Some fun with imagestring:
This function is a product of too much time..
It opens an image and create a new image with one letter instead of a pixel.
<?php
error_reporting(E_ALL);
/**
* generates a image with chars instead of pixels
*
* @param string $url Filepath or url
* @param string $chars The chars which should replace the pixels
* @param int $shrpns Sharpness (2 = every second pixel, 1 = every pixel ... )
* @param int $size
* @param int $weight font-weight/size
* @return sesource
* @author Nicolas 'KeksNicoh' Heimann <www.salamipla.net>
* @date 02nov08
*/
function pixelfuck($url, $chars='ewk34543§G§$§$Tg34g4g', $shrpns=1, $size=4,$weight=2)
{
list($w, $h, $type) = getimagesize($url);
$resource = imagecreatefromstring(file_get_contents($url));
$img = imagecreatetruecolor($w*$size,$h*$size);
$cc = strlen($chars);
for($y=0;$y <$h;$y+=$shrpns)
for($x=0;$x <$w;$x+=$shrpns)
imagestring($img,$weight,$x*$size,$y*$size, $chars{@++$p%$cc}, imagecolorat($resource, $x, $y));
return $img;
}
$url = 'http://upload.wikimedia.org/wikipedia/commons/b/be/Manga_Icon.png';
$text = 'I-dont-like-manga-...-Why-do-they-have-such-big-eyes? Strange-...-WHAT-WANT-YOU-DO?';
Header('Content-Type: image/png');
imagepng(pixelfuck($url, $text, 1, 6));
?>
Have fun :)imagestring
(PHP 4, PHP 5, PHP 7, PHP 8)
imagestring — Draw a string horizontally
Description
Draws a string at the given coordinates.
Parameters
-
image A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
-
font Can be 1, 2, 3, 4, 5 for built-in fonts in latin2 encoding (where higher numbers corresponding to larger fonts) or GdFont instance, returned by imageloadfont().
x-
x-coordinate of the upper left corner.
y-
y-coordinate of the upper left corner.
string-
The string to be written.
color-
A color identifier created with imagecolorallocate().
Changelog
| Version | Description |
|---|---|
| 8.1.0 |
The font parameter now accepts both an GdFont instance
and an int; previously only int was accepted.
|
| 8.0.0 |
image expects a GdImage
instance now; previously, a valid gd resource was expected.
|
Examples
Example #1 imagestring() example
<?php
// Create a 100*30 image
$im = imagecreate(100, 30);
// White background and blue text
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);
// Write the string at the top left
imagestring($im, 5, 0, 0, 'Hello world!', $textcolor);
// Output the image
header('Content-type: image/png');
imagepng($im);
imagedestroy($im);
?>The above example will output something similar to:
See Also
- imagestringup() - Draw a string vertically
- imageloadfont() - Load a new font
- imagettftext() - Write text to the image using TrueType fonts
＋add a note
User Contributed Notes 30 notes
keksnicoh at googlemail dot com ¶
16 years ago
Booteille ¶
9 years ago
Here is a function with similar declaration of imagestring() but who handles whitespaces (It creates new lines and 4 spaces instead of \n and \t) and image's size limits
<?php
/**
* @author Booteille
*
* @param resource $image
* @param int $font
* @param int $x
* @param int $y
* @param string $string
* @param int $color
*/
function whitespaces_imagestring($image, $font, $x, $y, $string, $color) {
$font_height = imagefontheight($font);
$font_width = imagefontwidth($font);
$image_height = imagesy($image);
$image_width = imagesx($image);
$max_characters = (int) ($image_width - $x) / $font_width ;
$next_offset_y = $y;
for($i = 0, $exploded_string = explode("\n", $string), $i_count = count($exploded_string); $i < $i_count; $i++) {
$exploded_wrapped_string = explode("\n", wordwrap(str_replace("\t", " ", $exploded_string[$i]), $max_characters, "\n"));
$j_count = count($exploded_wrapped_string);
for($j = 0; $j < $j_count; $j++) {
imagestring($image, $font, $x, $next_offset_y, $exploded_wrapped_string[$j], $color);
$next_offset_y += $font_height;
if($next_offset_y >= $image_height - $y) {
return;
}
}
}
}
?>
jordanslost at gmail ¶
15 years ago
Here is a small bit I made for writing to a image from right to left when you are limited to imagestring()
<?php
$pageview_letters = preg_split('//', $string, -1 ); // Form are original array of letters.
