What is Image Registration?
Image registration is the process of aligning images through the transformation of each image into one coordinate system. This is traditionally done by setting one image as a fixed image and the other as a moving image, where the moving image is the one whose coordinates are transformed to align with the fixed image based on intensity or feature patterns within the images. When transforming the images, the moving image is iteratively improved upon through an optimization equation. The process of alignment is checked by a similarity metric, which guides the registration algorithm to the correct solution by comparing the altered moving image to the fixed image based on a pattern, such as intensities. There are two main ways to transform an image to align with a fixed image. One way is a linear transformation, where you can either rotate, scale, translate, shear, or do a combination of these affine transformations, which transforms the image on a global scale and does not account for local alterations between images. The other option, non-linear or elastic transformations, account for these local differences by warping the moving image locally to account for these differences, thus providing a better alignment when it is less important to keep the overall shape of the object in the image.
How Visikol Utilizes Image Registration
Visikol routinely performs image registration with its multiplex services, which allows scientists to use a large number of labels on the same sample. In order to use that many labels, Visikol has to take multiple imaging runs on each sample, therefore, Visikol utilizes a non-linear image registration approach to ensure perfect alignment of the multiple sample images. Figure 1 shows an example of Visikol’s registration capabilities by showing two images from the same sample overlayed atop one another in different colors. The left shows the original images overlaid, and the right image shows the output of the registration where both sample images are perfectly aligned.
If you are in need of image registration or multiplexing, feel free to contact Visikol to inquire about these services.
Figure 1: An illustration of image registration through the registration of a tissue sample where two separate images of the same sample were overlaid atop of one another before (left) and after (right) registration.