Efficient Denoising Method to Improve The Resolution of Satellite Images

Abstract

Satellites are widely used to estimate and monitor ground cover, providing critical information to address the challenges posed by climate change. High-resolution satellite images help to identify smaller features on the ground and classification of ground cover types. Small satellites have become very popular recently due to their cost-effectiveness. However, smaller satellites have weaker spatial resolution, and preprocessing using recent generative models made it possible to enhance the resolution of these satellite images. The objective of this paper is to propose computationally efficient guided or image-conditioned denoising diffusion models (DDMs) to perform super-resolution on low-quality images. Denoising based on stochastic ordinary differential equations (ODEs) typically takes hundreds of iterations and it can be reduced using deterministic ODEs. I propose Consistency Models (CM) that utilize deterministic ODEs for efficient denoising and perform super resolution on satellite images. The DOTA v2.0 image dataset that is used to develop object detectors needed for urban planning and ground cover estimation, is used in this project. The Stable Diffusion model is used as the base model, and the DDM in Stable Diffusion is converted into a Consistency Model (CM) using Teacher-Student Distillation to apply deterministic denoising. Stable diffusion with modified CM has successfully improved the resolution of satellite images by a factor of 16, and the computational time was reduced by a factor of 20 compared to stochastic denoising methods. The FID score of low-resolution images improved from 10.0 to 1.9 after increasing the image resolution using my algorithm for consistency models.