Depth-Histogram Autofocus for Image Sensors

Solution Overview

Problem

Advanced autofocus processes in image capturing devices require significant processing time and computing power, leading to delays in capturing properly focused images, especially when determining regions of interest.

Innovation Solution

A histogram-based autofocus method that categorizes depth values into ranges, determines autofocus distance based on depth histogram peaks, and adjusts focus settings without identifying regions of interest, thereby reducing processing time and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If advanced autofocus processes are used to determine regions of interest, then focus accuracy is improved, but processing time and computing power consumption increase

Engineering Contradiction:

Improvefocus accuracyVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential depth information needed for autofocus by generating a depth histogram that categorizes depth values into ranges. This extracts the critical focusing data while discarding unnecessary detailed depth information, thereby reducing processing time and computing power while maintaining sufficient focus accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms continuous depth values into discrete depth value ranges through histogram binning. This parameter transformation simplifies the data structure from continuous to discrete categories, reducing computational complexity and processing time while preserving the essential depth distribution information needed for accurate autofocus.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If advanced autofocus processes are used to determine regions of interest, then focus accuracy is improved, but computing power consumption increases

Engineering Contradiction:

Improvefocus accuracyVSAvoidcomputing power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential depth information needed for autofocus by generating a depth histogram that categorizes depth values into ranges. This extracts the critical focusing data while discarding unnecessary detailed depth information, thereby reducing processing time and computing power while maintaining sufficient focus accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms continuous depth values into discrete depth value ranges through histogram binning. This parameter transformation simplifies the data structure from continuous to discrete categories, reducing computational complexity and processing time while preserving the essential depth distribution information needed for accurate autofocus.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If region of interest identification is performed, then autofocus precision is improved, but device complexity increases

Engineering Contradiction:

Improveautofocus precisionVSAvoidprocessing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential depth information needed for autofocus by generating a depth histogram that categorizes depth values into ranges. This extracts the critical focusing data while discarding unnecessary detailed depth information, thereby reducing processing time and computing power while maintaining sufficient focus accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms continuous depth values into discrete depth value ranges through histogram binning. This parameter transformation simplifies the data structure from continuous to discrete categories, reducing computational complexity and processing time while preserving the essential depth distribution information needed for accurate autofocus.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20240430567A1Depth-Histogram Based Autofocus

Publication Date: 2024.12.26 GOOGLE LLC

AI summary

A method includes receiving a plurality of depth values corresponding to a plurality of areas depicted in an image captured by an image sensor. The method also includes generating a depth histogram categorizing each depth value of the plurality of depth values into a depth value range of a plurality of depth value ranges. The method further includes determining an autofocus distance based on the depth histogram. The method additionally includes causing the image sensor to capture an image based on the autofocus distance.