[Rtk-users] About Kaiser-Bessel Filter
Simon Rit
simon.rit at creatis.insa-lyon.fr
Wed Nov 19 14:40:58 CET 2014
Hi,
I think you are looking at the code generated by gengetopt for the rtksart
application. In general, it's simpler to simply do "rtksart --help" when
you want to find out how to use a parameter. You will then find the
following help section
Projectors:
-f, --fp=ENUM Forward projection method (possible
values="Joseph", "RayCastInterpolator",
"CudaRayCast" default=`Joseph')
-b, --bp=ENUM Back projection method (possible
values="VoxelBasedBackProjection", "Joseph",
"CudaVoxelBased", "NormalizedJoseph"
default=`VoxelBasedBackProjection')
That should answer your question rtksart -b CudaVoxelBased. -p is the
option for the path where the program will look for your projection images.
Simon
On Wed, Nov 19, 2014 at 2:26 PM, Guangming Zang <guangming.zang at kaust.edu.sa
> wrote:
> Hi,Simon and Chao,
> i want to test the cuda performance in SART algorithm.
> but when i looked in the parameters in forwardprojection and
> backprojection. i got the enum:
>
> enum enum_fp { fp__NULL = -1, fp_arg_Joseph = 0,
> fp_arg_RayCastInterpolator, fp_arg_CudaRayCast };
> enum enum_bp { bp__NULL = -1, bp_arg_VoxelBasedBackProjection = 0,
> bp_arg_Joseph, bp_arg_CudaVoxelBased, bp_arg_NormalizedJoseph };
>
> So if i want to use the trilinear intrtpolation forwardprojection you
> mentioned , how should i set the -b and -p in SART? or how to choose -b and
> -p that i can get a fastest reconstruction in SART in this case??
>
> thanks for your help in advance.
> Best
> Guangming
>
> *Guangming Zang (Alex)*
> *King Abdullah University of Science and Technology(KAUST)*
> *University of Chinese Academy of Sciences(UCAS)*
>
>
> 2014-11-18 19:47 GMT+03:00 Simon Rit <simon.rit at creatis.insa-lyon.fr>:
>
>> The trilinear version is available with CUDA:
>>
>> http://www.openrtk.org/Doxygen/classrtk_1_1CudaForwardProjectionImageFilter.html
>> Simon
>>
>> On Tue, Nov 18, 2014 at 5:43 PM, Guangming Zang <
>> guangming.zang at kaust.edu.sa> wrote:
>>
>>> Hi Chao,
>>> Thanks very much for your prompt and so kind reply.
>>> I will recheck the process of setting carefully with your suggestions
>>> and a short report may be given later.
>>> BTW, do you have any plan recently to add other interpolation
>>> filter(e.g.Kaiser-Bessel or Trilinear)??
>>> Thanks for your time.
>>> Regards
>>> Guangming
>>>
>>>
>>>
>>> 2014-11-18 19:09 GMT+03:00 Chao Wu <wuchao04 at gmail.com>:
>>>
>>>> Hi Guangming,
>>>>
>>>> To reconstruct a volume from a series of tiff files you have to let the
>>>> algorithm know the geometrical relationship among the source, the volume
>>>> and the projections stored in the tiffs. The idea is the same: RTK uses
>>>> projection matrices and image coordinates to understand the positioning of
>>>> those projections. The projection matrices are based on a lot of
>>>> geometrical parameters like gantry angle, source position, detector
>>>> position, in-plane and out-of-plane rotation angles of the detector etc. I
>>>> won't go though all since most of them have no differences if you use tiff
>>>> files or whatever format as input. I focus on some tiff tips.
>>>>
>>>> In the simplest situation, the tiff files contain correct resolution
>>>> (DPI) information, then you need to do nothing on these files. You have to
>>>> specify the correct detector offset though, since in the tiff image
>>>> coordinates the origin is the first pixel (corner pixel) which is
>>>> apparently not the intersection of the central ray and the detector. The
>>>> detector offsets in x and y actually mean the position of the image origin
>>>> (the first pixel) in the coordinate system centred at the intersection.
