No annotation outputted when using imageLabeler

Hi,

I'm trying to label some data inside the imageLabeler tool, export to workspace then export to COCO format using exportGroundTruthToJSON. I load my images into the labeler, put labels on, then export to workspace. At this point I never see any annotations despite having classes setup and labels created on the labeler, an when I export to COCO the annotations section is empty.

I'm sure I'm doing something obviously wrong. But after reading through the documentation on it I can't see anything.

For clarity my workflow is.

> Load images into imageLabeler

> Create classes

> Label data using Flood Fill tool

> Export to workspace. (There is no meantions of annotations or similar in the groundTruth object)

> Export to COCO using, exportGroundTruthToJSON(gTruth, 'anno.json', 'COCO', true). (Subsequently still no annotation data)

I'm doing this in a indivdual project using R2023b.

Thanks in advance

Answer 1

[Adeline]

Hi,

I understand you are using the “imageLabeler” tool to create annotations for images and ultimately export them into COCO format. The steps involved in this task have been represented appropriately in the mentioned workflow.

The flood fill tool used for annotation is part of the pixel ROI label which supports semantic segmentation. When an image is labelled/annotated, the relevant information i.e., the label data and definitions are updated. This information can be exported into the workspace using the “groundTruth” object. This object contains the source path of the images and tabular data regarding the labels. The object information can also be exported into COCO data format JSON file using the “exportGroundTruthToJSON” function.

For more information on pixel labelling, “groundTruth” object and JSON export, please refer to the following links:

https://www.mathworks.com/help/vision/ug/label-pixels-for-semantic-segmentation.html

https://www.mathworks.com/help/vision/ug/get-started-with-the-image-labeler.html#mw_72146e4f-e569-457d-91b9-9ac80caffb67

https://www.mathworks.com/help/vision/ug/export-ground-truth-object-to-custom-and-coco-json-files.html

Hope this information was helpful.