Viewpoints And Keypoints

Shubham Tulsiani and Jitendra Malik. Viewpoints and Keypoints. In CVPR, 2015.

0) Setup

• We first need to download the required datasets (PASCAL VOC and PASCAL3D+). In addition, we also need to reorgaanize some data and fetch precomputed R-CNN detections. To do this automatically, run

bash initSetup.sh

(if PASCAL VOC server is not working, uncomment the corresponding lines from the script and move a local copy to the desired location)

• Edit the required paths in 'startup.m', specially if you've used a local copy of some data instead of downloading via initSetup.sh

• Compile caffe (this is a slightly modified and outdated version of the original). Sample compilation instructions are provided below. In case of any issues, refer to the installation instructions on the caffe website.

cd external/caffe
cp Makefile.config.example Makefile.config
make -j 8
#edit MATLAB_DIR in Makefile.config
make matcaffe
cd ../..

1) Viewpoint Prediction

Preprocessing :

We first need to create some data-structures which store the annotations for each object category. To do this run in matlab -

mainVpsPreprocess 

Network Training :

• We train two networks here - one for predicting all the euler angles (vggJointVps), other for various bin sizes of azimuth as required by AVP evaluation (vggAzimuthVps). If you want to skip training, pretrained models are available here
• Update the solver files in prototxts/[vggJointVps/vggAzimuthVps]/solver.prototxt to refer to the locations of the net configuration file as well as update the directory for saving snapshots.
• Update the window file paths in the data layers of prototxts/[vggJointVps/vggAzimuthVps]/trainTest.prototxt and to refer to the Train/Val files created by above functions.
• Train the networks. Run the commands below from the caffe directory :

./build/tools/caffe.bin train -solver ../../prototxts/vggJointVps/solver.prototxt -weights PATH_TO_PRETRAINED_VGG_CAFFEMODEL
./build/tools/caffe.bin train -solver ../../prototxts/vggAzimuthVps/solver.prototxt -weights PATH_TO_PRETRAINED_VGG_CAFFEMODEL

• After training/downloading the models, save the final snapshot in SNAPSHOT_DIR/finalSnapshots/[vggJointVps,vggAzimuthVps].caffemodel/, where SNAPSHOT_DIR is set in startup.m

Predciting Pose for PASCAL VOC

• We will predict viewpoints for objects in PASCAL VOC validation set as well as for the R-CNN detections. To compute this, run

mainVpsPredict

(computing pose for all R-CNN detections might take a while, you can comment the corresponding lines if you just want to reproduce the evaluation given ground-truth boxes)

Evaluation and Analysis

• To evaluate the pose predicted for objects with known ground-truth box, run

mainRigidViewpoint

• To evaluate the poses predicted via the three metrics used in the original paper, run

runAvpExperiments

• To analyze the effect of object characteristics and error modes of our system, run

perfCharachteristics = smallVsLarge() ;
perfModes = errorModes();

2) Keypoint Prediction :

Preprocessing :

We first need to create some data-structures which store the annotations for each object category. To do this run in matlab -

mainKpsPreprocess

Network Training :

• We train two networks here - one for predicting keypoints at a coarse scale (6 X 6) and another for afiner scale (12 X 12). If you want to skip training, pretrained models are available here.
• Update the solver files in prototxts/[vggConv6Kps/vggConv12Kps]/solver.prototxt to refer to the locations of the net configuration file as well as update the directory for saving snapshots.
• Update the window file paths in the data layers of prototxts/[vggJointVps/vggAzimuthVps]/trainTest.prototxt and to refer to the Train/Val files created by above functions.
• Train the networks. Run the commands below from the caffe directory :

./build/tools/caffe.bin train -solver ../../prototxts/vggConv6Kps/solver.prototxt -weights PATH_TO_PRETRAINED_VGG_CAFFEMODEL
./build/tools/caffe.bin train -solver ../../prototxts/vggConv12Kps/solver.prototxt -weights PATH_TO_TRAINED_VGG_6_X_6_KPS_CAFFEMODEL

Note that for training the finer scale model, we initialize from a coarse scale model. An alternate is to finetune from a classification VGG model but this requires the use of cumulative gradients and a much longer training time.

• After training/downloading the models, save the final snapshot in SNAPSHOT_DIR/finalSnapshots/[vggConv6Kps,vggConv12Kps].caffemodel/, where SNAPSHOT_DIR is set in startup.m

Predciting Pose for PASCAL VOC

• We will predict keypoints for objects in PASCAL VOC validation set as well as for the R-CNN detections. To compute this, run

mainKpsPredict

(computing pose for all R-CNN detections might take a while, you can comment the corresponding lines if you just want to reproduce the evaluation given ground-truth boxes)

Evaluation and Analysis

• To evaluate the keypoints predicted for objects with known ground-truth box, run

mainRigidPck

• To evaluate the poses predicted via the three metrics used in the original paper, run

mainRigidApk

• To analyze the effect of object characteristics and error modes of our system, run

objectCharacteristics