[Rtk-users] rtkfdk and rtksart application input projection type and voxel value range

[louis.godon at student.uliege.be]

Hi,

I am currently using RTK for my Electrician Master's thesis and I am finding some difficulties... 

We observed that reconstructed values range using fdk algorithm and sart are different. How can this range be interpreted depending on the algortihm used in order to compare the image quality between both algorithms?

Furthermore, some voxels have negative value, is it possible to obtain negative values with rtkfdk or rtksart application? does it make sens and how can that be? 

And finally, last question, is there a specific projection file type (.tif, .mha, ...) and/or pixel type (unsigned short, float, ...) to use when using rtkfdk or rtksart?

Here are some informations that may be useful:
Object scanned:
 Rock sample and homogeneous polymer cylinder 
Projection are:
 -type: .tif (unsigned short) or .mha (float)
 -projection set: 360 seperated (.tif) files or 360 seperated (.mha) files or one single (.mha) file

Reconstructed image:
 -type: .mha (float)

Algorithm used:
 -rtkfdk (without ramp filter)
 -rtksart (3~5 iterations, 1 projections processed between each update of the reconstructed volume (1 for SART))

Here is a link to download some projection and reconstructed image:
https://www.dropbox.com/sh/sgrzrylphe4dar2/AAAFW3hJYzyZGbPevf_CYteka?dl=0

Thanks in advance for your help or advices. 

Best regards, 

Louis