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GooglePatent applicationCameras & imagingInterest 6/10

Google patents camera software that cleans up blurry images to help autofocus work in the dark

Patent drawing
Patent drawing from the official filing.

This filing describes a software method that helps cameras focus accurately in low light or when subjects have little contrast. It works by first blurring and shrinking the image to remove noise, then applying specific filters to make the picture clearer before the camera calculates the correct focus distance.

Why it mattersThis could lead to sharper photos in dim environments, such as indoor events or night scenes, where cameras often struggle to lock focus.

In the filing’s own words

The present document describes techniques for an image-denoising preprocess for robust contrast-detection autofocus with low-light and low-contrast subjects. The techniques described herein provide a software preprocessing approach for denoising image data for contrast-detection autofocus, particularly with low-light conditions and low-contrast subjects. This software autofocus technique utilizes a Gaussian pyramid to reduce noise and downscale the image to reduce computation costs. In aspects, a spatially adaptive denoise preprocessing technique (e.g., Wiener filter, bilateral filter) is then applied to further reduce noise prior to contrast-detection autofocus measurement generation. The denoise preprocessing technique provides a denoised output that is used as input to a focus-value filter for multizone focus-value measurements usable for focusing a camera.

What exactly they claim (claim 1)

1. A method for an image-denoising preprocess for robust contrast-detection autofocus with low-light conditions and low-contrast subjects, the method comprising: receiving image data for a contrast-detection autofocus operation by a digital camera; applying a Gaussian pyramid blur to the image data to provide blurred-image data; executing a denoising preprocess on the blurred-image data to provide noise-reduced image data; filtering the noise-reduced image data using a focus-value filter to provide a filtered output; and extracting a focus value from the filtered output to use in the contrast-detection autofocus operation for focusing the digital camera.

Facts

Company
Google (Google LLC)
Official title
Image-Denoising Preprocess for Robust Contrast-Detection Autofocus with Low-Light and Low-Contrast Subjects
Publication number
US20260323161A1
Application number
18880636
Filed
Oct 3, 2023
Published
Oct 15, 2026
Inventors
2
Claims
20

Classified under

H04N 23/675 Electricity & electronicsG06T 5/20 Physics & computingG06T 5/70 Physics & computingH04N 23/632 Electricity & electronics
Read the full filing (official PDF) ↗ Open in the Patent Tracker

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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.