CSIRO Patch-based 8-class Morphology Model

A patch-based segmentation model designed for seagrass morphological class identification and habitat mapping. The model segments images into fixed-size patches (e.g., 280×280 pixels) and classifies each patch into foreground classes (various seagrass species) or background classes (such as substrate, coral, and macroalgae). Morphological seagrass coverage is quantified by calculating the percentage of patches classified into each class, enabling precise assessments of seagrass distribution and density.

Input

The model is trained on images from Indo-Pacific regions, including Indonesia, Thailand, and Fiji. While it can process images from other regions, accuracy may decrease.

Classes

This model classifies seagrass into the following morphological categories:

  • Oval Seagrass - Ho, Hd, Hb
  • Cylindrical Seagrass - Si
  • Stemmy Seagrass - Tc
  • Strappy Medium/Thin Seagrass - Cs, Th, Hu, Cr, Zc
  • Strappy Hair-Thin Seagrass - Hp
  • Strappy Thick Seagrass - Ea
  • Unknown or Mixed Seagrass
  • Others

Note: The morphological codes in italics correspond to specific seagrass species.
For full species names and descriptions, refer to the Seagrass-Watch Species ID Guide.

Annotation Method

Each image represents a 50x50 cm quadrat captured by a camera positioned at a fixed distance. The images are resized to 3008x3008 pixels, achieving a resolution of approximately 60 pixels per cm.

Patch Size

280x280 pixels: Corresponds to a 5x5 cm area.

Annotated Patches on Reefcloud

Due to software limitations, annotators are required to label 20 patches per image slice, arranged in a 5x4 grid. This setup allows for a maximum of 1024 patches (32x32 grid) per image.

Patch Labeling Methodology

Single Seagrass Species Present: Assign the specific seagrass class label to the patch, regardless of the percentage of coverage within the patch.​

Multiple Seagrass Species Present:

  • If one species is clearly dominant, label the patch with the dominant species’ class.
  • If no species is dominant, use a generic seagrass class label.​
  • Seagrass vs. Benthos Classes: Seagrass classifications take precedence over benthic classes. If no seagrass is visible, label the patch with the dominant benthic class.

Contextual Considerations

Annotators focus on the content within the patch while also considering the broader context of the entire image. This approach ensures that local features are interpreted in alignment with the global scene, leading to more accurate and meaningful annotations.

Model Metadata

Version: 1.0

Tags: Morphology Seagrass

Credits: Yang Li, Rizwan Khokher, Brendan Do, Asheley Stacey, Jeremy Oorloff, Jiajun Liu, Brano Kusy

Performance on Test Dataset

Accuracy
Class Group Accuracy Support
Others 0.7626 2,759
S_CY(Si) 0.0714 14
S_OV(Ho Hd Hb) 0.5000 6
S_STM(Tc) 0.7582 335
S_STP_M&N(Cs Th Cr) 0.5079 5,475
S_STP_N(Hp) 0.5294 272
S_STP_T(Ea) 0.5558 2,134
S_UKN 0.0635 945

Confusion Matrix

Example Output

Example Input