getimagesize

(PHP 4, PHP 5, PHP 7, PHP 8)

getimagesize — 画像の大きさを取得する

説明

getimagesize(string $filename, array &$image_info = null): array|false

getimagesize() 関数は、サポートする任意の形式の画像ファイルの大きさを決定し、ファイルの型と高さ/幅を表す文字列を返します。これらは HTML の IMG タグや HTTP の content type として使用できます。

警告

この関数は、filename が適切な画像ファイルであることを想定しています。画像以外のファイルを渡してもそれを画像だと判断してしまい、関数の処理は成功するでしょう。しかし、配列には意味のない値が含まれる場合があります。

getimagesize() を使って、そのファイルが画像であるかどうかを確かめることはできません。そのようなことをしたい場合は、そのために用意されたソリューション (Fileinfo 拡張モジュールなど) を使いましょう。

getimagesize() は、 image_info パラメータで追加情報を返します。

注意: JPC と JP2 は異なるビット深度のコンポーネントを含むことが可能なことに注意してください。この場合 "bits" に対する値は、最も大きい深度になります。また、JP2 ファイルは 複数の JPEG 2000 コードストリームを含む場合があります。この場合、 getimagesize() はファイルのルートから最初に遭遇するコードストリームに対する値を返します。

注意: アイコンに関する情報は、ビットレートが最大のアイコンから取得します。

注意: GIF 画像はひとつ以上のフレームからなります。個々のフレームは画像の一部のみを占めます。 getimagesize() が報告する画像のサイズは、 (logical screen descriptor から読み込まれた) 全部のサイズです。

パラメータ

filename: このパラメータは、情報を取得したいファイルの名前を指定します。ローカルファイルへの参照、あるいは (設定で許可されているなら) ストリームを用いたリモートファイルへの参照を指定できます。
image_info: オプションのパラメータで、画像ファイルから何らかの拡張情報を引き出すことが可能です。現在、この変数にはJPGファイルについて異なった複数のAPPマーカーが連想配列として返されます。いくつかのプログラムは、これらのAPPマーカーを画像の中の埋込テキストの情報として使用します。最も一般的な例は、マーカーAPPl3に埋込IPTC » http://www.iptc.org/情報が返されることです。バイナリ形式のマーカーAPP13を読むことができるよう処理するために iptcparse() 関数を使用することができます。

注意:
image_info は、 JFIF ファイルのみをサポートします。

戻り値

最大 7 つの要素からなる配列を返します。画像の形式によっては、 channels や bits は含まれないことがあります。

0 番目および 1 番目の要素は、それぞれ画像の幅と高さを表します。

注意:
形式によっては、画像を含まないものや複数の画像を含むものがあります。これらの場合、getimagesize() は画像のサイズを適切に決定することができません。このような場合、 getimagesize() が返す幅と高さはいずれもゼロとなります。

2 番目の要素は IMAGETYPE_XXX constants 定数のひとつで、画像の形式を表します。

3 番目の要素は IMG タグで直接利用できる文字列 height="yyy" width="xxx" です。

mimeは画像のMIMEタイプに一致します。この情報は画像とともに正しい HTTP Content-type ヘッダを転送するために使用できます。

例1 getimagesize() および MIME 型

<?php
$size = getimagesize($filename);
$fp = fopen($filename, "rb");
if ($size && $fp) {
    header("Content-type: {$size['mime']}");
    fpassthru($fp);
    exit;
} else {
    // エラー
}
?>

channels は RGB 画像の場合に 3、CMYK 画像の場合に 4 です。

bits は個々の色のビット数です。

画像の形式によっては、channels や bits の値の存在は混乱の元です。たとえば、GIF は常に 1 ピクセルあたり 3 チャンネルを使用しますが、グローバルカラーテーブルを使ったアニメーション GIF のピクセルあたりのビット数を計算することはできません。

失敗した場合には false を返します。

エラー / 例外

もし filename のイメージにアクセスできない場合、 getimagesize() は false を返し、E_WARNING レベルのエラーを発生させます。読み込み時にエラーが発生した場合は、 getimagesize() は E_NOTICE レベルのエラーを発生させます。

