METHOD AND DEVICE FOR ESTIMATING OBSOLUTE SIZE DIMENSIONS OF TEST OBJECT

The present invention relates to a method for estimating absolute size dimensions of a test object (32) based on image data of the test object (32), the test object (32) being a face or part of a face of a test person, the method comprising the steps of: -receiving (S101) image data of the test object (32); -determining (S102) a first model (30) of the test object (32) based on the received image data, wherein the first model (30) has an unknown scale; -aligning and scaling the first model (30) of the test object (32) to a first average model, wherein the first average model includes an average of a plurality of first models of reference objects being faces or parts of faces of reference persons, wherein said first models of the reference objects are of a same type as the first model (30) of the test object (32) and have an unknown scale; -determining a shape difference between the test object (32) and an average of the reference objects by determining a difference between the aligned and scaled first model of the test object (32) and the first average model; -determining a second model (34) of the test object (32) with an estimated scale based on (i) the determined shape difference, (ii) a statistical operator that is indicative of a statistical correlation between shape and size dimensions of the reference objects, and (iii) a second average model, wherein the second average model includes an average of a plurality of second models of the reference objects, wherein said second models of the reference objects are of a same type as the second model of the test object and have a known scale; and -determining the size dimensions of the test object (32) based on the second model (34) of the test object (32).