Blurry Images on Category Pages

[distributedsav]

Hi, we've recently started to re-populate our website from scratch but are having issues with blurry images.  On our category pages we have an image across the top (above the products) that is 940 x 160 to fit on a page with a column on the left.  We've uploaded the images to Product Catalogue/Manage Categories and we've also tried the 'Easy Content Blocks' Extension but the images appear blurry.

If we right click on the image and select 'Open image in new tab', the image on the new browser tab is crisp.  We can't understand why this is happening.  We've read lots of posts about re-sizing product images but this isn't a product image.  Any help would be very much appreciated.

[katheer]

Use better resolution images for banners.
for the example:
Requirement : Main image need to be stretch width screen
If screen width is 1200px, banner image width should be grater than 1200px. (Please use ratina images (2X or 3X) for banner images.)

If you had an issue with product images, please check the following links.
http://www.mindyourownwebsite.com.au/magento-jpg-images-looking-blurry-in-category-view/
http://forum.azmagento.com/how-to/images-are-blurry-8230-how-to-resolve-47755.html
http://stackoverflow.com/questions/8384678/magento-resize-image-quality-dirty-white-background

 https://github.com/dbashyal/Magento-resize-category-images (Git - Module)