変更履歴

バージョン	説明
8.2.0	AVIF 画像のビット数、チャンネル情報、幅と高さの情報(dimensions) を返すようになりました。これより前のバージョンでは、幅と高さの情報は `0x0` として報告され、ビット数とチャンネル情報は全く報告されていませんでした。
7.1.0	WebP に対応しました。

例

例2 getimagesize() の例

<?php
list($width, $height, $type, $attr) = getimagesize("img/flag.jpg");
echo "<img src=\"img/flag.jpg\" $attr alt=\"getimagesize() example\" />";
?>

例3 getimagesize (URL)

<?php
$size = getimagesize("http://www.example.com/gifs/logo.gif");

// ファイル名にスペースが含まれる場合は適切にエンコードしてください
$size = getimagesize("http://www.example.com/gifs/lo%20go.gif");

?>

例4 IPTC を返す getimagesize()

<?php
$size = getimagesize("testimg.jpg", $info);
if (isset($info["APP13"])) {
    $iptc = iptcparse($info["APP13"]);
    var_dump($iptc);
}
?>

注意

注意:
この関数は、GD 画像ライブラリは必要ありません。

参考

image_type_to_mime_type() - getimagesize, exif_read_data, exif_thumbnail, exif_imagetypeから返される画像形式のMIMEタイプを取得する
exif_imagetype() - イメージの型を定義する
exif_read_data() - 画像ファイルから EXIF ヘッダを読み込む
exif_thumbnail() - 画像に埋め込まれたサムネイルを取得する
imagesx() - 画像の幅を取得する
imagesy() - 画像の高さを取得する

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User Contributed Notes 24 notes

down

james dot relyea at zifiniti dot com ¶

15 years ago

As noted below, getimagesize will download the entire image before it checks for the requested information. This is extremely slow on large images that are accessed remotely. Since the width/height is in the first few bytes of the file, there is no need to download the entire file. I wrote a function to get the size of a JPEG by streaming bytes until the proper data is found to report the width and height:

<?php
// Retrieve JPEG width and height without downloading/reading entire image.
function getjpegsize($img_loc) {
    $handle = fopen($img_loc, "rb") or die("Invalid file stream.");
    $new_block = NULL;
    if(!feof($handle)) {
        $new_block = fread($handle, 32);
        $i = 0;
        if($new_block[$i]=="\xFF" && $new_block[$i+1]=="\xD8" && $new_block[$i+2]=="\xFF" && $new_block[$i+3]=="\xE0") {
            $i += 4;
            if($new_block[$i+2]=="\x4A" && $new_block[$i+3]=="\x46" && $new_block[$i+4]=="\x49" && $new_block[$i+5]=="\x46" && $new_block[$i+6]=="\x00") {
                // Read block size and skip ahead to begin cycling through blocks in search of SOF marker
                $block_size = unpack("H*", $new_block[$i] . $new_block[$i+1]);
                $block_size = hexdec($block_size[1]);
                while(!feof($handle)) {
                    $i += $block_size;
                    $new_block .= fread($handle, $block_size);
                    if($new_block[$i]=="\xFF") {
                        // New block detected, check for SOF marker
                        $sof_marker = array("\xC0", "\xC1", "\xC2", "\xC3", "\xC5", "\xC6", "\xC7", "\xC8", "\xC9", "\xCA", "\xCB", "\xCD", "\xCE", "\xCF");
                        if(in_array($new_block[$i+1], $sof_marker)) {
                            // SOF marker detected. Width and height information is contained in bytes 4-7 after this byte.
                            $size_data = $new_block[$i+2] . $new_block[$i+3] . $new_block[$i+4] . $new_block[$i+5] . $new_block[$i+6] . $new_block[$i+7] . $new_block[$i+8];
                            $unpacked = unpack("H*", $size_data);
                            $unpacked = $unpacked[1];
                            $height = hexdec($unpacked[6] . $unpacked[7] . $unpacked[8] . $unpacked[9]);
                            $width = hexdec($unpacked[10] . $unpacked[11] . $unpacked[12] . $unpacked[13]);
                            return array($width, $height);
                        } else {
                            // Skip block marker and read block size
                            $i += 2;
                            $block_size = unpack("H*", $new_block[$i] . $new_block[$i+1]);
                            $block_size = hexdec($block_size[1]);
                        }
                    } else {
                        return FALSE;
                    }
                }
            }
        }
    }
    return FALSE;
}
?>

down

nikolam3244 at gmail dot com ¶

6 years ago

There's a code snippet for getting JPEG image dimensions by getting only first few bytes of the file, but it doesn't work for PNG files, so I wrote one. It will download only the first 24 bytes instead of the whole image, and thus being much faster than getimagesize() and it will save bandwidth at the same time:

