How can i get proper image back after inverse discrete wavelet transform?

I performed 2 level 2D dwt on the cover image(gray) and performed 1 level 2D dwt on the secret image. on the lowest LL2 subband of cover i hide the LL1 subband of message using an encryption algorithm but i am having problem performing the inverse dwt operation...after the inverse operation i am not getting the proper image back. i am getting an image lost in noise. So how can i get proper recovered image?