Digital Signal Scaling for Illegal Video and Audio Values

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Solution Overview

Problem

Existing methods for correcting 'illegal' values in digital video and audio data, such as linear scaling and clamping, often reduce contrast and introduce undesirable artefacts, as they either diminish the dynamic range or alter the visual and audio intensity uniformly across all values.

Innovation Solution

A non-linear scaling algorithm is applied to data samples with values outside predefined ranges, using a knee point and connected areas to preserve local maxima and minima, ensuring that only samples exceeding specific thresholds are scaled, thereby maintaining contrast and intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If linear scaling is applied to correct illegal values, then the illegal values are removed, but the contrast and colour intensity are reduced across the whole picture

Engineering Contradiction:
Improvecompliance with broadcast specificationsVSAvoidcontrast and colour intensity
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies different processing treatments to different regions of the signal based on their local characteristics. Illegal values are corrected using non-linear scaling that preserves local contrast, while legal values maintain their original properties. This localized approach ensures that only necessary modifications are made, preserving overall image quality and contrast.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transforms the correction approach by changing from linear scaling to non-linear scaling with specific parameters (knee point, slope). This parameter-based transformation allows the system to maintain contrast and colour intensity while still correcting illegal values, as the non-linear function preserves the relative differences between adjacent values.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If clamping is applied to remove illegal values, then the illegal values are corrected, but contrast is reduced and visual artefacts are introduced

Engineering Contradiction:
Improvecompliance with broadcast specificationsVSAvoidvisual artefacts and contrast reduction
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the simple clamping operation with a non-linear scaling function characterized by specific parameters including knee point, slope, and curvature. This parameterized transformation smoothly transitions values near the legal boundary while preserving the original contrast and avoiding the abrupt cutoff that causes visual artefacts.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of forcing illegal values down to the legal boundary (clamping), the patent inverts the approach by using non-linear scaling that preserves the relative relationships between values. This inverted logic maintains contrast and avoids the creation of large uniform areas that cause visual artefacts.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If linear scaling is applied to audio data, then illegal audio values are corrected, but the dynamic contrast in the middle and lower ranges is reduced

Engineering Contradiction:
Improvecompliance with broadcast audio specificationsVSAvoiddynamic contrast
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies non-linear scaling with configurable parameters to audio data, preserving the dynamic contrast characteristics while correcting illegal values. The non-linear function maintains the relative differences between audio samples, ensuring that the perceived dynamic range and contrast are preserved even after correction.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2499831B1A method of digital signal processing
Publication Date: 2016.08.17 VIDCHECK
  • EP2499831B1 patent drawingFigure 1~2
  • EP2499831B1 patent drawingFigure 3~4
  • EP2499831B1 patent drawingFigure 5

AI summary

A method of digitally processing images and/or audio in the form of a plurality of data samples, each data sample having a value representative of a visual or audio property, the method comprising: identifying a first set of data samples having values outside a first predefined range of data values; identifying a second set of data samples having values outside a second predefined range of data values, the second predefined range being within the first predefined range; and applying a non-linear scaling algorithm to the data values of the first and second sets of data samples to generate a set of modified data samples having data values within the first predefined range.