Image classification

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This article explain working with image classification in annotation tool.

Annotation tool set

It is set to View mode. If you want to use shortcuts click on Question mark icon next to mode selection.

Adding class

To start work with classes click on EDIT next to “Image classification”.

Class manager window pop up. Fill up name of the object and then click on ADD. With edit icon on the right side of the name you can rename object or by clicking on trash icon delete it.

Starting with classification process

When all classes are added, you can start with image classification. Status of each class is represented by question mark (?) and NONE next to them. If you want to assign picture to one of the classes, click on appropriate class. Class is now marked by a thick. If object does not belong to certain class, click on NONE

Example:

In this example you can see that there are 3 classes (1). Bird in this picture is correctly in Pheasant class and not in Cardinal or Redbreast class (2). When you finish with object detection, click on EXPORT PROJECT (3). This will download JSON file with all images from your project as ZIP file to your computer


JSON file

JSON file structure is based on COCO structure (Common objects in context). It contains the following objects:

FieldsDescriptionAttributes




info





Main information about project

year
version
description
contributor
url
date_created





images





Information about all images contained in project

id
width
height
file_name
license
flickr_url
coco_url
date_captured




annotations




Annotation data of each image, its classification, coordinates of detected objects

id
image_id
category_id
segmentation
area
bbox


categories


Name and id of each class

id
name
supercategory

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