# Contributing to the Tensorflow Object Detection API
Patches to Tensorflow Object Detection API are welcome!
We require contributors to fill out either the individual or corporate
Contributor License Agreement (CLA).
* If you are an individual writing original source code and you're sure you own the intellectual property, then you'll need to sign an [individual CLA](http://code.google.com/legal/individual-cla-v1.0.html).
* If you work for a company that wants to allow you to contribute your work, then you'll need to sign a [corporate CLA](http://code.google.com/legal/corporate-cla-v1.0.html).
Inference and evaluation on the Open Images dataset</a><br>
*<ahref='g3doc/instance_segmentation.md'>
Run an instance segmentation model</a><br>
## Getting Help
To get help with issues you may encounter using the Tensorflow Object Detection
API, create a new question on [StackOverflow](https://stackoverflow.com/) with
the tags "tensorflow" and "object-detection".
Please report bugs (actually broken code, not usage questions) to the
tensorflow/models GitHub
[issue tracker](https://github.com/tensorflow/models/issues), prefixing the
issue name with "object_detection".
Please check [FAQ](g3doc/faq.md) for frequently asked questions before
reporting an issue.
## Release information
### April 30, 2018
We have released a Faster R-CNN detector with ResNet-101 feature extractor trained on [AVA](https://research.google.com/ava/) v2.1.
Compared with other commonly used object detectors, it changes the action classification loss function to per-class Sigmoid loss to handle boxes with multiple labels.
The model is trained on the training split of AVA v2.1 for 1.5M iterations, it achieves mean AP of 11.25% over 60 classes on the validation split of AVA v2.1.
For more details please refer to this [paper](https://arxiv.org/abs/1705.08421).
<b>Thanks to contributors</b>: Chen Sun, David Ross
### April 2, 2018
Supercharge your mobile phones with the next generation mobile object detector!
We are adding support for MobileNet V2 with SSDLite presented in
[MobileNetV2: Inverted Residuals and Linear Bottlenecks](https://arxiv.org/abs/1801.04381).
This model is 35% faster than Mobilenet V1 SSD on a Google Pixel phone CPU (200ms vs. 270ms) at the same accuracy.
Along with the model definition, we are also releasing a model checkpoint trained on the COCO dataset.
<b>Thanks to contributors</b>: Menglong Zhu, Mark Sandler, Zhichao Lu, Vivek Rathod, Jonathan Huang
### February 9, 2018
We now support instance segmentation!! In this API update we support a number of instance segmentation models similar to those discussed in the [Mask R-CNN paper](https://arxiv.org/abs/1703.06870). For further details refer to
[our slides](http://presentations.cocodataset.org/Places17-GMRI.pdf) from the 2017 Coco + Places Workshop.
Refer to the section on [Running an Instance Segmentation Model](g3doc/instance_segmentation.md) for instructions on how to configure a model
that predicts masks in addition to object bounding boxes.
<b>Thanks to contributors</b>: Alireza Fathi, Zhichao Lu, Vivek Rathod, Ronny Votel, Jonathan Huang
### November 17, 2017
As a part of the Open Images V3 release we have released:
* An implementation of the Open Images evaluation metric and the [protocol](g3doc/evaluation_protocols.md#open-images).
* Additional tools to separate inference of detection and evaluation (see [this tutorial](g3doc/oid_inference_and_evaluation.md)).
* A new detection model trained on the Open Images V2 data release (see [Open Images model](g3doc/detection_model_zoo.md#open-images-models)).
See more information on the [Open Images website](https://github.com/openimages/dataset)!
<b>Thanks to contributors</b>: Stefan Popov, Alina Kuznetsova
### November 6, 2017
We have re-released faster versions of our (pre-trained) models in the
<ahref='g3doc/detection_model_zoo.md'>model zoo</a>. In addition to what
was available before, we are also adding Faster R-CNN models trained on COCO
with Inception V2 and Resnet-50 feature extractors, as well as a Faster R-CNN
with Resnet-101 model trained on the KITTI dataset.
<b>Thanks to contributors</b>: Jonathan Huang, Vivek Rathod, Derek Chow,
Tal Remez, Chen Sun.
### October 31, 2017
We have released a new state-of-the-art model for object detection using
the Faster-RCNN with the
[NASNet-A image featurization](https://arxiv.org/abs/1707.07012). This
model achieves mAP of 43.1% on the test-dev validation dataset for COCO,
improving on the best available model in the zoo by 6% in terms
of absolute mAP.
<b>Thanks to contributors</b>: Barret Zoph, Vijay Vasudevan, Jonathon Shlens, Quoc Le