cifar100 dataset consists of repeated image?
I randomly browsed some images in cifar100, and found many images like this:
. 

Anything went wrong? Or cifar100 indeed consist of such images?

I think you did not load in the images correctly. Take a look at loading an image from cifar-10 dataset to see that others also have those problems. The correct way to reshape one of those cifar images is as follows:

single_img_reshaped = np.transpose(np.reshape(single_img,(3, 32,32)), (1,2,0))

