Rigid registration

Align aligns images relative to each other, for example, to correct shifts in the optical path of a microscope in each channel of a multi-channel set of images.

For two or more input images, this module determines the optimal alignment among them. Aligning images is useful to obtain proper measurements of the intensities in one channel based on objects identified in another channel, for example. Alignment is often needed when the microscope is not perfectly calibrated. It can also be useful to align images in a time-lapse series of images. The module stores the amount of shift between images as a measurement, which can be useful for quality control purposes.

Note that the second image (and others following) is always aligned with respect to the first image. That is, the X/Y offsets indicate how much the second image needs to be shifted by to match the first. This module does not perform warping or rotation, it simply shifts images in X and Y. For more complex registration tasks, you might preprocess images using a plugin for that purpose in FIJI/ImageJ.

| Supports 2D? | Supports 3D? | Respects masks? |
|--------------|--------------|-----------------| | Yes | No | Yes |

Measurements made by this module

• Xshift, Yshift: The pixel shift in X and Y of the aligned image with respect to the original image.

References

• Lewis JP. (1995) “Fast normalized cross-correlation.” Vision Interface, 1-7.

TrakEM2 is an ImageJ plugin for morphological data mining, three-dimensional modeling and image stitching, registration, editing and annotation (Fiji comes with TrakEM2). It supports arbitrary-sized datasets. 

This plugin registers (= aligns, matches) a stack of image slices.

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."