Image File XMP Area Layout for Authenticity Without File Bloat

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Solution Overview

Problem

Existing digital image authentication methods fail to prevent erroneous determination of tampering when data is appended to areas excluded from authenticity certification, leading to unnecessary file size increase due to reserved blank areas that may not be used.

Innovation Solution

The system pre-expands areas in digital files where data appending is expected, ensuring authenticity certification by hashing and encrypting only relevant areas, thus preventing file size growth when data is appended.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a blank area is reserved in the image file for potential data appending, then data can be appended after photographing without shifting hash positions, but the file size increases unnecessarily when data appending is not performed

Engineering Contradiction:
Improveauthenticity certification accuracyVSAvoidfile size
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent makes the reserved area size dynamic rather than fixed. The system determines the actual size needed based on whether data appending operations are performed, adjusting the reserved area accordingly. This resolves the contradiction by making the file structure adaptive - when data appending occurs, sufficient space is reserved; when it doesn't occur, no excessive space is wasted.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of reserved area size based on operational conditions. By monitoring whether data appending is performed and adjusting the reserved area size parameter dynamically, the system maintains authenticity certification reliability while optimizing file size. The reserved area expands only when necessary for data appending operations.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the position of the area to be hashed is shifted due to data appending, then more space is available for data storage, but the digital image is erroneously determined to have been altered

Engineering Contradiction:
Improvedata storage flexibilityVSAvoidauthenticity determination accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent performs preliminary action by reserving the necessary space in advance before data appending occurs. By pre-allocating the required area size based on expected data appending needs, the system prevents position shifts of hashed areas while maintaining authenticity certification. The reserved space is prepared beforehand, eliminating the need to shift hash positions during data appending.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4672069A1Electronic apparatus capable of suppressing unnecessary increase in size of digital file whose authenticity is capable of being certified even if data is changed after generation, control method for electronic apparatus, storage medium, and program
Publication Date: 2025.12.31 CANON KK
  • EP4672069A1 patent drawingFigure 1A~1B
  • EP4672069A1 patent drawingFigure 2
  • EP4672069A1 patent drawingFigure 3A

AI summary

An electronic apparatus (100) capable of suppressing an unnecessary increase in a size of a digital file whose authenticity is capable of being certified even if data is changed after generation is provided. A digital camera (100) that has an authenticity certification photographing mode in which an image file (309) whose authenticity is capable of being certified is generated, includes a system control unit (50) that, in a case where the digital camera has been set to the authenticity certification photographing mode and a plan, in which data appending is performed with respect to an XMP area (304), which has been excluded from a subject of authenticity certification, from among areas constituting the image file after the image file is generated, has been set, enlarges a size of the XMP area than when the digital camera has been set to a normal photographing mode and generates the image file.