phpcms 缩略图函数

function generateThumbnail($sourceImage, $thumbnailWidth, $thumbnailHeight, $destinationImage) {
    // 获取原始图片信息
    list($sourceWidth, $sourceHeight, $sourceType) = getimagesize($sourceImage);

    // 根据图片类型创建图像资源
    switch ($sourceType) {
        case IMAGETYPE_GIF:
            $sourceResource = imagecreatefromgif($sourceImage);
            break;
        case IMAGETYPE_JPEG:
            $sourceResource = imagecreatefromjpeg($sourceImage);
            break;
        case IMAGETYPE_PNG:
            $sourceResource = imagecreatefrompng($sourceImage);
            break;
        default:
            return false;
    }

    // 创建目标图像资源
    $destinationResource = imagecreatetruecolor($thumbnailWidth, $thumbnailHeight);

    // 计算缩放比例
    $ratio = min($thumbnailWidth / $sourceWidth, $thumbnailHeight / $sourceHeight);

    // 计算裁剪位置
    $cropX = ($sourceWidth - $thumbnailWidth / $ratio) / 2;
    $cropY = ($sourceHeight - $thumbnailHeight / $ratio) / 2;

    // 缩放并裁剪图片
    imagecopyresampled($destinationResource, $sourceResource, 0, 0, $cropX, $cropY, $thumbnailWidth, $thumbnailHeight, $sourceWidth / $ratio, $sourceHeight / $ratio);

    // 保存缩略图
    switch ($sourceType) {
        case IMAGETYPE_GIF:
            imagegif($destinationResource, $destinationImage);
            break;
        case IMAGETYPE_JPEG:
            imagejpeg($destinationResource, $destinationImage);
            break;
        case IMAGETYPE_PNG:
            imagepng($destinationMedia, $destinationImage);
            break;
    }

    // 销毁图像资源
    imagedestroy($sourceResource);
    imagedestroy($destinationResource);

    return true;
}

memory_limit = 256M