vedaldi / mcnssd

A matconvnet implementation of the Single Shot Detector

Single Shot MultiBox Detector

This directory contains code to train and evaluate the SSD object detector described in the paper:

SSD: Single Shot MultiBox Detector
by Wei Liu, Dragomir Anguelov, Dumitru Erhan, Christian Szegedy, 
Scott Reed, Cheng-Yang Fu, Alexander C. Berg

The code is based on the caffe implementation made available by Wei Liu.

Performance

The matconvnet training code aims to reproduce the results achieved by the caffe training routine. Using the "zoom out" data augmentation scheme described in the updated SSD paper the model trained with matconvnet achieves a similar mAP on the 2007 test set to the caffe model.

Test Set Results - comparison of the ssd-pascal-vggvd-300 model:

-------------- -------------------- ------------------------
               trained with caffe   trained with matconvnet
-------------- -------------------- ------------------------
aeroplane      80.53                82.39
bicycle        83.77                85.82
bird           76.40                77.40
boat           71.53                71.43
bottle         50.17                52.82
bus            86.90                86.54
car            86.05                86.20
cat            88.57                87.04
chair          59.96                60.07
cow            81.39                81.59
diningtable    76.30                75.57
dog            85.92                84.65
horse          86.60                86.65
motorbike      83.62                84.94
person         79.57                79.47
pottedplant    52.62                50.30
sheep          79.22                79.19
sofa           78.89                78.82
train          86.52                87.02
tvmonitor      76.31                77.15
-------------- -------------------- ------------------------
mean           77.54                77.75
-------------- -------------------- ------------------------

Pre-trained models

The public caffe models released by Wei Liu have been imported into matconvnet for use. The MobileNet model released by chuanqi305 has also been imported. In addition, some sample models trained with the matconvnet implementation have been made available. These can be downloaded directly from here (a few pre-trained models will be downloaded automatically upon running the core/ssd_pretrained_benchmarks.m script).

Speed

The pre-trained ssd-pascal-vggvd-300 model runs at approximately 58 Hz on a Tesla M-40.

Dependencies

CPU-mode:

• matconvnet (tested with v1.0-beta23, v1.0-beta24)
• MATLAB (tested with 2016a)

additional GPU-mode dependency:

• CUDA (tested with v7.5, v8)

mcnSSD also requires the following two modules:

• autonn - automatic differenation
• mcnExtraLayers - extra MatConvNet layers

Both of these can be setup directly with vl_contrib (i.e. run vl_contrib install <module-name> then vl_contrib setup <module-name>).

Installation

The easiest way to use this module is to install it with the vl_contrib package manager. mcnSSD can be installed with the following commands from the root directory of your MatConvNet installation:

vl_contrib('install', 'mcnSSD') ;
vl_contrib('compile', 'mcnSSD') ;
vl_contrib('setup', 'mcnSSD') ;
vl_contrib('test', 'mcnSSD') ; % optional

Demo

The ssd_demo.m script gives an example of how to run a pre-trained model on a single image. The core/ssd_pretrained_benchmarks.m will download and evaluate a range of pre-trained SSD models on the Pascal VOC 2007 test set.

An example of model training can be found in pascal/ssd_pascal_train.m

FAQ

1. If you get the following error: Undefined function or variable 'vl_argparsepos', it indicates that autonn is not on your path. It can be added by running vl_contrib install autonn ; vl_contrib setup autonn ; from the root of your MatConvNet install.