<?php
// Retrieve PNG width and height without downloading/reading entire image.
function getpngsize( $img_loc ) {
    $handle = fopen( $img_loc, "rb" ) or die( "Invalid file stream." );

    if ( ! feof( $handle ) ) {
        $new_block = fread( $handle, 24 );
        if ( $new_block[0] == "\x89" &&
            $new_block[1] == "\x50" &&
            $new_block[2] == "\x4E" &&
            $new_block[3] == "\x47" &&
            $new_block[4] == "\x0D" &&
            $new_block[5] == "\x0A" &&
            $new_block[6] == "\x1A" &&
            $new_block[7] == "\x0A" ) {
                if ( $new_block[12] . $new_block[13] . $new_block[14] . $new_block[15] === "\x49\x48\x44\x52" ) {
                    $width  = unpack( 'H*', $new_block[16] . $new_block[17] . $new_block[18] . $new_block[19] );
                    $width  = hexdec( $width[1] );
                    $height = unpack( 'H*', $new_block[20] . $new_block[21] . $new_block[22] . $new_block[23] );
                    $height  = hexdec( $height[1] );

                    return array( $width, $height );
                }
            }
        }

    return false;
}
?>

down

tomasz at trejderowski dot pl ¶

11 years ago

If you want to "convert" value returned by "getimagesize()" as index "2" into something more human-readable, you may consider using a function like this one:

    $imageTypeArray = array
    (
        0=>'UNKNOWN',
        1=>'GIF',
        2=>'JPEG',
        3=>'PNG',
        4=>'SWF',
        5=>'PSD',
        6=>'BMP',
        7=>'TIFF_II',
        8=>'TIFF_MM',
        9=>'JPC',
        10=>'JP2',
        11=>'JPX',
        12=>'JB2',
        13=>'SWC',
        14=>'IFF',
        15=>'WBMP',
        16=>'XBM',
        17=>'ICO',
        18=>'COUNT'  
    );
    
    $size = getimagesize($filename);
    
    $size[2] = $imageTypeArray[$size[2]];

Or something similar.

down

php dot net at dannysauer dot com ¶

19 years ago

Note that, if you're going to be a good programmer and use named constatnts (IMAGETYPE_JPEG) rather than their values (2), you want to use the IMAGETYPE variants - IMAGETYPE_JPEG, IMAGETYPE GIF, IMAGETYPE_PNG, etc.  For some reason, somebody made a horrible decision, and IMG_PNG is actually 4 in my version of PHP, while IMAGETYPE_PNG is 3.  It took me a while to figure out why comparing the type against IMG_PNG was failing...

down

simon dot waters at surevine dot com ¶

9 years ago

Note: getimage size doesn't attempt to validate image file formats

It is possible for malformed GIF images to contain PHP and still have valid dimensions.

Programmers need to ensure such images are validated by other tools, or never treated as PHP or other executable types (enforcing appropriate extensions, avoiding user controlled renaming, restricting uploaded images to areas of the website where PHP is not enabled).

http://ha.ckers.org/blog/20070604/passing-malicious-php-through-getimagesize/

down

redcore at gmail dot com ¶

17 years ago

It's always good to check out an image's dimensions while attempting to upload to your server or database...especially if it's going to be displayed on a page that doesn't accomodate images beyond a particular size.

<?php

$tmpName = $_FILES['userfile']['tmp_name'];
        
list($width, $height, $type, $attr) = getimagesize($tmpName);

if($width>275 || $height>275)
{
die("exceeded image dimension limits.");
}

?>

down

utilmind ¶

13 years ago

Here is the function which determines whether the PNG image contains alpha or not:



<?php

function is_alpha_png($fn){

  return (ord(@file_get_contents($fn, NULL, NULL, 25, 1)) == 6);

}

?>



The color type of PNG image is stored at byte offset 25. Possible values of that 25'th byte is:

