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<p>Hi Inge,</p>
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<p>To be generic and to allow for any possible geometry, no assumption are made.</p>
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<p>This means that CASToR is using histograms and not sinograms, because sinograms are based on a specific geometry organisation.</p>
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<p>The current solution for you is to use a blur in the image space.</p>
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<p>In the future, a generic sinogram-based virtual scanner will be added in CASToR, so that for any modality (PET, SPECT or CT), a scanner could be described as a sinogram instead of describing the detector arrangement.</p>
<p>In this case, sinogram PSF blur will be allowed.</p>
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<p>Best</p>
<p>Simon<br>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>De :</b> Castor-users <castor-users-bounces@lists.castor-project.org> de la part de Schagt, I.H. van der <i.h.v.d.schagt@student.tue.nl><br>
<b>Envoyé :</b> vendredi 15 janvier 2021 13:56<br>
<b>À :</b> castor-users@lists.castor-project.org<br>
<b>Objet :</b> [Castor-users] Construction of Castor histogram data file</font>
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Hi Castor developers and users,</div>
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A few moths ago I got the code for saving the forward projections (castor-proj) and I have used this a lot to generate PET-data so far. </div>
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I try to manually put Gaussian blur over the sinogram data to simulate the poorer resolution of PET data by PSF. I want to do this by putting a Gaussian blur on every single 2D-sinogram. In order to do this, I need to understand how the sinogram datafile is
constructed and this has not become very clear to me yet. I know that every 16 bytes (for my data) describe one bin in the sinogram, but I don't know in what order this dat is stored and whether I can properly separate the sinograms here to apply Gaussian
blur. </div>
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Is it possible to provide more clarity on how the sinogram datafiles are constructed when formed with castor-proj?</div>
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Many thanks in advance,</div>
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Inge</div>
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