imagecreate

JamesM (2010-03-26 00:03:11)

doesnt ruin the image but adds display to the output.
this will generate an image with a random color. if you like it you can use it because you have the RBG result too.
<?php
header("content-type:image/png");
$im = imagecreate(100, 100);
$a = sprintf('%04x',mt_rand(0, 65535));
$b = sprintf('%04x',mt_rand(0, 65535));
$c = sprintf('%04x',mt_rand(0, 65535));
$white = imagecolorallocate($im,$a,$b,$c);
imagepng($im);
imagedestroy($im);
echo "\n\n\n$a-$b-$c";
?>

dan at wow dot com (2009-09-23 10:29:31)

if you want to create an image with a specific DPI, you can't control this directly from GD. 

If you have access to gd.h (rarely on a shared hosting) you can modify GD_RESOLUTION and give it your desired value.

The solution that I found was directly manipulating the jpeg header bytes. 
I hope this sample code would helps someone because it took me 5 hours of digging to figure out i have no other options.

<?php
header('Content-Disposition: attachment; filename="myimg.jpg"');
header('Cache-Control: private');
$dst    = imagecreatetruecolor(300, 300); /*this creates a 300x300 pixels image*/
ob_start(); /*don't send the output to the browser since we'll need to manipulate it*/
ImageJpeg($dst);
$img = ob_get_contents();
ob_end_clean();

//byte #14 in jpeg sets the resolution type: 0=none, 1=pixels per inch, 2=pixels per cm
//bytes 15-16 sets X resolution
//bytes 17-18 sets Y resolution
$img = substr_replace($img, pack('cnn',1,300,300),13,5);

echo $img;

?>

gpanz.blogspot.com (2008-12-12 07:02:50)

function ImageCreateFromBMP($filename)
16 bit images do not have a palette...
use this :
$PALETTE = array();
if ($BMP['colors'] < 16777216 && $BMP['colors'] != 65536)
{
$PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4));
#nei file a 16bit manca la palette,
}
another fix:
elseif ($BMP['bits_per_pixel'] == 16)
{
$COLOR = unpack("v",substr($IMG,$P,2));
$blue = (($COLOR[1] & 0x001f) << 3) + 7;
$green = (($COLOR[1] & 0x03e0) >> 2) + 7;
$red = (($COLOR[1] & 0xfc00) >> 7) + 7;
$COLOR[1] = $red * 65536 + $green * 256 + $blue;
}

sk89q (2008-03-14 14:14:44)

Loads a file based on its filetype and returns false if it fails.

<?php
function imagecreatefromfile($path, $user_functions = false)
{
    $info = @getimagesize($path);
    
    if(!$info)
    {
        return false;
    }
    
    $functions = array(
        IMAGETYPE_GIF => 'imagecreatefromgif',
        IMAGETYPE_JPEG => 'imagecreatefromjpeg',
        IMAGETYPE_PNG => 'imagecreatefrompng',
        IMAGETYPE_WBMP => 'imagecreatefromwbmp',
        IMAGETYPE_XBM => 'imagecreatefromwxbm',
        );
    
    if($user_functions)
    {
        $functions[IMAGETYPE_BMP] = 'imagecreatefrombmp';
    }
    
    if(!$functions[$info[2]])
    {
        return false;
    }
    
    if(!function_exists($functions[$info[2]]))
    {
        return false;
    }
    
    return $functions[$info[2]]($path);
}
?>

domelca at terra dot es (2008-03-05 17:04:10)

function ImageCreateFromBMP($filename)
don't work with bmp 16 bits_per_pixel
change pixel generator for this
elseif ($BMP['bits_per_pixel'] == 16)
{
$COLOR = unpack("v",substr($IMG,$P,2));
$blue = ($COLOR[1] & 0x001f) << 3;
$green = ($COLOR[1] & 0x07e0) >> 3;
$red = ($COLOR[1] & 0xf800) >> 8;
$COLOR[1] = $red * 65536 + $green * 256 + $blue;
}

scottlindh pwnd at hushmail dot com (2007-08-19 10:40:42)

to install on UBUNTU do the following..
sudo apt-get install php5-gd
After installing the package I restarted the apache
sudo /etc/init.d/apache reload
goto love ubuntu...

Sohel Taslim (2007-07-25 00:22:13)

It is easy and simple example to convert Text to Image with selected font. 
It helps me to display Bangla text as image when users have no installed bangla font.

I hope it can help you too!

