CAJ | 학술논문

针对SPIHT算法的不足，为了兼顾图像编解码时间与解码图像质量，提出了一种改进的SPIHT图像压缩算法。采用LS9／7提升格式小波变换，结合人眼视觉系统的特点，对原算法高低频子带的扫描方式和阈值的确定方法进行了改进；针对SPIHT算法重复扫描的问题，在编码时使用最大值链表的思想，大大减少了计算量，节省了运行时间。实验结果表明，本文提出的改进算法在图像编解码时间和重构图像质量两方面均优于原算法，尤其在低码率情况下提高了解码图像的质量。
침대SPIHT산법적불족，위료겸고도상편해마시간여해마도상질량，제출료일충개진적SPIHT도상압축산법。채용LS9／7제승격식소파변환，결합인안시각계통적특점，대원산법고저빈자대적소묘방식화역치적학정방법진행료개진；침대SPIHT산법중복소묘적문제，재편마시사용최대치련표적사상，대대감소료계산량，절성료운행시간。실험결과표명，본문제출적개진산법재도상편해마시간화중구도상질량량방면균우우원산법，우기재저마솔정황하제고료해마도상적질량。
Aiming at shortage of the SPIHT algorithm, this paper proposes an improved image compression algorithm in order to overcome the shortcomings of decoding image quality and coding time. It adoptes LS9/7 lifting wavelet transform. According to the characteristics of the human visual system （HVS）, the scanning mode and the method to determine the threshold of algorithm are changed to improve the quality of reconstruction image. On the question of repeating scan of SPIHT algorithm, it uses maximum table thought, which greatly reduces the computation and saves operating time. The experimental results proves that the image deeoding time and the quality of reeonstruetion image of the improved algorithm are better than the original algorithm, especially in the case of low bit rate.