ImageMagick 实例

<?php

function resize($src,$destSrc, $w,$h)
    {
        $temp=pathinfo($src);
        $name=$temp["basename"];
        $dir=$temp["dirname"];
        $savepath = empty($destSrc) ? "{$dir}/{$name}.thumb.jpg" : $destSrc;


        $image = new Imagick();
        $image->newImage($w, $h, new ImagickPixel('white'));
        $image->setImageFormat('png');

        $imagick = new Imagick();
        $imagick->readImage($src);
        $width = $imagick->getImageWidth();
        $height = $imagick->getImageHeight();

        if ($width > $w || $height > $h) {
            $imagick->resizeImage($w, $h, Imagick::FILTER_CATROM, 1, true);
        }

        $imagick->setImageFormat('JPEG');
        $imagick->setImageCompression(Imagick::COMPRESSION_JPEG);
        $a = $imagick->getImageCompressionQuality() * 0.75;
        if ($a == 0) {
            $a = 75;
        }
        $imagick->setImageCompressionQuality($a);
        $imagick->stripImage();

        $per1 = round($width/$height,2);//计算原图长宽比
        $per2 = round($w/$h,2);//计算缩略图长宽比

        if($per1 == $per2){
            $imagick->writeImage($savepath);
        }else{
            if($per1 > $per2){
                $x=0;
                $y=($h - $imagick->getImageHeight())/2;//垂直居中
            }elseif($per1 < $per2){
                $x=($w - $imagick->getImageWidth())/2;//水平居中
                $y=0;
            }else{
              $x = $y = 0;
            }
            $image->compositeImage($imagick, $imagick->getImageCompose(), $x, $y);
            $image->writeImage($savepath);
        }

        return $savepath;
    }
?>