# Pretrained models

This section describes how pre-trained models can be downloaded and
used in MatConvNet. Using the pre-trained model is easy; just start
from the example code included in the [quickstart guide](quick.md).

> **Remark:** The following CNN models may have been *imported from
> other reference implementations* and are equivalent to the originals
> up to numerical precision. However, note that:
>
> 1.  Images need to be pre-processed (resized and cropped) before
>     being submitted to a CNN for evaluation. Even small differences
>     in the prepreocessing details can have a non-negligible effect
>     on the results.
>
> 2.  The example below shows how to evaluate a CNN, but does not
>     include data augmentation or encoding normalization as for
>     example provided by the
>     [VGG code](http://www.robots.ox.ac.uk/~vgg/research/deep_eval).
>     While this is easy to implement, it is not done automatically
>     here.
>
> 3.  These models are provided here for convenience, but please
>     credit the original authors.

## Face recognition

These models are trained for face classification and verification.

-   **VGG-Face**. The face classification and verification network from
    the
    [VGG project](http://www.robots.ox.ac.uk/~vgg/software/vgg_face/).

    > Deep face recognition, O. M. Parkhi and A. Vedaldi and
    > A. Zisserman, Proceedings of the British Machine Vision
    > Conference (BMVC), 2015
    > ([paper](http://www.robots.ox.ac.uk/~vgg/publications/2015/Parkhi15/parkhi15.pdf)).

    - [vgg-face](models/vgg-face.mat) [<i class="fa fa-file-image-o"></i>](models/vgg-face.svg)

    See the script `examples/cnn_vgg_face.m` for an example of using
    VGG-Face for classification. To use this network for face
    verification instead, extract the 4K dimensional features by removing the
    last classification layer and normalize the resulting vector in L2
    norm.

## Semantic segmentation

These models are trained for semantic image segmentation using the
PASCAL VOC category definitions.

-   **Fully-Convolutional Networks** (FCN) training and evaluation
    code is available
    [here](https://github.com/vlfeat/matconvnet-fcn).

-   **BVLC FCN** (the original implementation) imported from the
    [Caffe version](https://github.com/BVLC/caffe/wiki/Model-Zoo)
    [*DagNN format*].

    > 'Fully Convolutional Models for Semantic Segmentation',
    *Jonathan Long, Evan Shelhamer and Trevor Darrell*, CVPR, 2015
    ([paper](http://www.cv-foundation.org/openaccess/content_cvpr_2015/papers/Long_Fully_Convolutional_Networks_2015_CVPR_paper.pdf)).

    - [pascal-fcn32s-dag](models/pascal-fcn32s-dag.mat) [<i class="fa fa-file-image-o"></i>](models/pascal-fcn32s-dag.svg)
    - [pascal-fcn16s-dag](models/pascal-fcn16s-dag.mat) [<i class="fa fa-file-image-o"></i>](models/pascal-fcn16s-dag.svg)
    - [pascal-fcn8s-dag](models/pascal-fcn8s-dag.mat) [<i class="fa fa-file-image-o"></i>](models/pascal-fcn8s-dag.svg)

    These networks are trained on the PASCAL VOC 2011 training and (in
    part) validation data, using Berekely's extended annotations
    ([SBD](http://www.cs.berkeley.edu/~bharath2/codes/SBD/download.html)).

    The performance measured on the PASCAL VOC 2011 validation data
    subset used in the revised version of the paper above (dubbed
    RV-VOC11):

    | Model   | Test data |Mean IOU | Mean pix. accuracy | Pixel accuracy |
    |---------|-----------|---------|--------------------|----------------|
    | FNC-32s | RV-VOC11  | 59.43   | 89.12              | 73.28          |
    | FNC-16s | RV-VOC11  | 62.35   | 90.02              | 75.74          |
    | FNC-8s  | RV-VOC11  | 62.69   | 90.33              | 75.86          |

-   **Torr Vision Group FCN-8s**. This is the FCN-8s subcomponent of the
    CRF-RNN network from the paper:

    > 'Conditional Random Fields as Recurrent Neural Networks' *Shuai
    > Zheng, Sadeep Jayasumana, Bernardino Romera-Paredes, Vibhav
    > Vineet, Zhizhong Su, Dalong Du, Chang Huang, and Philip
    > H. S. Torr*,
    > ICCV 2015 ([paper](http://www.robots.ox.ac.uk/~szheng/papers/CRFasRNN.pdf)).

