http://www.k-wave.org/forum/topic/an-outward-imaging-grid-type Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 00:49:34 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/an-outward-imaging-grid-type#post-3785 Tue, 16 Jul 2013 18:54:46 +0000 krishnakt031990 3785@http://www.k-wave.org/forum/ <p>Thanks sir. </p> http://www.k-wave.org/forum/topic/an-outward-imaging-grid-type#post-3783 Tue, 16 Jul 2013 09:46:04 +0000 bencox 3783@http://www.k-wave.org/forum/ <p>Hi krishnakt031990,</p> <p>That's an interesting question. Given some measurements made at points around a circle, the 'interior problem' of recovering an image inside that circle has been widely studied. However, the 'exterior problem' of recovering an image outside the circle has been much less widely studied, perhaps because it is, generally speaking, much less well posed. One paper that springs to mind is by Gaik Ambartsoumanian et al. "Inversion of the circular Radon transform on an annulus" Inverse Problems, 26 (2010) 105015. I'd recommend reading their Additional Remarks first, and seeing who they reference.</p> <p>There are two reconstruction algorithms currently included in k-Wave: time reversal and a Fourier domain inversion when the data is measured on a plane. The planar reconstruction algorithm is not appropriate in this case, as the measurements are not made on a plane. You could use time reversal, but strictly it will only give an exact image when the measurement surface encloses the image region, ie. for the interior problem. I've not seen it used for the exterior problem, and while it would give some sort of image there is no guarantee that it would be the best image that could be obtained with the data.</p> <p>I hope that helps.</p> <p>Ben </p> http://www.k-wave.org/forum/topic/an-outward-imaging-grid-type#post-3780 Mon, 15 Jul 2013 23:35:22 +0000 krishnakt031990 3780@http://www.k-wave.org/forum/ <p>Sir,<br /> I meant if I imaged using an endoscopic probe would i still be able to recover an image using this software? </p> http://www.k-wave.org/forum/topic/an-outward-imaging-grid-type#post-3777 Mon, 15 Jul 2013 09:45:57 +0000 bencox 3777@http://www.k-wave.org/forum/ <p>Hi krishnakt031990,</p> <p>Do you mean that the image you want to form is outside the (let's say) circular array of sensors? As it would be if you imaged with an endoscopic probe, for example? Or do you mean that you have a scatterer and want to simulate the field external to it? Or something else?</p> <p>Ben </p> http://www.k-wave.org/forum/topic/an-outward-imaging-grid-type#post-3776 Thu, 11 Jul 2013 03:26:27 +0000 krishnakt031990 3776@http://www.k-wave.org/forum/ <p>I would want to simulate a grid type which is a outwardly imaging geometry. Is it feasible with the toolbox? </p>