BLEFF Dataloader

[Skyy93]

Hello @ziruiw-dev,

could you please provide the BLEFF dataloader?

Thank you very much
BR

[ziruiw-dev]

Hi @Skyy93,

I should be able to upload a full file in early April. If you are in a hurry, here are some basic functions and it should be fairly easy to load BLEFF camera parameters.

def load_blender_gt_meta(gt_json):
    with open(gt_json, 'r') as json_f:
        gt_json = json.load(json_f)
        fov_x = gt_json['cam_angle_x']  # fov in rad
        fov_y = gt_json['cam_angle_y']  # fov in rad
        c2ws = np.array(gt_json['c2ws']).astype(np.float32)  # (N, 4, 4)

    # centre poses
    c2ws, pose_avg = center_poses(c2ws[:, :3])  # (N, 3, 4)
    c2ws = convert3x4_4x4(c2ws)  # (N, 4, 4)

    # scale gt to a unit sphere
    c2ws[:, :3, 3] /= pts_dist_max(c2ws[:, :3, 3])
    c2ws[:, :3, 3] *= 2.0

    results = {
        'fov_x': fov_x,
        'fov_y': fov_y,
        'c2ws': c2ws  # (N_gt, 4, 4)
    }

    return results


def fov2focal_pix(fov, hw):
    """
    :param fov: float or double
    :param hw:  float or double
    :return:    float or double
    """
    focal_pix = 0.5 * hw / np.tan(fov / 2.0)
    return focal_pix

and you can get data by

gt_meta = load_blender_gt_meta(os.path.join(scene_dir, 'gt_metas.json'))
gt_c2ws_all = gt_meta['c2ws']  # (N_gt, 4, 4)
gt_fx = fov2focal_pix(gt_meta['fov_x'], W)
gt_fy = fov2focal_pix(gt_meta['fov_y'], H)

[Skyy93]

Thank you, that helps very much!