使用matlab处理.nii图像

柔情只为你懂 2022-10-22 07:41 305阅读 0赞

## 一、工具包准备 ##

1. 下载 [Tools for NIfTI and ANALYZE image][]

([https://ww2.mathworks.cn/matlabcentral/fileexchange/8797-tools-for-nifti-and-analyze-image?s\_tid=srchtitle][https_ww2.mathworks.cn_matlabcentral_fileexchange_8797-tools-for-nifti-and-analyze-image_s_tid_srchtitle])

2. 解压后整个移动到文件夹matlab->toolbox中

3. 添加路径

![20210405103419917.png][]

![2021040510345875.png][]

4.更新工具包缓存

![20210405103515165.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01JS0FTQTM_size_16_color_FFFFFF_t_70][]

## 二、读取.nii图像 ##

使用load\_nii

nii = load_nii( 'Brats17_2013_2_1_t1.nii.gz' );  % 装载.nii数据
    img = nii.img;  %文件包含img和head，img是图像数据

因为nii一般包含多个slice，第i个slice的读取和显示：

Image = img(:,:,i);
    imshow(Image,[]);

## 三、保存.nii图像为其他格式 ##

根据[imwrite][]的文档可知，不同格式对应要求的数据格式也不相同：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01JS0FTQTM_size_16_color_FFFFFF_t_70 1][]

如果第i个slice的图片Image格式是int16，需要修改成符合要求的可imwrite的格式，即修改灰度值范围为0-255：

Image = mat2gray(Image);

再保存成任意希望的格式即可：

imwrite(Image,[savepath,int2str(i),'.bmp']);

保存当前.nii图像中所有的slice：

[n1,n2,n3] = size(img);
    for i = 1:n3
        Image = img(:,:,i);
        %figure(i);
        %imshow(Image,[]);
        Image = mat2gray(Image);
        imwrite(Image,[savepath,int2str(i),'.bmp']);
    end

对于groundtruth，是标记好的图像，一般不改变其灰度

可能需要改变图像格式从int16-int16：

[n1,n2,n3] = size(img);
    for i = 1:n3
        Image = img(:,:,i);
        X = Image(1:end);
        Y = typecast(X,'uint16');
        [mm,nn] = size(Image);
        Image = reshape(Y,mm,nn);
        imwrite(Image,[savepath,int2str(i),'.png']);
    end

可能需要改变图像格式为uint8：

Image = uint8(Image)

## 参考 ##

[https://www.cnblogs.com/glam/p/13712362.html][https_www.cnblogs.com_glam_p_13712362.html]

[https://blog.csdn.net/wrj199421/article/details/84645844][https_blog.csdn.net_wrj199421_article_details_84645844]

[Tools for NIfTI and ANALYZE image]: https://ww2.mathworks.cn/matlabcentral/fileexchange/8797-tools-for-nifti-and-analyze-image?s_tid=srchtitle%C2%A0
[https_ww2.mathworks.cn_matlabcentral_fileexchange_8797-tools-for-nifti-and-analyze-image_s_tid_srchtitle]: https://ww2.mathworks.cn/matlabcentral/fileexchange/8797-tools-for-nifti-and-analyze-image?s_tid=srchtitle
[20210405103419917.png]: /images/20221022/f9ccb47295cb41d48ea2e60f8922bf7c.png
[2021040510345875.png]: /images/20221022/c21a4892063245c895ae37c211321320.png
[20210405103515165.png]: /images/20221022/9363a4594c97483e9211f81a1776f3c1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01JS0FTQTM_size_16_color_FFFFFF_t_70]: /images/20221022/0e1ab4e3016a40c48daed76af5a47127.png
[imwrite]: https://www.mathworks.com/help/matlab/ref/imwrite.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01JS0FTQTM_size_16_color_FFFFFF_t_70 1]: /images/20221022/1942d9dacd1445f08e1ba26a808fca97.png
[https_www.cnblogs.com_glam_p_13712362.html]: https://www.cnblogs.com/glam/p/13712362.html
[https_blog.csdn.net_wrj199421_article_details_84645844]: https://blog.csdn.net/wrj199421/article/details/84645844