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;
}
?>
getimagesize
(PHP 4, PHP 5, PHP 7, PHP 8)
getimagesize — Obtener el tamaño de una imagen
Descripción
La función getimagesize() determinará el tamaño
de un fichero de imagen dado y devolverá las dimensiones junto con
el tipo de fichero, una cadena de texto con el alto/ancho para
utilizarla dentro una etiqueta IMG de HTML, y el
tipo de contenido HTTP correspondiente.
getimagesize() también puede devolver alguna información más
con el parámetro imageinfo.
Nota: Observe que JPC y JP2 pueden tener componentes con diferente profundidad de bit. En tal caso, el valor para "bits" es la mayor profundidad de bit encontrada. También, los ficheros JP2 pueden contener
múltiples flujos de código JPEG 2000. En este caso, getimagesize() devuelve los valores del primer flujo de código que encuentre en la raíz del fichero.
Nota: La información sobre iconos se recupera desde el icono con la mayor tasa de bit.
Parámetros
-
filename -
Este parámetro especifica el fichero del cual recuperar información. Puede hacer referencia a un fichero local o (si la configuración lo permite) a un fichero remoto usando uno de los flujos soportados.
-
imageinfo -
Este parámetro opcional permite extraer alguna información ampliada del fichero de imagen. Actualmente, devolverá los diferentes marcadores APP de JPG como un array asociativo. Algunos programas usan estos marcadores APP para incluir información de texto en imágenes. Un uso muy común es incluir información » IPTC en el marcador APP13. Se puede usar la función iptcparse() para convertir el marcador binario APP13 en algo que sea legible.
Valores devueltos
Devuelve un array de hasta 7 elementos. No todos los tipos de imagen incluirán
los elementos channels y bits.
Los índices 0 y 1 contienen el ancho y el alto de la imagen, respectivamente.
Nota:
Algunos formatos podrían no contener imágenes o contener múltiples imágenes. En estos casos, getimagesize() no será capaz de determinar apropiadamente el tamaño de la imagen. getimagesize() devolverá cero para el ancho y el alto en estos casos.
El índice 2 es una de las constantes IMAGETYPE_XXX que indican el tipo de imagen.
El índice 3 es una cadena de texto con el string correcot
height="yyy" width="xxx" que puede ser usada
dierectamente en una etiqueta IMG.
mime es el tipo MIME correspondiente de la imagen.
Esta información se puede usar para emitir imágenes con la cabecera HTTP
Content-type correcta:
Ejemplo #1 getimagesize() y tipos MIME
<?php
$tamaño = getimagesize($nombre_fichero);
$fp = fopen($nombre_fichero, "rb");
if ($tamaño && $fp) {
header("Content-type: {$tamaño['mime']}");
fpassthru($fp);
exit;
} else {
// error
}
?>
Los channels serán 3 para ímagenes RGB y 4 para ímagenes
CMYK.
bits es el número de bits de cada color.
Para algunos tipos de imagen, la presencia de los valores channels y
bits pueden ser un poco confusos. Como
ejemplo, GIF siempre usa 3 canales
por píxel, pero el número de bits por pixel no puede ser calculado para un
GIF animado con una tabla de colores global.
En caso de error devuelve false.
Errores/Excepciones
Si el acceso a la imagen filename es imposible,
getimagesize() generará un error de nivel
E_WARNING. Si se produce un error de lectura,
getimagesize() generará un error de nivel
E_NOTICE.
Historial de cambios
| Versión | Descripción |
|---|---|
| 5.3.0 | Se añadió el soporte para iconos. |
| 5.2.3 |
Los errores de lectura generados por esta función se degradaron desde
E_WARNING a E_NOTICE.
|
| 4.3.2 | Se añadió el soporte para JPC, JP2, JPX, JB2, XBM y WBMP. |
| 4.3.2 |
Se añadió el soporte para JPEG 2000 para el parámetro
imageinfo.
|
| 4.3.0 |
bits y channels están presentes
para otro tipo de imágenes también.
|
| 4.3.0 | Se añadió el soporte para SWC y IFF. |
| 4.2.0 | Se añadió el soporte para TIFF. |
| 4.0.6 | Se añadió el soporte para BMP y PSD. |
Ejemplos
Ejemplo #2 Ejemplo degetimagesize()
<?php
list($ancho, $alto, $tipo, $atributos) = getimagesize("img/flag.jpg");
echo "<img src=\"img/flag.jpg\" $atributos alt=\"Ejemplo de getimagesize()\" />";
?>Ejemplo #3 getimagesize (URL)
<?php
$tamaño = getimagesize("http://www.example.com/gifs/logo.gif");
// si el nombre de fichero contiene espacios, codifíquelo apropiadamente
$tamaño = getimagesize("http://www.example.com/gifs/lo%20go.gif");
?>Ejemplo #4 getimagesize() devolviendo IPTC
<?php
$tamaño = getimagesize("prueba.jpg", $info);
if (isset($info["APP13"])) {
$iptc = iptcparse($info["APP13"]);
var_dump($iptc);
}
?>Notas
Nota:
Esta función no requiere la librería GD image.
Nota:
Esta función requiere que
filenamesea un fichero de imagen válido. Si se proporciona un fichero que no sea imagen, este podría ser detectado incorrectamente como una imagen y la función devolver como éxito.No de debe usar getimagesize() para comprobar que una fichero dado es una imagen válida. Use una solución a propósito tal como la extensión Fileinfo en su lugar.
Ver también
- image_type_to_mime_type() - Obtiene el tipo Mime de un tipo de imagen devuelto por getimagesize, exif_read_data, exif_thumbnail, exif_imagetype
- exif_imagetype() - Determinar el tipo de una imagen
- exif_read_data() - Lee las cabeceras EXIF desde un JPEG o un TIFF
- exif_thumbnail() - Recuperar la miniatura embebida de una imagen TIFF o JPEG
add a note
User Contributed Notes 24 notes
james dot relyea at zifiniti dot com ¶
15 years ago
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;
}
?>
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.
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...
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/
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 * $x1;
}
The new image proportionally scaled will be x2 = 800, y2 = 533 (rounded).
To do it from the y side, simply reverse the x's and y's.
utilmind ¶
13 years ago
Here is the function which determines whether the PNG image contains alpha or not:
<?php
function is_alpha_png($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
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.");
}
?>
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 ? $errors : null );
}
Steve ¶
13 years ago
The list of defined IMAGETYPE_ constants is on the manual page for exif_imagetype:
http://www.php.net/manual/en/function.exif-imagetype.php
kazuya ¶
10 years ago
i made function img_resize($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;
}
?>
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}' />");
}
}
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.
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 ) )
?>
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);
}
}
?>
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);
?>
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" '
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>
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().
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.
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);
?>
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;
?>
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.
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 =)
