Thread: Resizing the Blog post featured header images

Resizing the Blog post featured header images

I'm trying to apply a re-size of the Blog posts Featured images, the ones that show up on the right side at a default resolution of 150x100.

I'm trying to display them horizontally at a 580px x 160 px, but no matter what modifications I did, the image is stretched and using Chrome, I see the following:
<img width="150" height="99" src="http://domain.com/wp-content/uploads/2012/12/48ff9999285cd-150x99.jpg" class="attachment-blog-thumbnail wp-post-image" alt="EEditsz_lim opts-sharp 0.7KeyPoint0.41375 0.173585">


What I did prior to that:

1. Media settings: Changed the Thumbnail size and Medium size to 580 x 160

2. Theme-functions.php:
// this theme uses post thumbnails
add_theme_support('post-thumbnails', array('post', 'page'));
set_post_thumbnail_size(580, 160); // normal post thumbnails

// add default posts and comments RSS feed links to head
add_theme_support( 'automatic-feed-links' );
}

// setup different image sizes
if ( function_exists( 'add_image_size' ) ) {
add_image_size('blog-thumbnail', 580, 160); // blog post thumbnail size, box crop mode
add_image_size('sidebar-thumbnail', 50, 50, true); // sidebar blog thumbnail size, box crop mode

3. style.css
.entry img, img.attachment-blog-thumbnail{border:1px solid #CCC; padding:5px; float:left; /*margin:15px 15px 5px 0;*/ width:580px; height:160px;}

4. master-rtl.css
.entry img, img.attachment-blog-thumbnail{border:1px solid #CCC; padding:5px; float:left; margin:15px 15px 5px 0; width:580px; height:160px}

Reuploaded a new image and set it as featured (To avoid the Regenerate thumbnails) and still, the image is stretched.

Something is forcing the uploaded images to be set at half the image size no matter the original dimension that it was uploaded, I need to know which one to tackle that affect the Blog posts thumbs and not the ads thumbs.

Anyone else trying a similar tweak?