1. Figure and Ground
The most fundamental way we organize visual information is to divide it into a foreground and background.

3. simplicity
The visual system selects the simplest or most likely interpretation for what we see.

4. closure
We fill in missing elements of a visual scene, perceiving edges that are separated by gaps.

5. Continuity
We group together edges or contours with the same orientation. So here we see two crossing lines instead of V shapes.

6. similarity
Regions similar in color, lightness, shape, or texture are perceived as belonging to the same object.

7. proximity
Objects that are close together tend to be grouped together.

8. Linear perspective
Parallel lines that run away from the viewer seem to get closer together.

9. Texture Gradient
As distance increases, a texture gradually becomes denser and less distinct.

10. interposition
The shapes of near objects overlap those of distant ones.

11. Relative Size
If separate objects are expected to be the same size, the larger ones are seen as closer.

12. Height in Plane
Near objects are low in the visual field, but more distant ones are higher up.

13. Light and Shadow
Patterns of light and dark suggest shadows that create 3D impression.

14. Muller-Lyer and Ponzi Illusions: Lines are actually same size.
geometric illusions
Muller-Lyer and Ponzi Illusions: Lines are actually same size.
Poggendorff Illusion: line is actually diagonal.
Zollner Illusion: lines are actually parallel.

15. Necker cube Penrose Stairs Is the X on the front or the back?
Wil we ever reach the top?

16. There are 12 dots on this grid? Can you see them all at once?
What color are the circles anyway?