# Transformation Matrix Pictures/Pointclouds

**URL:** <https://community.pix4d.com/t/transformation-matrix-pictures-pointclouds/5887>\
**Category:** PIX4Dmapper Questions/Troubleshooting\
**Created:** [January 29, 2018, 5:49pm UTC](https://community.pix4d.com/t/transformation-matrix-pictures-pointclouds/5887 "2018-01-29T17:49:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Michel\_Sehn](https://avatars.discourse-cdn.com/v4/letter/m/db5fbb/32.png) [@Michel\_Sehn](https://community.pix4d.com/u/Michel_Sehn)\
**Post date:** [January 29, 2018, 5:49pm UTC](https://community.pix4d.com/t/transformation-matrix-pictures-pointclouds/5887/1 "2018-01-29T17:49:59Z")

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Hello, i need to know&nbsp; how the pictures are connected to the pointcloud there is any file that relation the pictures to the pointclouds ? I think that file should be a matrix or something that connect the XY of pictures with XYZ of the pointclouds.

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**Author:** ![Pierangelo\_Rothenbuhler](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/pierangelo_rothenbuhler/32/2439_2.png) [@Pierangelo\_Rothenbuhler](https://community.pix4d.com/u/Pierangelo_Rothenbuhler)\
**Post date:** [January 30, 2018, 12:57pm UTC](https://community.pix4d.com/t/transformation-matrix-pictures-pointclouds/5887/2 "2018-01-30T12:57:15Z")

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Hello Michel,&nbsp;

This article describes what files are in the Params folder that is created after step 1. Initial Processing. The file&nbsp; **project\_name\_pmatrix** is what you are looking for:&nbsp;[https://support.pix4d.com/hc/en-us/articles/202977149#label12](https://support.pix4d.com/hc/en-us/articles/202977149#label12)

I copy the relevant portion of the article below:&nbsp;

**project\_name\_pmatrix**

The P-Matrix contains information about the internal and external camera parameters. It allows to convert the 3D coordinates (X,Y,Z) of a 3D point into 2D coordinates (u,v) of an undistorted image. The 3D coordinates are expressed in the output coordinate system.

It can only be used with perspective lens cameras and with the undistorted images that are generated by Pix4Dmapper. (u,v) are the coordinates in the undistorted images given in pixels.

The first four numbers in the file correspond to the first row in the matrix.

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**Author:** ![Michel\_Sehn](https://avatars.discourse-cdn.com/v4/letter/m/db5fbb/32.png) [@Michel\_Sehn](https://community.pix4d.com/u/Michel_Sehn)\
**Post date:** [February 2, 2018, 12:20pm UTC](https://community.pix4d.com/t/transformation-matrix-pictures-pointclouds/5887/3 "2018-02-02T12:20:32Z")

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Hi again, thanks for the reply. Is there an example describing the use of the formula with the pmatrix file? It’s a little confusing for me

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**Author:** ![Antigoni\_Makri](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/antigoni_makri/32/187_2.png) [@Antigoni\_Makri](https://community.pix4d.com/u/Antigoni_Makri)\
**Post date:** [April 12, 2018, 8:52am UTC](https://community.pix4d.com/t/transformation-matrix-pictures-pointclouds/5887/4 "2018-04-12T08:52:18Z")

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Hello Michel,

We have some news regarding the pmatrix file. You can find&nbsp;the updates&nbsp;in the following&nbsp;[post](https://community.pix4d.com/t/6012-Matching-pixels-in-orthomosaic-to-corresponding-pixels-in-undistorted-input-images?page=1#community_comment_360000363226).  
Feel free to add your comments there.

Please allow me to close this post so that all the&nbsp;feedback regarding the pmatrix file is&nbsp;gathered&nbsp;on the other post.

Regards,