get frames & nii2png

+inputheader = '..\data\MICCAI_BraTS_2019_Data_Training\HGG_seg_flair\';
+outfolder = '..\data\MICCAI_BraTS_2019_Data_Training\frame\';
+
+files = dir(inputheader);
+id = {files.name};
+%  files + dir  file 
+flag = ~strcmp(id, '.') & ~strcmp(id, '..'); 
+files = files(flag);
+
+
+for i = 1 : length(files)
+
+    id = split(files(i).name, '.nii');
+    id = char(id(1));
+    fprintf('ID #%d = %s\n', i, id);
+    filename = id; % BraTS19_2013_2_1_seg_flair.nii
+    data_path = strcat(inputheader,'\', filename);
+    data = niftiread(data_path); %size 240x240x155 
+
+    [x,y,z] = size(data);
+
+    for i = 1 : z 
+        [row, col] = find(data(:,:,i) ~= 0);
+        if(size(row) > 0)
+            st = i;
+            break;
+        end
+    end
+
+    for i = z : -1 : 1 
+        [row, col] = find(data(:,:,i) ~= 0);
+        if(size(row) > 0)
+            en = i;
+            break;
+        end
+    end
+
+    c = 0;
+    step = round(((en) - (st))/11);
+    for k = st + step : step : st + step*10
+        c = c+ 1; 
+
+        type = '.png';
+        filename = strcat(id, '_', int2str(c), type); % BraTS19_2013_2_1_seg_flair_c.png
+        outpath = strcat(outfolder, filename);
+        % typecase int16 to double, range[0, 1], rotate 90 and filp updown
+        cp_data = flipud(rot90(mat2gray(double(data(:,:,k)))));
+        imwrite(cp_data, outpath);
+    end
+    
+end
+
+
+% p = 'st: %d\n';
+% fprintf(p, st);
+% p = 'en: %d\n';
+% fprintf(p, en);
+