缩略图含裁剪文件

/**
 * Function createThumb
 * 生成缩略图
 * @param $srcImg string 源图地址
 * @param $maxWidth int 缩略图最大宽度
 * @param $maxHeight int 缩略图最大高度
 */
function createThumb($srcImg,$maxWidth="200",$maxHeight="200",$is_list = true){

    //$srcImg = $srcImg);
    if($is_list){
        if(empty($srcImg))return '/Public/static/bootstrap/images/headpic.jpg' ;
    }else{
        if(empty($srcImg))return false;
    }

    $pathinfo = pathinfo($srcImg);

    $extension = strtolower($pathinfo['extension'])=='jpg'?'jpeg':strtolower($pathinfo['extension']);

    $extName = '_'.$maxWidth.'x'.$maxHeight.'.'.$extension;

    //$newName = $pathinfo['basename'].$extName;

    //$srcImgFile = substr($srcImg,strpos($srcImg,'uploadfile')); //获取图片位置

    $srcImgFile = ROOT.$srcImg; //获取图片位置

    $outSrc = $srcImgFile.$extName;  //缩略图位置

    //判断是否存在
    if(!file_exists($srcImgFile)){
        return $srcImg ;
    }elseif(file_exists($outSrc)){
        $srcImgName = $srcImg.$extName;
        return $srcImgName ;
    }else{

        //
        $arr = array();
        list($souWidth,$souHeight,$type,$arr[]) = getimagesize($srcImgFile); //获取图像信息


        $newImg = imagecreatetruecolor($maxWidth,$maxHeight);   //缩略新建图像
        $bgColor = imagecolorallocate($newImg,255,255,255);  //背景色
        imagefill($newImg,0,0,$bgColor);  //填充背景色

        $imagecreatefromN = $extension=='bmp'?'imagecreatefromw'.$extension:'imagecreatefrom'.$extension;
        $sourceImg = $imagecreatefromN($srcImgFile);  //打开图像

        $maxScale = $maxWidth / $maxHeight;  //计算目标图像的宽高比
        $souScale = $souWidth / $souHeight;  //计算源图像的宽高比

        $dstOffsetH = 0 ;   //预设高度偏移量
        $dstOffsetW = 0 ;   //预设宽度偏移量
        $souOffsetH = 0 ;   //源图高度偏移量
        $souOffsetW = 0 ; //源图宽度偏移量

        if($souScale > $maxScale){  //源图比例较目标图比例宽
            if($souWidth > $maxWidth && $souHeight > $maxHeight){
                $srcWidth = $souHeight * ($maxWidth / $maxHeight);
                $srcHeight = $souHeight ;
                $dstWidth = $maxWidth ;
                $dstHeight = $maxHeight ;
                $souOffsetW = ($souWidth - $srcWidth)/2;    //计算偏移量
            }elseif($souWidth > $maxWidth && $souHeight < $maxHeight){
                $dstOffsetH = ($maxHeight - $souHeight) / 2 ; //计算高度偏移量,以调整居中
                $srcWidth = $maxWidth ;
                $srcHeight = $souHeight ;
                $dstWidth = $maxWidth ;
                $dstHeight = $souHeight ;
                $souOffsetW = ($souWidth - $srcWidth)/2;    //计算偏移量
            }elseif($souWidth < $maxWidth && $souHeight < $maxHeight){
                $dstOffsetH = ($maxHeight - $souHeight) / 2 ; //计算高度偏移量,以调整居中
                $dstOffsetW = ($maxWidth - $souWidth) / 2 ; //计算宽度偏移量,以调整居中
                $srcWidth = $souWidth ;
                $srcHeight = $souHeight ;
                $dstWidth = $souWidth ;
                $dstHeight = $souHeight ;
            }
        }elseif($souScale < $maxScale){  //源图比例较目标图比例高
            if($souWidth > $maxWidth && $souHeight > $maxHeight){
                $srcWidth = $souWidth ;
                $srcHeight = $souWidth * ($maxHeight / $maxWidth);
                $dstWidth = $maxWidth ;
                $dstHeight = $maxHeight ;
                $souOffsetH = ($souHeight - $srcHeight)/2;  //计算偏移量
            }elseif($souWidth < $maxWidth && $souHeight > $maxHeight){
                $dstOffsetW = ($maxWidth - $souWidth) / 2 ; //计算宽度偏移量,以调整居中
                $srcWidth = $souWidth ;
                $srcHeight = $maxHeight ;
                $dstWidth = $souWidth ;
                $dstHeight = $maxHeight ;
                $souOffsetH = ($souHeight - $srcHeight)/2;  //计算偏移量
            }elseif($souWidth < $maxWidth && $souHeight < $maxHeight){
                $dstOffsetH = ($maxHeight - $souHeight) / 2 ; //计算高度偏移量,以调整居中
                $dstOffsetW = ($maxWidth - $souWidth) / 2 ; //计算宽度偏移量,以调整居中
                $srcWidth = $souWidth ;
                $srcHeight = $souHeight ;
                $dstWidth = $souWidth ;
                $dstHeight = $souHeight ;
            }
        }else{  //源图比例和目标图比例一样
            if($souWidth > $maxWidth && $souHeight > $maxHeight){
                $srcWidth = $souWidth ;
                $srcHeight = $souHeight ;
                $dstWidth = $maxWidth ;
                $dstHeight = $maxHeight ;
            }else{
                $dstOffsetH = ($maxHeight - $souHeight) / 2 ; //计算高度偏移量,以调整居中
                $dstOffsetW = ($maxWidth - $souWidth) / 2 ; //计算宽度偏移量,以调整居中
                $srcWidth = $souWidth ;
                $srcHeight = $souHeight ;
                $dstWidth = $souWidth ;
                $dstHeight = $souHeight ;
            }
        }

