Image resizer will not be able to resize images that are a part of a javascript.
image resizer works only with img tags.
image resizer looks at the image tag:
<img src="myimage.jpg" height="26" />
and looks for the height o width attribute, it uses those attributes to determine the size to use for resizing the image.
I believe with nevo slider, the image source, and dimensions are set trough javascript. Image resizer wont work properly in this way.