The figure-ground relationship is not always clear-cut, and the figure and ground can sometimes merge or overlap, depending on the context and the viewer's interpretation.

Contrast, or the difference in brightness, color, or texture between an object and its surroundings, is the main factor that determines whether an object is perceived as a figure or ground.

All of the examples provided are classic examples of figure-ground ambiguity, where the same image can be interpreted as two different objects, depending on the viewer's perception.

Context plays a significant role in figure-ground perception. It can help disambiguate figure from ground, create figure-ground reversals, and influence the viewer's interpretation of the image.

All of the examples provided are classic examples of figure-ground reversals, where the figure and ground can switch roles, depending on the viewer's perception.

The Gestalt principle of continuity states that the brain tends to perceive smooth, continuous lines and shapes as belonging together, which is closely associated with figure-ground perception.

Relative size is a monocular depth cue that helps us perceive depth in an image based on the relative sizes of objects. Objects that are closer to the viewer appear larger than objects that are farther away.

Perceptual shrinkage is the tendency to perceive objects as being closer to the viewer than they actually are, which is often caused by the brain's attempt to compensate for the effects of perspective.

Binocular disparity is a binocular depth cue that helps us perceive depth in an image based on the difference in the position of an object in the left and right eyes.

Perceptual expansion is the tendency to perceive objects as being farther away than they actually are, which is often caused by the brain's attempt to compensate for the effects of perspective.

All of the examples provided are examples of motion parallax, which is a depth cue that helps us perceive depth in an image based on the relative motion of objects.

Size constancy is the tendency to perceive objects as being the same size, regardless of their distance from the viewer, which is often caused by the brain's attempt to compensate for the effects of perspective.

Linear perspective is a pictorial depth cue that helps us perceive depth in an image based on the convergence of parallel lines.

Shape constancy is the tendency to perceive objects as having the same shape, regardless of their orientation, which is often caused by the brain's attempt to compensate for the effects of perspective.

All of the examples provided are examples of texture gradients, which are depth cues that help us perceive depth in an image based on the changes in texture density.