摘要
研究了基于小波变换的光栅投影图的压缩．首先介绍了三维形貌测量的光栅投影图及 其需要进行压缩的原因;简介可用于图像压缩的小波余弦变换技术,利用haar小波和db7小波对 光栅投影图进行小波变换．按照不同的压缩比保留最大的小波系数．实验结果表明此方法能有效 地压缩光栅投影图,使用压缩后还原的位相图解调出来的物体形貌信息能得到有效的保留,而且 使用不同的小波进行压缩变换的效果有着很大的区别．
The grating projective image compression technology based on wavelet transformation is stydies. Firstly grating projective images used in three - dimentioned shape measurement are introduced and the needness for compressing these images is discussed. Then the wavelet transformation technology which could compress images is indicated. The haar wavelet and db7 wavelet are used to transform the grating projective images. Then containing max coefficients according to certain ratio and using them to reconstruct the images. The db7 wavelet is better than the haar wavelet in compressing these grating projective images. Applying images compressed by db7 wavelet and demodulating the phase, then it is compared with the phase demodulated with original images. Finding out that image compression could degenerate the phase demodulated, but under certain compress ratio the errors of the phase are acceptable. The experiment result shows that this method could compress the grating projective images effectively and the choice of wavelet is crucial.
出处
《暨南大学学报（自然科学与医学版）》
CAS
CSCD
北大核心
2005年第5期626-632,共7页
Journal of Jinan University(Natural Science & Medicine Edition)
基金
广东省自然科学资金(010377)资助项目
关键词
小波变换
图像压缩
光栅投影图
四步相移法
wavelet transformation
image compression
grating projective images
four- step phase - measuring method