    - [pascal-fcn8s-tvg-dag](models/pascal-fcn8s-tvg-dag.mat) [<i class="fa fa-file-image-o"></i>](models/pascal-fcn8s-tvg-dag.svg)

    These networks are trained on the PASCAL VOC 2011 training and (in
    part) validation data, using Berekely's extended annotations, as
    well as Microsoft COCO.

    While the CRF component is missing (it may come later to
    MatConvNet), this model still outperforms the FCN-8s network
    above, partially because it is trained with additional data from
    COCO. In the table below, the RV-VOC12 data is the subset of the
    PASCAL VOC 12 data as described in the 'Conditional Random Fields'
    paper:

    | Model      | Tes data  | mean IOU | mean pix. accuracy | pixel accuracy |
    |------------|-----------|----------|--------------------|----------------|
    | FNC-8s-TVG | RV-VOC12  | 69.85    | 92.94              | 78.80          |

    *TVG implementation note*: The model was obtained by first
    fine-tuning the plain FCN-32s network (without the CRF-RNN part)
    on COCO data, then building built an FCN-8s network with the
    learnt weights, and finally training the CRF-RNN network
    end-to-end using VOC 2012 training data only. The model available
    here is the FCN-8s part of this network (without CRF-RNN, while
    trained with 10 iterations CRF-RNN).

## ImageNet ILSVRC classification

These modesl are trained to perform classification in the ImageNet
ILSVRC challenge data.

-   **ResNet** models imported from the
    [MSRC version](https://github.com/KaimingHe/deep-residual-networks).

    > 'Deep Residual Learning for Image Recognition', K. He, X. Zhang,
    S. Ren and J. Sun, ICCV, 2015
    ([paper](http://arxiv.org/pdf/1512.03385.pdf)).

    -  [imagenet-resnet-50-dag](models/imagenet-resnet-50-dag.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-resnet-50-dag.svg)
    -  [imagenet-resnet-101-dag](models/imagenet-resnet-101-dag.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-resnet-101-dag.svg)
    -  [imagenet-resnet-152-dag](models/imagenet-resnet-152-dag.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-resnet-152-dag.svg)

-   **GoogLeNet** model imported from the
    [Princeton version](http://vision.princeton.edu/pvt/GoogLeNet/)
    [*DagNN format*].

    > `Going Deeper with Convolutions', *Christian Szegedy, Wei Liu,
    Yangqing Jia, Pierre Sermanet, Scott Reed, Dragomir Anguelov,
    Dumitru Erhan, Vincent Vanhoucke, Andrew Rabinovich*, CVPR, 2015
    ([paper](http://www.cv-foundation.org/openaccess/content_cvpr_2015/papers/Szegedy_Going_Deeper_With_2015_CVPR_paper.pdf)).

    - [imagenet-googlenet-dag](models/imagenet-googlenet-dag.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-googlenet-dag.svg)

-   **VGG-VD** models from the
    [Very Deep Convolutional Networks for Large-Scale Visual Recognition](http://www.robots.ox.ac.uk/~vgg/research/very_deep/) project.

    > `Very Deep Convolutional Networks for Large-Scale Image
    Recognition', *Karen Simonyan and Andrew Zisserman,* arXiv
    technical report, 2014,
    ([paper](http://arxiv.org/abs/1409.1556/)).

    - [imagenet-vgg-verydeep-16](models/imagenet-vgg-verydeep-16.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-verydeep-16.svg)
    - [imagenet-vgg-verydeep-19](models/imagenet-vgg-verydeep-19.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-verydeep-19.svg)

-   **VGG-S,M,F** models from the
    [Return of the Devil](http://www.robots.ox.ac.uk/~vgg/research/deep_eval)
    paper (v1.0.1).

    > `Return of the Devil in the Details: Delving Deep into
    Convolutional Networks', *Ken Chatfield, Karen Simonyan, Andrea
    Vedaldi, and Andrew Zisserman,* BMVC 2014
    ([BibTex and paper](http://www.robots.ox.ac.uk/~vgg/publications/2014/Chatfield14/)).

