| 1 | Simple Face Identification |
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| 2 | -------------------------- |
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| 3 | |
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| 4 | A simple approach to face identification, built on top of OpenCV and given a |
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| 5 | YARP network interface. |
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| 6 | |
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| 7 | The program has two modes of operation. The first is calibration, where each |
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| 8 | user must show their face to the camera separately - press the number keys to |
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| 9 | assign each user with a different ID. You can see which face is mapped to |
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| 10 | which ID at the bottom of the window. |
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| 11 | |
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| 12 | The second mode of operation is face detection, where each visible detected |
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| 13 | face is given an ID based on it's closest match (within a given error |
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| 14 | threshold) with the faces recorded during calibration. The boxes drawn around |
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| 15 | the faces display the closest matched image, the id and confidence value of the |
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| 16 | match. When in this mode the program sends the following YARP messages: |
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| 17 | |
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| 18 | Output port Bottle contents Meaning |
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| 19 | /faceident "user appeared" ID confidence A user has entered the view of the camera |
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| 20 | /faceident "user disappeared" ID The user has left the camera view |
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| 21 | |
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| 22 | You can also drive the program via yarp with the following input messages: |
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| 23 | |
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| 24 | Input port Bottle contents Meaning |
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| 25 | /faceident-ctrl "train" ID Train for this user |
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| 26 | /faceident-ctrl "detect" Switch to detection mode |
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| 27 | /faceident-ctrl "save" sessionname Save the detected faces |
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| 28 | /faceident-ctrl "load" sessionname Load previously detected faces |
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| 29 | /faceident-ctrl "clear" Clears all faces |
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| 30 | /faceident-ctrl "idle" Switch to idle mode, mostly frees up cpu |
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| 31 | /faceident-ctrl "multiimages" 1/0 Turn on or off multiple images per face, experimental |
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| 32 | /faceident-ctrl "errorthresh" value Set the error threshold (default 0.2) |
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| 33 | /faceident-ctrl "newimagethresh" value Set the threshold greater than which new images are |
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| 34 | stored in training (default 0.1) |
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| 35 | |
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| 36 | Faces are saved in png format along with a xml file to map them to id numbers. The sessionname |
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| 37 | will be prepended onto the filenames for the xml file and the image files, so you can save |
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| 38 | multiple sessions. |
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| 39 | |
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| 40 | Key Meaning |
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| 41 | 0-9 number keys Calibrate a given id against a face in the scene |
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| 42 | d Start detect mode, which will send YARP messages |
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| 43 | c Clear all faces in the database |
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| 44 | |
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| 45 | Requires: OpenCV, YARP |
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| 46 | |
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| 47 | Written and tested on Linux, but it should work in Windows too. At the moment |
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| 48 | you'll probably have to run it with: |
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| 49 | |
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| 50 | simple-faceident -cascade=/path/to/haarcascade_frontalface_alt.xml |
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| 51 | |
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| 52 | In order to find OpenCV's data, on my machine it's in: |
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| 53 | /usr/local/share/opencv/haarcascades/haarcascade_frontalface_alt.xml |
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| 54 | |
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| 55 | Todo: |
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| 56 | * Try normalised cross correlation instead of image differencing |
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| 57 | * Expose image size via yarp |
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| 58 | |
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| 59 | Questions to: |
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| 60 | |
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| 61 | dave@fo.am |
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| 62 | |
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