<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif; "><div>Hi all,</div><div><br></div><div>I would like to calculate the hessian matrix and get an output of type SymmetricSecondRankTensor pixel from a gradient image.</div><div><br></div><div>The irk HessianRecursiveGaussianImageFilter uses as input an intensity image.</div><div>However, I would like to implement a method for vessel detection based on the following algorithm:</div><div><br></div><div>1. GradientImageFilter</div><div>2. GradientVectorFlowImageFilter</div><div>3. get the hessian Matrix from 2. (this is my problem)</div><div>4. Hessian3DToVesselnessImageFilter</div><div><br></div><div><br></div><div>How can I get from the vector field in 2. to the hessian matrix I need for 3.?</div><div><br></div><div>Thanks for your help,</div><div>Thomas</div></body></html>