如何将图片转换为base64呢
我按照网络上找到的编码规则，自己写的，可能有些错误。因为起名困难，所以有些变量的名字有点奇葩，但还能读的。
let path = ""; // 图片路径
path = fileToBase(path);
log(path);
function fileToBase(p) { // 文件编码
let data = files.readBytes(p);
data = byteToBit(data);
// 补位
let lack = 6 - data.length % 6;
for (let i = 0; i < lack; i++) data += "0";
data = bitToBase(data);
// 加入文件信息
data = "data:image/jpeg;base64," + data;
for (let i = 0; i < lack / 2; i++) data += "=";
return data;
}
function byteToBit(b) { // 字节数组转二进制字符串
let r = "";
b.forEach((i) => {
// 判断符号位
if (i < 0) {
i = (-i).toString(2).split("");
i.reverse();
i = complement(i);
i[7] = "1";
} else {
i = i.toString(2).split("");
i.reverse();
for (let j = i.length; j < 8; j++) i[j] = "0";
}
i.reverse();
r += i.join("");
});
return r;
}
function bitToBase(b) { // 编码器
// 分组（6bit 一组）
let bit = [];
for (let i = 0; i < b.length; i += 6)
bit.push(b.substr(i, 6));
// 建立编码对照表
let code = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
"abcdefghijklmnopqrstuvwxyz" +
"0123456789+/";
code = code.split("");
let base = "";
bit.forEach((i) => {
i = i.split("");
let n = 0;
for (let j = 0; j < 6; j++) {
if (i[j] == "1") n += Math.pow(2, 5 - j);
}
base += code[n];
});
return base;
}
function complement(n) { // 求补码
// 取反
for (let i = 0; i < 7; i++) {
if (n[i] == undefined) n[i] = "0";
if (n[i] == "0") n[i] = "1";
else n[i] = "0";
}
// 加一
for (let i = 0; i < 7; i++) {
if (n[i] == "0") {
n[i] = "1";
break;
} else n[i] = "0";
}
return n;
}
1、简化进制转换
2、优化部分逻辑
2、添加文件类型判断（jpg，gif，png）
let path = ""; // 图片路径
path = fileToBase(path);
console.log(path);
function fileToBase(p) { // 文件编码
let data, lack;
data = byteToBit(files.readBytes(p));
// 补位
lack = 6 - data.length % 6;
for (let i = 0; i < lack; i++) {
data += "0";
}
data = bitToBase(data);
// 加入文件信息
data = "data:" + fileType(p) + ";base64," + data;
for (let i = 0; i < lack / 2; i++) {
data += "=";
}
return data;
}
function byteToBit(b) { // 字节数组转二进制字符串
let bit = "";
b.forEach((i) => {
// 判断符号位
let mark = i < 0 ? true : false;
i = Math.abs(i).toString(2).split("");
i.reverse();
if (mark) {
i = complement(i);
i[7] = "1";
} else {
for (let j = i.length; j < 8; j++) {
i[j] = "0";
}
}
i.reverse();
bit += i.join("");
});
return bit;
}
function bitToBase(b) { // 编码器
let bit = [],
base = "",
code;
// 分组（6位一组）
for (let i = 0; i < b.length; i += 6) {
bit.push(b.substr(i, 6));
}
// 建立编码对照表
code = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
"abcdefghijklmnopqrstuvwxyz" +
"0123456789+/";
code = code.split("");
bit.forEach((i) => {
base += code[parseInt(i, 2)];
});
return base;
}
function complement(n) { // 计算补码（补码的补码为原码）
// 取反
for (let i = 0; i < 7; i++) {
if (n[i] == undefined) n[i] = "0";
if (n[i] == "0") n[i] = "1";
else n[i] = "0";
}
// 加一
for (let i = 0; i < 7; i++) {
if (n[i] == "0") {
n[i] = "1";
break;
} else n[i] = "0";
}
return n;
}
function fileType(f) { // 文件类型判断
// 文件后缀列表
let img = ["jpeg", "png", "gif"],
txt = ["css", "html", "js"];
f = files.getExtension(f);
if (f == "jpg") f = img[0]; // jpg 是 jpeg 的简写
for (let i = 0; i < img.length; i++) {
if (f == img[i]) {
return "image/" + img[i];
}
}
for (let i = 0; i < txt.length; i++) {
if (f == txt[i]) {
return "text/" + txt[i];
}
}
// 错误提示
f = "不支持此类型文件！";
toast(f);
console.error(f);
}
@o了吗 在 如何将图片转换为base64呢 中说：
