选择图像中最大的对象 [英] Select largest object in an image

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本文介绍了选择图像中最大的对象的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我试图找到图像中最大的对象,并删除图像中小于它的任何其他对象.

I am trying to find the the largest object in an image and remove any other objects in the image that are smaller than it.

这就是我所拥有的,但我无法让它工作.

This is what I have but I cannot get it to work.

 l=bwlabel(BW);

 %the area of all objects in the image is calculated
 stat = regionprops(l,'Area','PixelIdxList');
 [maxValue,index] = max([stat.Area]);

  %remove any connected areas smaller than the biggest object
  BW2=bwareaopen(BW,[maxValue,index],8);
  subplot(5, 5, 4);
  imshow(BW2, []);

我正在处理数字乳房 X 光照片,例如 这些.我正在尝试从图像中删除除乳房区域之外的所有对象.

I am working with digital mammograms such as these. I am trying to remove all objects from the image except for the breast region.

推荐答案

使用 bwconncomp 因为它返回单独单元格中区域的坐标索引,其中每个单元的大小很容易辨别:

Use bwconncomp instead since it returns the coordinate indexes for region in a separate cell, where the size of each is easily discerned:

>> BW = [1 0 0; 0 0 0; 0 1 1]; % two regions
>> CC = bwconncomp(BW)
CC = 
    Connectivity: 8
       ImageSize: [3 3]
      NumObjects: 2
    PixelIdxList: {[1]  [2x1 double]}

PixelIdxList 字段是一个元胞数组,其中包含每个区域的坐标索引.每个数组的长度就是每个区域的大小:

The PixelIdxList field is a cell array with the indexes of coordinates for each region. The length of each array is the size of each region:

>> numPixels = cellfun(@numel,CC.PixelIdxList)
numPixels =
     1     2
>> [biggestSize,idx] = max(numPixels)
biggestSize =
     2
idx =
     2

然后你可以很容易地用这个组件制作一个新的图像:

Then you can easily make a new image with just this component:

BW2 = false(size(BW));
BW2(CC.PixelIdxList{idx}) = true;

<小时>

编辑:根据评论,可以使用 regionprops 使用BoundingBox"选项:


EDIT: From the comments, the need to crop the output image so that the region comes to the edges can be addressed with regionprops using the 'BoundingBox' option:

s  = regionprops(BW2, 'BoundingBox');

它给你一个矩形 s.BoundingBox,你可以用它来裁剪 BW3 = imcrop(BW2,s.BoundingBox);.

which gives you a rectangle s.BoundingBox which you can use to crop with BW3 = imcrop(BW2,s.BoundingBox);.

这篇关于选择图像中最大的对象的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!

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