利用傅立叶变换研究铁杉木材管胞横截面尺寸

Cross section size analysis of tracheids in Tsuga chinensis wood with Fourier transformation

利用傅立叶变换图像处理技术研究铁杉木材管胞尺寸,把每一个管胞都用其中心的1条长9个像素点、宽2个像素点的线段点图来表示,进行傅立叶变换,其能量光谱图在水平和垂直方向上的频率,除零值以外的最大值,为管胞径向、弦向直径。结果表明:该方法与光学显微镜、图像处理软件的结果基本相同,说明傅立叶变换图像处理技术适用于管胞尺寸的测定,扩大了其应用领域,也为建立木材几何参数识别的数学模型提供了理论依据。

Fourier transformation image-processing technology was applied to measure cross section size of Tsuga chinensis tracheids. In this method, each tracheid was mapped by the center point on the cell of transverse section with each point was extended up and down for four pixels （nine-pixel length in total） and two pixels in width, and thereafter line convoluted dot map （LCDM） was obtained. Through Fourier transformation, the frequency distribution of power spectrum patterns from both horizontal and vertical directions was obtained and the cell diameters in radius and tangential direction were known from the maximum value except 0 in the distribution. The results indicated that there was no significant difference from the optical microscope or imageprocessing software. It shows that this method can be applied to the tracheid measurement and expand the Fourier transform application domain, and it also provides a theoretical basis for the establishment of the mathematical model to identify cell geometric parameters.