i couldn't understand convex area

Question

selim 2012-7-12

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/43435-i-couldn-t-understand-convex-area

 i know ''area'' command calculates the number of pixels in the region.
 As far as i see,  The value of ''ConvexArea'' is bigger than ''area'' 
 In regionprops,  The term ''ConvexArea'' what is it exactly? 
what does it calculate? For what purpose can we use this property?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

David Legland 2012-7-12

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/43435-i-couldn-t-understand-convex-area#answer_53322

Hi Selim,

the 'convexArea' property corresponds the area of the convex hull of the region. The convex hull of a region is the smallest region that satisfy two conditions: (1) it is convex (2) it contains the original region.

The convex area is by definition greater than or equal to the area of the region. It can be used to compute a shape factor known either as "convexity" or "solidity", defined as the ratio of area over convex area. It can be obtained by using the 'solidity' parameter in regionprops function.

The solidity can be used to discriminate or classify regions using shape criteria.

regards,