Selecting an image area

Toloka provides an editor for selecting an image area. It lets the performer select a polygon or rectangle area.

Let's say you have many photos with animals and you need to select dogs and identify their breed. To do this, create a task: the performer is shown a photo and has to select the dog and specify its breed.

Example of a prepared task

To release tasks for completion and get responses:

Create a project

The project defines what the task will look like for a performer.

  1. Click the + Create project button and choose the Object segmentation in an image template.

  2. Enter a clear name and a short description for the project. Performers will see this in the task list.

  3. Write short and clear instructions (see recommendations) in the visual editor or using HTML markup. To make it clear, add pictures.
  4. The image area selection editor is automatically included in the template. This means that the performer will see the image and can select an area with the editor tools.

    Define which objects you are going to pass to the performers and receive from them in response. To do this, add input and output fields in the Specifications block.
    What are input and output data?

    Input data is types of objects that are passed to the performer for completing the task. For example, this could be a text, an image, or geographic coordinates.

    Output data is types of objects that you receive after the task is completed. For example, this could be one of several response options, typed text, or an uploaded file.

    Learn more about input and output data fields.

    The template includes the fields:

    • The image input data field for a link to an image.

      Change the data type to string to upload audio files stored on Yandex.Disk.

    • The result output data field with the "json" type for the JSON object with the point coordinates.

    Add the output data field — the required breed string to write the dog breed specified by the performer.

  5. Create the task interface in the HTML block. It describes how the task elements should be arranged in the task.

    You can use standard HTML tags and special expressions in double curly brackets for input and output data fields.

    {{field type="image-annotation" name="result" src=(proxy image)}}{{field type="input" name="breed" placeholder="Enter the dog's breed" width="100%"}}
    This notation describes the following task design:
    • A picture with the area selection tool.
    • Text input field.

    Leave the CSS and JavaScript blocks unchanged.

  6. Click the Preview button to see the performer's view of the task.
    Note. The preview shows four tasks with standard data. You can define the number of tasks to show on the page later.
  7. Save the project.

Add a task pool

A pool is a set of paid tasks sent out for completion at the same time.

  1. Open the project and click Add pool → Add pool.
  2. Give any name and description to the pool. The pool info is only available to you. Performers can view only the project name and description.
  3. Set the price per task page (for example, $0.02).
    What is a task page?

    A page can contain one or several tasks. If the tasks are simple, you can add 10-20 tasks per page. Don't make pages too long because it slows down loading speed for performers.

    Performers get paid for completing the whole page.

    The number of tasks on the page is set when uploading tasks.

    What is the fair price for a task page?

    The general rule of pricing is the more time the performer spends to complete the task, the higher the price is.

    You can register in Toloka as a performer and find out how much other requesters pay for tasks.

  4. Set the Time allowed for completing a task page. It should be long enough to read the guidelines and wait for task data to download For example, 1200 seconds.
  5. Set the Overlap, which is the number of performers to complete the same task. For image area selection tasks, it is usually 1.
  6. Turn on the Offline accept option and enter the number of days for checking in the Deadline field. (for example, 7).
    What is offline accept?

    The review of assignments option allows you to review completed tasks before accepting them and paying for them. If the performer didn't follow instructions, you can reject the task. The maximum allowed period for the review is set in the Deadline field.

  7. Add Filters to choose performers.
  8. Save the pool.

Upload tasks

  1. Download the File example for task uploading (tsv) in the pool.
    What is TSV?
    A TSV file presents a table as a text file in which columns are separated by tabs.
    You can work with it both in a table editor and a text editor, and then save it to the desired format. More about working with a TSV file.
    Note. Before uploading the file, make sure it is saved in UTF-8 encoding.
  2. Add input data in it. The header of the input data column contains the word INPUT. Leave the other columns empty.
  3. Load the tasks: choose Set manually and set the number of tasks (for example, 4 tasks per page).

Set up quality control

Quality control rules allow you to filter out inattentive performers. You can configure quality control both in the project and in the pool.

  1. Go to the project and click Project actionsSet up quality control.
  2. Add a restriction for fast responses and specify the following values:

    This means that a user who completes a task page in less than 20 seconds will be blocked for ten days and won't be able to complete your tasks.

  3. Add the Offline accept block and enter the following values:

    This means that if 35% or more of performer's responses are rejected, the performer is blocked and can't complete your tasks for 15 days. The rule takes effect after 3 responses of the performer are reviewed.

Start the pool and get the results

  1. Start the pool by clicking .
  2. Track the completion of tasks in the Pool statistics section.
  3. When the first results are received, you can start the review . After the specified time period, all responses are automatically accepted, regardless of their quality.
    To review assignments, go to the pool and click Review assignments.
    Note. The point coordinates are saved in JSON.