        if($extension == 'png'){
            $newImg = imagecreatetruecolor($maxWidth,$maxHeight);   //缩略新建图像
            $bgColor = imagecolorallocatealpha($newImg,$color,$color,$color,127);  //背景色
            imagefill($newImg,0,0,$bgColor);  //填充背景色
            $sourceImg = imagecreatefrompng($srcImgFile);  //打开图像

            // imagecopyresampled($newImg,$sourceImg,0,0,0,0,$dstWidth,$dstHeight,$souWidth,$souHeight);  //缩放图像
            imagecopyresampled($newImg,$sourceImg,$dstOffsetW,$dstOffsetH,$souOffsetW,$souOffsetH,$dstWidth,$dstHeight,$srcWidth,$srcHeight);  //缩放图像



            imagesavealpha($newImg, true);
            imagepng($newImg,$outSrc);  //输出图像
        }else{
            imagecopyresampled($newImg,$sourceImg,$dstOffsetW,$dstOffsetH,$souOffsetW,$souOffsetH,$dstWidth,$dstHeight,$srcWidth,$srcHeight);  //缩放图像

        $imageN = $extension=='bmp'?'imagew'.$extension:'image'.$extension;
        $imageN($newImg,$outSrc);  //输出图像
        imagedestroy($newImg);  //释放图像


        }
        $newSrcImg = $srcImg.$extName;

        return $newSrcImg ;

    }
}
/**
 * Function createThumbNoCut
 * 生成缩略图
 * @param $srcImg string 源图地址
 * @param $maxWidth int 缩略图最大宽度
 * @param $maxHeight int 缩略图最大高度
 */
function createThumbNoCut($srcImg,$maxWidth="200",$maxHeight="200",$color = 255){
    $srcImgFile = ROOT.$srcImg; //获取图片位置
    if(empty($srcImg)) {
        $srcImg = '/Public/static/bootstrap/images/headpic.jpg';
        $srcImgFile =  ROOT.$srcImg;
    }

    if(!file_exists($srcImgFile)){
        $srcImg = '/Public/static/bootstrap/images/headpic.jpg';
        $srcImgFile =  ROOT.$srcImg;
    }
    $pathinfo = getimagesize($srcImgFile);
    $pathinfo['extension'] = substr($pathinfo['mime'],6);
    // var_dump($pathinfo);
    // var_dump($pathinfo['extension']);
    $extension = strtolower($pathinfo['extension'])=='jpg'?'jpeg':strtolower($pathinfo['extension']);
    // $extName = '_'.$maxWidth.'x'.$maxHeight.'.'.$extension;

    // return $srcImgFile;
    $extName = '_'.$maxWidth.'x'.$maxHeight.'.'.$extension ;
    $outSrc = $srcImgFile.$extName ;  //缩略图位置
    //$extension = 'jpeg';
    // RETURN $pathinfo;
     // return $extension;
    //判断是否存在
    if(file_exists($outSrc)){
        return $srcImg.$extName;
    }else{

