A computer system may elicit from a human observer ground truth data useful in automatically detecting one or more features in images. The elicitation may include presenting an image to a human observer that has a visual indicator in an image, the visual indicator indicating having a location and orientation with respect to the image asking the human observer to judge whether a particular image feature is present in the image at the location and orientation indicated by the visual indicator receiving input from the human observer indicative of whether the particular image feature is present at the location and orientation indicated by the visual indicator storing the input received from the human observer as part of the human-labeled ground truth data and repeating the process described above one or more times in connection with a visual indicator that has a different location or orientation with respect to the image or that uses a different image. The stored human-labeled ground truth data may have a content that is useful in automatically detecting one or more features in other images.
