bounding box

FracLac is for digital image analysis. Use it to measure difficult to describe morphological features.
FracLac is a plugin for ImageJ. It is freely available software developed and maintained by our lab at the School of Community Health, Faculty of Science, Charles Sturt University, Australia. The author of the software and project lead is also the author of this document (me, Audrey Karperien). The basic box counting algorithm was originally modified from ImageJ's box counting algorithm and H. Jelinek's NIH Image plugin, and was further elaborated based on extensive research and development. The convex hull algorithm was provided by Thomas Roy, University of Alberta, Canada. As open source software, with the continuing help of a host of users and collaborators, FracLac has evolved to a suite of fractal analysis and morphology functions.

This plugin can find the smallest bounding box of an image (or a rectangular part defined by a selection) by cropping as much background as possible. Found in Fiji, under Image> Adjust.

In the version labeled with (guess background color), the plugin tries to determine the background color by looking at the pixels on the border of the image, while Auto Crop uses the currently selected background color which can be changed by double-clicking on the pipette symbol or using the Image > Color > Color Picker....

Instead of cropping right away, you can set the selection to the rectangle that would be cropped to using Edit > Selection > Select Bounding Box.