The following is a summary of “Spatial structure, phase, and the contrast of natural images,” published in the January 2022 issue of Ophthalmology by Rideaux, et al.

Researchers believe that the environment influences the sensitivity of human vision. Therefore, vision scientists were working to identify the image statistics that affect perception and cognition. For example, a recent theory suggested that when looking for objects in natural images, the ability to detect the object decreases when it is visually similar to its surroundings. To test this idea, they conducted an experiment that measured participants’ ability to detect objects embedded in natural images with varying degrees of similarity to the background. 

Contrary to the theory, the results showed that participants were most sensitive to objects similar to the background. They proposed that when the object and background have a coincidental phase alignment, it creates a contrast signal that helps with detection when there is a high similarity between them. This prediction was confirmed in a second experiment where manipulating the phase of the object relative to the background resulted in either easy visibility or undetectability. 

Therefore, the study suggested that besides structural similarity, the phase of the object relative to the background also played a crucial role in predicting detection sensitivity in natural images.

Reference: jov.arvojournals.org/article.aspx?articleid=2778242