本文是一个简单的jquery图片预览+裁剪的例子，原理是在前端获取要裁剪的信息，如宽高比、裁剪坐标，上传图片之后在后端php进行切割
jquery代码（必须在最后面引入）
function showCutImg(showImg){
var showImg = $(showImg);
var changeInput = showImg.parents(\'.showImgDiv\').siblings(\'.CutImage\');
var size = changeInput.siblings(\'.imgCoord\').attr(\'ratio\').split(\'*\');
var needWidth = size[0];
var needHeight = size[1];
var ratio = parseInt(needWidth)/parseInt(needHeight);
ratio = parseFloat(ratio.toFixed(2));
var thisFullDiv = showImg.parent();
var coordArr = changeInput.siblings(\'.imgCoord\').val().split(\',\');
thisCutImgWidth = showImg.width();
thisCutImgHeight = showImg.height()
thisFullDiv.css(\'width\',thisCutImgWidth);
thisFullDiv.css(\'height\',thisCutImgHeight);
if((thisCutImgWidth/thisCutImgHeight)>=ratio){
var thisCutDivHeight = thisCutImgHeight;
var thisCutDivWidth = thisCutDivHeight*ratio;
}else{
var thisCutDivWidth = thisCutImgWidth;
var thisCutDivHeight = thisCutDivWidth/ratio;
}
var hideWidth = (thisFullDiv.width()-thisCutDivWidth)/2;
showImg.siblings(\'.hideImgLeft\').width(hideWidth);
showImg.siblings(\'.hideImgRight\').width(hideWidth);
var hideHeight = (thisFullDiv.height()-thisCutDivHeight)/2;
showImg.siblings(\'.hideImgTop\').width(thisCutDivWidth);
showImg.siblings(\'.hideImgBottom\').width(thisCutDivWidth);
showImg.siblings(\'.hideImgTop\').height(hideHeight);
showImg.siblings(\'.hideImgBottom\').height(hideHeight);
if(hideWidth>0){
var cutRatioX = thisCutImgWidth/hideWidth;
}else{
var cutRatioX = 0
}
if(hideHeight>0){
var cutRatioY = thisCutImgHeight/hideHeight;
}else{
var cutRatioY = 0;
}
var coord = needWidth+\'#\'+needHeight+\'#\'+(cutRatioX)+\'#\'+(cutRatioY);
if(coordArr!=\'\'){
coordArr.push(coord);
}else{
coordArr = [coord];
}
changeInput.siblings(\'.imgCoord\').val(coordArr);
$(\'.fullDiv\').on(\'mousedown\',function(e){
var me = $(this);
var changeInput = me.parent().siblings(\'.CutImage\');
var index = me.attr(\'index\');
var oldx = e.pageX;
var oldy = e.pageY;
var imgleft = me.children(\'.cutImg\').position().left;
var imgtop = me.children(\'.cutImg\').position().top;
var maxw = me.children(\'.hideImgLeft\').width();
var maxh = me.children(\'.hideImgTop\').height();
var goordArr = changeInput.siblings(\'.imgCoord\').val().split(\',\');
var cutDivSize = goordArr[index].split(\'#\');
$(document).mousemove(function(e){
var newx = e.pageX;
var newy = e.pageY;
var movex = newx - oldx;
var movey = newy - oldy;
var x = movex + imgleft;
var y = movey + imgtop;
if(Math.abs(x)>maxw){
if(x>0) x = maxw;
if(x<0) x = -maxw;
}
if(Math.abs(y)>maxh){
if(y>0) y = maxh;
if(y<0) y = -maxh;
}
me.children(\'.cutImg\').css(\'left\',x+\'px\');
me.children(\'.cutImg\').css(\'top\',y+\'px\');
if(parseInt(maxw - x)>0){
var cutRatioX = me.children(\'.cutImg\').width()/parseInt(maxw - x);
}else{
var cutRatioX = 0;
}
if(parseInt(maxh - y)>0){
var cutRatioY = me.children(\'.cutImg\').height()/parseInt(maxh - y)
}else{
var cutRatioY = 0;
}
var cutImgPo = (cutRatioX) +\'#\'+ (cutRatioY);
var coordVal = cutDivSize[0]+\'#\'+cutDivSize[1]+\'#\'+cutImgPo;
goordArr[index] = coordVal;
changeInput.siblings(\'.imgCoord\').val(goordArr);
});
});
$(document).on(\'mouseup\',function(e){
