光电工程
光電工程
광전공정
OPTO-ELECTRONIC ENGINEERING
2010年
5期
104-109
,共6页
图像分割%能量最小化%Graph Cuts算法%MRF模型
圖像分割%能量最小化%Graph Cuts算法%MRF模型
도상분할%능량최소화%Graph Cuts산법%MRF모형
image segmentation%energy minimization%Graph Cuts algorithms%MRF model
在最小化由马尔科夫随机场(MRF)图像分割模型建立的能量函数方面,基于Graph Cuts的alpha-expansion是一种比较有效的算法.但是,由此算法构建的s/t图中边的数目非常多,运算速度很慢.为了减少alpha-expansion算法的计算量,本文在标号为alpha的像素向其它像素膨胀的过程中,先隔离非alpha类间的联系,而只考虑alpha类与非alpha类之间的关系,从而避免了alpha-expansion算法需要构造辅助结点的问题,减少了s/t图中边的数目,提高了算法的计算效率.因放松了非alpha类间的关系对alpha膨胀的约束,使得算法可以更容易得跳出能量函数的局部极小点而获得更优的分割结果.实验中将改进的算法与传统的基于Graph Cuts的算法做了对比,显示了新算法在运算时间和最小化能量方面的有效性.
在最小化由馬爾科伕隨機場(MRF)圖像分割模型建立的能量函數方麵,基于Graph Cuts的alpha-expansion是一種比較有效的算法.但是,由此算法構建的s/t圖中邊的數目非常多,運算速度很慢.為瞭減少alpha-expansion算法的計算量,本文在標號為alpha的像素嚮其它像素膨脹的過程中,先隔離非alpha類間的聯繫,而隻攷慮alpha類與非alpha類之間的關繫,從而避免瞭alpha-expansion算法需要構造輔助結點的問題,減少瞭s/t圖中邊的數目,提高瞭算法的計算效率.因放鬆瞭非alpha類間的關繫對alpha膨脹的約束,使得算法可以更容易得跳齣能量函數的跼部極小點而穫得更優的分割結果.實驗中將改進的算法與傳統的基于Graph Cuts的算法做瞭對比,顯示瞭新算法在運算時間和最小化能量方麵的有效性.
재최소화유마이과부수궤장(MRF)도상분할모형건립적능량함수방면,기우Graph Cuts적alpha-expansion시일충비교유효적산법.단시,유차산법구건적s/t도중변적수목비상다,운산속도흔만.위료감소alpha-expansion산법적계산량,본문재표호위alpha적상소향기타상소팽창적과정중,선격리비alpha류간적련계,이지고필alpha류여비alpha류지간적관계,종이피면료alpha-expansion산법수요구조보조결점적문제,감소료s/t도중변적수목,제고료산법적계산효솔.인방송료비alpha류간적관계대alpha팽창적약속,사득산법가이경용역득도출능량함수적국부겁소점이획득경우적분할결과.실험중장개진적산법여전통적기우Graph Cuts적산법주료대비,현시료신산법재운산시간화최소화능량방면적유효성.
Alpha-expansion algorithm based on Graph Cuts is a useful method for minimizing energy function established by Markov Random Field model of image segmentation.However,the number of edge of the graph constructed by the algorithm is large,So the speed is rather slow.In order to reduce the complexity of the alpha-expansion algorithm,the relationship between the pixels labeled alpha and pixels labeled non-alpha was only considered and the relationship between the pixels labeled non-alpha was omitted.This idea avoided adding auxiliary nodes which were one of main factor to affect the efficiency of the alpha-expansion algorithm.Since the constraints on the relationship between pixels set labeled different non-alpha was loosed,it Was easier for the new algorithm to escape some local minimum of energy function so as to gain more optimal segmentation results.In experiments,compared with the standard algorithms based on Graph cuts,the algorithm had the better performance in the running time and the minimum energy.
