Base64是一种基于64个可打印字符来表示二进制数据的表示方法。由于 log 2 64 = 6 ,所以每6个比特为一个单元,对应某个可打印字符。3个字节相当于24个比特,对应于4个Base64单元,即3个字节可由4个可打印字符来表示。在Base64中的可打印字符包括字母A-Z
、a-z
、数字0-9
,这样共有62个字符,此外两个可打印符号在不同的系统中而不同。一些如uuencode的其他编码方法,和之后BinHex的版本使用不同的64字符集来代表6个二进制数字,但是不被称为Base64。
base64
就是把一个人熟悉的文件(文本或者图片)转换成一段只有计算机熟悉的“乱码”。
可能有人会不信,那我们看图说话吧。
上图转成base64的结果
data:image/png;base64,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
是不是就是把一个人类熟悉的转换成了计算机熟悉的东东。
手动狗头:还能这么理解,高手666.
每个图片转成的base64码的开头都是data:image/png;base64,
然后接“乱码”,一顿搜索发现
简单理解一下:
Data URL Scheme
(百度翻译结果:数据URL方案), 它是一种允许向WEB文档里插入外部小文件的一种固定协议,具有一定的使用格式。
所谓Base64,就是说选出64个字符----小写字母a-z、大写字母A-Z、数字0-9、符号"+"、"/"(再加上作为垫字的"=",实际上是65个字符)----作为一个基本字符集。然后,其他所有符号都转换成这个字符集中的字符。(来自http://www.ruanyifeng.com/blog/2008/06/base64.html)
Encode Data URL
aTool在线工具
Duri.me
DATAURL