    - [imagenet-vgg-f](models/imagenet-vgg-f.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-f.svg)
    - [imagenet-vgg-m](models/imagenet-vgg-m.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-m.svg)
    - [imagenet-vgg-s](models/imagenet-vgg-s.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-s.svg)
    - [imagenet-vgg-m-2048](models/imagenet-vgg-m-2048.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-m-2048.svg)
    - [imagenet-vgg-m-1024](models/imagenet-vgg-m-1024.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-m-1024.svg)
    - [imagenet-vgg-m-128](models/imagenet-vgg-m-128.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-vgg-m-128.svg)

    The following models have been trained using MatConvNet (beta17)
    and batch normalization using the code in the `examples/imagenet`
    directory, and using the ILSVRC 2012 data:

    - [imagenet-matconvnet-vgg-f](models/imagenet-matconvnet-vgg-f.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-matconvnet-vgg-f.svg)
    - [imagenet-matconvnet-vgg-m](models/imagenet-matconvnet-vgg-m.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-matconvnet-vgg-m.svg)
    - [imagenet-matconvnet-vgg-s](models/imagenet-matconvnet-vgg-s.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-matconvnet-vgg-s.svg)
    - [imagenet-matconvnet-vgg-verydeep-16](models/imagenet-matconvnet-vgg-verydeep-16.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-matconvnet-vgg-verydeep-16.svg)

-   **Caffe reference model** [obtained
    here](http://caffe.berkeleyvision.org/getting_pretrained_models.html)
    (version downloaded on September 2014).

    > Citation: please see the [Caffe homepage](http://caffe.berkeleyvision.org).

    - [imagenet-caffe-ref](models/imagenet-caffe-ref.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-caffe-ref.svg)

-   **AlexNet**

    > `ImageNet classification with deep convolutional neural
    networks', *A. Krizhevsky and I. Sutskever and G. E. Hinton,* NIPS
    2012 ([BibTex and
    paper](http://papers.nips.cc/paper/4824-imagenet-classification-with-deep-))

    - [imagenet-caffe-alex](models/imagenet-caffe-alex.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-caffe-alex.svg)
    - [imagenet-matconvnet-alex](models/imagenet-matconvnet-alex.mat) [<i class="fa fa-file-image-o"></i>](models/imagenet-matconvnet-alex.svg)

    The first model has been imported from
    [Caffe](http://caffe.berkeleyvision.org/getting_pretrained_models.html).

    The MatConvNet model was trained using using MatConvNet (beta17)
    and batch normalization using the code in the `examples/imagenet`
    directory.

This is a summary of the performance of these models on the ILSVRC
2012 validation data:

* 2016 models:

    |                         model|top-1 err.|top-5 err.|  images/s|
    |------------------------------|----------|----------|----------|
    |                 resnet-50-dag|      26.6|       8.6|     141.3|
    |                resnet-101-dag|      25.0|       7.9|     100.8|
    |                resnet-152-dag|      24.5|       7.6|      74.6|

* 2015 models:

    |                         model|top-1 err.|top-5 err.|  images/s|
    |------------------------------|----------|----------|----------|
    |    matconvnet-vgg-verydeep-16|      28.3|       9.5|     161.8|
    |               vgg-verydeep-19|      28.7|       9.9|     135.6|
    |               vgg-verydeep-16|      28.5|       9.9|     161.2|
    |                 googlenet-dag|      32.2|      11.6|     291.3|

    Please note that GoogLeNet is the Princeton's version.

* 2014 models:

    |                         model|top-1 err.|top-5 err.|  images/s|
    |------------------------------|----------|----------|----------|
    |              matconvnet-vgg-s|      37.0|      15.8|     470.5|
    |              matconvnet-vgg-m|      36.9|      15.5|     663.5|
    |              matconvnet-vgg-f|      41.4|      19.1|     768.1|
    |                         vgg-s|      36.7|      15.3|     476.7|
    |                         vgg-m|      37.3|      15.9|     599.1|
    |                         vgg-f|      41.1|      18.8|     745.9|
    |                     vgg-m-128|      40.8|      18.4|     600.7|
    |                    vgg-m-1024|      37.8|      16.1|     604.5|
    |                    vgg-m-2048|      37.1|      15.8|     610.1|

* 2013 models

    |                         model|top-1 err.|top-5 err.|  images/s|
    |------------------------------|----------|----------|----------|
    |               matconvnet-alex|      41.8|      19.2|     702.6|
    |                     caffe-ref|      42.4|      19.6|     392.2|
    |                    caffe-alex|      42.6|      19.6|     387.4|


Important notes:

* Some of the models trained using MatConvNet are slightly better than
  the original, probably due to the use of batch normalization during
  training.

