Quality of pictures in image carousel is not good

Q: I am very concerned about the quality of my pictures in my wowslider. They were decent pictures but tend to look pixelated.
I am using wowslider 2.0 on a Mac using Snow Leopard v. 10.6.8 and am using Firefox 8.0 but the browser is not the problem. What can I do so that images are sharper or clearer? I normally have to lighten my pictures in Photoshop.
1. Is the custom size that I am using a problem? 300 px x 220 px? or do I need to use a different size? (I have constraints due to the layout of my website).
2. Would I get better quality pictures if I saved each picture to the same size as the wowslider, in other words 300 px x 220 px or should I save each picture at its full original size?
3. What dpi should I be saving at? 300 dpi, 240 dpi, 180 dip, 72 dpi?
4. Is there a minimum size for best quality of pictures (number of pixels)?
I imagine that the quality of the pictures is being affected by either the compression using .png or the resizing.
What can I do to show better quality pictures? Can you help me?
Thanks so much.

A: To improve quality of your images you can do the following:
1) Go to
Gallery->Properties->Images

and increase value of "Image quality" parameter.

2) Use original images with the same resolution that your slideshow should have (300x220).
wowslider app. is not graphic editor, so the best way to resize your images is use of special products (for example, Photoshop).

3) wowslider app. generates images in .jpg format. So, if your original images will be in .jpg format too, it'll help to save quality of original images.

Also, quality of images doesn't depends on dpi and there is no "minimum size for best quality".