error on index.codec

[lqian]

I'm new beginner at elasticsearch-image. I compile and install the plugin following instructions of the README on the project. My test environment is elasticsearch 2.4.1 and elasticsearch-image-2.4.1
however, I found the warning log..
[Danger] [my_index] no index mapper found for field: [my_img.CEDD.hash.BIT_SAMPLING] return default position format [Danger] [my_index] no index mapper found for field: [my_img.JCB.hash.BIT_SAMPLING] return default position format [Danger] [my_index] no index mapper found for field: [my_img.JCB.hash.LSH] return default position format
it seems that the plugin is not installed successfully.
also the size of elasticsearch index is greater than raw image dataset. like Issue 22.

any suggestion?