Exploiting perceptual redundancy plays an important role in image processing. Conventional JND models describe the visibility of the minimally perceptible difference by assuming that the visual acuity is consistent over the whole image. Some earlier work considers the space-variant properties of HVS-based on the non-uniform density of photoreceptor cells. In this paper, we aim to exploit the relationship between the masking effects and the foveation properties of HVS. We design the psychophysical experiments which are conducted to model the foveation properties in response to the masking effects. The experiment examines the reduction of visual sensitivity in HVS due to the increased retinal eccentricity. Based on these experiments, the developed Foveated JND model measures the perceptible difference of images according to masking effects therefore provides the information to quantify the perceptual redundancy in the images. Subjective evaluations validate the proposed FJND model.