如何在悬停时将文本放在img上 - 宽度和高度是可变的

I know how to put text on hover on an image if the height and the width is fixed. but I have a responsive slider (owl-slider) and want to add link (easy - yeah.) and a blue overlay with white text in it and a simple fading/sliding transition from the overlay.I know how to put text on hover on an image if