Can I change image's background fullscreen slideshow jquery?

Q: I am using wowslider on my website. I have a slide show with both landscape and portrait orientation images. When a vertical image is shown, the unfilled areas on the sides are stark white. Is there a way to change it so the background is transparent and the website background shows through or to simply change the color so it blends easier?

A: If you want to use the transparent background, you should use .png images.

But you can change images on .png images manually.
1) Upload your .png images to data/images folder
2) Change image format in generated .html code. For example:

...
<span><img src="data1/images/image1.jpg" alt="" title="" id="wows1"/></span>
...

Unfortunately, it's impossible to change image's background. You can do it in any graphic editor only.