先给大家炫下效果图，如果大家觉得还很满意，请继续往下阅读：

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");

以上内容给大家介绍了PHP利用imagick生成组合缩略图的相关知识，希望对大家有所帮助！