>>>> Since the direction cosines is an identity matrix and pixel sizes are
>>>> positive, the detector offsets in x and y will be negative.
>>>>
>>>> If the resolution information of the tiff files is not correct, you
>>>> have to rewrite this information. You can of course perform a
>>>> pre-processing to change the DPI of all tiff files with a third-party
>>>> software, or you can alter the RTK code to allow such changes after reading
>>>> the images, by using a itk::ChangeInformationImageFilter filter.
>>>>
>>>> Another non-geometrical issue with tiff files is that when their
>>>> integer pixel values are converted into attenuation, the maximum possible
>>>> integer is used as the reference value. This may not be correct in
>>>> practice, e.g. in your 16-bit tiffs you use 62000 to represent air (no
>>>> attenuation) leaving the integer range from 62001 to 65535 for statistical
>>>> fluctuation. If for instance you only use the lower 14 bits for your data
>>>> then this problem is more severe. For sure you can correct this by changing
>>>> the code and specify the correct reference value.
>>>>
>>>> Hope these can help.
>>>>
>>>> Regards,
>>>> Chao
>>>>
>>>> 2014-11-18 15:09 GMT+01:00 Guangming Zang <guangming.zang at kaust.edu.sa>
>>>> :
>>>>
>>>>> Thanks
>>>>>
>>>>> *Guangming Zang (Alex)*
>>>>> *King Abdullah University of Science and Technology(KAUST)*
>>>>> *University of Chinese Academy of Sciences(UCAS)*
>>>>>
>>>>>
>>>>> 2014-11-18 16:46 GMT+03:00 Guangming Zang <guangming.zang at kaust.edu.sa
>>>>> >:
>>>>>
>>>>>> Hi,
>>>>>> I am using the sart reconstruction in RTK, it works well.Thanks for
>>>>>> your great work.
>>>>>> and i was wondering do you have any plan to add other filters except
>>>>>> Joseph, such as Kaiser-Bessel??? ( described here
>>>>>> http://wscg.zcu.cz/wscg2003/papers_2003/herman.pdf)
>>>>>> BTW, i have read the messages sent by other users(
>>>>>> http://public.kitware.com/pipermail/rtk-users/2014-October/000573.html
>>>>>> )
>>>>>> but i still can not make it. can u help me and explain again about
>>>>>> using a series of .tiff images ans sart algorithms to get the volume.
>>>>>> Thanks in advance
>>>>>> Best
>>>>>> *King Abdullah University of Science and Technology(KAUST)*
>>>>>> *University of Chinese Academy of Sciences(UCAS)*
>>>>>>
>>>>>>
>>>>>
>>>>> ------------------------------
>>>>> This message and its contents, including attachments are intended
>>>>> solely for the original recipient. If you are not the intended recipient or
>>>>> have received this message in error, please notify me immediately and
>>>>> delete this message from your computer system. Any unauthorized use or
>>>>> distribution is prohibited. Please consider the environment before printing
>>>>> this email.
>>>>> _______________________________________________
>>>>> Rtk-users mailing list
>>>>> Rtk-users at public.kitware.com
>>>>> http://public.kitware.com/mailman/listinfo/rtk-users
>>>>>
>>>>>
>>>>
>>>
>>> ------------------------------
>>> This message and its contents, including attachments are intended solely
>>> for the original recipient. If you are not the intended recipient or have
>>> received this message in error, please notify me immediately and delete
>>> this message from your computer system. Any unauthorized use or
>>> distribution is prohibited. Please consider the environment before printing
>>> this email.
>>>
>>> _______________________________________________
>>> Rtk-users mailing list
>>> Rtk-users at public.kitware.com
>>> http://public.kitware.com/mailman/listinfo/rtk-users
>>>
>>>
>>
>
> ------------------------------
> This message and its contents, including attachments are intended solely
> for the original recipient. If you are not the intended recipient or have
> received this message in error, please notify me immediately and delete
> this message from your computer system. Any unauthorized use or
> distribution is prohibited. Please consider the environment before printing
> this email.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.creatis.insa-lyon.fr/pipermail/rtk-users/attachments/20141119/541781bf/attachment.htm>
More information about the Rtk-users
mailing list