上海交通大学学报
上海交通大學學報
상해교통대학학보
JOURNAL OF SHANGHAI JIAOTONG UNIVERSITY
2001年
2期
201-204
,共4页
杜啸晓%施鹏飞%杨新%严京旗
杜嘯曉%施鵬飛%楊新%嚴京旂
두소효%시붕비%양신%엄경기
图像平滑%异性扩散%偏微分方程%特征提取
圖像平滑%異性擴散%偏微分方程%特徵提取
도상평활%이성확산%편미분방정%특정제취
针对退化扩散方程在图像平滑时对角点的圆弧化,提出由梯度及与其正交方向上的二阶方向导数共同决定扩散速度.在图像的角点位置上,扩散速度趋于零,在线条点位置上,扩散速度由梯度的模值来决定,并在与梯度正交的方向上进行平滑;在灰度变化不大的区域上,采用传导系数为常数的热方程进行平滑.文中的理论上说明了扩散速度的构造方法.实验结果表明,该扩散模型在对图像进行平滑的同时,对特征点的保留是明显的.
針對退化擴散方程在圖像平滑時對角點的圓弧化,提齣由梯度及與其正交方嚮上的二階方嚮導數共同決定擴散速度.在圖像的角點位置上,擴散速度趨于零,在線條點位置上,擴散速度由梯度的模值來決定,併在與梯度正交的方嚮上進行平滑;在灰度變化不大的區域上,採用傳導繫數為常數的熱方程進行平滑.文中的理論上說明瞭擴散速度的構造方法.實驗結果錶明,該擴散模型在對圖像進行平滑的同時,對特徵點的保留是明顯的.
침대퇴화확산방정재도상평활시대각점적원호화,제출유제도급여기정교방향상적이계방향도수공동결정확산속도.재도상적각점위치상,확산속도추우령,재선조점위치상,확산속도유제도적모치래결정,병재여제도정교적방향상진행평활;재회도변화불대적구역상,채용전도계수위상수적열방정진행평활.문중적이론상설명료확산속도적구조방법.실험결과표명,해확산모형재대도상진행평활적동시,대특정점적보류시명현적.
As a cornen in an image is rounded when using degenerate diffusion equation to smooth the image, it proposed to use both the gradient and the second order directional derivative in the direction orthogonal to the gradient to control the diffusion velocity. This diffusion velocity is about zero at the corner position. At the position of the edge it is dominated by the gradient, and the smoothing is executed on the direction orthogonal to the gradient. In the area where the intensity of the image is changed small the image is smoothed by the heat equation whose conduction coefficient is constant. A method was given to construct the diffusion velocity in theory. The experiment shows that this method is valid on the image smoothing while preserving the features.