        $arr = array();
        list($souWidth,$souHeight,$type,$arr[]) = getimagesize($srcImgFile); //获取图像信息

        $maxScale = $maxWidth / $maxHeight;  //计算目标图像的宽高比
        $souScale = $souWidth / $souHeight;  //计算源图像的宽高比

        $dstOffsetH = 0 ;  //目标高度偏移量
        $dstOffsetW = 0 ;  //目标宽度偏移量
        $souOffsetH = 0 ;  //源图高度偏移量
        $souOffsetW = 0 ;  //源图宽度偏移量

        if($souScale > $maxScale){  //源图比例较目标图比例宽
            if($souWidth > $maxWidth){
                $dstWidth = $maxWidth;
                $dstHeight = $dstWidth / $souScale ;
            }elseif($souWidth < $maxWidth){
                $dstWidth = $souWidth ;
                $dstHeight = $souHeight ;
                $dstOffsetW = ($maxWidth - $dstWidth) / 2 ;
            }
            $dstOffsetH = ($maxHeight - $dstHeight) / 2 ;
        }elseif($souScale < $maxScale){  //源图比例较目标图比例高
            if($souHeight > $maxHeight){
                $dstHeight = $maxHeight ;
                $dstWidth = $dstHeight * $souScale ;
            }elseif($souHeight < $maxHeight){
                $dstWidth = $souWidth ;
                $dstHeight = $souHeight ;
                $dstOffsetH = ($maxHeight - $dstHeight) / 2 ;
            }
            $dstOffsetW = ($maxWidth - $dstWidth) / 2 ;
        }else{  //源图比例和目标图比例一样
            if($souWidth > $maxWidth && $souHeight > $maxHeight){
                $dstWidth = $maxWidth ;
                $dstHeight = $maxHeight ;
            }elseif($souWidth = $maxWidth && $souHeight = $maxHeight){
                return $srcImg ;
            }else{
                $dstWidth = $souWidth ;
                $dstHeight = $souHeight ;
                $dstOffsetH = ($maxHeight - $dstHeight) / 2 ;
                $dstOffsetW = ($maxWidth - $dstWidth) / 2 ;
            }
        }
        if($extension == 'png'){
            $newImg = imagecreatetruecolor($maxWidth,$maxHeight);   //缩略新建图像
            $bgColor = imagecolorallocatealpha($newImg,$color,$color,$color,127);  //背景色
            imagefill($newImg,0,0,$bgColor);  //填充背景色
            $sourceImg = imagecreatefrompng($srcImgFile);  //打开图像

            // imagecopyresampled($newImg,$sourceImg,0,0,0,0,$dstWidth,$dstHeight,$souWidth,$souHeight);  //缩放图像
            imagecopyresampled($newImg,$sourceImg,$dstOffsetW,$dstOffsetH,$souOffsetW,$souOffsetH,$dstWidth,$dstHeight,$souWidth,$souHeight);  //缩放图像



            imagesavealpha($newImg, true);
            imagepng($newImg,$outSrc);  //输出图像
        }else{
            // return array($srcImgFile,$dstOffsetW,$dstOffsetH,0,0,$dstWidth,$dstHeight,$souWidth,$souHeight);
            $newImg = imagecreatetruecolor($maxWidth,$maxHeight);   //缩略新建图像
            $bgColor = imagecolorallocate($newImg,$color,$color,$color);  //背景色
            imagefill($newImg,0,0,$bgColor);  //填充背景色

            $imagecreatefromN = $extension=='bmp'?'imagecreatefromw'.$extension:'imagecreatefrom'.$extension;
            // var_dump($extension);
            // var_dump($imagecreatefromN);exit;
            $sourceImg = $imagecreatefromN($srcImgFile);  //打开图像

            imagecopyresampled($newImg,$sourceImg,$dstOffsetW,$dstOffsetH,$souOffsetW,$souOffsetH,$dstWidth,$dstHeight,$souWidth,$souHeight);  //缩放图像

            $imageN = $extension=='bmp'?'imagew'.$extension:'image'.$extension;
            $imageN($newImg,$outSrc);  //输出图像 
        }

        imagedestroy($newImg);  //释放图像

        $newSrcImg = $srcImg.'_'.$maxWidth.'x'.$maxHeight.'.'.$extension; 
        return $newSrcImg ;
    }
}
原文地址:https://www.cnblogs.com/godehi/p/13087109.html