Questions about using ImageDataStore and only some subfolders in a folder

These are related, so I will ask them both here:

1. Is it possible to specify which subfolders in a folder are to be used in an ImageDataStore? For example, if you have 5 subfolders but would like to use just 3 of the subfolders in your ImageDataStore, is that possible? I cannot tell from the ImageDataStore documentation.

2. Alternatively, is it possible to create an ImageDataStore and then add to it? If #1 is not possible then I can imagine a workaround in which I add to an ImageDataStore subfolder by subfolder.

Answer 1

[HW]

Sean's suggestion was helpful, although it took a long time to run. I eventually figured out that I could import into the ImageDataStore everything in all the subfolders, using the subfolder names as labels, and then delete out everything that matched the labels I did not want to retain.

Answer 2

[Sean de Wolski]

Build files with dir. For example, all pngs at this level and below. Then strip out any you don't want or keep just the ones you do:

d = struct2table(dir(fullfile(pwd, '**','*.png')));
d = d(ismember(d.folder, folders_you_want), :);
files = fullfile(d.folder, d.name)

(Untested in MATLAB)

Answer 3

[michael scheinfeild]

use filter on subfolder

dbpathSave={'mainfold\case*\Na',...
     'mainfold\case*\Nb',...
      'mainfold\case*\Nc',};

exts ={'.jpg'};
     imds = imageDatastore( dbpathSave,'FileExtensions',exts,'IncludeSubfolders',0,'LabelSource' ,'foldernames');