# OpenCV - Where is it?  How to test it?

**URL:** <https://forums.developer.nvidia.com/t/opencv-where-is-it-how-to-test-it/44404>\
**Category:** Other Tools\
**Tags:** opencv\
**Created:** [August 16, 2016, 1:48am UTC](https://forums.developer.nvidia.com/t/opencv-where-is-it-how-to-test-it/44404 "2016-08-16T01:48:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![x92127](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@x92127](https://forums.developer.nvidia.com/u/x92127)\
**Post date:** [August 16, 2016, 1:48am UTC](https://forums.developer.nvidia.com/t/opencv-where-is-it-how-to-test-it/44404/1 "2016-08-16T01:48:38Z")

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The JetPack 2.2.1 installs the prebuilt OpenCV4Tegra library.  
I then followed the instructions here:  
[http://elinux.org/Jetson/Installing\_OpenCV](http://elinux.org/Jetson/Installing_OpenCV)  
…and ran the commands below to manually install the prebuilt packages:  
sudo dpkg -i libopencv4tegra-repo\_2.4.13\_armhf\_l4t-r21.deb  
sudo apt-get update  
sudo apt-get install libopencv4tegra libopencv4tegra-dev

That last command resulted in the following: “already the newest version” so I’m not sure why it was recommended. (Does anyone actually review and update those elinux sites??)

OK, so now what? How do I test the OpenCV installation?

Following the instructions on that same site:  
cd ~/opencv-2.4.9/samples/cpp  
…results in “No such file or directory” which seems obvious since I doubt that version 2.4.9 is correct. However, fishing around in my TK1 file directory I cannot find any reference to an OpenCV folder, only the original folder containing the deb file.

So now what? How do I find where OpenCV is on my TK1? How do I test the samples? How do I update my path so that can use OpenCV with code I already have?

Most of sites out there gloss over the really basic stuff for noobs like me. =)  
Thanks in advance for your help!

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<div class="post-metadata">

**Author:** ![x92127](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@x92127](https://forums.developer.nvidia.com/u/x92127)\
**Post date:** [October 15, 2016, 9:21pm UTC](https://forums.developer.nvidia.com/t/opencv-where-is-it-how-to-test-it/44404/2 "2016-10-15T21:21:08Z")

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I just installed JetPack 2.3, same question as above → Where is OpenCV?

After the JetPack is successfully installed, I can open a terminal window, type “python” to get the python prompt. Then, if I type “import cv2” I get the following error:

ImportError: No module named cv2

So, I’m asking again, where is OpenCV and how do I access it to use it?