matlab中边界框的最小值和最大值

Question

这是我用于边界框的代码
  propied = regionprops(L,'Area','BoundingBox','MajorAxisLength');

多个边界框，以便循环使用

`for n=1:size(propied,1)`

     we need to find minima and maxima for those 
     whose major axis length less than 28
     there are too many bounding boxes

    `if (propied(n).MajorAxisLength < 28)` 

         to get the bounding box of non-zero elements                       
        and  i am using 2 D image 

        `[y,x] = ind2sub(size(L), find(L));`
        `coord = [x, y];`
        `mc = min(coord)-0.5;`
        `Mc = max(coord)+0.5;`
    `end`
`end`

Answer 1

您正在处理阿拉伯语脚本并尝试将Tashkil (Diacritics)与其相关字母ligature相关联。） 您假设adiacritic标记的'MajorAxisLength'属性小于28像素，并且您希望将这些蒙版与不具有变音符号的主要字母的掩码相关联。

首先，让我们创建两个面具：一个用于装饰，一个用于主要字母

鉴于此输入图像BW

L = bwlabel( BW ); % label each component in the text
st = regionprops( BW, 'MajorAxisLength', 'PixelIdxList', 'Centroid' );    
diac = [ st(:).MajorAxisLength ] < 28; % this is your threshold, it is not very good.
DM = zeros( size(BW) );
DM( vertcat( st(diac).PixelIdxList ) ) = 1; % mask for diacritics

LM = zeros( size(BW) );
LM( vertcat( st(~diac).PixelIdxList ) ) = 1; % mask for letters body

现在我们将使用每个变音符号的质心来定位最接近结扎的像素

[y x] = find( LM ); % coordinates of all ligature pixels
dc = vertcat( st(diac).Centroid ); % centroids of all diacritics
dst = sum( bsxfun( @minus, cat( 3, x, y), permute( dc, [3 1 2] ) ).^2, 3 ); % distance
[mn mi] = min( dst, [], 1 ); % closest LM pixel to each centroid
ll = L( sub2ind( size(L), y(mi), x(mi) ) ); % get the label of the closest ligature

可视化匹配结果

ac = vertcat( st(:).Centroid ); % all centroids
figure;
imagesc( DM + 2*LM );axis image;
hold on;
plot( [dc(:,1)'; ac(ll,1)'], [dc(:,2)';ac(ll,2)'], 'r');
colormap hot

请注意，
在'MajorAxisLength'上使用阈值似乎并不能很好地识别变音符号，您可能需要考虑不同的阈值，或者改为对'Area'属性进行阈值处理。