 * 0 - greyscale

 * 2 - RGB

 * 3 - RGB with palette

 * 4 - greyscale + alpha

 * 6 - RGB + alpha

down

info at alex-lawrence dot com ¶

16 years ago

Could be useful (didn´t know where to post it):

function getImageErrors( $filename, $type = "", $minWidth = 0, $minHeight = 0, $maxWidth = 0, $maxHeight = 0, $maxFileSize = 0 )
{
    $errors = array();
    if ( file_exists( $filename ) )
    {
        $ending = substr( $filename, strpos( $filename, "." ) );
        if ( is_array( $type ) )
        {
            $isTypeOf = false;
            foreach( $type as $eachtype )
            {
                if ( $ending == $eachtype )
                {
                    $isTypeOf = true;
                }
            }
            if ( ! $isTypeOf )
            {
                $errors[ 'type' ] = $ending;
            }
        }
        elseif ( $type != "" )
        {
            if ( $ending != $type )
            {
                $errors[ 'type' ] = $ending;
            }
        }
        $size = getimagesize( $filename );
        if ( $size[ 0 ] < $minWidth )
        {
            $errors[ 'minWidth' ] = $size[ 0 ];
        }
        if ( $size[ 1 ] < $minHeight )
        {
            $errors[ 'minHeight' ] = $size[ 1 ];
        }
        if ( ( $maxWidth > $minWidth ) && ( $size[ 0 ] > $maxWidth ) )
        {
            $errors[ 'maxWidth' ] = $size[ 0 ];
        }
        if ( ( $maxHeight > $minHeight ) && ( $size[ 1 ] > $maxHeight ) )
        {
            $errors[ 'maxHeight' ] = $size[ 1 ];
        }
        if ( ( $maxFileSize > 0 ) && ( filesize( $filename ) > $maxFileSize ) )
        {
            $errors[ 'maxFileSize' ] = filesize( $filename );
        }
    }
    else
    {
        $errors[ 'filename' ] = "not existing";
    }
    return ( count( $errors ) > 0 ? $errors : null );
}

down

Steve ¶

13 years ago

The list of defined IMAGETYPE_ constants is on the manual page for exif_imagetype:

http://www.php.net/manual/en/function.exif-imagetype.php

down

shmohel at gmail dot com ¶

16 years ago

Rather than making a lengthy function that essentially runs twice (once as width, once as height) I came up with a helpful function that uses variable variables to set a maximum height/width. Hope someone finds this helpful.

function scaleimage($location, $maxw=NULL, $maxh=NULL){
    $img = @getimagesize($location);
    if($img){
        $w = $img[0];
        $h = $img[1];

        $dim = array('w','h');
        foreach($dim AS $val){
            $max = "max{$val}";
            if(${$val} > ${$max} && ${$max}){
                $alt = ($val == 'w') ? 'h' : 'w';
                $ratio = ${$alt} / ${$val};
                ${$val} = ${$max};
                ${$alt} = ${$val} * $ratio;
            }
        }

        return("<img src='{$location}' alt='image' width='{$w}' height='{$h}' />");
    }
}

down

info at personalmis dot com ¶

16 years ago

Seems the various ways people are trying to proportionaly scale an image, up or down, could be more straight forward if one remembers ones algebra.

The formula is, y = mx, where m is the slope of the line. This is the ratio of y:x or m = y/x.

So if...

// max values for x and y
$y_max = 600;
$x_max = 800;

// image size
$y1 = 2000;
$x1 = 3000;

// use width for scaling
if ($x1 > $x_max)
{
    // find slope 
    $m = $y1/$x1;
    // set x side to max
    $x2 = $x_max;
    // set y side to a proportional size
    $y2 = $m * $x1;
}

The new image proportionally scaled will be x2 = 800, y2 = 533 (rounded).

To do it from the y side, simply reverse the x's and y's.

down

geoff at spacevs dot com ¶

15 years ago

This function returns the width and height of a JPEG image from a string, allowing the dimensions of images stored in a database to be retrieved without writing them to the disk first, or using "imagecreatefromstring" which is very slow in comparison.

