Context Encoding for Semantic Segmentation (EncNet)
===================================================

Install Package
---------------

- Clone the GitHub repo::
    
    git clone https://github.com/zhanghang1989/PyTorch-Encoding

- Install PyTorch Encoding (if not yet). Please follow the installation guide `Installing PyTorch Encoding <../notes/compile.html>`_.

Get Pre-trained Model
---------------------

.. hint::
    The model names contain the training information. For instance ``FCN_ResNet50_PContext``:
      - ``FCN`` indicate the algorithm is “Fully Convolutional Network for Semantic Segmentation”
      - ``ResNet50`` is the name of backbone network.
      - ``PContext`` means the PASCAL in Context dataset.

    How to get pretrained model, for example ``FCN_ResNet50_PContext``::

        model = encoding.models.get_model('FCN_ResNet50_PContext', pretrained=True)

    After clicking ``cmd`` in the table, the command for training the model can be found below the table.

.. role:: raw-html(raw)
   :format: html


.. tabularcolumns:: |>{\centering\arraybackslash}\X{4}{5}|>{\raggedleft\arraybackslash}\X{1}{5}|

==============================================================================  ==============    ==============    =============================================================================================
Model                                                                           pixAcc            mIoU              Command                                                                                      
==============================================================================  ==============    ==============    =============================================================================================
Encnet_ResNet50_PContext                                                        79.2%             51.0%             :raw-html:`<a href="javascript:toggleblock('cmd_enc50_pcont')" class="toggleblock">cmd</a>`  
EncNet_ResNet101_PContext                                                       80.7%             54.1%             :raw-html:`<a href="javascript:toggleblock('cmd_enc101_pcont')" class="toggleblock">cmd</a>` 
EncNet_ResNet50_ADE                                                             80.1%             41.5%             :raw-html:`<a href="javascript:toggleblock('cmd_enc50_ade')" class="toggleblock">cmd</a>`    
EncNet_ResNet101_ADE                                                            81.3%             44.4%             :raw-html:`<a href="javascript:toggleblock('cmd_enc101_ade')" class="toggleblock">cmd</a>`   
EncNet_ResNet101_VOC                                                            N/A               85.9%             :raw-html:`<a href="javascript:toggleblock('cmd_enc101_voc')" class="toggleblock">cmd</a>`   
==============================================================================  ==============    ==============    =============================================================================================


.. raw:: html

    <code xml:space="preserve" id="cmd_fcn50_pcont" style="display: none; text-align: left; white-space: pre-wrap">
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset PContext --model FCN
    </code>

    <code xml:space="preserve" id="cmd_enc50_pcont" style="display: none; text-align: left; white-space: pre-wrap">
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset PContext --model EncNet --aux --se-loss
    </code>

    <code xml:space="preserve" id="cmd_enc101_pcont" style="display: none; text-align: left; white-space: pre-wrap">
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset PContext --model EncNet --aux --se-loss --backbone resnet101
    </code>

    <code xml:space="preserve" id="cmd_psp50_ade" style="display: none; text-align: left; white-space: pre-wrap">
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset ADE20K --model PSP --aux
    </code>

    <code xml:space="preserve" id="cmd_enc50_ade" style="display: none; text-align: left; white-space: pre-wrap">
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset ADE20K --model EncNet --aux --se-loss
    </code>


    <code xml:space="preserve" id="cmd_enc101_ade" style="display: none; text-align: left; white-space: pre-wrap">
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset ADE20K --model EncNet --aux --se-loss --backbone resnet101 --base-size 640 --crop-size 576
    </code>

    <code xml:space="preserve" id="cmd_enc101_voc" style="display: none; text-align: left; white-space: pre-wrap">
    # First finetuning COCO dataset pretrained model on augmented set
    # You can also train from scratch on COCO by yourself
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset Pascal_aug --model-zoo EncNet_Resnet101_COCO --aux --se-loss --lr 0.001 --syncbn --ngpus 4 --checkname res101 --ft
    # Finetuning on original set
    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset Pascal_voc --model encnet --aux  --se-loss --backbone resnet101 --lr 0.0001 --syncbn --ngpus 4 --checkname res101 --resume runs/Pascal_aug/encnet/res101/checkpoint.params --ft
    </code>

Test Pretrained
~~~~~~~~~~~~~~~

- Prepare the datasets by runing the scripts in the ``scripts/`` folder, for example preparing ``PASCAL Context`` dataset::

      python scripts/prepare_pcontext.py
  
- The test script is in the ``experiments/segmentation/`` folder. For evaluating the model (using MS),
  for example ``Encnet_ResNet50_PContext``::

      python test.py --dataset PContext --model-zoo Encnet_ResNet50_PContext --eval
      # pixAcc: 0.792, mIoU: 0.510: 100%|████████████████████████| 1276/1276 [46:31<00:00,  2.19s/it]

Quick Demo
~~~~~~~~~~

.. code-block:: python

    import torch
    import encoding

    # Get the model
    model = encoding.models.get_model('Encnet_ResNet50_PContext', pretrained=True).cuda()
    model.eval()

    # Prepare the image
    url = 'https://github.com/zhanghang1989/image-data/blob/master/' + \
          'encoding/segmentation/pcontext/2010_001829_org.jpg?raw=true'
    filename = 'example.jpg'
    img = encoding.utils.load_image(
        encoding.utils.download(url, filename)).cuda().unsqueeze(0)

    # Make prediction
    output = model.evaluate(img)
    predict = torch.max(output, 1)[1].cpu().numpy() + 1

    # Get color pallete for visualization
    mask = encoding.utils.get_mask_pallete(predict, 'pcontext')
    mask.save('output.png')


.. image:: https://raw.githubusercontent.com/zhanghang1989/image-data/master/encoding/segmentation/pcontext/2010_001829_org.jpg
   :width: 45%

.. image:: https://raw.githubusercontent.com/zhanghang1989/image-data/master/encoding/segmentation/pcontext/2010_001829.png
   :width: 45%

Train Your Own Model
--------------------

- Prepare the datasets by runing the scripts in the ``scripts/`` folder, for example preparing ``PASCAL Context`` dataset::

    python scripts/prepare_pcontext.py

- The training script is in the ``experiments/segmentation/`` folder, example training command::

    CUDA_VISIBLE_DEVICES=0,1,2,3 python train.py --dataset pcontext --model encnet --aux --se-loss

- Detail training options, please run ``python train.py -h``. Commands for reproducing pre-trained models can be found in the table.

.. hint::
    The validation metrics during the training only using center-crop is just for monitoring the
    training correctness purpose. For evaluating the pretrained model on validation set using MS,
    please use the command::

        CUDA_VISIBLE_DEVICES=0,1,2,3 python test.py --dataset pcontext --model encnet --aux --se-loss --resume mycheckpoint --eval

Citation
--------

.. note::
    * Hang Zhang, Kristin Dana, Jianping Shi, Zhongyue Zhang, Xiaogang Wang, Ambrish Tyagi, Amit Agrawal. "Context Encoding for Semantic Segmentation"  *The IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2018*::

        @InProceedings{Zhang_2018_CVPR,
        author = {Zhang, Hang and Dana, Kristin and Shi, Jianping and Zhang, Zhongyue and Wang, Xiaogang and Tyagi, Ambrish and Agrawal, Amit},
        title = {Context Encoding for Semantic Segmentation},
        booktitle = {The IEEE Conference on Computer Vision and Pattern Recognition (CVPR)},
        month = {June},
        year = {2018}
        }