$(document).unbind(\'mousemove\');
});
}
$(\".CutImage\").change(function(){
$(this).siblings(\'.imgCoord\').val(\'\');
if($(this).prop(\'multiple\')!=true){ //判断是否多文件上传
var objUrl = get URL1(this.files[0]) ;
var showImgWidth = $(this).siblings(\'.showImgDiv\').attr(\'showImgWidth\');
if(!showImgWidth)
{
showImgWidth = \'150\';
}
if (objUrl) {
html = \'\';
html += \'<div style=\"border:1px solid #000;position:relative;z-index:2;overflow:hidden;cursor:move;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;\" index=\"0\" class=\"fullDiv\">\';
html += \'<div style=\"position:absolute;background:#ccc;top:0;z-index:4;opacity:0.95;left:0;right:0;margin:auto;\" class=\"hideImgTop\"></div>\';
html += \'<div style=\"position:absolute;background:#ccc;bottom:0;z-index:4;opacity:0.95;left:0;right:0;margin:auto;\" class=\"hideImgBottom\"></div>\';
html += \'<div style=\"position:absolute;height:100%;background:#ccc;left:0;z-index:4;opacity:0.95;\" class=\"hideImgLeft\"></div><div style=\"position:absolute;z-index:3;left:0;right:0;top:0;bottom:0;margin:auto;\" class=\"cutDiv\"></div>\';
html += \'<div style=\"position:absolute;height:100%;background:#ccc;right:0;z-index:4;opacity:0.95;\" class=\"hideImgRight\"></div>\';
html += \'<img style=\"position:absolute;z-index:1;width:\'+showImgWidth+\'px\" =\"showCutImg(this)\" class=\"cutImg\" class=\"imgshover\" src=\"\'+objUrl+\'\" alt=\"图片加载失败\" />\';
html += \'</div>\';
$(this).siblings(\'.showImgDiv\').html(html);
}
}else{
var objUrl = get URL2($(this).get(0).files);
if (objUrl) {
var showImgWidth = $(this).siblings(\'.showImgDiv\').attr(\'showImgWidth\');
if(!showImgWidth)
{
showImgWidth = \'150\';
}
var html = \'\';
for(var i=0;i<objUrl.length;i++)
{
html += \'<div style=\"margin-bottom:5px;border:1px solid #000;position:relative;z-index:2;overflow:hidden;cursor:move;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;\" index=\"\'+i+\'\" class=\"fullDiv\">\';
html += \'<div style=\"position:absolute;background:#ccc;top:0;z-index:4;opacity:0.95;left:0;right:0;margin:auto;\" class=\"hideImgTop\"></div>\';
html += \'<div style=\"position:absolute;background:#ccc;bottom:0;z-index:4;opacity:0.95;left:0;right:0;margin:auto;\" class=\"hideImgBottom\"></div>\';
html += \'<div style=\"position:absolute;height:100%;background:#ccc;left:0;z-index:4;opacity:0.95;\" class=\"hideImgLeft\"></div><div style=\"position:absolute;z-index:3;left:0;right:0;top:0;bottom:0;margin:auto;\" class=\"cutDiv\"></div>\';
html += \'<div style=\"position:absolute;height:100%;background:#ccc;right:0;z-index:4;opacity:0.95;\" class=\"hideImgRight\"></div>\';
html += \'<img style=\"position:absolute;z-index:1;width:\'+showImgWidth+\'px\" =\"showCutImg(this)\" class=\"cutImg\" class=\"imgshover\" src=\"\'+objUrl[i]+\'\" alt=\"图片加载失败\" />\';
html += \'</div>\'; //修改img标签的width样式可改变预览图大小
}
$(this).siblings(\'.showImgDiv\').html(html);
}
//$(\'.fullDiv\').css(\'float\',\'left\');
}
}) ;
//建立一??可存取到?file的url
function get URL1(file) {
var url = null ;
if (window.create URL!=undefined) { // basic
url = window.create URL(file) ;
} else if (window.URL!=undefined) { // mozilla(firefox)
