AID : An affine invariant descriptor for SIFT

This repository implements SIFT-AID, an affine invariant method for matching two images. The companion paper can be found here.

Prerequisites

Before starting to use SIFT-AID be sure of the following.

Creating a conda environment for SIFT-AID

conda create --name aid python=3.5.4

source activate aid

pip install --upgrade pip
pip install -r requirements.txt --ignore-installed

Compiling the C++ library

mkdir -p build && cd build && cmake .. && make

Deactivate the environment

conda deactivate

Delete the environment

conda-env remove -n aid

Possible install errors

If AttributeError: module 'cv2.cv2' has no attribute 'xfeatures2d' reinstall opencv-contrib

pip uninstall opencv-contrib-python
pip install opencv-python==3.4.2.16

Launching SIFT-AID

The function siftAID in libLocalDesc.py will execute SIFT-AID with the network descritor loaded from model.AID_simCos_BigDesc_dropout_75.hdf5.

from libLocalDesc import *

img1 = cv2.cvtColor(cv2.imread('./acc-test/coca.1.png'),cv2.COLOR_BGR2GRAY)
img2 = cv2.cvtColor(cv2.imread('./acc-test/coca.2.png'),cv2.COLOR_BGR2GRAY)

_, good_HC, ET_KP, ET_M = siftAID(img1,img2, MatchingThres = 4000, Simi = 'SignProx', Visual=True)
print("SIFT-AID --> FilteredMatches = %d, KeypointsTime = %3.3f, MatchingTime = %3.3f" %(len(good_HC),ET_KP,ET_M))

An example of its use can be found in gen-ICIP19-TeaserImages.py.

Training the descriptor network

Creating the needed directory structure

For training you need to specify three image datasets. These images will be used to generate optical affine views. Create default folders by typing:

mkdir -p imgs-train && mkdir -p imgs-val && mkdir -p imgs-test

Now, for example, you can download correspondent datasets from MS-COCO into the default folders.

Also, we need to create the following folders in order to storage tensorboard summaries and the resulting output images and data:

mkdir -p summaries && mkdir -p temp

Training

Once image datasets are available in imgs-train and imgs-val you can train the network.

python AID-train-model.py

Generated pairs of patches will be saved into their respective folders, e.g. (db-gen-train-60, db-gen-val-60). Those folders will have scattered files corresponding to patchs pairs. To create blocks of data that can be quickly (and automatically) reused by the trainer please launch also:

python py-tools/in2blocks.py

Some key variables in AID-train-model.py

Maximal viewpoint angle of the affine maps to be optically simulated.

DegMax = 60

Set this variable to False if you want to really train. Use for test when modifying the code.

Debug = True

Set this to True if no blocks of patch-data have been created yet. It will use all your CPU power for affine simulations. Deactivate back when you have created a sufficient amount of data blocks with in2blocks.py.

Parallel = False

Set this variable to True if you want to cycle over blocks of patch-data.

DoBigEpochs = True

Depending on you GPU, select the percentage of GPU memory to be used when training.

config.gpu_options.per_process_gpu_memory_fraction = 0.1

Summaries with tensorboard

Show all images (slider step = 1)

tensorboard --logdir="./" --samples_per_plugin="images=0"

If tensorboard crashes, try reinstalling it first !!! If locale error (unsupported locale) setting, do:

export LC_ALL="en_US.UTF-8"
export LC_CTYPE="en_US.UTF-8"
sudo dpkg-reconfigure locales

Authors

• Mariano Rodríguez - web page
• Gabriele Facciolo
• Rafael Grompone Von Gioi
• Pablo Musé
• Jean-Michel Morel - web page
• Julie Delon - web page

License

The code is distributed under the permissive MIT License - see the LICENSE file for more details.

Acknowledgements

Contributors

• Jéremy Anger (web page) and Axel Davy (web page) pointed out the need of CPU vector operations to optimize time computations.

This project can optionally

• call libOrsa, libMatch and libNumerics. Copyright (C) 2007-2010, Lionel Moisan, distributed under the BSD license.
• call libUSAC. Copyright (c) 2012 University of North Carolina at Chapel Hill / See its web page to see their specific associated licence.

Github repository

https://github.com/rdguez-mariano/sift-aid