<?php
//Kip the font file together or write proper location.
makeImageF("Life in PHP.","CENTURY.TTF");

function makeImageF($text, $font="CENTURY.TTF", $W=200, $H=20, $X=0, $Y=0, $fsize=18, $color=array(0x0,0x0,0x0), $bgcolor=array(0xFF,0xFF,0xFF)){
        
    $im = @imagecreate($W, $H)
        or die("Cannot Initialize new GD image stream");
        
    $background_color = imagecolorallocate($im, $bgcolor[0], $bgcolor[1], $bgcolor[2]);        //RGB color background.
    $text_color = imagecolorallocate($im, $color[0], $color[1], $color[2]);            //RGB color text.
            
    imagettftext($im, $fsize, $X, $Y, $fsize, $text_color, $font, $text);
    
    header("Content-type: image/gif");                
    return imagegif($im);
}

?>

Pawka (2007-04-14 13:31:13)

To make the gd library available for Apache2/mod_php on Fedora Linux the following commands are required:
1) yum install php-gd
2) /etc/init.d/httpd restart

php dot net at kingsquare dot nl (2007-01-07 15:02:28)

To create an image from a PSD file, you can use imagecreatefrompsd(). It is available for download here: http://www.kingsquare.nl/phppsdreader/ . It returns a resource like the other ImageCreateFrom - functions

tc_ at anti dot gmx dot ch dot spam (2006-09-19 04:50:42)

Small piece of code to display a preview of a file in an image (usefull for thumbnail view of a folder etc.)

<?php
$file = "test.txt"; //FILEADDRESS
$size = "100"; //IMAGE SIZE
$data = file($file);
$im = @ imagecreate($size, $size) or die();
$bc = imagecolorallocate($im, 255, 255, 255);
$tc = imagecolorallocate($im, 0, 0, 0);
$lines = (int) $size / 10;
for ($t = 0; $t < $lines; $t++)
{
    imagestring($im, 3, 4, 4, $data[$t], $tc);
    imagestring($im, 3, 4, 4 + ($t * 10), $data[$t], $tc);
}
header("Content-type: image/png");
imagepng($im);
imagedestroy($im);
?>

Maybe it will be usefull for somebody.

Ortreum (2006-09-07 04:45:33)

Use image as javascript test

There are two files - an image and an executive file. The image is loaded if the JavaScript is enabled. After (!) the page is loaded $_SESSION['js'] + 0 is 0 or 1.

the image (js.img.php):
<?php
session_start();
$_SESSION['js'] = 1;
header('Content-type: image/gif');
imagegif($im = imagecreate(1, 1));
imagedestroy($im);
?>

the html file (file.php):
<html>
<head>
<!--
<script type="text/javascript">
    var img = new Image();
    img.src = "js.img.php";
</script>
-->
</head>
<body>
<?php
if ($_SESSION['js'] . '' == '') echo 'Not checked for JavaScript.';
else if ($_SESSION['js'] + 0 == 0) echo 'JavaScript is disabled.';
if ($_SESSION['js'] + 1 == 1) echo 'JavaScript is enabled.';
?>
</body>
</html>

There are much more hidden actions that you can do by "pictures".

help at nanomc dot com (2005-11-08 11:29:37)

// A simple XY graph 

<html>
<head>
        
 <title>XY Graph</title>

<h2>Practice XY Graph</h2>
</head>
<body>

<?php 
$left = 0;
$top = 0;
$x_size = 400;
$y_size = 400;

$char_width = 8;
$char_height = 11;

$x_start = $x_left + 100;
$y_start = $top + $char_height * 1.5;
$x_end = $x_start + $x_size;
$y_end = $y_start + $y_size;
$right = $x_start + $x_size + 40;
$bottom = $y_start + $y_size + $char_height * 1.5;

$graph_n = 100;
for($i = 0; $i < $graph_n; $i++ )
    {
    $graph_x[$i] = $i;
    $graph_y[$i] = $i * $i;
    }

    $min_x = 9e99;
    $min_y = 9e99;
    $max_x = -9e99;
    $max_y = -9e99;

    $avg_y = 0.0;
    
    for($i = 0; $i < $graph_n; $i++ )
        {
        if( $graph_x[$i] < $min_x )
            $min_x = $graph_x[$i];

        if( $graph_x[$i] > $max_x )
            $max_x = $graph_x[$i];

        if( $graph_y[$i] < $min_y )
            $min_y = $graph_y[$i];

        if( $graph_y[$i] > $max_y )
            $max_y = $graph_y[$i];

        $avg_y += $graph_y[$i];
        }
    
    $avg_y = $avg_y / $graph_n;

    $min_x = 0;
    $min_y = 0;
    $max_x += $max_x * 0.05;
    $max_y += $max_y * 0.05;

