WQbZS: Wavelet Quantization by Z-Scores for JPEG2000
| Autor: | Oswaldo Morales-Matamoros, Ana Lilia Coria-Paes, Jesús Jaime Moreno-Escobar, Teresa Ivonne Contreras-Troya, Ricardo Tejeida-Padilla |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Mathematical optimization
General Computer Science Computer science Quantization (signal processing) Trellis quantization Vector quantization computer.file_format Lossy compression Quantization (physics) Wavelet JPEG 2000 Entropy (information theory) Entropy encoding Quantization (image processing) Algorithm computer Color Cell Compression |
| Zdroj: | International Journal of Advanced Computer Science and Applications. 7 |
| ISSN: | 2156-5570 2158-107X |
| Popis: | In this document we present a methodology to quantize wavelet coefficients for any wavelet-base entropy coder, we apply it in the particular case of JPEG2000. Any compression system have three main steps: Transformation in terms of fre-quency, Quantization and Entropy Coding. The only responsible for reducing or maintaining precision is the second element, Quantization, since it is the element of lossy compression that reduces the precision of dequantized pixels in order to make quantized pixels more compressible. We modify the well-known dead zone scalar Quantization introducing Z-Scores in the pro-cess. Thus, Z-scores are expressed in terms of standard deviations from their means. Resultantly, these z-scores have a distribution with a mean of 0 and a standard deviation of 1, in this way we increase redundancies into the image, which produces a lower compression ratio. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|