I have changed themes recently, and after changing the Image Size setting in the Settings > Media page, I have used the Regenerate Thumbnails (v2.2.4) plugin to regenerate the images. This worked fine, and I've confirmed the new images exist.
The problem I have is that all of the posts (and I have hundreds) still have their original HTML: (example)
<a href="http://www.myblog.com/wp-content/uploads/2013/04/germany01.jpg"><img class="size-large wp-image-3310 aligncenter" src="http://www.myblog.com/wp-content/uploads/2013/04/germany01-600x450.jpg" alt="germany01" width="600" height="450" />
In this case, 600px is the old size, and the new 700px images aren't referenced in the post.
I can't seem to find a plugin to bulk regenerate the code for these images, and it'd be a nightmare to go do all of this by hand for hundreds of posts.
There doesn't seem to be a reliable Search and Replace strategy either, as there are many different aspect ratios and too much room for error.
Anyone have a great idea?