CameraLocalization

Description

Based on the SfM results, we can perform camera localization and retrieve the motion of an animated camera in the scene of the 3D reconstruction. This is very useful for doing texture reprojection in other software as part of a texture clean up pipeline. Could also be used to leverage Meshroom as a 3D camera tracker as part of a VFX pipeline. [AVC]

settings

Name

Description

SfM Data

The sfm_data.json kind of file generated by AliceVision

Media File

The folder path or the filename for the media to track

Visual Debug Folder

If a folder is provided it enables visual debug and saves all the debugging info in that folder

Descriptor Path

Folder containing the descriptors for all the images (ie the .desc.)

Match Desc Types

Describer types to use for the matching: sift’, ‘sift*float’, ‘sift*upright’, ‘akaze’, ‘akaze*liop’, ‘akaze*mldb’, ‘cctag3’, ‘cctag4’, ‘sift*ocv’, ‘akaze*ocv

Preset

Preset for the feature extractor when localizing a new image (low, medium, normal, high, ultra)

Resection Estimator

The type of /sac framework to use for resection (acransac, loransac)

Matching Estimator

The type of /sac framework to use for matching (acransac, loransac)

Calibration

Calibration file

Refine Intrinsics

Enable/Disable camera intrinsics refinement for each localized image

Reprojection Error

Maximum reprojection error (in pixels) allowed for resectioning. If set to 0 it lets the ACRansac select an optimal value (0.1 - 50)

Nb Image Match

[voctree] Number of images to retrieve in database (1 - 1000)

Max Results

[voctree] For algorithm AllResults, it stops the image matching when this number of matched images is reached. If 0 it is ignored (1 - 100)

Commonviews

[voctree] Number of minimum images in which a point must be seen to be used in cluster tracking (2 - 50)

Voctree

[voctree] Filename for the vocabulary tree

Voctree Weights

[voctree] Filename for the vocabulary tree weights

Algorithm

[voctree] Algorithm type: (FirstBest, AllResults)

Matching Error

[voctree] Maximum matching error (in pixels) allowed for image matching with geometric verification. If set to 0 it lets the ACRansac select an optimal value (0 - 50)

Nb Frame Buffer Matching

[voctree] Number of previous frame of the sequence to use for matching (0 = Disable) (0 - 100)

Robust Matching

[voctree] Enable/Disable the robust matching between query and database images, all putative matches will be considered

N Nearest Key Frames

[cctag] Number of images to retrieve in the database Parameters specific for final (optional) bundle adjustment optimization of the sequence: (1-100)

Global Bundle

[bundle adjustment] If –refineIntrinsics is not set, this option allows to run a final global bundle adjustment to refine the scene

No Distortion

[bundle adjustment] It does not take into account distortion during the BA, it consider the distortion coefficients all equal to 0

No BA Refine Intrinsics

[bundle adjustment] It does not refine intrinsics during BA

Min Point Visibility

[bundle adjustment] Minimum number of observation that a point must have in order to be considered for bundle adjustment (2-50)

Output Alembic

Filename for the SfMData export file (where camera poses will be stored) desc.Node.internalFolder + ‘trackedCameras.abc

Output JSON

Filename for the localization results as .json desc.Node.internalFolder + ‘trackedCameras.json