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Gulf Coast Repository

Section Half Imaging Logger (SHIL)

Overview

Thumbnail image of Section Half Imaging Logger Images of the flat face surfaces of split core are often considered a fundamental dataset. Cores are typically imaged fresh after being split into section halves, but older sections can be rescanned for differences and changes in core quality. Whole-round hard rock core sections can also be imaged. Digital image collection also allows for the determination of red-green-blue (RGB) color space for a core section.

Maximum core diameter: 11.43 cm (o.d.)
Maximum core length: 155 cm

Instrument Make and Model

Custom-built system.

Estimated Measurement Time

  • Sample Preparation: 2–20 mins/section
  • Measurement Time: ~15–20 sections/hour

Principles & Analytical Capabilities

Images are taken on flat faces of split core using a line scan camera at 20 lines/mm (50 microns). Camera exposures are calibrated and color corrected prior to data collection. Camera height is adjustable for different core sizes (diameters). RGB values depend on decimation settings (1 cm is standard, <1 mm for high resolution), which can be updated based on user needs. RGB values are calculated based on the cropped image, of which the area is determined by the user.

Data Generated

Data components:

  • R: average of digitized red (R) channel over a defined rectangle along the core section. Values range from 0 to 255 (8-bit color digitization).
  • G: average of digitized green (G) channel over a defined rectangle along the core section. Values range from 0 to 255 (8-bit color digitization).
  • B: average of digitized blue (B) channel over a defined rectangle along the core section. Values range from 0 to 255 (8-bit color digitization).

Image files:

  • JPEG (raw): Raw image that includes ruler and naming nomenclature of the core section.
  • JPEG (cropped): lower-resolution of the raw file, with core section cropped to exclude ruler and naming nomenclature. Standard resolution RGB values are generated from this file.
  • TIFF: high-resolution image, approximately 160MB filesize

Data files:

  • Standard resolution (CSV): data decimated at 1 cm or a user selected resolution
  • High resolution (DAT): data decimated at <1 mm

Raw files:

  • ROI (instrument file): data file containing ROI reduced data and metadata
  • RGB (instrument file): data file containing RGB reduced data and metadata

Data Example

Graph of RGB (red, green, blue) color space with section half core image from Hole U1613A.
RGB (red, green, blue) color space with section half core image from Hole U1613A of IODP Expedition 402 in the Tyrrhenian Sea.1, 2

Procedures & Manuals

References

1  Malinverno, A., Zitellini, N., Estes, E. R., Abe, N., Akizawa, N., Bickert, M., Cunningham, E. H., Di Stefano, A., Filina, I. Y., Fu, Q., Gontharet, S. B. L., Kearns, L. E., Koorapati, R. K., Lei, C., Loreto, M. F., Magri, L., Menapace, W., Morishita, T., Pandey, A., … Zhao, X. (2025). IODP Expedition 402 RGB channels (calculated from core photos) [Data set]. International Ocean Discovery Program. https://doi.org/10.5281/zenodo.15238669

2  Malinverno, A., Zitellini, N., Estes, E. R., Abe, N., Akizawa, N., Bickert, M., Cunningham, E. H., Di Stefano, A., Filina, I. Y., Fu, Q., Gontharet, S. B. L., Kearns, L. E., Koorapati, R. K., Lei, C., Loreto, M. F., Magri, L., Menapace, W., Morishita, T., Pandey, A., … Zhao, X. (2025). IODP Expedition 402 Section-half images [Data set]. International Ocean Discovery Program. https://doi.org/10.5281/zenodo.15238608