将文件夹中的所有图像进行RGB到灰度转换，将它们保存到具有原始名称的其他文件夹中

Question

我有这段代码可以将图像转换为灰色并将其保存在当前文件夹中：

directory = dir('AM01AFS.jpg');
for i = 1 : size(directory,1)
   filename = directory(i).name;
   img = rgb2gray(imread(filename));
   imwrite(img, ['Gr_' filename]);
end

我需要将一个文件夹（图像）从 RGB 转换为灰色，并将它们保存在具有相同原始名称的 Output 文件夹中。

Answer 1

您的代码看起来不错。
我希望您需要将 RGB 转换为 Gary，而不是 GRB 转换为 Gary...

1. 修改directory = dir('AM01AFS.jpg');为directory = dir('*.jpg');

2. 如果您不想覆盖现有图像，请创建新的输出目录。

   %Assume jpg images are in the same directory as the m file.
   indir = cd; %Modify the indir to location of the jpg files.
   outdir = 'Gray'; %Name or output directory.
   directory = dir([indir, '\', '*.jpg']);
   
   if ((~exist(outdir, 'dir') && length(directory) > 0))
       %Create new directory named outdir if directory not exist.
       mkdir(outdir);
   end
   
   for i = 1 : length(directory)
       filename = directory(i).name;
       rgb_img = imread([indir, '\', filename]);    
       if (ndims(rgb_img) == 3) %Make sure img is RGB (not gray).
           img = rgb2gray(rgb_img);
           %Save gray image to outdir (keep original name).
           imwrite(img, [outdir, '\', filename]);
       end
   end
   

---

如果你喜欢打开文件夹选择对话框，可以使用下面的例子：

%Open folder selection dialog box, for selecting input and output folders.
indir = uigetdir(cd, 'Select input folder');
outdir = uigetdir(cd, 'Select output folder');
directory = dir([indir, '\', '*.jpg']);

for i = 1 : length(directory)
    filename = directory(i).name;
    rgb_img = imread([indir, '\', filename]);    
    if (ndims(rgb_img) == 3) %Make sure img is RGB (not gray).
        img = rgb2gray(rgb_img);
        %Save gray image to outdir (keep original name).
        imwrite(img, [outdir, '\', filename]);
    end
end