Bnotate creates a more natural way to annotate images for training computer vision and object detection artificial intelligence (AI) models from images. The visual object annotation methodology follows “Extreme clicking for efficient object annotation” by Papadopolous et al. (ICCV 2017) where one simply touches the four extreme points of the object, i.e. points belonging to the top, bottom, left-most, and right-most parts of the object. Once complete, the annotations are exported into a convenient CSV format similar to the bounding boxes format for the Open Images Dataset V5. This tool is similar to Microsoft’s visual object tagging tool (VoTT) adapted for mobile devices.

Key Functionality

  • Download image files from cloud data stores to the device for use in a offline mode of operation
  • Pinch to zoom (up to 5x) and press and drag to pan for easy image manipulation before locking in an annotation
  • Export format is similar to expectations for many pre-trained neural networks and cloud computer vision platforms

Frequently Asked Questions

How do I edit a Bounding Box Annotation after I submitted it?

Unfortunately, once submitted the bounding box is frozen. To remove it, you can only delete all annotations from the image and start again. This was a design decision to keep a single workflow for adding and removing annotations.

What is the coordinate system used in the exported annotations?

XMin, XMax, YMin, YMax: coordinates of the box, in graphics format image coordinates where the top leftmost pixel is (0, 0) and the bottom rightmost pixel is (width, height). To convert all coordinates to Open Images’ normalized image coordinates divide the X-coordinates by the image width, and Y-coordinates by the image height.

Where are my exported annotations?
  • On iOS: Open the Files app, Navigate to the “On My …” folder, Select the Bnotate folder, Search ‘Annotations’ or ‘Bnotate’ and a CSV file corresponding to each export should appear.
  • On Android: Open the Files app or your File Manager app, Search ‘Bnotate’ or Select your top-level device folder, then navigate the following directory path: Android/data/com.sideworkai.bnotate/files.

After locating the exported annotations file, one can use the file manager application to email or upload to a cloud drive.


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