* Error rates are computed on a **single centre-crop** and are
  therefore higher than what reported in some publications, where
  multiple evaluations per image are combined. Likewise, no model
  ensembles are evaluated.

* The **evaluation speed** was measured on a 12-cores machine using a
  single *NVIDIA Titan X*, MATLAB R2015b, and CuDNN v4; performance
  varies hugely depending on the network but also on how the data was
  preprocessed; for example, `caffe-ref` and `caffe-alex` should be as
  fast as `matconvnet-alex`, but they are not since images were
  pre-processed in such a way that MATLAB had to call `imresize` for
  each input image for the Caffe models.

* The GoogLeNet model performance is a little lower than expected (the
  model should be on par or a little better than VGG-VD). This network
  was imported from the Princeton version of GoogLeNet, not by the
  Google team, so the difference might be due to parameter setting
  during training. On the positive side, GoogLeNet is much smaller (in
  terms of parameters) and faster than VGG-VD.

## File checksums

The following table summarizes the MD5 checksums for the model files.

| MD5                              | File name                               |
|----------------------------------|-----------------------------------------|
| 77ba5337725eb77362e9f318898af494 | imagenet-caffe-alex.mat                 |
| 7001959cb66a3d62a86d52efff42f168 | imagenet-caffe-ref.mat                  |
| 051332469fbba9a002722f8a4302f031 | imagenet-googlenet-dag.mat              |
| d79a53b79b62aee8a6c48755c29448fa | imagenet-matconvnet-alex.mat            |
| 5c00773832303a2a9656afec097fb1c1 | imagenet-matconvnet-vgg-f.mat           |
| 2ccbc5c4d77a56fbfc288ca810d12206 | imagenet-matconvnet-vgg-m.mat           |
| 79c64eedb1fa49668997342b02dea863 | imagenet-matconvnet-vgg-s.mat           |
| 7502ff082bf53ce9cc67110399bbdf53 | imagenet-matconvnet-vgg-verydeep-16.mat |
| 4775484a70e8bac3e9521aed59f31dfc | imagenet-vgg-f.mat                      |
| 0545aea6fc5173b2806784f2a8bd3333 | imagenet-vgg-m-1024.mat                 |
| 80ec27ef99e2faefb9c837216c9ea0e4 | imagenet-vgg-m-128.mat                  |
| 620aca6468345e4a791a0396c6a51ce1 | imagenet-vgg-m-2048.mat                 |
| b4e8616c0ab66b1fda72854226f82d02 | imagenet-vgg-m.mat                      |
| 2f83043a38e71e9dd9b1c5c0cb3ef6f9 | imagenet-vgg-s.mat                      |
| 5a68244cf55c66fea59e23ee63cf56ef | imagenet-vgg-verydeep-16.mat            |
| b9b4a9eb1c2fb3b50e1ec1aca6f22342 | imagenet-vgg-verydeep-19.mat            |
| fb58bc62a17e21dfed8c2b8648dda33b | pascal-fcn16s-dag.mat                   |
| 98158e126af7e9100fd4f2a10e312c15 | pascal-fcn32s-dag.mat                   |
| 64d7b41efddefc93bfeded599e2448cc | pascal-fcn8s-dag.mat                    |
| 32d4f9ad465fa9d952c64069f8dae705 | pascal-fcn8s-tvg-dag.mat                |
| 5069daad93d2937554325e30388463ca | vgg-face.mat                            |

## Older file versions

Older models for MatConvNet beta16 are available
[here](models/beta16). They should be numerically equivalent, but in
beta17 the format has changed slightly for SimpleNN models. Older
models can also be updated using the `vl_simplenn_tidy` function.
