Home > Article > Backend Development > How to use php to handle the compression function of multiple image uploads
This article mainly introduces the function of php processing multi-image upload compression code. It is very good and has certain reference value. Friends who need it can refer to it
I read some information online about processing image compression , most of the ones I found were single-image compression, either single front-end or back-end, so I adjusted the front-end and front-end compression myself, and supported multi-image compressed image instances. There is a lot of code, it will be clearer if you copy it directly to the editor
1. First create a simple upload page upload.php. First compress the image through the front-end code, and directly upload the code
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no, minimal-ui">
<title>实名验证</title>
<script type="text/javascript">
/*
三个参数
file：一个是文件(类型是图片格式)，
w：一个是文件压缩的后宽度，宽度越小，字节越小
objp：一个是容器或者回调函数
photoCompress()
*/
function photoCompress(file,w,objp){
var ready=new FileReader();
/*开始读取指定的Blob对象或File对象中的内容. 当读取操作完成时,readyState属性的值会成为DONE,如果设置了onloadend事件处理程序,则调用之.同时,result属性中将包含一个data: URL格式的字符串以表示所读取文件的内容.*/
ready.readAsDataURL(file);
ready.onload=function(){
var re=this.result;
canvasDataURL(re,w,objp)
}
}
function canvasDataURL(path, obj, callback){
var img = new Image();
img.src = path;
img.onload = function(){
var that = this;
// 默认按比例压缩
var w = that.width,
h = that.height,
scale = w / h;
w = obj.width || w;
h = obj.height || (w / scale);
var quality = 0.7; // 默认图片质量为0.7
//生成canvas
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
// 创建属性节点
var anw = document.createAttribute("width");
anw.nodeValue = w;
var anh = document.createAttribute("height");
anh.nodeValue = h;
canvas.setAttributeNode(anw);
canvas.setAttributeNode(anh);
ctx.drawImage(that, 0, 0, w, h);
// 图像质量
if(obj.quality && obj.quality <= 1 && obj.quality > 0){
quality = obj.quality;
}
// quality值越小，所绘制出的图像越模糊
var base64 = canvas.toDataURL('image/jpeg', quality);
// 回调函数返回base64的值
callback(base64);
}
}
/**
* 将以base64的图片url数据转换为Blob
* @param urlData
* 用url方式表示的base64图片数据
*/
function convertBase64UrlToBlob(urlData){
var arr = urlData.split(','), mime = arr[0].match(/:(.*?);/)[1],
bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
while(n--){
u8arr[n] = bstr.charCodeAt(n);
}
return new Blob([u8arr], {type:mime});
}
var xhr;
//上传文件方法
function uploadClick() {
document.getElementsByClassName("uploadbtn")[0].value = '上传中...';
document.getElementsByClassName("uploadbtn")[0].disabled=true;
var obj = document.getElementsByClassName("myfile");
for(var i=0;i<2;i++){
UploadFile(obj[i].files[0],'file'+i);
}
}
function UploadFile(fileObj,filed){
var shopid = document.getElementById('shopid').value;
var adminid = document.getElementById('adminid').value;
var url = "newshimingupload.php"; // 接收上传文件的后台地址
var form = new FormData(); // FormData 对象
if(fileObj.size/1024 > 100) { //大于100k，进行压缩上传
photoCompress(fileObj, {
quality: 0.2
}, function(base64Codes){
//console.log("压缩后：" + base.length / 1024 + " " + base);
var bl = convertBase64UrlToBlob(base64Codes);
form.append("file", bl, "file_"+Date.parse(new Date())+".jpg"); // 文件对象
form.append("shopid", shopid); // 文件对象
form.append("adminid", adminid); // 文件对象
form.append("filed", filed); // 文件对象
xhr = new XMLHttpRequest(); // XMLHttpRequest 对象
xhr.open("post", url, false); //post方式，url为服务器请求地址，true 该参数规定请求是否异步处理。
xhr.onload = uploadComplete; //请求完成
xhr.onerror = uploadFailed; //请求失败
// xhr.upload.onprogress = progressFunction;//【上传进度调用方法实现】
xhr.upload.onloadstart = function(){//上传开始执行方法
ot = new Date().getTime(); //设置上传开始时间
oloaded = 0;//设置上传开始时，以上传的文件大小为0
};
xhr.send(form); //开始上传，发送form数据
});
}else{ //小于等于1M 原图上传
form.append("file", fileObj); // 文件对象
form.append("shopid", shopid); // 文件对象
form.append("adminid", adminid); // 文件对象
form.append("filed", filed); // 文件对象
xhr = new XMLHttpRequest(); // XMLHttpRequest 对象
xhr.open("post", url, false); //post方式，url为服务器请求地址，true 该参数规定请求是否异步处理。
xhr.onload = uploadComplete; //请求完成
xhr.onerror = uploadFailed; //请求失败
xhr.upload.onloadstart = function(){//上传开始执行方法
ot = new Date().getTime(); //设置上传开始时间
oloaded = 0;//设置上传开始时，以上传的文件大小为0
};
xhr.send(form); //开始上传，发送form数据
