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Create Project for a Labeling Team and Publish Tasks

The Image Labeler app enables you to collaborate with a team to label large image data sets by distributing labeling tasks among the team members. The team member responsible for the project setup, and for tracking the progress of the labeling project, is known as the Project Owner. The team members responsible for completing tasks assigned to them are Task Owners.

This example walks you through the steps that a project owner must follow to set up a project, create label definitions, assign images to tasks, and distribute them among the labeling team members. Those labeling team members are task owners who must then work on completing their labeling tasks.

Load Image Data and Create Label Definitions

Open the Image Labeler app by entering this command. Alternatively, you can open the app from the Apps tab of the MATLAB® toolstrip, under Image Processing and Computer Vision.

imageLabeler
Click New Team Project to open an empty team project session.

Load Image Data

Load a set of image files directly into the app.

  1. On the app toolstrip, click Import > From File. The Open Images dialog box opens.

  2. In the File Name parameter, specify this folder. <matlabroot> is the full path to your MATLAB installation folder, as returned by the matlabroot function.

    <matlabroot>\toolbox\vision\visiondata\NewTsukuba

  3. Select all 150 images in the folder using Ctrl + A. Click Open to load all the images into the app session under the Image Browser tab.

  4. Alternatively, if you have an existing imageDatastore object in the workspace that links to a collection of images, you can load that data by selecting Import > From Workspace.

Create Label Definitions

Label definitions contain information about the labels that the labeling task owners must mark on the images. In this example, you interactively add a few label definitions for the labeling team members to work with. You can add any type of label definition by selecting options from the Add Label drop-down on the app toolstrip.

  1. Add a rectangle label definition to indicate the location of the lamp in each image. On the app toolstrip, select Add Label > Rectangle. A Define New Rectangle Label dialog opens. For the Label Name parameter, enter Lamp.

  2. Using the same procedure, add another rectangle label definition to indicate the location of the video camera in each image. In the Label Name parameter, enter VideoCamera.

  3. Add a scene label indicating the presence of the bust in the frame. On the app toolstrip, select Label > Scene. A Define New Scene Label dialog opens. For the Label Name parameter, enter BustPresent.

For more information about the different types of label definitions, see Create Label Definitions.

Alternatively, if you already have label definitions created and stored in the workspace, you can import them by selecting Import > Label Definitions.

Create Label Tasks and Assign to Task Owners

To distribute the labeling work among different team members, you must create one or more label tasks, add images to each task, and then assign them to the individual labeling team members. You can use one of these options:

  • Create label tasks manually, one at a time, and assign images to each task.

  • Create multiple label tasks at once, and auto-distribute image assignment.

Create Label Tasks and Manually Assign Images

  1. On the app toolstrip, select Add Label Task(s) > Add Single Label Task.

  2. In Task Information pane, for the Name parameter, enter Task 1.

  3. For the Instruction parameter, enter Label all images with ROI and Scene labels.

  4. Add the first 50 images in the data set to this task using these steps:

    1. Select the first image in the Image Browser.

    2. Then, in the Task Information pane, for the Select Images parameter, enter 50 and press Enter. This selects a total of 50 images sequentially, starting from the initial image selected. All selected images appear highlighted in blue background in the Image Browser.

    3. Click Add Images To List to add the selected images to the task. Once added, the image names show up as entries in the Images List. Also, in the Image Browser, the thumbnails for the added images will have a blue image status legend in the top right corner, indicating that they are associated with a label task.

    Task information pane for a single task.

  5. Alternatively, you can add images to the task by manually selecting them in the Image Browser while holding Ctrl. Also, note that you cannot distribute different label definitions to different tasks. All tasks inherit all label definitions.

  6. Repeat steps 1–4 to create a new task named Task 2, and add the next 50 images to it. You must select the 51st image in the step 4a. It is the first image in Image Browser without the blue legend entry in the top right corner.

  7. Repeat steps 1–4 to create a new task named Task 3, and add the next 50 images to it. You must select the 101st image in the step 4a. It is the first image in Image Browser without the blue legend entry in the top right corner.

