Transformation determination device and method for determining a transformation for image registration

A transformation determination device for determining a registration transformation for image registration of a first image relative to a second image, comprising:

• a first memory configured to store first computer-readable instructions thereon;
• and
• at least one first processor coupled to the first memory and configured to execute the first computer-readable instructions to
• generate a plurality of test elements, each test element among the plurality of test elements including a test transformation and a test value, the generation including determining a test element among the plurality of test elements by at least
• determining a test transformation of the test element based on at least one of
• a sequence of test transformations, or
• one or more previously determined test elements among the test plurality of test elements,
• transforming the first image via the determined test transformation,
• generating a difference image based on the transformed first image and the second image,
• calculating a frequency distribution of pixel values of the difference image, and
• determining a test value of the test element based on the frequency distribution such that the test value increases as one or more frequencies of higher pixel values increase,
• determine a minimum test value among the test values included in the plurality of test elements, and
• determine the registration transformation as the test transformation included in the same test element as the minimum test value.