Large image size stuck on old value, even for new images

Question

I changed the 'Large' image size in Settings > Media > Image Sizes from the default to max-width 586px. That was wrong, so I changed it back to max-width 1024px. However, the smaller size seems to have stuck. When I upload new images now, the size option for Large is 586px wide, even if the image is larger than that (e.g. 1600 x 2133)

Wordpress version is 3.7.1

I have some custom image sizes, which were working correctly before I changed the Large size, and now will not insert as any larger than 586px wide. Here's the relevant section in functions.php for the custom image sizes:

if ( function_exists( 'add_image_size' ) ) { 
    add_image_size( 'top-stories-home', 1014, 672, true );
    add_image_size( 'full-width-desktop', 576, 9999 );
    add_image_size( 'text-wrapping', 350, 9999 );
}
add_filter( 'image_size_names_choose', 'my_custom_sizes' );
function my_custom_sizes( $sizes ) {
    return array_merge( $sizes, array(
        'top-stories-home' => 'Home Top Stories',
        'full-width-desktop' => 'Post Photo wCaption',
        'text-wrapping' => 'For Wrapped Text'
    ) );
 }

Here is a screenshot of the Dashboard:

And here is a screenshot of the dialog you get when you click 'Add Media' inside a post:

Answer 1

Find the actual large version of the image file (i.e., wp-content/uploads/2014/03/my-image-1024x576.jpg) and see if in fact it has the smaller dimensions or if it is just being rendered that way in your theme. If the large version is in fact 1024px wide, then the filter is working.

Make sure you are referencing the right image size in the theme:

<?php echo get_the_post_thumbnail($post->ID, 'top-stories-home'); ?>

Also, makes sure that your CSS is not manually reducing the size of the image. If the image is being used as a DIV background and the CSS is reducing the size of the DIV, the image will also be smaller.

For example:

.div {
    max-width: 586px;
    max-height: 500px;
}

If the actual values in the drop down boxes are incorrect, clear cache if you use caching plugins.