Light Field Vision

Module: Computer Vision | Difficulty: Advanced

Light Field Parameterization

Two-plane parameterization: where is the lens plane and is the focal plane.

Synthetic Refocusing

Epipolar Plane Image (EPI)

Slice shows disparity as slope:

Depth from Focus

import numpy as np

def refocus_lightfield(LF, alpha):
    B, U, V, H, W, C = LF.shape
    result = np.zeros((H, W, C))
    for u in range(U):
        for v in range(V):
            shift_x = int((u - U//2) * (1 - 1/alpha))
            shift_y = int((v - V//2) * (1 - 1/alpha))
            shifted = np.roll(np.roll(LF[0, u, v], shift_x, axis=1), shift_y, axis=0)
            result += shifted
    return result / (U * V)

Key Takeaways

• Light fields capture both spatial and angular information
• Synthetic refocusing enables post-capture focus adjustment
• EPI analysis reveals depth through disparity patterns