$image = ImageCreate($right - $left, $bottom - $top);
$background_color = imagecolorallocate($image, 255, 255, 255);
$text_color = imagecolorallocate($image, 233, 14, 91);

$grey = ImageColorAllocate($image, 204, 204, 204); 
$white = imagecolorallocate($image, 255, 255, 255);
$black = imagecolorallocate($image, 0, 0, 0);
$red = imagecolorallocate($image, 255, 0, 0);

imagerectangle($image, $left, $top, $right - 1, $bottom - 1, $black );
imagerectangle($image, $x_start, $y_start, $x_end, $y_end, $grey );

for($i = 0; $i < $graph_n; $i++ )
   {
   $pt_x = $x_start + ($x_end-$x_start)*($graph_x[$i]-$min_x)/($max_x-$min_x);
   $pt_y = $y_end - ($y_end - $y_start)*($graph_y[$i]-$min_y)/($max_y-$min_y);

 //  imagesetpixel( $image, $pt_x, $pt_y, $black );
   imagechar($image, 2, $pt_x - 3, $pt_y - 10, '.', $black);
   }

$string = sprintf("%2.5f", $max_y);
imagestring($image, 4, $x_start - strlen($string) * $char_width, $y_start - $char_width, $string, $black);

$string = sprintf("%2.5f", $min_y);
imagestring($image, 4, $x_start - strlen($string) * $char_width, $y_end - $char_height, $string, $black);

$string = sprintf("%2.5f", $min_x);
imagestring($image, 4, $x_start - (strlen($string) * $char_width)/2, $y_end, $string, $black);
    
$string = sprintf("%2.5f", $max_x);
imagestring($image, 4, $x_end - (strlen($string) * $char_width) / 2, $y_end, $string, $black);

$x_title = 'x axis';
$y_title = 'y axis';

imagestring($image, 4, $x_start + ($x_end - $x_start) / 2 - strlen($x_title) * $char_width / 2, $y_end, $x_title, $black);

imagestring($image, 4, $char_width, ($y_end - $y_start) / 2, $y_title, $black);

header('Content-type: image/png');
$filename = sprintf("%d.png", time());
ImagePNG($image,$filename);
ImageDestroy($image);

printf("<img src='%s'> ", $filename);
?> 

</body>
</html>

DHKold (2005-06-15 14:52:37)

to create an image from a BMP file, I made this function, that return a resource like the others ImageCreateFrom function:

<?php
/*********************************************/
/* Fonction: ImageCreateFromBMP              */
/* Author:   DHKold                          */
/* Contact:  admin@dhkold.com                */
/* Date:     The 15th of June 2005           */
/* Version:  2.0B                            */
/*********************************************/

function ImageCreateFromBMP($filename)
{
 //Ouverture du fichier en mode binaire
   if (! $f1 = fopen($filename,"rb")) return FALSE;

 //1 : Chargement des ent?tes FICHIER
   $FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1,14));
   if ($FILE['file_type'] != 19778) return FALSE;

 //2 : Chargement des ent?tes BMP
   $BMP = unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'.
                 '/Vcompression/Vsize_bitmap/Vhoriz_resolution'.
                 '/Vvert_resolution/Vcolors_used/Vcolors_important', fread($f1,40));
   $BMP['colors'] = pow(2,$BMP['bits_per_pixel']);
   if ($BMP['size_bitmap'] == 0) $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];
   $BMP['bytes_per_pixel'] = $BMP['bits_per_pixel']/8;
   $BMP['bytes_per_pixel2'] = ceil($BMP['bytes_per_pixel']);
   $BMP['decal'] = ($BMP['width']*$BMP['bytes_per_pixel']/4);
   $BMP['decal'] -= floor($BMP['width']*$BMP['bytes_per_pixel']/4);
   $BMP['decal'] = 4-(4*$BMP['decal']);
   if ($BMP['decal'] == 4) $BMP['decal'] = 0;

 //3 : Chargement des couleurs de la palette
   $PALETTE = array();
   if ($BMP['colors'] < 16777216)
   {
    $PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4));
   }

 //4 : Cr?ation de l'image
   $IMG = fread($f1,$BMP['size_bitmap']);
   $VIDE = chr(0);