@zhan-0 谢谢大佬，谢谢，你知道怎么调用百度识图api吗？
我通过抓包，抓到了一个 API，但 Auto.js 提供的 Http 模块里面的 http.postMultipart() 不能在上传文件时附加头信息。
POST /n/image?fr=form&target=pcSearchImage&needText=true HTTP/1.1
Host: image.baidu.com
Connection: keep-alive
Content-Length: 1268
Accept: */*
Origin: https://image.baidu.com
X-Requested-With: XMLHttpRequest
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.73 Safari/537.36
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryy4lc41n2nBzTbQ86
Referer: https://image.baidu.com/n/pc_search
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,en-US;q=0.9
Cookie: sttbHint=sttbHintShow; shituhistory=%7B%220%22%3A%22http%3A%2F%2Fd.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2F3bf33a87e950352aad36f80c5f43fbf2b2118b5b.jpg%22%2C%221%22%3A%22http%3A%2F%2Ff.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2Fb151f8198618367aef2086d922738bd4b31ce50d.jpg%22%2C%222%22%3A%22http%3A%2F%2Fg.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2F241f95cad1c8a7862f97b70a6b09c93d70cf5071.jpg%22%2C%223%22%3A%22http%3A%2F%2Fd.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2Ffaedab64034f78f0d49968f775310a55b3191c27.jpg%22%2C%224%22%3A%22http%3A%2F%2Fc.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2Fc9fcc3cec3fdfc03689110bcd83f8794a5c226cd.jpg%22%7D; BAIDUID=8FA575190E10E28116ACF1026CECFEF9:FG=1; BIDUPSID=8FA575190E10E28116ACF1026CECFEF9; PSTM=1519211756; BDRCVFR[fBLL8ZbbiMm]=WH-qyqYMsFCmv9EUhIBIykdUz4WUvY; H_WISE_SIDS=122758_100806_121885_122156_100100_122640_120140_121999_118886_118870_118851_118833_118786_120549_107312_117336_121862_117435_122789_122735_122138_122672_120852_122542_120035_116408_122624_122498_110085_122303; PSINO=3; __cfduid=db8860ba6e8c652f7f09cca217c5de1291521374571; BDRCVFR[kAjskz-82g3]=mk3SLVN4HKm; FEEDSID=30D852BBF580132BA666A3564D0AC780; BDRCVFR[5GQZCjFg8mf]=mk3SLVN4HKm; userFrom=null; firstShowTip=1; tip_show_limit=5
再次改进，编码速度提升 10~20%
let path = ""; // 图片路径
path = fileToBase(path);
log(path);
function fileToBase(p) { // 文件编码
let data, lack;
data = byteToBit(files.readBytes(p));
// 补位
lack = 6 - data.length % 6;
for (let i = 0; i < lack; i++) {
data += "0";
}
data = bitToBase(data);
// 加入文件信息
data = "data:" + fileType(p) + ";base64," + data;
for (let i = 0; i < lack / 2; i++) {
data += "=";
}
return data;
}
function byteToBit(b) { // 字节数组转二进制字符串
let bit = "";
b.forEach((i) => {
i = (i < 0 ? i + 256 : i).toString(2);
if (i.length < 8) {
// 字节补位
i = i.split("");
i.reverse();
for (let j = i.length; j < 8; j++) {
i[j] = "0";
}
i.reverse();
i = i.join("");
}
bit += i;
});
return bit;
}
function bitToBase(b) { // 编码器
let code = [],
base = "",
key;
// 分组，6 位一组
for (let i = 0; i < b.length; i += 6) {
code.push(b.substr(i, 6));
}
// 建立编码对照表
key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".split("");
code.forEach((i) => {
base += key[parseInt(i, 2)];
});
return base;
}
function fileType(f) { // 文件类型判断
// 文件后缀列表
let img = ["jpeg", "png", "gif"],
txt = ["css", "html", "js"];
f = files.getExtension(f);
if (f == "jpg") f = "jpeg"; // jpg 是 jpeg 的简写
for (let i = 0; i < img.length; i++) {
if (f == img[i]) {
return "image/" + img[i];
}
}
for (let i = 0; i < txt.length; i++) {
if (f == txt[i]) {
return "text/" + txt[i];
}
}
// 错误提示
f = "不支持此类型文件！";
toast(f);
console.error(f);
exit();
}