why blur?

[tengshaofeng]

hi,
I am so appreciated with your great job. And i have read your code carefully.
When i read the convert.py, it confused me in
" blurred = img.filter(ImageFilter.BLUR)
ba = np.array(blurred)"

why should blur the image?
look forward to your reply.
thanks.

[tengshaofeng]

also， i am confused about：
0.2 with batch sampled such that classes are balanced
0.5 with batch sampled uniformly from all images (shuffled)

0.2, 0.5 means what?
please help me.