# How to convert normalization factor

**URL:** <https://castor-project.discourse.group/t/how-to-convert-normalization-factor/418>\
**Category:** General Discussions\
**Created:** [October 11, 2022, 7:43pm UTC](https://castor-project.discourse.group/t/how-to-convert-normalization-factor/418 "2022-10-11T19:43:09Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Hadi\_Rezaei](https://avatars.discourse-cdn.com/v4/letter/h/ebca7d/32.png) [@Hadi\_Rezaei](https://castor-project.discourse.group/u/Hadi_Rezaei)\
**Post date:** [October 11, 2022, 7:43pm UTC](https://castor-project.discourse.group/t/how-to-convert-normalization-factor/418/1 "2022-10-11T19:43:09Z")

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Dear CASToR users and developers

I simulated a uniform phantom to calculate the normalization factor. How can I convert it (Root file) to Castor normalization data file? Based on the benchmark I need .cdh and .cdf related to normalization factors to feed to the castor-recon.

Thank you so much for your advance help.

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**Author:** ![akmal871026](https://avatars.discourse-cdn.com/v4/letter/a/45deac/32.png) [@akmal871026](https://castor-project.discourse.group/u/akmal871026)\
**Post date:** [October 12, 2022, 1:23am UTC](https://castor-project.discourse.group/t/how-to-convert-normalization-factor/418/2 "2022-10-12T01:23:51Z")

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You can generate cdf and cdh file using SIMIND

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**Author:** ![Hadi\_Rezaei](https://avatars.discourse-cdn.com/v4/letter/h/ebca7d/32.png) [@Hadi\_Rezaei](https://castor-project.discourse.group/u/Hadi_Rezaei)\
**Post date:** [October 12, 2022, 6:09am UTC](https://castor-project.discourse.group/t/how-to-convert-normalization-factor/418/3 "2022-10-12T06:09:29Z")

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Thank you for your answer. Sorry, I forgot to write that I am using PET.

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**Author:** ![tmerlin](https://yyz2.discourse-cdn.com/free1/user_avatar/castor-project.discourse.group/tmerlin/32/216_2.png) [@tmerlin](https://castor-project.discourse.group/u/tmerlin)\
**Post date:** [October 12, 2022, 6:52pm UTC](https://castor-project.discourse.group/t/how-to-convert-normalization-factor/418/4 "2022-10-12T18:52:24Z")

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Hi Hadi,

The GATE converter does not currently include tools to generate the normalization datafile, so you must do it manually.  
There is a discussion on this matter here: [Formula of normalization when using GATE simulation data](https://castor-project.discourse.group/t/formula-of-normalization-when-using-gate-simulation-data/402)

Hope this helps,  
Thibaut