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This is an implementation of the cascade algorithm described in [1]. This algorithm is used to accelerate detection for Deformable Part Models [2] with a high number of components (~10x the usual number of components). To train and test our DPMs we use the AirplanOID dataset, which contains 7413 aeroplane images with annotations for five object part types (nose, verticalStabilizer, wheel, wing, aeroplane).

For questions concerning the code or bug reports, please send an email to: stavros DOT tsogkas AT ecp DOT fr


[1] Understanding Objects in Detail with Fine-grained Attributes, A. Vedaldi, S. Mahendran, S. Tsogkas, S. Maji, B. Girshick, J. Kannala, E. Rahtu, I. Kokkinos, M. B. Blaschko, D. Weiss, B. Taskar, K. Simonyan, N. Saphra, and S. Mohamed, in Proceedings of the IEEE Conf. on Computer Vision and Pattern Recognition (CVPR), 2014

[2] Object detection with discriminatively trained part based models, P. F. Felzenszwalb, R. B. Girshick, D. McAllester, and D. Ramanan. PAMI 2010.

How to cite

@inproceedings{vedaldi14understanding, Author = {A. Vedaldi and S. Mahendran and
S. Tsogkas and
S. Maji and
B. Girshick and J. Kannala and
E. Rahtu and
I. Kokkinos and
M. B. Blaschko and D. Weiss and
B. Taskar and
K. Simonyan and
N. Saphra and
S. Mohamed}, Title = {Understanding Objects in Detail with Fine-grained Attributes},
Booktitle = {Proceedings of the {IEEE} Conf. on Computer Vision and Pattern Recognition ({CVPR})},
Year = {2014}}

Folder structure

In the root directory you will find the following folders:

###data/ This is where all your data go. Dataset images, saved models, cascade .mat files and results go into separate corresponding folders.

###jar-tools/ Functions for collecting data, loading the AirplanOID annotations with additional fields, evaluating a trained model etc.

###voc-release5/ The code for training and testing a typical DPM, slightly modified/extended to support our cascade. You can find the original version here.

###cpp/ c++ source code and mex-files.

Getting started

To get started just do the following:

  1. Download the AirplanOID dataset and place the images under oid_1.0/data/images/aeroplane/.

  2. Download and install VLFeat. If you don't want to train/test a model on PASCAL and you just want to try out the cascade, you can skip this step.

  3. Open a Matlab session, cd into the root directory oid_1.0/ and run startupOID.m. This will add all subfolders in your working path and compile the necessary mex files placing them into the cpp/ directory.

  4. Run demo.m to visualize and compare the cascade. If you want more information about different configurations, run: help oidConfig.m.

Hint: If you want to automatically add the paths and compile the mex files each time you open matlab while in the oid_1.0/ folder, just change the name of the startup script from startupOID.m to startup.m

Building your own hierarchical filter cascade

The above steps use the files and pre-trained models already included in this distribution. If you want to train a new model and build an hierarchical filter tree on top of that, perform the following steps:

  1. Download the 2007 trainval data and VOCdevkit and place the merged 2007 folder in oid_1.0/data/.

  2. Change training configuration settings (if you do not want to use the defaults) in voc_config.m

  3. Run model = jar_train(part, nComp, 1, 1), where part is the name of the aeroplane part (e.g. 'nose') and nComp the number of components for your model. Please before training a new model read the section 'Model alignment' below.

  4. Use the testCascade function to build the hierarchical filter tree and evaluate the performance of your model using precision-recall curves.

Model alignement

There are two ways to train a DPM model on the OID dataset using left/right facing clusters during the first round of training (see jar_train.m).

  • The first one is to use the default function lrsplit that comes with voc-release5 (call jar_train with usevp = 0). This function clusters the positive examples in left- and right- facing but arranges left- and right-facing filters in a random way inside the model structure.

  • The second way is to use getOrientationStrings and splitLeftRight. These functions take advantage of the viewpoint annotations that come with the OID and arrange filters so that left-facing are assigned odd indices and right-facing are assigned even indices. While the filter order in the model structure does not affect the final result (since all filters are considered at test time), the code that constructs the filter tree hierarchy assumes that odd indices correspond to left-facing filters and even indices to right-facing filters. For this reason we suggest that you use the second way (call jar_train.m with usevp = 1) if you want to train a new model and use our cascade.


Hierarchical filter cascade for efficient detection with multi-component DPMs




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