vidar/geometry/camera_utils.py

# TRI-VIDAR - Copyright 2022 Toyota Research Institute.  All rights reserved.

from vidar.utils.types import is_seq


def invert_intrinsics(K):
    """Invert camera intrinsics"""
    Kinv = K.clone()
    Kinv[:, 0, 0] = 1. / K[:, 0, 0]
    Kinv[:, 1, 1] = 1. / K[:, 1, 1]
    Kinv[:, 0, 2] = -1. * K[:, 0, 2] / K[:, 0, 0]
    Kinv[:, 1, 2] = -1. * K[:, 1, 2] / K[:, 1, 1]
    return Kinv


def scale_intrinsics(K, ratio):
    """Scale intrinsics given a ratio (tuple for individual hw ratios, float for the same ratio)"""
    if is_seq(ratio):
        ratio_h, ratio_w = ratio
    else:
        ratio_h = ratio_w = ratio

    K = K.clone()
    K[..., 0, 0] *= ratio_w
    K[..., 1, 1] *= ratio_h
    # K[..., 0, 2] = (K[..., 0, 2] + 0.5) * x_scale - 0.5
    # K[..., 1, 2] = (K[..., 1, 2] + 0.5) * y_scale - 0.5
    K[..., 0, 2] = K[..., 0, 2] * ratio_w
    K[..., 1, 2] = K[..., 1, 2] * ratio_h

    return K