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| Online Access: | http://ndltd.ncl.edu.tw/handle/76454073717365139363 |
| Summary: | 碩士 === 國立清華大學 === 資訊工程學系 === 86 === Block-Adaptive Discrete Cosine Transform with Rate-Distortion
ControlDiscrete Cosine Transform (DCT) has been used for many
image or video coding standards such as JPEG, H.261/3,
MPEG-1/2/4, etc. In this paper, a block adaptive DCT coder by
using a quadtree-based variable blocksize DCT is proposed. It
can achieve the best trade-off between the bitrate and the image
quality by using the Lagrange multiplier λ merge rate and
distortion. By using the quantization matrix generated by the
visual model, our performance has a significant improvement on
image quality. Simulation resultsshow that our coding scheme
outperforms the standard JPEG coder about 1-2 dB at typical bit
rates. It can compete with other coding schemes like embedded
zerotree wavelet (EZW) and embedded zerotree DCT(EZDCT).
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