Hi: I am a new user for itk. Now I used the Matlab to create a 3D '.JPG' file, D = rand(2,3,4); imwrite(D,'test.jpg'); Who can tell me how to create such .jpg file into MetaIMage File (including test.hdr and test.raw) so that some itk registration solution can use it. Thanks a lot Weihua(Wallace) Xiong