The structure of your dataset should follow the structure of DAVIS (Densely Annotated VIdeo Segmentation) 2017 Unsupervised dataset.

DAVIS Structure Example

The DAVIS dataset is organized as follows:

DAVIS
├── JPEGImages
│   └── 480p
│       └── object1
│           ├── 00000.jpg
│           ├── 00001.jpg
│           ├── 00002.jpg
│           └── ...
│       └── object2
│           ├── 00000.jpg
│           ├── 00001.jpg
│           ├── 00002.jpg
│           └── ...
├── Annotations
│   └── 480p
│       └── object1
│           ├── 00000.png
│           ├── 00001.png
│           ├── 00002.png
│           └── ...
│       └── object2
│           ├── 00000.png
│           ├── 00001.png
│           ├── 00002.png
│           └── ...
└── ImageSets
    └── 2017
        ├── train.txt
        ├── val.txt
        └── test-dev.txt

Also, the same for YTVOS:

YouTubeVOS
├── train
│ ├── Annotations
│ ├── JPEGImages
│ └── meta.json
└── valid
├── Annotations
├── JPEGImages
└── meta.json

For Pascal VOC in the evaluation time :

dataset root.
└───SegmentationClass
│   │   *.png
│   │   ...
└───SegmentationClassAug # contains segmentation masks from trainaug extension 
│   │   *.png
│   │   ...
└───images
│   │   *.jpg
│   │   ...
└───sets
│   │   train.txt
│   │   trainaug.txt
│   │   val.txt

Please ensure your dataset adheres to this structure for compatibility. For datasets that deviate from the standard structure, such as VISOR, we've included a snippet of code to manage the necessary conversion.