You can use this blurring effect on images which can be used as a subtle hover effect.
*Increase the pixel amount to increase the amount of blur applied.
/*--Blur filter on hover--*/
.entry-content img.blur-filter {-webkit-filter: blur(0px); /* Chrome, Safari, Opera */ filter: blur(0px);}
.entry-content img.blur-filter:hover {-webkit-filter: blur(1px); /* Chrome, Safari, Opera */ filter: blur(1px);}