Images in Digital Edition look pixelated

After creating a EPUB and viewing it in Adobe Digital edition the images look pixelated. They do not look good at all. Even after checking the resolution they do not look good at all.

However, the same epub with the same images, looks great if I use iBooks or other readers.  ADE seems to do a poor job with that.

Anyone knows how to fix this problem?

This problem is for every images in every epub.