Definition of central projection

Central projection refers to the projection imaging mode in which any straight line in space is projected onto the plane through a fixed point (projection center).

1, central projection has imaging law, also known as perspective law. Central projection refers to the projection formed by light scattering from a point, which is the projection mode of aerial photography, and refers to the perspective relationship formed by the projection of any straight line in space onto a plane (bearing surface) through a fixed point (projection center).

2. A point light source illuminates a figure on a plane, and the shadow of this figure is its central projection on this plane. After the center of the space figure is projected, the straight line becomes a straight line, but parallel lines may also become intersecting straight lines. Compared with the original picture, the figure after central projection has changed greatly, but it is intuitive and looks in line with human visual effects.

Application of Central Projection in Real Life

1. First of all, in the field of photography, central projection is one of the most common projection methods. The camera lens focuses the light on the photosensitive element, forming inverted, inverted and reduced two-dimensional images for many times. This projection method can produce a realistic effect when taking pictures, so that people can see what the objects in the three-dimensional world look like on the two-dimensional plane.

2. Secondly, in the field of geography, the central projection is used to make constellations and globes. By shrinking and projecting celestial bodies and the earth onto a sphere, people can better understand their relative positions and distances. This projection method presents a beautiful and true constellation image in the night sky, which helps people to better understand the universe.

3. In addition, in the field of engineering and architecture, central projection is also widely used in drawing and design. Designers can show their design ideas and schemes by projecting three-dimensional objects or models onto two-dimensional planes. This projection method can clearly show the shape, size and proportion of the object, which is convenient for designers to communicate with others.

4. Central projection is a very important projection method, which is widely used in real life. It helps people better know and understand various objects and phenomena in the real world, and becomes an indispensable part of people's life and work.