Yolov2 for Openframworks addon
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Latest commit b1f0678 Sep 6, 2018




ofxYolov2 is a YOLO(You Look Only Once) addon for openframeworks. Please refer YOLO official website for more details of YOLO. https://pjreddie.com/darknet/yolo/ If you have a Nvidia GPU(s) on your PC, I just recommend to use ofxDarknet instead of this addon, https://github.com/mrzl/ofxDarknet.

OpenCV v.3.3.1 or upper includes Yolov2 library ( https://docs.opencv.org/3.4.1/da/d9d/tutorial_dnn_yolo.html ) in their own package. Therefore I designed ofxYolov2 with OpenCV v.3.3.1 or upper version.

I created this addon for beginers or learner who are going to try object detection with Yolo on OF. Attention: it runs on OpenCL.


See Examples


single_image screenshot Detection example for single image.


Realtime Detection example for webcam video.


annotation screenshot Simple annotation example to export a yolo format.


1. Install OpenCV by brew.

$ brew install opencv

2. confirm your opencv version

Based on OpenCV version, Please re-write ofxYolov2/addon_config.mk file. End of the file, there are some description about opencv path for your system. Please re-write the version according to your OpenCV version. Current (2018/6/15) is 3.4.1_5, If you find other version on your directory tree, /usr/local/Cellar/opencv , please do not forget fill in the correct version on the addon_config.mk file. You can get your current opencv version by typing below command.

$ ls /usr/local/Cellar/opencv

3. Download cfg and weights file

Download cfg and weights file to each examples directories. You can find download shell script on the top of ofxYolov2 directory.

$ cd ofxYolov2
$ sh getYolov2Weights.sh

4. Edit yolov2-tiny.cfg

Edit "thresh .6" to "thresh .01" on each yolov2-tiny.cfg.

5. Update each examples by project generator, then run.

Example/camera, single_image or annotation by project generator and add only ofxYolov2 as an addon. Then update it. Attention Please do not include OpenCV addon in OF. Be sure to add only ofxYolov2 addon by projectgenerator.


  • only macOS ( tested on Hight Sierra and Sierra)
  • of version: 0.9.8






  1. How to implement OpenCV Yolo on Openframeworks: https://qiita.com/buchayaty/items/4020100f531c07418f38
  2. YOLO: https://pjreddie.com/darknet/yolo/