Stay Positive: Non-Negative Image Synthesis for Augmented Reality

Katie Luo* Guandao Yang* Wenqi Xian Harald Haraldsson Bharath Hariharan Serge Belongie
StayPositive Method Intro

Abstract

In applications such as optical see-through and projector augmented reality, producing images amounts to solving non-negative image generation, where one can only add light to an existing image. Most image generation methods, however, are ill-suited to this problem setting, as they make the assumption that one can assign arbitrary color to each pixel. In fact, naive application of existing methods fails even in simple domains such as MNIST digits, since one cannot create darker pixels by adding light. We know, however, that the human visual system can be fooled by optical illusions involving certain spatial configurations of brightness and contrast. Our key insight is that one can leverage this behavior to produce high quality images with negligible artifacts. For example, we can create the illusion of darker patches by brightening surrounding pixels. We propose a novel optimization procedure to produce images that satisfy both semantic and non-negativity constraints. Our approach can incorporate existing state-of-the-art methods, and exhibits strong performance in a variety of tasks including image-to-image translation and style transfer.


Motivation
In applications such as optical see-through and projector augmented reality, producing images amounts to solving non-negative image generation, where one can only add light to an existing image. We face two major challenges:

  1. Naively, we cannot create darker pixels by adding more light
  2. Most image generation methods, are ill-suited to this problem setting, since they assume full control of colors for each pixel

Our key insight: Leverage optical illusions to produce high quality images with negligible artifacts, e.g. we can create the illusion of darker patches by brightening surrounding pixels.

We use a two stage optimization process. Our framework's overall schematic consists of the image proposal step and semantic-preserving generator step for the residual. The final output is an optical combination between the input and residual, clipped to be physically feasible. We rely on very few parameters for efficient training.
StayPositive Framework

Result Visualizations

With our two stage framework, we are also able to leverage a variety of state-of-the-art image generation models, including (from left to right): Anokhin et al. 2020, AdaIN, InterFaceGAN, and MuNIT. Below, we compare our results across a variety of domains. From top to bottom: input (with proposal overlaid), heuristic baseline, our method. Observe that with our framework, we are able to obtain multimodal outputs from the generative model.
flow-airplane-4

Video Presentation


Acknowledgements

This work was supported in part by grants from Magic Leap and Facebook AI, and a donation from NVIDIA.