For the feature of the liver B-ultrasound image, we adopt the Gaussian low-pass filter and contrast-stretchingtransformation methods.
针对肝脏B超声图像的特点，本文在对图像进行预处理时采用了高斯低通滤波与灰度拉伸相结合的技术。
2
Since FEM has no such requirement that the grid line are of orthogonality, a sequence of shearing and stretchingtransformation, both prior to and subsequent to the elliptic mapping is used.
因有限元法对网格无正交性要求，因而可在椭圆变换前后进行剪切和延伸变换。
3
This feature makes it possible to produce the filler by isometric transformation of thin sheet through local bending without material stretching.