svg What is it ?
1 The main points of
The main points of 1：svg And jpg/png The purpose of the format is completely different , Can't be compared with , No comparability , There is no substitute for each other .
The main points of 2： In daily life , We take pictures and videos of natural scenes with our cameras , You can and can only use jpg/png/mp4 And so on , Unavailable svg Format store . In the natural scene , There is no definite mathematical function between pixels . We call natural scenes images , It can only be described in pixels , Cannot be described by mathematical functions .
The main points of 3：svg For artificial design ( Special emphasis on artificial design , It's not natural ) The point of 、 Line 、 A figure made up of faces , These graphs can be expressed by mathematical functions .svg Not suitable for describing and expressing natural scenes .
|
Concept |
characteristic |
Generator |
Describe the method |
File format |
|
Images |
There is no definite mathematical function between pixels |
natural |
Pixel by pixel |
jpg/png/mp4 etc. |
|
graphics |
There is a definite mathematical function relationship between points |
artificial |
Mathematical functions |
svg |
2 svg Illustrate with examples
Suppose you want to design an icon with beautiful lines , By the ellipse 、 Hyperbola and parabola make up .
Suppose this icon is very large , It's made up of a trillion dots .
We can describe this icon with the following elements ：
S1： Elliptic equation ： Long axis length , Length of stub shaft ,x The scope of the , line color .
S2： Hyperbolic function or equation ：x The scope of the , line color
S3： A parabolic function or equation ：x The scope of the , line color
To describe the above elements, you need to 256 byte , With this 256 byte , Software will be based on x Draw each curve point by point , Finally, a beautiful icon of a trillion dots ！
imagine , If this icon is used jpg/png To draw , How much data will be consumed .
Conclusion
Conclusion 1：svg Only for artificial graphics , These graphs can be expressed in mathematical functions , These mathematical functions can be expressed with very little data . The ultimate goal ： It's complicated to express with very little data 、 Beautiful graphics .
Conclusion 2： The natural scene ( Images ) There is no correlation between the points in , It can't be expressed in mathematical functions , It can only be expressed in pixels ,jpg/png/mp4 It is suitable for expressing natural scenes ( Images ).
in addition , Be sure to distinguish the two concepts of figure and image .
Graphics are designed by man , It can be expressed by mathematical functions ,svg For this purpose .
Images are natural , Can't be expressed in mathematical functions ,jpg/png/mp4 For this purpose .
