This plugin enable bloggers to upload images, crop and save it as post thumbnails without manually copy-n-paste custom field values. For theme develop
WP Post Thumbnail plugin adds an image upload, crop and save panel in 'Write Post' screen. It allows you to easily upload a .jpg image file. Once the image file is uploaded, you can crop it before saving it as your thumbnail. That's it.
Spend less time messing around with Photoshop everytime you need to make a thumbnail (or two) for your post. Also, saves you time and trouble from manually copy-and-pasting uploaded image URLs into custom key value fields.
For theme developers, particularly magazine-style WordPress theme developers, you can configure up to 3 different thumbnails to be used in each post. For instance,
a big 320px by 180px widescreen thumbnail for leading featured post to be displayed prominently on the front page.
a square 125px by 125px thumbnail for recent posts.
Dimensions as varied as your theme requires can be easily configured in an XML file. Save the file as 'wppt.xml' and put it in your theme's folder (ideally, the main folder but any folder will do). WP Post Thumbnail will scan your theme folders, look for your theme's 'wppt.xml' file and read your theme's thumbnail(s) configuration.