Free and open source

From the plugin inline help:

" Align RGB planes v1.7 by G.Landini Changes the alignment of the RGB planes independently.

Red Green and Blue checkboxes switch ON and OFF the planes and undo the alignment since last plane change. Note that when switching planes, the portion of the previously edited plane left outside the image frame is lost. Rotation, Width and Height changes are interpolated (so there is some loss of sharpness) and do not retain the image portions outside the image frame. You can use the Resize2Rotate macro to avoid losing any image data.

The Rotate, Width and Height sliders set integer values, but fractional values can also be typed in the entry boxes. Just make sure you press [RETURN] after the number is typed.

The Revert button works only with single images, not stacks.

Note: When using stacks, 2 buttons [< Prev] and [Next >] are added to the panel. Do not use the slide bar in the stack window, but use those buttons instead."

The Sholl technique is used to describe neuronal arbors. This plugin can perform Sholl directly on 2D and 3D grayscale images of isolated neurons. Its internal algorithm to collect data is based upon how Sholl analysis is done by hand — it creates a series of concentric shells (circles or spheres) around the focus of a neuronal arbor, and counts how many times connected voxels defining the arbor intersect the sampling shells. The major advantages of this plugin over other implementations are:

• When analyzing images directly, it does not require previous tracing of the arbor (although it can also analyze traced arbors)
• It combines curve fitting with several methods to automatically retrieve quantitative descriptors from sampled data, which allows direct statistical comparisons between arbors
• It allows continuous and repeated sampling around user-defined foci
• It allows batch processing

Some functions for PDE filtering.