SLAMorris Final Thesis After Corrections.pdf - Cranfield University

8.3 Methodology
The problem definition highlighted two areas for investigation in this research.
Firstly methods to improve the identification of H3 fragments will be considered;
as these are JPEG image data only fragments standard image fragment
recovery techniques can be considered. After research relating to JPEG
fragment identification has been considered a new method for H3 identification
will be implemented. This will be followed by the construction of a hybrid
approach for thumbnail cache file fragment identification; the implementation
will take the strengths of the four methods evaluated in the previous chapter
and aims to improve the statistics for identification.
In order to conduct this research the three data sets constructed in Chapter 7
will be used to evaluate the resulting implementation of a thumbnail cache file
fragment identification method. Previous work has highlighted the importance of
understanding the structural characteristics of files in order to identify potential
fragments and this will be considered throughout the construction of an
identification method for each classification. The research conducted to
implement a new method for H3 identification will be used in the hybrid
approach constructed in Section 8.6. The results of the hybrid approach will
then be described in Section 8.7 and evaluated against the identification
methods constructed in Chapter 7 [Section 8.8].
8.4 JPEG Identification Research
One of the most common image formats is JPEG; JPEG is a compression
method which is commonly used for images such as those on web pages and
those taken with digital cameras. Like PNG images, JPEG files are split into
sections, however the sections do not contain information about the length of
their content. Each section begins with a marker to denote its start and type;
since the file type is less structured than a PNG file the markers can occur at
any point and therefore at any point in a file fragment. The structure of JPEG
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