Attention classifier using head pose.
TLDR;
run tester.py on a directory of household images and their set of annotations.
This model classifies the level of viewing attention for a person in a living room. The attention classifications are 0, 1, and 2, where 0 is not paying attention, 1 is likely paying attention, and 2 is definitely paying attention. The model can also be set to a binary classification as well, as 0 and 2.
The model extracts and uses convolutional neural networks (CNNs) to get the location of the face in the frame, and the angles of the head (head pose) as features into the attention prediction. A pipeline of tasks are created for the system.
Requirements:
It's recommended to use a conda virtual environment. You can use the requirements.txt file (conda install --yes --file requirements.txt), which include TensorFlow, PyTorch, OpenCV, Numpy, pandas, sklearn, imutils, pickle, scipy, glob, pylab, PIL, and a few others.
Model pipeline tasks: face ROI -> face bounding box -> head pose -> attention score
Model modules/scripts: for tasks: face_roi.py -> tiny_face_detect.py -> head_pose.py -> thresholded_model.py
Pipeline description
1. Face ROI: The first step is to create the face region of interest (ROI).
This model currently assumes facial features from PAF to create the face ROI.
These are the coordinates for the eyes, ears, nose and neck. This
step may not be needed in the future if a better face detector is used.
The face_roi.py script takes in a list of facial features for each face in a frame. This narrows the search area for face detection for the actual face detection.
2. Face bounding box: Next, the script tiny_face_detect.py in the TinyFace module is used to find a tighter fitting face bounding box. The tighter bounding box significantly improves the accuracy of the head pose model (next step). It takes in a list of face ROIs in frame.
3. Head pose: The script head_pose.py in the headpose module is used to find the angle of the face given as yaw, pitch and roll. These represent angles in the x (horizontal), y (vertical), and z (into the image) axis, respectively. It takes in a list of face boxes bounding for each face in a frame.
4. Attention prediction: The thresholded_model.py script uses a simple thresholding to classify angles where a person is estimated to be paying attention to the screen in front of them. The camera is assumed to be placed in the very center of the camera image. This predictor uses the face location in the room, for each x, y, z directions, and the angle of the head. It takes in a list of face boxes and head poses in a frame.
Note: each of these tasks are done by faces in a image frame. Each module accepts lists of ROIs, bounding boxes, and head poses, representing annotations for each face in a single frame.
#Using the modules:# Any modules can be swapped out or used independently. For specific tasks, directions are provided below.
1. Train and Test: to train and test on a set of images/frames, the tester.py script is provided. The main purpose of this script is to extract all face bounding boxes and head poses features. This will take significant amount of time, hours, at ~1 sec / frame.
By default, a thresholded model is also used to predict the attention score.
This does not need to be trained as it takes in the features and simple thresholds
values to predict attention. Evaluation results are also automatically done at
the end of feature extraction.
To run, pass in the following arguments (change args as necessary):
python tester.py --test_frames_path test-frames --annotations_path Inderbir-annotations.csv --output_training_name output_training_data_test.csv --display_frame True --write_csv False
Note: this script takes many hours, a day or more on large data sets. (~1 sec/frame)
After extracting all the features from the frames, you need to decide which predictor to use. The most complete is the thresholded model, which thresholds angles based on a person's position in the room to predict attention.
To run the tester.py script, you will need a directory of frames, and a csv file of the annotations for the facial features and true attention labels. It uses frame_reader.py and annotation_reader.py scripts to traverse a directory and read a csv file. See these scripts and the 'test-frames directory' and the 'Inderbir-annotations.csv' files for the format structure of the input.
Options to display the images with select annotations are also given in this script.
When providing a csv of annotations, the following fields are used. If you alter the features or rearrange the order, you will need to change the face_roi.py file correspondingly to read the appropriate facial features from your csv annotation file. Alternatively, you can directly feed in face bounding boxes to the head pose script, and by pass the face ROI and face bounding box creation.
Annotation fields used in face_roi.py:
0 - vatic.video
1 - vatic.frame_id
2 - vatic.bbox_x1 # not needed in this model
3 - vatic.bbox_y1 # not needed in this model
4 - vatic.bbox_x2 # not needed in this model
5 - vatic.bbox_y2 # not needed in this model
6 - reye_x
7 - reye_y
8 - leye_x
9 - leye_y
10 - rear_x
11 - rear_y
12 - lear_x
13 - lear_y
14 - nose_x
15 - nose_y
16 - neck_x
17 - neck_y
18 - attention
2. Training: optional
Skip this step if using the threshold_model.py script.
There are trained models using an SVM and random forest classifier based on the output features of the tester.py script.
See the machine-learning-trainers to train a predictor on the features instead of the thresholded coded model. Note, these models are less documented and ready to use and need modifying (paths to features file, for example). They did not provide good accuracy. However, they may provide a good basis code for cross validating and for testing other machine learning models.
These scripts will also test the training and validation data.
3. Test results evaluation: optional
After feature extraction from the tester.py script, you can evaluate the overall accuracy of the thresholded code model predictor by using the test-thresholded-model.py script. This may be redundant as the tester.py script evaluates the accuracy, but this test-thresholded-model.py lets you fine tune the classification, such as convert 1s to 2s. You can also swap out the classified and use this script to test other machine learning models, ie, random forest, SVM.
To run, pass in the following arguments (change args as necessary):
python test-thresholded-model.py --frame_directory test-frames --output_name_path predicted_labels_hardcode_rev2.csv --csv_results output_features_aug7.csv --one_to_two False --write_csv True
Results directory has the output of some test evaluations for the thresholded coded, SVM and random forest models. These include features and the predicted and annotated labels.