Principle of image generation and verification code image generation

Principle of image generation and verification code image generation_PHP tutorial

WBOY

Release： 2016-07-13 10:45:14

Original

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This PHP image generation and verification code image generation principle code is supported by the PHP gd library. If your system cannot create images, remove the ";" in front of gd.dll and restart apache. If it is iis, It's OK after starting iis.

This php tutorial image generation and verification code image generation principle code is supported by the php gd library. If your system cannot create images, remove the ";" in front of gd.dll and re- Start apache, if it is iis, restart iis and it will be OK.

$w?$RESIZEWIDTH=$w:$RESIZEWIDTH=400;// 生成图片的宽度
$h?$RESIZEHEIGHT=$h:$RESIZEHEIGHT=400;// 生成图片的高度
function ResizeImage($im,$maxwidth,$maxheight,$name){
    $width = imagesx($im);
    $height = imagesy($im);
    if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
        if($maxwidth && $width > $maxwidth){
            $widthratio = $maxwidth/$width;
            $RESIZEWIDTH=true;//www.bKjia.c0m
        }
        if($maxheight && $height > $maxheight){
            $heightratio = $maxheight/$height;
            $RESIZEHEIGHT=true;
        }
        if($RESIZEWIDTH && $RESIZEHEIGHT){
            if($widthratio < $heightratio){
                $ratio = $widthratio;
            }else{
                $ratio = $heightratio;
            }
        }elseif($RESIZEWIDTH){
            $ratio = $widthratio;
        }elseif($RESIZEHEIGHT){
            $ratio = $heightratio;
        }
        $newwidth = $width * $ratio;
        $newheight = $height * $ratio;
        if(function_exists("imagecopyresampled")){
              $newim = imagecreatetruecolor($newwidth, $newheight);
              imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
        }else{
            $newim = imagecreate($newwidth, $newheight);
              imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
        }
        ImageJpeg ($newim,$name);
        ImageDestroy ($newim);
    }else{
        ImageJpeg ($im,$name);
    }
}

if($_FILES['uploadfile']['size']){
    if($_FILES['uploadfile']['type'] == "image/pjpeg"){
        $im = imagecreatefromjpeg($_FILES['uploadfile']['tmp_name']);
    }elseif($_FILES['uploadfile']['type'] == "image/x-png"){
        $im = imagecreatefrompng($_FILES['uploadfile']['tmp_name']);
    }elseif($_FILES['uploadfile']['type'] == "image/gif"){
        $im = imagecreatefromgif($_FILES['uploadfile']['tmp_name']);
    }
    if($im){
        if(file_exists('bbs.jpg')){
            unlink('www.bKjia.c0m.jpg');
        }
        ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,'bbs.jpg');
        ImageDestroy ($im);

    }
}
//$uploadfile="bbs.jpg";

创建图片后记得用ImageDestroy 清空内存哦。