<?PHP
function getJPEGImageXY($data) {
        $soi = unpack('nmagic/nmarker', $data);
        if ($soi['magic'] != 0xFFD8) return false;
        $marker = $soi['marker'];
        $data   = substr($data, 4);
        $done   = false;

        while(1) {
                if (strlen($data) === 0) return false;
                switch($marker) {
                        case 0xFFC0:
                                $info = unpack('nlength/Cprecision/nY/nX', $data);
                                return array($info['X'], $info['Y']);
                                break;

                        default:
                                $info   = unpack('nlength', $data);
                                $data   = substr($data, $info['length']);
                                $info   = unpack('nmarker', $data);
                                $marker = $info['marker'];
                                $data   = substr($data, 2);
                                break;
                }
        }
}
?>

Doing this 10,000 times takes 0.43 seconds, compared with using imagecreatefromstring/imagesx/imagesy which takes around 1.52 seconds to do the same.

Do not use this instead of getimagesize when dealing with files, getimagesize is much faster coming in at 0.15 seconds.

down

cloned at clonedmadman dot com ¶

16 years ago

Well, I am making a script which will resize the image when uploaded, however, i am making a multi-uploader, so i came across with a problem: an efficient way of getting a pictures height and width and storing them in an array to resize later. This is what i came up with:

<?php
$links = array("test1.jpg", "test2.png");
$sizearray = array();
$count = count($links);
for($i = 0; $i < $count; $i++) {
    $size = getimagesize($links[$i]);
    list($width, $height) = $size;
    $sizearray[$links[$i]] = array("width" => $width, "height" => $height);
}
print_r($sizearray);
// which will print out: Array ( [test1.jpg] => Array ( [width] => 300 [height] => 400 ) [test2.png] => Array ( [width] => 680 [height] => 100 ) )
?>

down

diablx at hotmail dot com ¶

20 years ago

I'm sorry for they other scripts, but I made one mistake about the image resizing... here is a working script !
<?
    // Some configuration variables !
    $maxWidth = 90;
    $maxHeight = 90;
    $maxCols = 8;
    $webDir = "https://localhost/images/";
    $localDir = $_SERVER['DOCUMENT_ROOT']."/images/";

    $AutorisedImageType = array ("jpg", "jpeg", "gif", "png");
?>

<center>
<table border='1' cellspacing='5' cellpadding='5' style="border-collapse:collapse; border-style: dotted">
<tr>
   <?
   // Open localDir
   $dh = opendir($localDir);
   while (false !== ($filename = readdir($dh))) {
       $filesArray[] = $filename;
   }

   // Display and resize
   foreach ($filesArray as $images) {
   
       $ext = substr($images, strpos($images, ".")+1, strlen($images));
       
       if( in_array($ext, $AutorisedImageType) ) {

           list($width, $height, $type, $attr) = @getimagesize( $localDir.$images );

            $xRatio = $maxWidth / $width; 
            $yRatio = $maxHeight / $height; 
            
            if ( ($width <= $maxWidth) && ($height <= $maxHeight) ) { 
              $newWidth = $width; 
              $newHeight = $height; 
            } 
            else if (($xRatio * $height) < $maxHeight) { 
              $newHeight = ceil($xRatio * $height); 
              $newWidth = $maxWidth; 
            } 
            else { 
              $newWidth = ceil($yRatio * $width); 
              $newHeight = $maxHeight; 
            } 
           
           if($i == $maxCols) {
               echo "</tr><tr>";
               $i = 0;
           }
           echo "<td align='center' valign='middle' width='$maxWidth' height='$maxHeight'><img src='".$webDir.$images."' width='$newWidth' height='$newHeight'></td>";
           $i++;
       }
   }
?>
</tr>
</table>
</center>

down

kazuya ¶

10 years ago

i made function img_resize($path,$tmp_name,$new_name,$new_width)
this could be useful.

<?php

$new_file = img_resize("./img/", "test.jpg","copy_test.jpg",300);
echo "<IMG src = '$new_file'>";

function img_resize($path,$tmp_name,$new_name,$new_width){
    if (!file_exists($path.$filename)){
        echo "file not found!";
        exit;
    }
    if (!is_writable($path)){
        echo "error:permission denied!";
        exit;
    }
    list($width, $height) = getimagesize($path . $tmp_name);
    $new_height = abs($new_width * $height / $width); 
    $image_p = imagecreatetruecolor($new_width, $new_height);
    $image = imagecreatefromjpeg($path . $tmp_name); 
    imagecopyresampled($image_p, $image, 0, 0, 0, 0,
                        $new_width, $new_height, $width, $height); 
    imagejpeg($image_p, $path . $new_name); 
    return $path.$new_name;
}

?>

down

alexyam at live dot com ¶

12 years ago

I wanted to use getimagesize() on .SWF files stored in the database as blob data and couldn't find a simple solution, so I created my own.

