To compute the displacement vector field (DVF) for image registration in MATLAB, you can use the Image Processing Toolbox, which provides various functions for image registration. Several registration methods are supported in MATLAB.
Among the supported methods in MATLAB, the "imregdemons" method is particularly suitable for computing the DVF. For more information, please refer to the documentation by entering the following commands in the MATLAB command line:
web(fullfile(docroot, "/images/ref/imregdemons.html"))
web(fullfile(docroot, "/images/image-registration.html"))
Below is a basic example demonstrating how to compute the DVF using the "imregdemons" method:
% Load the fixed and moving images
fixed = imread('Fixed.png');
moving = imread('Moving.png');
% Convert images to grayscale if they are not already
if size(fixed, 3) == 3
fixed = rgb2gray(fixed);
end
if size(moving, 3) == 3
moving = rgb2gray(moving);
end
% Normalize the images
fixed = im2double(fixed);
moving = im2double(moving);
% Perform the registration using imregdemons
[displacementField, registeredImage] = imregdemons(moving, fixed, ...
[500 400 200], 'AccumulatedFieldSmoothing', 1.0);
disp(displacementField)
In this example, we first load the images, preprocess them by converting to grayscale and normalizing, and then perform the registration to calculate the displacement vector field corresponding to the images.
