How to implement proportional scaling of images in php

Mainly introduces how to use PHP to scale images in equal proportions, and you can specify the required width and length of the original image.

This article introduces the method of image compression in PHP. Readers can refer to the specific application or To improve it, directly enter the code. The function imgzip($src,$newwid,$newhei) brings in the original image, the width required for scaling, and the length of scaling.

<?php 
//压缩图片 缩略图
$src= "xiezheng.jpg";
$newwid=640;
$newhei= 480;
function imgzip($src,$newwid,$newhei){
 $imgInfo = getimagesize($src);

 $imgType = image_type_to_extension($imgInfo[2], false);

 $fun = "imagecreatefrom{$imgType}";
//声明图片 打开图片 在内存中
 $image = $fun($src);
//方便配置长度宽度、高度，设置框为变量wid,高度为hei
 $wid=$imgInfo[0];
 $hei=$imgInfo[1];
//判断长度和宽度，以方便等比缩放,规格按照500, 320
 if($wid>$hei){
 $wid=$newwid;
 $hei=$newwid/($wid/$hei);
 }else {
 $wid = $newhei * ($wid / $hei);
 $hei = $newhei;
 }
//在内存中建立一张图片
 $images2 = imagecreatetruecolor($newwid, $newhei); //建立一个500*320的图片

//将原图复制到新建图片中
//imagecopyresampled($dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h)

 imagecopyresampled($images2, $image, 0, 0, 0, 0, $wid,$hei, $imgInfo[0],$imgInfo[1]);
//销毁原始图片
 imagedestroy($image);
//直接输出图片文件

 header("Content-type: ".$imgInfo[&#39;mime&#39;]);
 imagejpeg($images2);
//保存图片 到新文件
 imagejpeg($images2, &#39;new.jpg&#39;, 100); //10代码输出图片的质量 0-100 100质量最高
//销毁
 imagedestroy($images2);
}
imgzip($src,$newwid,$newhei);
?>

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