I am releasing this code under the MIT license to save everyone some time:

<?php
/*
    ----------------------------------------------------------------------
    PHP Blob Data As File Stream v1.0 (C) 2012 Alex Yam <alexyam@live.com>
    This code is released under the MIT License.
    ----------------------------------------------------------------------
    [Summary]

    A simple class for PHP functions to read and write blob data as a file
    using a stream wrapper.

    Particularly useful for running getimagesize() to get the width and
    height of .SWF Flash files that are stored in the database as blob data.

    Tested on PHP 5.3.10.

    ----------------------------------------------------------------------    
    [Usage Example]

    //Include
        include('./blob_data_as_file_stream.php');

    //Register the stream wrapper
        stream_wrapper_register("BlobDataAsFileStream", "blob_data_as_file_stream");

    //Fetch a .SWF file from the Adobe website and store it into a variable.
    //Replace this with your own fetch-swf-blob-data-from-database code.
        $swf_url = 'http://www.adobe.com/swf/software/flash/about/flashAbout_info_small.swf';
        $swf_blob_data = file_get_contents($swf_url);
    
    //Store $swf_blob_data to the data stream
        blob_data_as_file_stream::$blob_data_stream = $swf_blob_data;
    
    //Run getimagesize() on the data stream
        $swf_info = getimagesize('BlobDataAsFileStream://');
        var_dump($swf_info);

    ----------------------------------------------------------------------
    [Usage Output]

    array(5) {
      [0]=>
      int(159)
      [1]=>
      int(91)
      [2]=>
      int(13)
      [3]=>
      string(23) "width="159" height="91""
      ["mime"]=>
      string(29) "application/x-shockwave-flash"
    }

*/

class blob_data_as_file_stream {

    private static $blob_data_position = 0;
    public static $blob_data_stream = '';

    public static function stream_open($path,$mode,$options,&$opened_path){
        static::$blob_data_position = 0;
        return true;
    }

    public static function stream_seek($seek_offset,$seek_whence){
        $blob_data_length = strlen(static::$blob_data_stream);
        switch ($seek_whence) {
            case SEEK_SET:
                $new_blob_data_position = $seek_offset;
                break;
            case SEEK_CUR:
                $new_blob_data_position = static::$blob_data_position+$seek_offset;
                break;
            case SEEK_END:
                $new_blob_data_position = $blob_data_length+$seek_offset;
                break;
            default:
                return false;
        }
        if (($new_blob_data_position >= 0) AND ($new_blob_data_position <= $blob_data_length)){
            static::$blob_data_position = $new_blob_data_position;
            return true;
        }else{
            return false;
        }
    }

    public static function stream_tell(){
        return static::$blob_data_position;
    }

    public static function stream_read($read_buffer_size){
        $read_data = substr(static::$blob_data_stream,static::$blob_data_position,$read_buffer_size);
        static::$blob_data_position += strlen($read_data);
        return $read_data;
    }

    public static function stream_write($write_data){
        $write_data_length=strlen($write_data);
        static::$blob_data_stream = substr(static::$blob_data_stream,0,static::$blob_data_position).
            $write_data.substr(static::$blob_data_stream,static::$blob_data_position+=$write_data_length);
        return $write_data_length;
    }

    public static function stream_eof(){
        return static::$blob_data_position >= strlen(static::$blob_data_stream);
    }

}
?>

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ajreading at classixshop dot com ¶

19 years ago

A simple piece of code i wrote to proportionally resize an image to a max height and width then display it

<?php
// Max height and width
$max_width = 100;
$max_height = 100;

// Path to your jpeg

$upfile '/path/to/file.jpg';
    Header("Content-type: image/jpeg");
    
    $size = GetImageSize($upfile); // Read the size
          $width = $size[0];
          $height = $size[1];
          
