# OpenCV deep learning module samples
## Model Zoo
Check [a wiki ](https://github.com/opencv/opencv/wiki/Deep-Learning-in-OpenCV ) for a list of tested models.
If OpenCV is built with [Intel's Inference Engine support ](https://github.com/opencv/opencv/wiki/Intel%27s-Deep-Learning-Inference-Engine-backend ) you can use [Intel's pre-trained ](https://github.com/opencv/open_model_zoo ) models.
There are different preprocessing parameters such mean subtraction or scale factors for different models.
You may check the most popular models and their parameters at [models.yml ](https://github.com/opencv/opencv/blob/master/samples/dnn/models.yml ) configuration file. It might be also used for aliasing samples parameters. In example,
```bash
python object_detection.py opencv_fd --model /path/to/caffemodel --config /path/to/prototxt
```
Check `-h` option to know which values are used by default:
```bash
python object_detection.py opencv_fd -h
```
#### Face detection
[An origin model ](https://github.com/opencv/opencv/tree/master/samples/dnn/face_detector )
with single precision floating point weights has been quantized using [TensorFlow framework ](https://www.tensorflow.org/ ).
To achieve the best accuracy run the model on BGR images resized to `300x300` applying mean subtraction
of values `(104, 177, 123)` for each blue, green and red channels correspondingly.
The following are accuracy metrics obtained using [COCO object detection evaluation
tool](http://cocodataset.org/#detections-eval) on [FDDB dataset ](http://vis-www.cs.umass.edu/fddb/ )
(see [script ](https://github.com/opencv/opencv/blob/master/modules/dnn/misc/face_detector_accuracy.py ))
applying resize to `300x300` and keeping an origin images' sizes.
```
AP - Average Precision | FP32/FP16 | UINT8 | FP32/FP16 | UINT8 |
AR - Average Recall | 300x300 | 300x300 | any size | any size |
--------------------------------------------------|-----------|----------------|-----------|----------------|
AP @[ IoU=0.50:0.95 | area= all | maxDets=100 ] | 0.408 | 0.408 | 0.378 | 0.328 (-0.050) |
AP @[ IoU=0.50 | area= all | maxDets=100 ] | 0.849 | 0.849 | 0.797 | 0.790 (-0.007) |
AP @[ IoU=0.75 | area= all | maxDets=100 ] | 0.251 | 0.251 | 0.208 | 0.140 (-0.068) |
AP @[ IoU=0.50:0.95 | area= small | maxDets=100 ] | 0.050 | 0.051 (+0.001) | 0.107 | 0.070 (-0.037) |
AP @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] | 0.381 | 0.379 (-0.002) | 0.380 | 0.368 (-0.012) |
AP @[ IoU=0.50:0.95 | area= large | maxDets=100 ] | 0.455 | 0.455 | 0.412 | 0.337 (-0.075) |
AR @[ IoU=0.50:0.95 | area= all | maxDets= 1 ] | 0.299 | 0.299 | 0.279 | 0.246 (-0.033) |
AR @[ IoU=0.50:0.95 | area= all | maxDets= 10 ] | 0.482 | 0.482 | 0.476 | 0.436 (-0.040) |
AR @[ IoU=0.50:0.95 | area= all | maxDets=100 ] | 0.496 | 0.496 | 0.491 | 0.451 (-0.040) |
AR @[ IoU=0.50:0.95 | area= small | maxDets=100 ] | 0.189 | 0.193 (+0.004) | 0.284 | 0.232 (-0.052) |
AR @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] | 0.481 | 0.480 (-0.001) | 0.470 | 0.458 (-0.012) |
AR @[ IoU=0.50:0.95 | area= large | maxDets=100 ] | 0.528 | 0.528 | 0.520 | 0.462 (-0.058) |
```
## References
* [Models downloading script ](https://github.com/opencv/opencv_extra/blob/master/testdata/dnn/download_models.py )
* [Configuration files adopted for OpenCV ](https://github.com/opencv/opencv_extra/tree/master/testdata/dnn )
* [How to import models from TensorFlow Object Detection API ](https://github.com/opencv/opencv/wiki/TensorFlow-Object-Detection-API )
* [Names of classes from different datasets ](https://github.com/opencv/opencv/tree/master/samples/data/dnn )