   $res = imagecreatetruecolor($BMP['width'],$BMP['height']);
   $P = 0;
   $Y = $BMP['height']-1;
   while ($Y >= 0)
   {
    $X=0;
    while ($X < $BMP['width'])
    {
     if ($BMP['bits_per_pixel'] == 24)
        $COLOR = unpack("V",substr($IMG,$P,3).$VIDE);
     elseif ($BMP['bits_per_pixel'] == 16)
     {  
        $COLOR = unpack("n",substr($IMG,$P,2));
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     elseif ($BMP['bits_per_pixel'] == 8)
     {  
        $COLOR = unpack("n",$VIDE.substr($IMG,$P,1));
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     elseif ($BMP['bits_per_pixel'] == 4)
     {
        $COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
        if (($P*2)%2 == 0) $COLOR[1] = ($COLOR[1] >> 4) ; else $COLOR[1] = ($COLOR[1] & 0x0F);
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     elseif ($BMP['bits_per_pixel'] == 1)
     {
        $COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
        if     (($P*8)%8 == 0) $COLOR[1] =  $COLOR[1]        >>7;
        elseif (($P*8)%8 == 1) $COLOR[1] = ($COLOR[1] & 0x40)>>6;
        elseif (($P*8)%8 == 2) $COLOR[1] = ($COLOR[1] & 0x20)>>5;
        elseif (($P*8)%8 == 3) $COLOR[1] = ($COLOR[1] & 0x10)>>4;
        elseif (($P*8)%8 == 4) $COLOR[1] = ($COLOR[1] & 0x8)>>3;
        elseif (($P*8)%8 == 5) $COLOR[1] = ($COLOR[1] & 0x4)>>2;
        elseif (($P*8)%8 == 6) $COLOR[1] = ($COLOR[1] & 0x2)>>1;
        elseif (($P*8)%8 == 7) $COLOR[1] = ($COLOR[1] & 0x1);
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     else
        return FALSE;
     imagesetpixel($res,$X,$Y,$COLOR[1]);
     $X++;
     $P += $BMP['bytes_per_pixel'];
    }
    $Y--;
    $P+=$BMP['decal'];
   }

 //Fermeture du fichier
   fclose($f1);

 return $res;
}
?>

(2005-01-05 13:30:35)

This is how you can create a thumbnail with maximum height and width. This way it will fit nicely in a gallery table. In this example $im is the source image
<?
    //calculate thumb size
            $ow = imagesx($im);
            $oh = imagesy($im);
            $maxh = 100;
            $maxw = 150; 
            $new_h = $oh;
            $new_w = $ow;

            if($oh > $maxh || $ow > $maxw){
               $new_h = ($oh > $ow) ? $maxh : $oh*($maxw/$ow);
               $new_w = $new_h/$oh*$ow;
            }

            //create dst image
            $dst_img = ImageCreateTrueColor($new_w,$new_h);
            //resize and copy image
            ImageCopyResized($dst_img, $im, 0,0,0,0, $new_w, $new_h, ImageSX($im), ImageSY($im));    
            $function_image_new($dst_img,$galdir.$file);
?>

info at henrici dot biz (2004-08-13 10:27:35)

To make the gd library available for Apache2/mod_php on Gentoo the following steps are required (and sufficient):
1) Add a USE flag for gd in "/etc/make.conf":
USE="<other use flags> gd"
A list of all of the USE flags can be found at: http://www.gentoo.org/dyn/use-index.xml
2) Re-emerge mod_php by executing "emerge mod_php"
3) Restart apache2 by executing "/etc/init.d/apache2 restart"
You need not uncomment the "extension=php_gd2.dll" line in "php.ini" as mentioned in a previous posting (since that line is only relevant for Windows).

cstevens at gencom dot us (2004-04-20 16:56:48)

Here's how I resolved the "Fatal error: Call to undefined function: imagecreate()" error using Gentoo:
1) add a USE flag for gdb in /etc/make.conf

USE="3dnow avi [whatever else you have] gdb"
Note: here's a list of all of the USE flags:
http://www.gentoo.org/dyn/use-index.xml
2) unmerged mod_php
*Note* It could take awhile to "remerge" as it may need to compile several dependancies...do this during not production hours and have a backup if you absolutely cannot have downtime
emerge -C mod_php
3) emerged mod_php
emerge -p mod_php
# find out if it's going to take awhile
4) edit /etc/php/apach2-php4/php.ini
uncomment the "extension=php_gd2.dll" line
5) Restart apache2
/etc/init.d/apache2 restart
Hope this helps!
--
Cooper Stevenson
GenCom
http://www.gencom.us

foxlovr1 at cox dot net (2004-04-12 16:11:56)

You can set it up so you can write a text which is controled from the URL.

Like this...

<?php
header("Content-type: image/png");
$im = @imagecreate(128, 16) or die("Cannot Initialize new GD image stream");
$bc = imagecolorallocate($im, 0, 255, 255);
$tc = imagecolorallocate($im, 0, 0, 0);
imagestring($im, 1, 4, 4,  $t, $tc);
imagepng($im);
imagedestroy($im);
?>

Then when you use the image, use this...

