php 等比例压缩

<?php
function resizeImage($source, $destination, $width, $height) {
    $info = getimagesize($source);
    if ($info['mime'] == 'image/jpeg') {
        $image = imagecreatefromjpeg($source);
    } elseif ($info['mime'] == 'image/png') {
        $image = imagecreatefrompng($source);
    } else {
        return false;
    }

    $newImage = imagescale($image, $width, $height);
    if ($info['mime'] == 'image/jpeg') {
        imagejpeg($newImage, $destination, 80);
    } elseif ($info['mime'] == 'image/png') {
        imagepng($newImage, $destination, 9);
    }

    imagedestroy($image);
    imagedestroy($newImage);

    return true;
}

$source = 'path/to/source/image.jpg';
$destination = 'path/to/destination/image.jpg';
$width = 300;
$height = 200;

resizeImage($source, $destination, $width, $height);
?>