Segmentation masks of ZooScan images focusing on images with several objects separated by a human operator

The first step in many image analysis tasks is the segmentation of objects of interest from a full image. This is the case for ZooScan images. The ZooScan is a waterproof flatbed scanner dedicated to the digitization of samples of zooplankton, from sizes of 300µm and up. The jar of plankton is poured on the scanning window, objects are physically separated as best as possible and the image is acquired. After background subtraction, the full grayscale image is segmented based on a simple grey intensity threshold and each segmented object is measured (in terms of area, transparency etc.). These segments, usually called "vignettes", are then classified taxonomically, often through the help of machine learning based on the measurements. The measurements also allow estimating the size and volume of each object.

Despite the carefulness of operators, it is frequent for some of the 1000 to 2000 vignettes typically detected on a single scan to contain more than one object, hence biassing the measurements and the further quantification of concentration and biovolume of plankton. To avoid this, operators go back on the initial full frame and digitally separate touching objects by drawing white lines between them. This dataset contains ~14k vignettes with objects separated by white lines, ~5k vignettes of single, correctly detected objects as well as the binary masks of all of them. This can be used to train deep learning segmentation models, such as semantic, instance or panoptic segmenters. All these images were acquired with a ZooScan, from samples taken by a WP2 net in various places of the world, during the Tara Oceans cruise.

Disciplines

Biological oceanography

Keywords

image, zooscan, segmentation, semantic, instance, panoptic, vignette

Location

44N, -64S, -74E, 159W

Devices

The WP2 net is a 200µm meshed net targeting mesozooplankton.

Fraser JH (1966) Zooplankton sampling. Nature 211(5052):915-6.

The ZooScan is a flatbed scanner used to digitise plankton samples such as those coming from the WP2.

Gorsky G, Ohman MD, Picheral M, Gasparini S, Stemmann L, Romagnan J-B, Cawood A, Pesant S, Garcia-Comas C, Prejger F (2010) Digital zooplankton image analysis using the ZooScan integrated system. J Plankton Res 32:285–303.

 

Data

FileSizeFormatProcessingAccess
Original images and binary masks of individual objects, sometimes separated by human operators.
448 MoIMAGEProcessed data
How to cite
Jalabert Laetitia, Amblard Emma, Berrenger Hugo, Bourhis Anthea, Desnos Corinne, Llopis Natalia, Martins Emmanuelle, Merland Camille, Serranito Bruno, Elineau Amanda, Irisson Jean-Olivier (2009). Segmentation masks of ZooScan images focusing on images with several objects separated by a human operator. SEANOE. https://doi.org/10.17882/99663

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