# BoofCV camera calibration error

**URL:** <https://discourse.processing.org/t/boofcv-camera-calibration-error/30286>\
**Category:** Libraries\
**Created:** [May 25, 2021, 9:03pm UTC](https://discourse.processing.org/t/boofcv-camera-calibration-error/30286 "2021-05-25T21:03:44Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![samuset](https://avatars.discourse-cdn.com/v4/letter/s/b77776/32.png) [@samuset](https://discourse.processing.org/u/samuset)\
**Post date:** [May 25, 2021, 9:03pm UTC](https://discourse.processing.org/t/boofcv-camera-calibration-error/30286/1 "2021-05-25T21:03:44Z")

</div>

Hi, I’m trying to use the camera calibration tool provided by the BoofCV library [here](https://sourceforge.net/projects/boofcv/files/apps/BoofApplications.zip/download), following the tutorial [here](https://boofcv.org/index.php?title=Tutorial_Camera_Calibration). My command is as follows:

```auto
java -jar applications.jar CameraCalibration --Camera=0 --Resolution=640:360 CHESSBOARD --Grid=7:5

```

However, it throws this error when trying to open to webcam for calibration:

```auto
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

```

I have found the same solution in many places for this issue (links below), but I have no idea how to change my “class path” or do this thing with maven.  
[solution 1](https://stackoverflow.com/questions/61819573/how-do-i-fix-slf4j-failed-to-load-class-org-slf4j-impl-staticloggerbinder)  
[solution 2](https://stackoverflow.com/questions/57473745/failed-to-load-class-org-slf4j-impl-staticloggerbinder-even-though-staticloggerb)

---

<div class="post-metadata">

**Author:** ![josephh](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/josephh/32/210_2.png) [@josephh](https://discourse.processing.org/u/josephh)\
**Post date:** [May 26, 2021, 8:29pm UTC](https://discourse.processing.org/t/boofcv-camera-calibration-error/30286/2 "2021-05-26T20:29:03Z")

</div>

Hi @samuset ,

> [@samuset](#):
>
> but I have no idea how to change my “class path” or do this thing with maven.

First of all, are you using Maven (it’s a build system) or do you use Processing?

Also please see : [SLF4J Error Codes](http://www.slf4j.org/codes.html#StaticLoggerBinder)

I see that you are running the library with `java` as a standalone command but not that your issue is not related to Processing and you might want to post on another forum 😉