This page outlines the primary and secondary objectives that informed the spectral image processing of Livingstone's 1871 Field Diary.
Spectral image processing uses tailored mathematical algorithms in order to manipulate and enhance raw spectral image data. In the case of Livingstone’s 1871 Field Diary, such processing relies on the fact that different ink types on a given page (for instance, Livingstone’s ink, the ink of the newsprint, etc.) behave differently under different bands of wavelengths of light. Imaging scientists can use this differentiated behavior to create processed images (renderings of combinations of bands) that distinguish among what may be otherwise very subtle differences in color.
|One natural light image and eight processed spectral images of a page of the 1871 Field Diary (Livingstone 1871f:CXXVI color and pack16 , pseudo_v1, pca621r, pca621r_adapThresh, pca621r_pcolor, spectral_ratio, sharpie, and raking). Copyright David Livingstone Centre, Blantyre. As relevant, copyright Dr. Neil Imray Livingstone Wilson. Creative Commons Attribution-NonCommercial 3.0 Unported. These images all show the same segment of the page. Each image offers data not available in the others.|
The Livingstone team has applied spectral image processing to nearly all the pages of the 1871 Field Diary in order to address the principal challenges posed by this manuscript:
- the fading of Livingstone’s handwritten text to the point of invisibility in much of the diary, and
- the additional difficulty in reading Livingstone’s text due to the continuing prominence of the newsprint over which he wrote.
Due to these challenges, the team took as its primary processing objectives, first, suppressing the printed text, and, second, enhancing Livingstone’s handwritten text. Additional objectives included developing the "intercept" processing method to clarify indecipherable text and processing with raking light images to highlight manuscript topography (in the latter case, limited to those folia that had not been laminated, see The Manuscript; for topographical processing also see Livingstone's 1870 Field Diary). The team also used raw spectral image data to produce highly accurate color images of each diary page.
A separte section provides details of the many processing methods developed for Livingstone's Letter from Bambarre and the 1870 and 1871 Field Diaries, each of which is the subject of a separate multispectral critical edition. Further information on the processing of Livingstone's 1871 Field Diary also appears in the relevant part of the project history.