Importing Reference Images as Overlay

You may upload reference images to support your annotation process. Users will then be able to switch between images while retaining the annotations currently on screen.

You may only upload such reference assets using the Cloud Import method outlined below.

Overlay images will be resized and stretched to fit the dimensions of the main image. The annotations' coordinates, as well as all data in the export, takes the main image's dimensions only into account.

Uploading Reference Images

Images added as overlay, when opened in the image labeling editor, will have their dimensions stretched to fit the dimensions of the main image.

We recommend uploading overlay images with the same dimension or ratio as the main image.

Without IDs for each overlay

Prepare a JSON like the following, where each URL points to an image you'd like to include in the asset. The order of the URLs will determine the order in which images will be presented to the annotator in the dropdown.

The following JSON will import two assets of three images each:

[
  {
    "externalId": "my-asset-external-id-1",
    "data": "https://url.com/65c18c8b-4513-4a0a-b876-main.png",
    "overlay": [
      "https://url.com/65c18c8b-4513-4a0a-b876-1aeb2e0908ec.png",
      "https://url.com/b0b70590-e4cc-42ef-8537-3ee3f7917fed.jpg",
      "https://url.com/38e11364-1ce0-417a-9e38-436468c555ce.jpg",
    ]
  },
  {
    "externalId": "my-asset-external-id-2",
    "data": "https://url.com/65c18c8b-4513-4a0a-b876-main.png",
    "overlay": [
      "https://url.com/65c18c8b-4513-4a0a-b876-1aeb2e0908ec.png",
      "https://url.com/b0b70590-e4cc-42ef-8537-3ee3f7917fed.jpg",
      "https://url.com/38e11364-1ce0-417a-9e38-436468c555ce.jpg",
    ]
  }
]

With IDs for each overlay

When you import overlays with IDs, their ID will be displayed in the dropdown as annotators pick the overlay.

[
  {
    "externalId": "my-asset-external-id-1",
    "data": "https://url.com/65c18c8b-4513-4a0a-b876-main.png",
    "overlay": [
      {id:"my_overlay_1",url:"https://url.com/65c18c8b-4513-4a0a-b876-1aeb2e0908ec.png"},
      {id:"my_overlay_2",url:"https://url.com/b0b70590-e4cc-42ef-8537-3ee3f7917fed.jpg"}
    ]
  },
  {
    "externalId": "my-asset-external-id-2",
    "data": "https://url.com/65c18c8b-4513-4a0a-b876-main.png",
    "overlay": [
      {id:"my_overlay_1",url:"https://url.com/65c18c8b-4513-4a0a-b876-1aeb2e0908ec.png"},
      {id:"my_overlay_2",url:"https://url.com/b0b70590-e4cc-42ef-8537-3ee3f7917fed.jpg"}
    ]
  }
]

From your project dashboard, go to the Assets tab and click on Add Data. Then, enter the Upload Data URL section and drag and drop your JSON on the file upload field. Then, press on Upload. Your multi-image asset(s) will be uploaded.

Assets uploaded this way will have a dropdown at the top, allowing annotators to navigate between the images in the dataset while retaining the annotations present on screen.

The user may press "O" (the letter) on their keyboard to switch between different images. If you have imported overlays with IDs, the IDs will appear in this dropdown.