Disclosed is a configuration for segmenting an image. For each user, the configuration computes an accuracy and contribution score. The configuration determines multiple tasks for segmenting an image. For each task, the configuration assigns a particular user to work on a task based on an accuracy or a contribution score of the particular user, receives an indication of a completed task from the particular user, and assesses an accuracy of the completed task based on the accuracy of the particular user. Responsive to determining all multiple tasks are completed accurately, the configuration combines the completed multiple tasks to form a segmented image.