Effect of Luminance Gradients in Measurement of Differential Limen

Objects in the visual field affect the appearance in the neighborhood. One of explanations to show a degree of its effect is a concept of a field of perception. It forms a contour map that is measured by upper and lower limen around a visual object. To clarify factors forming a field, we measured upper and lower limen for distribution of luminance according to a linear expression equation and a quadratic polynominal equation. The results show that upper and lower limen are affected by luminance itself, magnitude of luminance gradients. We conjectured a field of perception is shaped mainly by the maginitude of luminance gradients and its trend from the results.