Encoder-Supervised Camera Imaging Parameter Adjustment

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Solution Overview

Problem

Existing methods for adjusting imaging parameters in cameras do not consider the impact on video encoders, leading to degradation of image quality due to disruptive changes in pixel values, especially under constant bit-rate compression.

Innovation Solution

A method and apparatus that adjust camera imaging parameters, such as exposure and color balance, based on encoding properties received from a video encoder, to maintain higher image quality during prediction-based compression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If automatic exposure control adjusts imaging parameters based on lighting characteristics, then the camera can adapt to changing lighting conditions, but disruptive changes in pixel values occur under constant bit-rate compression leading to image quality degradation

Engineering Contradiction:
Improvelighting adaptationVSAvoidimage quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent implements feedback by having the video encoder provide encoding information back to the camera controller, which then adjusts imaging parameters accordingly. This closed-loop system allows the camera to adapt to lighting conditions while being aware of the encoder's bit-rate constraints, preventing disruptive pixel value changes that would degrade image quality under constant bit-rate compression.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by having the camera controller receive encoding information from the video encoder before making imaging parameter adjustments. This allows the camera to anticipate the encoder's constraints and make gradual, controlled adjustments to exposure and other parameters, avoiding sudden disruptive changes that would harm image quality under constant bit-rate compression.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If automatic white balance control adjusts color channel gains according to lighting hue, then color accuracy is improved, but pixel value disruptions occur causing image quality degradation in subsequent images

Engineering Contradiction:
Improvecolor accuracyVSAvoidimage quality consistency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The feedback mechanism allows the camera controller to receive encoding information from the video encoder and adjust white balance parameters accordingly. This enables the system to maintain color accuracy through gradual adjustments rather than sudden changes, ensuring reliability and consistency of image quality across subsequent frames under constant bit-rate compression.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

By receiving encoding information before making white balance adjustments, the camera controller can plan color channel gain changes in advance. This preliminary action ensures that color accuracy is maintained while avoiding disruptive pixel value changes that would compromise image quality consistency in subsequent images encoded under constant bit-rate constraints.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If imaging parameters are adjusted to respond to lighting changes, then the camera adapts to environmental conditions, but the predictive nature of video encoder compression extends quality degradation to subsequent images

Engineering Contradiction:
Improveenvironmental adaptationVSAvoidvideo quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The feedback loop between the video encoder and camera controller enables the system to adapt to environmental lighting changes while maintaining video quality. The encoder provides information about current encoding conditions, allowing the camera to make informed parameter adjustments that minimize disruptive pixel value changes and prevent quality degradation from propagating to subsequent images through predictive compression.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The camera controller receives encoding information in advance and makes preliminary adjustments to imaging parameters before capturing images. This allows the system to adapt to environmental conditions gradually and controlledly, ensuring that changes in exposure and other parameters do not cause disruptive pixel value changes that would extend quality degradation to subsequent images under constant bit-rate compression.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2727330B1Encoder-supervised imaging for video cameras
Publication Date: 2018.05.23 CISCO TECHNOLOGY INC
  • EP2727330B1 patent drawingFigure 1
  • EP2727330B1 patent drawingFigure 2
  • EP2727330B1 patent drawingFigure 3A~3B

AI summary

A controller controls a camera that produces a sequence of images and that has output coupled to a video encoder. The camera has an operating condition including a field of view and lighting, and one or more imaging parameters. The video encoder encodes images from the camera into codewords. The controller receives one or more encoding properties from the video encoder, and causes adjusting one or more of the imaging parameters based on at least one of the received encoding properties, such that the camera produces additional images of the sequence of images for the video encoder using the adjusted one or more imaging parameters.