Digital Zoom Calibration for Smooth Lens Switching

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Solution Overview

Problem

Image jumps and distortion occur during digital zoom due to optical axis misalignment and inconsistent in-plane rotation angles of lenses, leading to field angle loss and abrupt image changes.

Innovation Solution

A digital zoom method that includes pre-calibration to acquire distortion, rotation, and center deviation parameters, followed by gradual correction and reconstruction of images to ensure smooth transitions and minimize field angle loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple lenses with different focal lengths are used for digital zoom, then the zoom range is extended, but image jumps occur due to optical axis misalignment

Engineering Contradiction:
Improvezoom rangeVSAvoidimage stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by performing pre-calibration to obtain distortion correction parameters, rotation parameters, and center deviation parameters before actual zoom operations. These parameters are calculated in advance to compensate for optical axis misalignment, enabling smooth transitions when switching between lenses with different focal lengths without causing image jumps

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting distortion correction parameters, rotation parameters, and center deviation parameters based on the current zoom magnification and lens switching state. These parameter changes ensure that image corrections are continuously optimized throughout the zoom range, maintaining image stability while extending zoom capability

Inventive Principle:
Principle #35Parameter changes

2Reliability

If image correction is performed to solve optical axis spacing and rotation deviations, then image stability is improved, but field angles are lost

Engineering Contradiction:
Improveimage stabilityVSAvoidfield angle
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent applies parameter changes by using different distortion correction parameters for different zoom magnifications. For example, when zoom magnification is between 1x and 2x, a first distortion correction parameter is used that preserves more field angle, while when zoom magnification is between 2x and 4x, a second distortion correction parameter is used. This dynamic parameter adjustment maintains image stability while minimizing field angle loss at each zoom level

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies dynamics by making the distortion correction parameters dynamic rather than fixed. The parameters change continuously or in steps based on the zoom magnification level, allowing the system to adaptively balance between image stability correction and field angle preservation throughout the zoom range

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If lens switching is performed during digital zoom, then zoom flexibility is improved, but abrupt image changes occur

Engineering Contradiction:
Improvezoom flexibilityVSAvoidimage continuity
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing distortion correction parameters, rotation parameters, and center deviation parameters for each lens and zoom level combination. Before lens switching occurs, the appropriate parameters are already prepared, enabling seamless transitions without abrupt image changes when flexibility is needed

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies feedback by using the current zoom magnification and lens state to select appropriate correction parameters. The system continuously monitors the zoom level and adjusts the correction parameters accordingly, ensuring that image continuity is maintained through feedback-driven parameter selection during lens switching operations

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4637131A1Digital zoom method and apparatus, electronic device and storage medium
Publication Date: 2025.10.22 ZHEJIANG UNIVIEW TECH CO LTD
  • EP4637131A1 patent drawingFigure 1~2A
  • EP4637131A1 patent drawingFigure 2B~3
  • EP4637131A1 patent drawingFigure 4~5

AI summary

Provided are a digital zoom method and apparatus, an electronic device, and a storage medium. The method includes: acquiring a distortion correction parameter, a rotation parameter, and a center deviation parameter that are obtained through pre-calibration; determining digital zoom magnifications matching a plurality of frames of images according to a digital zoom threshold and zoom time; determining distortion correction parameters matching the plurality of frames of images according to a preset parameter determination rule and the distortion correction parameter, and determining rotation parameters matching the plurality of frames of images according to the preset parameter determination rule and the rotation parameter; and performing distortion correction on the plurality of frames of images sequentially according to the matched distortion correction parameters, performing translation according to the center deviation parameter, performing rotation according to the matched rotation parameters, and performing cropping and reconstruction according to the matched digital zoom magnifications to implement digital zoom.