这里说的imagick 是 ImageMagick 在PHP下的扩展。使用pecl安装起来那叫一个轻松简单一条命令就搞定：
复制代码 代码如下:
sudo pecl install imagick
（扩展装好后还是要在php.ini中加上extension=imagick.so，然后记得重启apache或php-fpm服务。）
最近有个需求是要把多张图片组合起来生成缩略图，刚好用用这个强大的imagick扩展。
这个需求是要这样生成缩略图：
1.如果有1张图片，就直接生成这张图片的缩略图；
2.如果有2张图片，则一张在左边一张在右边，各一半；
3.如果有3张图片，则两张左边平均分配，一张独占右边；
4.如果有4张图片，则像田字格一样平均分配空间；
5.更多张图片，则只取前4张，按田字格方式生成缩略图。
这规则还真不少，不过还不算太过复杂，很快搞出来了：
namespace \clarence\thumbnail; class Thumbnail extends \Imagick { /** * @param array $images * @param int $width * @param int $height * @return static * @throws ThumbnailException */ public static function createFromImages($images, $width, $height){ if (empty($images)){ throw new ThumbnailException("No images!"); } $thumbnail = new static(); $thumbnail->newImage($width, $height, 'white', 'jpg'); $thumbnail->compositeImages($images); return $thumbnail; } public function compositeImages($images){ $imagesKeys = array_keys($images); $compositeConfig = $this->calcCompositeImagesPosAndSize($images); foreach ($compositeConfig as $index => $cfg){ $imgKey = $imagesKeys[$index]; $img = new \Imagick($images[$imgKey]); $img = $this->makeCompositeThumbnail($img, $cfg); $this->compositeImage($img, self::COMPOSITE_OVER, $cfg['to']['x'], $cfg['to']['y']); } } protected function makeCompositeThumbnail(\Imagick $img, $cfg){ $img->cropThumbnailImage($cfg['size']['width'], $cfg['size']['height']); return $img; } protected function calcCompositeImagesPosAndSize($images){ $width = $this->getImageWidth(); $height = $this->getImageHeight(); switch(count($images)){ case 0: throw new ThumbnailException("No images!"); case 1: // | 0 | return [ 0 => [ 'to' => [ 'x' => 0, 'y' => 0 ], 'size' => [ 'width' => $width, 'height' => $height, ] ] ]; case 2: // | 0 | 1 | return [ 0 => [ 'to' => [ 'x' => 0, 'y' => 0 ], 'size' => [ 'width' => $width / 2, 'height' => $height, ] ], 1 => [ 'to' => [ 'x' => $width / 2, 'y' => 0], 'size' => [ 'width' => $width / 2, 'height' => $height, ] ] ]; case 3: // | 0 | 1 | // | 2 | | return [ 0 => [ 'to' => [ 'x' => 0, 'y' => 0 ], 'size' => [ 'width' => $width / 2, 'height' => $height / 2, ] ], 1 => [ 'to' => [ 'x' => $width / 2, 'y' => 0], 'size' => [ 'width' => $width / 2, 'height' => $height, ] ], 2 => [ 'to' => [ 'x' => 0, 'y' => $height / 2 ], 'size' => [ 'width' => $width / 2, 'height' => $height / 2, ] ], ]; default: // >= 4: // | 0 | 1 | // | 2 | 3 | return [ 0 => [ 'to' => [ 'x' => 0, 'y' => 0 ], 'size' => [ 'width' => $width / 2, 'height' => $height / 2, ] ], 1 => [ 'to' => [ 'x' => $width / 2, 'y' => 0], 'size' => [ 'width' => $width / 2, 'height' => $height / 2, ] ], 2 => [ 'to' => [ 'x' => 0, 'y' => $height / 2 ], 'size' => [ 'width' => $width / 2, 'height' => $height / 2, ] ], 3 => [ 'to' => [ 'x' => $width / 2, 'y' => $height / 2], 'size' => [ 'width' => $width / 2, 'height' => $height / 2, ] ], ]; } } }
用个试试：
复制代码 代码如下:
$thumbnail = \clarence\thumbnail\Thumbnail::createFromImages($srcImages, 240, 320);
$thumbnail->writeImage($outputDir."/example.jpg");