Vision provides us with information about the objects in the world around us;it also allows us to see the materials that they are made of. Material perception is important: for example, it lets people see whether a sidewalk is icy and it permits a physician to decide whether a mole looks dangerous. At present, very little is known about material perception. This project will study at both a theoretical and empirical level. The research will assess the importance of basic factors such as visual resolution in making material judgments. The material judgments can range from simple descriptions of appearance (e.g., """"""""how shiny is this surface?"""""""") to more complex judgments about the material properties (e.g., """"""""how soft is this carpet?"""""""") The answers will provide constraints for models of material perception, and will also help in understanding the impact that various visual deficits will have on a variety of tasks. There are losses in visual information that occur when materials are viewed on a computer monitor rather than seen in the real world. There are other losses that occur due to eye disease. By measuring the impact of specific kinds of information, the project will indicate the best directions to go in modeling the underlying perceptual mechanisms. Those mechanisms will also be studied in other ways. By recording eye movements, the researchers will learn the local image features that subjects fixate on when making material judgments. In other experiments, specific features based on the outputs of wavelet-like filters will be evaluated as potentially useful sources of information. If a candidate feature (e.g., the skewness of a filter output) is important to humans, then by manipulating this feature it should be possible to alter a material's appearance in predictable ways.
This project will help determine the visual mechanisms underlying material perception, which includes the perception of visual qualities like glossiness and more physical qualities like wetness or slipperiness. Material perception is of widespread importance, and when vision is impaired (by eye disease, or by limitations in digital displays) material perception is degraded. Understanding the basic mechanisms will help improve the visual performance of digital systems such as those used in telemedicine;it will also help understand the impact that eye diseases have on simple tasks such as avoiding icy patches on the sidewalk.
| Sharan, Lavanya; Rosenholtz, Ruth; Adelson, Edward H (2014) Accuracy and speed of material categorization in real-world images. J Vis 14: |
| Sharan, Lavanya; Liu, Ce; Rosenholtz, Ruth et al. (2013) Recognizing Materials using Perceptually Inspired Features. Int J Comput Vis 103:348-371 |
