1. Annotate selected images (more details at 2-1);
2. Read data from images and annotation xml files;
3. Reorganize data structure;
4. Save data into .mat files.

$ matlab
> cd matlab
> run img_anno.m
> run getData.m
> run checkData.m
> run splitData.m

1. Select images every (step=)n pictures from source dir;
2. Get all filenames under certain directory;
3. Create same-name annotation xml file according to example xml annotation;
4. Call GUI & annotate using mouse click.

./--data/----annotation/
  |       |--image/ #target dir
  |       |--validation/---annotation/ #validation dir
  |       |              `-image/
  |       `--rar/   #source dir
  |-python/--anno_img.py
  `-matlab/

organize data as above and run python script.

$ cd python/
$ python anno_img.py 

You can change selection-step & target-dir in script file as you like.

$ matlab
> cd matlab
> run img_anno.m