<img src="http://www.yourdomain.com/stuff/cool_image.php?t=Text">

This will create an image with a cyan background, and in black text it will say "Text"

EMail me at foxlovr1@cox.net or aquafox90@yahoo.com for comments/questions.

sjnorrie at hotmail dot com (2003-12-03 11:07:21)

On windows.
When you get undefined function image* it means the gd library isnt being used. Check the php.ini file. Make sure the php_gd.dll isnt commented out. Restarting apache should result in the image functions working.

tassader at xmail dot cz (2003-10-21 08:55:49)

It seems that imagecreate creates a grayscale image with gd2

tore at kyberheimen dot com (2002-08-29 14:33:37)

GD UPGRADE PROBLEM:
I used imagecreate with gd 1.6 to make resized images of big photos. Then, when using the same script on gd 2.0, the colors got all wrong.
Using imagecreatetruecolor() fixed the problem!

php at silisoftware dot com (2002-05-17 10:17:09)

Don't try and create an image with a really large width and/or height. First, $width x $height is (at least) the bytes of memory that need to be allocated. Secondly, if you exceed the range of int for either parameter, Apache crashes (before allocating any memory).
Don't ask how I figured this out ;)

robert at scpallas dot de (2002-02-08 08:09:08)

The function ImageCreate() creates a PALETTE image.
The function ImageCreateFromJPEG() creates a TRUE COLOR image.
When you use GD 2.0 you will get an error when you try to use ImageCopy()
with one True color image and one Palette image.
Be sure to convert one of the images before using ImageCopy() or use ImageCreateTrueColor() instead of ImageCreate().

andrus at vnet dot ee (2001-07-08 09:09:33)

Dont forget to use ImageDestoy after showed image. I forgot it, my webpage had about 15 pictures what was generated by GD and webserver died very fastly (server was Dual Xeon 900MHz and 4G RAM :[[ ). It died cos of not enough memory :\

wouter at rusman dot net (2001-07-06 05:31:04)

to compile GD support on some linux distributions you have to include these with the ./configure command :
--with=gd=/usr --with-jpeg=/usr --with-png=/usr --with-zlib=/usr
(i had to include this on Redhat 6.1)
this becase the libraries are in /usr/lib instead of /lib

altype at bellsouth dot net (2001-04-19 16:13:36)

ImagePNG($pic,"./dir/pic.png");
To save image as a file, I had to create a directory "dir" and CHMOD 777 to give read, write, and execute permission for everyone - or it wouldn't save it...

removethisbeforebayet at removethistooenseirb dot fr (2001-02-08 15:00:37)

Pay attention to a problem I encountered.
Png images created with the PHP function seems to be very badly recognised by old browsers, especially -well, mainly - by IE 4.0 (crash of the browser).
I think this is probably due to the fact that, when IE 4.0 was released, the png format was either very recent, either not very used, because of the widespread jpeg and gif formats...
So, if you plan to dynamically create images for a web site to be seen by IE 4.0 users, think of it...
May'be the jpeg format will do the job better.

kim at kimmccall dot org (2000-12-14 04:22:03)

How I fixed my "undefined function imagecreate()" problem:
I was having the same problem many have reported where most of PHP worked but the gd functions didn't. I'd installed the RedHat rpm php-4.0.1pl2. It said (phpinfo.php) that it had been configured with the '--with-gd=shared' option. In my /usr/lib directory, I had both libgd.so.1.8.3 and libgd.a. I decided to compile with the static library instead, so I downloaded the sources and built with all the same configuration flags except that I used --with-gd=/usr. Now my gd library works!!!

phantom at t-p-l dot com (2000-02-18 23:11:21)

after some experimenting I've come to the following concusions:
1) if you don't have GD when compiling PHP you have to recompile PHP to enable GD support..
2) imagepng() works the same way as imagegif() just creates png's ..
3) the first color you imagecolormatch becomes the background.. hmm..
hope this helps anyone =)

scott at mha dot ca (2000-02-09 23:49:30)

okay .. listen .. if you are getting fatal errors attempting to use ImageCreate() then you most probably do not have GD installed .. Likewise, if you are getting fatal errors attempting to use ImageGIF() then you are most probably using a version of GD which does not support the GIF format. Notice that in both of these examples that the problem has nothing to do with PHP or whether or not PHP "supports" any particular function. You must have the GD image library installed to make images work. It is as simple as that. Furthermore, although current versions of GD do NOT support the GIF format, I know that old versions of GD (ie. version 1.3) do support the GIF format but they are probably illegal to use now because of the fuss that unisys has been making about it.