Cityscapes

Overview

This converter allows to import images with .json annotations in Cityscapes format.

⚠️ Note: images must have suffix _leftImg8bit and annotations suffix _gtFine_polygons and .json extension. Check the example of the file structure below.

Result of the import

Format description

Supported image formats: .jpg, .jpeg, .mpo, .bmp, .png, .webp, .tiff, .tif, .jfif, .avif, .heic, and .heif With annotations: yes Supported annotation file extension: .json. Grouped by: any structure (uploaded to a single dataset)

Input files structure

Example data: download ⬇️

Recommended directory structure:

📦project name
 ┣ 📂gtFine
 ┃ ┣ 📂test
 ┃ ┃ ┗ 📂ds1
 ┃ ┃ ┃ ┗ 📜IMG_8144_gtFine_polygons.json
 ┃ ┣ 📂train
 ┃ ┃ ┗ 📂ds1
 ┃ ┃ ┃ ┣ 📜IMG_1836_gtFine_polygons.json
 ┃ ┃ ┃ ┣ 📜IMG_2084_gtFine_polygons.json
 ┃ ┃ ┃ ┣ 📜IMG_3861_gtFine_polygons.json
 ┃ ┃ ┃ ┗ 📜IMG_4451_gtFine_polygons.json
 ┃ ┗ 📂val
 ┃ ┃ ┗ 📂ds1
 ┃ ┃ ┃ ┗ 📜IMG_0748_gtFine_polygons.json
 ┣ 📂leftImg8bit
 ┃ ┣ 📂test
 ┃ ┃ ┗ 📂ds1
 ┃ ┃ ┃ ┗ 🖼️IMG_8144_leftImg8bit.png
 ┃ ┣ 📂train
 ┃ ┃ ┗ 📂ds1
 ┃ ┃ ┃ ┣ 🖼️IMG_1836_leftImg8bit.png
 ┃ ┃ ┃ ┣ 🖼️IMG_2084_leftImg8bit.png
 ┃ ┃ ┃ ┣ 🖼️IMG_3861_leftImg8bit.png
 ┃ ┃ ┃ ┗ 🖼️IMG_4451_leftImg8bit.png
 ┃ ┗ 📂val
 ┃ ┃ ┗ 📂ds1
 ┃ ┃ ┃ ┗ 🖼️IMG_0748_leftImg8bit.png
 ┗ 📜class_to_id.json

Format Config File

In order to import custom annotations for the images, you need to provide a class_to_id.json file. This file should contain a list with dictionaries. Each dictionary should contain information about the class with the following fields:

• name - the name of the class. It should be unique.

• id - the ID of the class. From 1 to N-1, where N is the number of classes.

• color - the color of the class in RGB format. If not specified, the color will be generated randomly

📜class_to_id.json

[
  {
    "name": "kiwi",
    "id": 1,
    "color": [255, 0, 0]
  },
  {
    "name": "lemon",
    "id": 2,
    "color": [81, 198, 170]
  }
]

Individual Image Annotations

Annotation file should contain the following fields:

• imgHeight - the height of the image

• imgWidth - the width of the image

• objects - a list of dictionaries, each containing information about the object

  • label - the name of the class

  • polygon - a list of points that form the polygon of the object

Example of the annotation file from provided sample data:

📜IMG_1836_gtFine_polygons.json

{
    "imgHeight": 800,
    "imgWidth": 1067,
    "objects": [
        {
            "label": "lemon",
            "polygon": [
                [772, 421],
                [771, 422],
                ...
                [785, 422],
                [784, 421]
            ]
        },
        {
            "label": "kiwi",
            "polygon": [
                [637, 122],
                [636, 123],
                ...
                [645, 123],
                [644, 122]
            ]
        },
        {
            "label": "kiwi",
            "polygon": [
                [543, 539],
                [542, 540],
                ...
                [548, 540],
                [547, 539]
            ]
        }
    ]
}

Useful links

• Cityscapes format

• [Supervisely Ecosystem] Import Cityscapes