Dataset Converters

Dataset Converters is a conversion toolset between different object detection and instance segmentation annotation formats.
It was written and is maintained by deep learning developers from Intelligent Security Systems company to simplify the research.

Introduction

There are multiple different dataset annotation formats for object detection and instance segmentation.
This repository contains a system of scripts, which simplify the conversion process between those formats. We rely on COCO format as the main representation.

Installation

Please, cd to DatasetConverters folder and then type

pip install -r requirements.txt

This will install the required dependencies.

Usage

Conversion

To perform conversion between different dataset formats, we provide the script called convert.py.

For example, suppose, you have ADE20K dataset and you want to convert it into COCO format.
For that purpose, please type

python convert.py --input-folder <path_to_folder_ADE20K_2016_07_26> --output-folder <output_path> \
                  --input-format ADE20K --output-format COCO --copy

Note. The shorter version of the same can be written as

python convert.py -i <path_to_folder_ADE20K_2016_07_26> -o <output_path> -I ADE20K -O COCO --copy

Note. --copy argument stands for copying images. In Linux you can instead pass --symlink to create symbolic links.

You are ready to use ADE20K in frameworks with COCO input format.

For the full list of supported conversions, please refer to Supported conversions section.

Merging

If you have multiple annotations, converted to COCO format, we provide script merge_json_datasets.py to merge them.
Suppose, you have COCO and Pascal VOC segmentations in COCO format and want to merge dog and horse annotations from them. This is how merge_json_datasets.py can serve that purpose

python merge_json_datasets.py -d <coco_images_folder> -a <coco_annotations.json> --ids 18 19 \
                              -d <vocsegm_images_folder> -a <vocsegm_annotations.json> --ids 12 13 \
                              --output-ids 1 2 -o <output_dir> -n dog horse

In this example, number of merged datasets is two, but it is not limited. You can merge as many datasets and classes in COCO format, as you need.
For each dataset in COCO format, one should provide the following arguments

• -d for images;
  
• -a for json file of annotations;
  
• --ids for list of ids of goal classes in the dataset.
  

After all datasets are specified with this pattern, output information is specified with the following arguments

• --output-ids for list of output ids of the goal classes;
  
• -o for output directory for the merged dataset;
  
• -n for names of the goal classes in the merged dataset.
  

Supported conversions

In this section we list all of the supported formats and their conversions.

• ADE20K
  
  Can be directly converted to
  • COCO
• CITYSCAPES
  
  Can be directly converted to
  • COCO
• COCO
  
  Can be directly converted to
  • TDG
  • TDGSEGM
  • VOCCALIB
  • YOLO
  Note.
  We expect names of the json annotation files correspond to names of their image folders. If annotation file is called ```XYZ.json```, the corresponding folder is expected to be called ```XYZ```.
  To convert original COCO dataset, please rename folders
  ```train2017``` to ```instances_train2017```;
  ```val2017``` to ```instances_val2017```
  and leave only two corresponding files in ```annotations``` folder: ```instances_train2017.json``` and ```instances_val2017.json```.
• CVAT
  
  Can be directly converted to
  • COCO
  Note.
  In case of CVAT input format, we expect the xml annotation file and images to be placed in the same folder. That folder is supposed to be ```input_folder``` argument of ```convert``` function.
• OID
  
  Stands for Open Images Dataset V4.
  Can be directly converted to
  • COCO
• TDG
  
  Custom format for bounding box annotation.
  You can use it to train Faster R-CNNs and SSDs in their Caffe branches.
  Can be directly converted to
  • COCO
  • FRCNN
  • SSD
• TDGSEGM
  
  Custom format for instance segmnentation.
  Can be directly converted to
  • COCO
• VOC
  
  Stands for bounding box annotations from Pascal VOC datasets.
  Can be directly converted to
  • COCO
• VOCCALIB
  
  Stands for bounding box annotations used in OpenVINO calibration tool.
  They are supposed to be "VOC-like". Convert to this format to use the result in OpenVINO calibration tool.
  No conversions from this format available.
• VOCSEGM
  
  Stands for instance segmentation annotations from Pascal VOC datasets.
  Can be directly converted to
  • COCO
• YOLO
  
  Can be directly converted to
  • COCO
  Note.
  We expect an `obj.data` file in the input folder. The following lines in any order must be presented: ``` train = valid = names = ``` The list of images consists of lines with relative paths to each image: ``` path/to/image1.jpg path/to/image2.jpg ... path/to/imageN.jpg ``` Near every imageM.jpg must be presented an imageM.txt file with annotations in yolo format.

How to contribute

We welcome community contributions to the Dataset Converters.

If you want to add a new dataset converter, please note, that we expect

• The new dataset is free and open, so we are able to download it and test your code;
• Your code is written from scratch and does not have parts copied from other repositories.

The list of the core files, which are the key to understand the implementation process is the following

Converter.py
ConverterBase.py
converters.py
formats.py

The new converter is a subclass of ConverterBase class with _run mehtod overloaded and conversion format added to the list formats.