          // Proportionally resize the image to the
          // max sizes specified above
          
          $x_ratio = $max_width / $width;
          $y_ratio = $max_height / $height;

          if( ($width <= $max_width) && ($height <= $max_height) )
          {
               $tn_width = $width;
               $tn_height = $height;
          }
          elseif (($x_ratio * $height) < $max_height)
          {
               $tn_height = ceil($x_ratio * $height);
               $tn_width = $max_width;
          }
          else
          {
               $tn_width = ceil($y_ratio * $width);
               $tn_height = $max_height;
          }
     // Increase memory limit to support larger files
     
     ini_set('memory_limit', '32M');
     
     // Create the new image!
     $src = ImageCreateFromJpeg($upfile);
     $dst = ImageCreateTrueColor($tn_width, $tn_height);
     ImageCopyResized($dst, $src, 0, 0, 0, 0, $tn_width, $tn_height, $width, $height);
     ImageJpeg($dst);
// Destroy the images
ImageDestroy($src);
ImageDestroy($dst);
?>

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freecorvette at gmail dot com ¶

7 years ago

For some images, using getimagesize() without the second parameter will return the correct info, but when you add the second parameter it will return false. This is most likely a bug (and it has been reported as such), but meanwhile, if you encounter this problem, a workaround is to use exif_read_data().

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Jesus Zamora ¶

13 years ago

Returns a array with 4 elements.
The 0 index is the width of the image in pixels.
The 1 index is the height of the image in pixels.
The 2 index is a flag for the image type:

1 = GIF, 2 = JPG, 3 = PNG, 4 = SWF, 5 = PSD, 6 = BMP, 7 = TIFF(orden de bytes intel), 8 = TIFF(orden de bytes motorola), 9 = JPC, 10 = JP2, 11 = JPX, 12 = JB2, 13 = SWC, 14 = IFF, 15 = WBMP, 16 = XBM. 

The 3 index contains ' height="yyy" width="xxx" '

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anonymous ¶

15 years ago

Note that if you specify a remote file (via a URL) to check the size of, PHP will first download the remote file to your server.

If you're using this function to check the size of user provided image links, this could constitute a security risk.  A malicious user could potentially link to a very large image file and cause PHP to download it.  I do not know what, if any, file size limits are in place for the download.  But suppose the user provided a link to an image that was several gigabytes in size?

It would be nice if there were a way to limit the size of the download performed by this function.  Hopefully there is already a default with some sensible limits.

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mail at soylentgreens dot com ¶

19 years ago

How about this for cropping images...

<?php

$imgfile = "img.jpg";
$cropStartX = 300;
$cropStartY = 250;
$cropW   = 200;
$cropH   = 200;

// Create two images
$origimg = imagecreatefromjpeg($imgfile);
$cropimg = imagecreatetruecolor($cropW,$cropH);

// Get the original size
list($width, $height) = getimagesize($imgfile);

// Crop
imagecopyresized($cropimg, $origimg, 0, 0, $cropStartX, $cropStartY, $width, $height, $width, $height);

// TODO: write code to save new image
// or, just display it like this:
header("Content-type: image/jpeg");
imagejpeg($cropimg);

// destroy the images
imagedestroy($cropimg);
imagedestroy($origimg);

?>

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-1

user at example dot net ¶

16 years ago

When validating images, allways check both, image type *AND* file extension!

Because most image types allow sections for comments or other irrelevant data. Those section can be used to infiltrate php code onto the server. If these files are stored as sent by the client, files with a ".php" extension can be executed and do tremendous harm.

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-1

pfarthing at hotmail dot com ¶

16 years ago

Correction: to find $y2 it should be...

// set y side to a proportional size
$y2 = $m * $x_max; // not $x1

Thanks Norbert =)

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-2

Coodiss at w3bbix dot net ¶

19 years ago

Heres a easy way to scale images to the <td> that they are in
*this is broken up so anyone can understand it :)

<?
$imageinfo = getimagesize("images/picture.jpg");
          
$ix=$imageinfo[0];
$iy=$imageinfo[1];

$widthscale = $ix/175;  //<TD> WIDTH
$heightscale = $iy/175; //<TD> HEIGHT

if($widthscale < 1)
$nwidth = $ix*$widthscale;
else
$nwidth = $ix/$widthscale;

if($heightscale < 1)
$nheight = $iy*$heightscale;
else
$nheight = $iy/$heightscale;

?>

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