We present the focal flow sensor. It is an unactuated, monocular camera that simultaneously exploits defocus and differential motion to measure a depth map and a 3D scene velocity field. It does this using an optical-flow-like, per-pixel linear constraint that relates image derivatives to depth and velocity. We derive this constraint, prove its invariance to scene texture, and prove that it is exactly satisfied only when the sensor’s blur kernels are Gaussian. We analyze the inherent sensitivity of the focal flow cue, and we build and test a prototype. Experiments produce useful depth and velocity information for a broader set of aperture configurations, including a simple lens with a pillbox aperture.

中文翻译：

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焦流：通过运动差分散焦的速度和深度

我们展示了焦点流量传感器。它是一种未驱动的单目相机，可同时利用散焦和微分运动来测量深度图和 3D 场景速度场。它使用类似光流的每像素线性约束来实现这一点，该约束将图像导数与深度和速度联系起来。我们推导出这个约束，证明它对场景纹理的不变性，并证明只有当传感器的模糊核是高斯时它才完全满足。我们分析了焦点流线索的固有敏感性，并构建并测试了原型。实验为更广泛的光圈配置产生有用的深度和速度信息，包括带有药盒光圈的简单镜头。