The Tasks pane now lists all three tasks.

Tasks pane showing unpublished and unassigned tasks.

Create Multiple Label Tasks and Auto Distribute Image Assignment

  1. On the app toolstrip, select Add Label Task(s) > Add Multiple Label Tasks and Auto Distribute Images.

  2. This opens the Add Label Tasks dialog box. Specify Number of Label Task(s) as 3 and Images to be distributed as 150 to auto distribute 150 images to 3 tasks, assigning 50 images to each task.

    Add label tasks pane showing image auto assignment options.

    Click Create Task(s). The Tasks pane now lists all three tasks with the default task names Untitled_1, Untitled_2, and Untitled_3.

  3. In the Tasks pane, select the task with the name Untitled_1. Then, in the Task Information pane, set the Name parameter to Task 1. For the Instruction parameter, add Label all images with ROI and Scene labels, and press Enter.

  4. Use the same process to modify the tasks Untitled_2 and Untitled_3 changing their names to Task 2 and Task 3, respectively

Assign Label Tasks to Task Owners

  1. To add the names of individual labeling task owners in your team, on the app toolstrip, select Add Team Members. This opens the Add Team Members dialog box. For this example, add three team members: Team Member A, Team Member B, and Team Member C.

  2. In the Tasks pane, click Task 1. Then, in the Task Information pane, set the Owner to Team Member A to assign the task to them.

  3. Use the same process to assign Task 2 and Task 3 to Team Member B and Team Member C, respectively.

  4. Alternatively, for each task, you can enter the names of task owners directly in the Owner column in the Task Information pane.

Tasks pane showing assigned tasks.

Publish Label Tasks and Share Project with Task Owners

Publishing the tasks saves the project in a state that enables individual labeling task owners to open the project and start working on their assigned labeling tasks.

  1. For this example, publish all the unpublished tasks at once. To do so, on the app toolstrip, select Publish Tasks > All Unpublished Tasks. In the Image Browser, the thumbnails for all images associated with published tasks will now have a yellow image status legend entry in the top right corner.

  2. Alternatively, to publish a single task, select the desired task in the Tasks pane. Then, on the app toolstrip, select Publish Tasks > Selected Task.

This opens a dialog box with a shareable link to the project location. Share the link with the task owners so that they can start working on their labeling tasks. When you save the project, ensure that you do so in a location for which the task owners have read/write permissions. You can access the shareable link from the toolstrip by selecting Publish Tasks > Share Instructions.

Note

Distribute the shareable link to the task owners through email, or as a message outside the Image Labeler app.

Under the Visualization tab of the toolstrip, you can modify the app layout and control the appearance of the image status legend on all images (on hover, always displayed, or never).

Image Labeler app layout showing published tasks, labels, and image browser with legend entries on each image.

Create Executable for Labeling Task Owners Without Full MATLAB License

For labeling task owners who do not have access to a full MATLAB license, you can create a compiled version of the labeling project in the form of a standalone executable using these steps:

  1. On the Image Labeler tab of the app toolstrip, click Compile.

  2. Choose the app options for compilation based on the task. For this example, set App Type to Label as you are creating this executable for labeling task owners.

  3. Specify the App Name, Location and include any automation algorithms necessary for labeling.

  4. Click Start Packaging. This creates an executable that you can share with the labeling task owners.

Review task owners can use the executable to install the standalone app, open the app, and then complete the labeling tasks.

Modify Published Tasks

Note

After all tasks are in the published state, you cannot make any of these modifications to the tasks:

  • Delete tasks

  • Add or remove label definitions

  • Add new images or remove current images associated with the tasks

  • Change owners for the individual tasks

To modify the published tasks, you must follow these steps:

  1. Open the saved project in Project Owner mode.

  2. On the app toolstrip, select Unpublish Tasks and either unpublish a single task or all tasks. Ensure that the respective task owners know that you are making modifications so that they do not work on tasks while you modify them.

  3. Edit the tasks as desired.

  4. Republish the tasks.

See Also

Apps

Related Topics