Closure

According to the principle of closure, we tend to see complete figures even when parts of the image are missing. In the picture above, we see a panda even though there is nothing outlining the white portions. We still perceive a panda due to the principle of closure. Our minds react to patterns that are familiar, even though we receive incomplete information.

Figure-Ground Perception

Figure-ground perception is the tendency of our minds to simplify a scene into a main object (the figure) and its background (ground). Most of the time, figure-ground illustrations can be reversible, and therefore show that it triggers more than one perception.
In the picture below, you might see a vase, or you might see the faces of two people looking at each other. If you see a vase, then the vase would be considered the figure while the black space around it would be considered the ground area. If, however, you see the two faces, the faces would now be considered the figures while the white area behind them would be the ground area. This picture shows how our sense of depth and area can be changed easily depending on what one is willing to interpret.

http://psychology.about.com/od/findex/g/figure-ground-perception.htm

Monocular Cue: Relative Size

A monocular cue is a depth cue that is available to either eye alone. One type of monocular cue is relative size, which is the size of an object that our eyes perceive based on the distance away from us. If two objects are similar in size, we assume that the one that is closest to our view is actually the bigger object than the other.
In the picture below, both the man and the Eiffel Tower are pretty similar in size. We already know from past experience and knowledge that the Eiffel Tower is much taller than the man in reality. Because the man is so far away from the tower, it makes it seem as if he is actually a bit taller than the tower. Because of his darker color compared to the tower, and the lines made by the bushes around him, we can assume that he is actually closer to us, but not as tall as the tower. It is only an illusion to make it seem as if he is as tall as the Eiffel Tower. So yes, he is bigger than the tower in this picture because he is closer to us, but in reality, the tower is much taller than him.



https://www.google.com/search?q=light+and+shadow+psychology&client=firefox-a&hs=dQS&rls=org.mozilla:en-US:official&

Mocoular Cue: Light and Shadow

A monocular cue is a depth cue available to either eye alone. One type of a monocular cue is light and shadow, which plays a part on how we perceive depth based on the amount of light or shadowing on an object.
In the picture below, light and shadow play a big part in depicting which tree is farther away. As our eyes move to the right of the picture, we see that the colors of the trees get lighter. From this, we are to assume that because the tree closest to the front is darkest that the lighter trees are farther away than the darkest tree in the front. Shading plays a role in this picture, too. Because some parts of the trees are lighter than some places, and darker in others, we can assume that the trees are 3-D objects instead of flat objects. 
 https://www.google.com/search?noj=1&biw=1280&bih=654&tbm=isch&sa=1&q=light+and+shadow&

Binocular Cue: Retinal Disparity

To better explain retinal disparity, I must define what a binocular cue is first. A binocular cue is a depth cue that depends on the use of two eyes working together to form a picture. Retinal disparity is one cue that falls under the category of a binocular cue. Retinal disparity is the slight difference in the two retinal images due to the angle from which each eye views an object. The picture below helps to explain how this type of cue works. When closing one eye at a time, the picture that one will see is shown on the left hand side. The tree will seem as if it moves some distance to the left or the right, depending on which eye is closed. The picture on the right, however, is the picture of the tree that we would normally see. Both eyes' pictures blend together to create one "whole" for an object. Just for one last clarification, the retinal disparity is the distance that is between those two trees that we see from each eye, or the picture on the left side.

http://www.google.com/imgres?imgurl=http://escience.anu.edu.au/lecture/ivr/sight/image/retinalDisparity.png&imgrefurl=http://escience.anu.edu.au/lecture/ivr/sight/retinalDisparity.en.html&h=472&