Any idea about application of deep dream?
There's already at least one application out, if you interpret 'application' broadly enough: Decoupled Deep Neural Network for Semi-supervised Semantic Segmentation by Hong, Noh and Han. They use it for image segmentation. Standard image recognition networks can only give you a bounding box for each object recognized on an image. If you want to know which pixels constitute that object, you have to do image segmentation.

Basically, after finding a dog on an image, Hong et al's architecture back-propagates the dog-ness through the neural network down to the pixel level, to find the pixels that were the most responsible for the dog appearing. (They then use this heatmap as input for a supervised segmentation network, there's no deep dreaming in that part.)

This is already kind of an existence proof that the Deep Dream idea can be useful outside image manipulation. But I wouldn't downplay image manipulation itself either. I mention two things that are not immediate applications of Deep Dreaming, and we don't have them currently, but I can kinda see a plausible road from the original Deep Dream algorithm towards these:


Beautifying pictures and human faces and bodies. (Automating what a Photoshop retouch artist does.)
CSI-style image upscaling with fake but believable interpolated detail.