url = window.URL.create URL(file) ;
} else if (window.webkitURL!=undefined) { // webkit or chrome
url = window.webkitURL.create URL(file) ;
}
return url ;
}
//建立一??可存取到?file的url
function get URL2(file) {
var url = new Array();
if (window.create URL!=undefined) { // basic
for(var i=0;i<file.length;i++)
{
url[i] = window.create URL(file[i]) ;
}
} else if (window.URL!=undefined) { // mozilla(firefox)
for(var i=0;i<file.length;i++)
{
url[i] = window.URL.create URL(file[i]) ;
}
} else if (window.webkitURL!=undefined) { // webkit or chrome
for(var i=0;i<file.length;i++)
{
url[i] = window.webkitURL.create URL(file[i]) ;
}
}
return url ;
}
html代码（这些代码要放在同一级）
<!-- 文件上传标签，添加class属性CutImage --> <input class=\"CutImage\" type=\"file\" name=\"img\" /> <!-- 传送图片裁剪比例等参数，要添加class属性imgCoord，ratio为裁剪后要保存的宽高width*height --> <input ratio=\"100*100\" type=\"hidden\" class=\"imgCoord\" name=\"imgCoord\"> <!-- 图片预览，要添加class属性showImgDiv，showImgWidth表示预览时的宽度 --> <div showImgWidth=\"100\" class=\"showImgDiv\"></div>
php代码
/*图片上传代码略 下面直接进行图片裁剪*/
/**
* [cut_img 图片裁剪函数]
* Author: 程威明
* @param array $imgs 图片路径数组
* @param array $info 裁剪信息?到M，包括裁剪后要保存的宽高、图片大小与裁剪开始坐标之比
* @param bool $cover 是否覆盖原图，默认不覆盖
* @return array 若覆盖原图返回裁剪数量，不覆盖返回图片路径组成的数组
*/
function cut_img($imgs=array(),$infoarr=null,$cover=false)
{
if($infoarr==null) return $imgs;
//判断是否为数组（必须是一个以图片路径组成的数组）
$imgs = is_array($imgs)?$imgs:array($imgs);
//把多个裁剪信息切成单个信息组成的数组
$infoarr = explode(\',\', $infoarr);
$save_file = array();
$i=0;
foreach($imgs as $file){
//如果不覆盖原图，可重新定义图片保存路径
if(false==$cover){
$file = $file;
}
//把裁剪信息切割成数组，第一个为要保存的宽第二个为要保存的高，第三和第四个为图片宽高与裁剪起点的比例
$info = explode(\'#\', $infoarr[$i]);
//裁剪宽高比
$ratio = $info[0]/$info[1];
//判断图片是否存在
if(!file_exists($file)) continue;
//获取图片信息
$imgize = getimagesize($file);
//图片宽度
$width = $imgize[0];
//图片高度
$height = $imgize[1];
//图片裁剪起点坐标
$x = $info[2]==0?0:$imgize[0]/$info[2];
$y = $info[3]==0?0:$imgize[1]/$info[3];
//判断图片原宽高比与裁剪宽高比的大小
if($width/$height>=$ratio){
$width = $height*$ratio;//如大于即为裁剪宽度
}else{
$height = $width/$ratio;//如小于即为裁剪高度
}
//裁剪的??高不能超出?D片大小
if(($width+$x)>$imgize[0]){
$width = $width-($width+$x-$imgize[0]);
}
if(($height+$y)>$imgize[1]){
$height = $height-($height+$y-$imgize[1]);
}
//创建源图的实例
$src = imagecreatefromstring(file_get_contents($file));
//??建一???D像
$new_image = imagecreatetruecolor($info[0], $info[1]);
//分配颜色
$color = imagecolorallocate($new_image,255,255,255);
//定义为透明色
imagecolortransparent($new_image,$color);
//填充图片
imagefill($new_image,0,0,$color);
//拷贝图片并保存成指定大小
imagecopyresized($new_image, $src, 0, 0, $x, $y, $info[0], $info[1], $width, $height);
//保存
if(false==$cover){
$file = rtrim(dirname($file),\'/\').\'/c_\'. name($file);
$save_file[] = $file;
}
imagejpeg($new_image,$file);
imagedestroy($new_image);
imagedestroy($src);
$i++;
}
if(false==$cover){
return $save_file;
}else{
return $i;
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
继续阅读与本文标签相同的文章
上一篇 :
python list格式数据excel导出方法
下一篇 :
验证码服务发布上线
-
简易区分物联网和互联网
2026-05-19栏目： 教程
-
二维码如此普及，为何三维码没办法普及
2026-05-19栏目： 教程
-
山东有效专利量前十企业和前十大专院校名单来啦，第一名你想到了吗
2026-05-19栏目： 教程
-
两种ASO应用优化的核心操作方法
2026-05-19栏目： 教程
-
第126届广交会15日开幕，新产品新技术受青睐
2026-05-19栏目： 教程