Ion-slide-box with local files cdvfile

just recently i make a change to an application i am developing, it was using api for all so it was somewhat slow because just to open the slider with the images it has to call each one from url, and more important, one requirement was that it has to have offline access.
So i though better to download everything at first, the information inserted in sqlite and the pictures downloaded to some local directory the first time user log in.
everything fine, but when i enter the slidebox i am surprised now the loading of the images are really slow than when i was using urls instead of local files, when first it enters it starts rendering the page as little blocks one by one. the pictures are like 120, 130k more or less each one.

this is the code:

 <ion-slide-box active-slide="currentIndex" show-pager="false" disable-scroll="false" on-slide-changed="slideHasChanged($index)"> 
     <ion-slide class="items" ng-repeat="(idpack, productos) in paquetes_productos">  
     <img ng-src="cdvfile://localhost/persistent/productos/default-producto-{{idpack}}.jpg" alt=""/>      ............