Visual thresholds for detection, recognition and visual impact in landscape settings

The concept of visual threshold has long been used in psychophysics, but has not been widely used in landscape research. This study developed a systematic procedure for the assessment of three visual thresholds detection, recognition, and visual impact. The thresholds were obtained through controlled slide-viewing tests using computer simulated images with modified visual attributes: size, contrast, object type and landscape type. Analyses yielded average and specific thresholds of high apparent reliability. Logistic models achieved an overall prediction success rate of around 90 per cent with contrast weighted visual magnitude being a key variable. (C) 2000 Academic Press.