Picnik Image Editor for Joomla is simple, but has all the features you need. You can browse your website for images to edit, upload new ones, and get detailed information and previews before editing.
The text editor for your content will have a new button at the bottom that opens up the image browser. Once there you are able to edit, and then insert the image into your content.
You can also access the editing page by using the administrator module which puts a link to the window in the upper right, or by going to the Picnik link in the administrator.
You can grab the Picnik Image Editor for Joomla for just $18 from Joomlashack