}
}
//上传成功响应
function uploadComplete(evt) {
//服务断接收完文件返回的结果
var data = JSON.parse(evt.target.responseText);
console.log(data);
if(data.status){
alert(data.msg);
if(data.msg == '门店照上传成功'){
window.location.href = "/dd_admin/index.php";
}
}
}
//上传失败
function uploadFailed(evt) {
alert("网络不稳定，请重新上传！");
}
</script>
</head>
<body>
<style type="text/css">
.main{text-align: center;padding-top: 50px;}
.main .myfile{margin-bottom: 15px;}
</style>
<p class="main">
营业执照：
<input type="file" class="myfile" id="file1" name="file1" accept="image/x-png, image/jpg, image/jpeg, image/gif"/><br>
门店照：
<input type="file" class="myfile" id="file2" name="file2" accept="image/x-png, image/jpg, image/jpeg, image/gif"/><br>
<input type="hidden" id="shopid" name="shopid" value="<?php echo $_GET['shopid']; ?>" maxlength="15">
<input type="hidden" id="adminid" name="adminid" value="<?php echo $_GET['adminid']; ?>" maxlength="15">
<input style="margin-top: 25px;" class="uploadbtn" type="button" onclick="uploadClick()" value="上传" /><br>
</p>
</body>
</html>
2、前端图片压缩后，请求到自定义的接口upload_deal.php.代码如下
<?php
require_once('public_func.php');
actionUpload('uploads/','file'); //参数分别代表图片存储的路径和上传的文件名
}
3、在第二部引入public_func.php,这块代码主要是对后端处理图片压缩
function actionUpload($path = '/uploads/',$filename='myFile')
{
// $path = 'uploads/'; //图片存放根目录 根据自己项目路径而定
$file = $_FILES[$filename]['name'];
$folder = $path.date('Ymd')."/";
$pre = rand(999,9999).time();
$ext = strrchr($file,'.');
$newName = $pre.$ext;
$out = array(
'msg'=>'',
'status'=>'error',
'img_url'=>''
);
if(!is_dir($folder))
{
if(!mkdir($folder, 0777, true)){
$out['msg'] = '图片目录创建失败！';
echo json_encode($out);
exit;
}
}
$im = $_FILES[$filename]['tmp_name']; //上传图片资源
$maxwidth="1056"; //设置图片的最大宽度
$maxheight="500"; //设置图片的最大高度
$imgname = $folder.$newName; //图片存放路径 根据自己图片路径而定
$filetype=$_FILES[$filename]['type'];//图片类型
$result = thumbImage($im,$maxwidth,$maxheight,$imgname,$filetype);
if($result){
$out['msg'] = '图片上传成功';
$out['status'] = 'success';
$out['img_url'] = $folder.$newName;
}else{
$out['msg'] = '图片上传失败';
}
return json_encode($out);
exit;
}
//压缩图片
function thumbImage($im,$maxwidth,$maxheight,$name,$filetype)
{
switch ($filetype) {
case 'image/pjpeg':
case 'image/jpeg':
$im = imagecreatefromjpeg($im); //PHP图片处理系统函数
break;
case 'image/gif':
$im = imagecreatefromgif($im);
break;
case 'image/png':
$im = imagecreatefrompng($im);
break;
case 'image/wbmp':
$im = imagecreatefromwbmp($im);
break;
}
$resizewidth_tag = $resizeheight_tag = false;
$pic_width = imagesx($im);
$pic_height = imagesy($im);
if(($maxwidth && $pic_width > $maxwidth) || ($maxheight && $pic_height > $maxheight))
{
$resizewidth_tag = $resizeheight_tag = false;
if($maxwidth && $pic_width>$maxwidth)
{
$widthratio = $maxwidth / $pic_width;
$resizewidth_tag = true;
}
if($maxheight && $pic_height>$maxheight)
{
$heightratio = $maxheight / $pic_height;
$resizeheight_tag = true;
}
if($resizewidth_tag && $resizeheight_tag)
{
if($widthratio < $heightratio)
$ratio = $widthratio;
else
$ratio = $heightratio;
}
if($resizewidth_tag && !$resizeheight_tag)
$ratio = $widthratio;
if($resizeheight_tag && !$resizewidth_tag)
$ratio = $heightratio;
$newwidth = $pic_width * $ratio;
$newheight = $pic_height * $ratio;
if(function_exists("imagecopyresampled"))
{
$newim = imagecreatetruecolor($newwidth,$newheight);//PHP图片处理系统函数
imagecopyresampled($newim,$im,0,0,0,0,$newwidth,$newheight,$pic_width,$pic_height);//PHP图片处理系统函数
}
else
{
$newim = imagecreate($newwidth,$newheight);
imagecopyresized($newim,$im,0,0,0,0,$newwidth,$newheight,$pic_width,$pic_height);
}
switch ($filetype) {
case 'image/pjpeg' :
case 'image/jpeg' :
$result = imagejpeg($newim,$name);
break;
case 'image/gif' :
$result = imagegif($newim,$name);
break;
case 'image/png' :
$result = imagepng($newim,$name);
break;
case 'image/wbmp' :
$result = imagewbmp($newim,$name);
break;
}
imagedestroy($newim);
}
else
{
switch ($filetype) {
case 'image/pjpeg' :
case 'image/jpeg' :
$result = imagejpeg($im,$name);
break;
case 'image/gif' :
$result = imagegif($im,$name);
break;
case 'image/png' :
$result = imagepng($im,$name);
break;
case 'image/wbmp' :
$result = imagewbmp($im,$name);
break;
}
}
return $result;
}
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