$minus = 6; // The letter spacing in pixels
$first = true; // Whether or not we have started the string
$x = 375; // X Location of imagestring
$y = 23; // Y Location of imagestring
$letters = array(); // Initiate the array o letters.
foreach ( $pageview_letters as $letter ) {
$letters[] = $letter;
}
$letters = array_reverse( $letters );
foreach ( $letters as $letter ) {
if ( $first ) {
imagestring( $image, 2, $x, $y, $letter, $light_blue );
$first = false;
} else {
$x = ( $x - $minus );
imagestring( $image, 2, $x, $y, $letter, $light_blue );
}
}
?>
eviloverlord+php at gmail dot com ¶
16 years ago
Simple script to convert a string (such as an email addresses) to a transparent image.
Usage:
<img src="stringtoimg.php?string=<?= urlencode(base64_encode($email)) ?>">
From a spambot's point of view, they see:
<img src="stringtoimg.php?string=ZpbXZG92ZXJsb3JkQGdtYWlsLmNvbQ%3D%3D">
Optional parameters:
font_size: 1 to 5, with the default at 3
R/G/B: the font color, in hex.
Usage:
<img src="stringtoimg.php?string=<?= urlencode(base64_encode($email)) ?>&font_size=4&R=FF&G=FF&B=00">
<?php
/*
Filename: stringtoimg.php
Parameters:
string: the string to print
font_size (optional): the size of the font from 1-5
R/G/B (optional): the RGB colors of the font in hex
*/
header ("Content-type: image/png");
//Get string info
$font_size = isset($_GET['font_size']) ? $_GET['font_size'] : 3;
$string = urldecode(base64_decode($_GET['string']));
//Get the size of the string
$width = imagefontwidth($font_size) * strlen($string);
$height = imagefontheight($font_size);
//Create the image
$img = @imagecreatetruecolor($width, $height)
or die("Cannot Initialize new GD image stream");
//Make it transparent
imagesavealpha($img, true);
$trans_colour = imagecolorallocatealpha($img, 0, 0, 0, 127);
imagefill($img, 0, 0, $trans_colour);
//Get the text color
$text_color = isset($_GET['R'], $_GET['G'], $_GET['B']) ?
imagecolorallocate($img, hexdec($_GET['R']), hexdec($_GET['G']), hexdec($_GET['B'])) :
imagecolorallocate($img, 0, 0, 0);
//Draw the string
imagestring($img, $font_size, 0, 0, $string, $text_color);
//Output the image
imagepng($img);
imagedestroy($img);
?>
gannon (at) portablesofdoom (dot) org ¶
17 years ago
I like this better than "tjpoe at cableaz dot com"'s function for wrapping text to fit width (auto-adjusts height as needed) since it doesn't only do 1 word per line.
function make_wrapped_txt($txt, $color=000000, $space=4, $font=4, $w=300) {
if (strlen($color) != 6) $color = 000000;
$int = hexdec($color);
$h = imagefontheight($font);
$fw = imagefontwidth($font);
$txt = explode("\n", wordwrap($txt, ($w / $fw), "\n"));
$lines = count($txt);
$im = imagecreate($w, (($h * $lines) + ($lines * $space)));
$bg = imagecolorallocate($im, 255, 255, 255);
$color = imagecolorallocate($im, 0xFF & ($int >> 0x10), 0xFF & ($int >> 0x8), 0xFF & $int);
$y = 0;
foreach ($txt as $text) {
$x = (($w - ($fw * strlen($text))) / 2);
imagestring($im, $font, $x, $y, $text, $color);
$y += ($h + $space);
}
header('Content-type: image/jpeg');
die(imagejpeg($im));
}
Piotr dot Sulecki at traxelektronik dot pl ¶
18 years ago
The built-in fonts used to be in latin-2 (iso8859-2) encoding. For some time, they are in latin-1 (iso8859-1) encoding. There is no way to change the encoding at all. If you need to use any other encoding, you have to use TrueType fonts.
deejay_world at yahoo dot com ¶
22 years ago
Width ImageString, the strings you draw are not automatically wrapped width the edge of the image. You may use this function to automatically wrap them:
function ImageStringWrap($image, $font, $x, $y, $text, $color, $maxwidth)
{
$fontwidth = ImageFontWidth($font);
$fontheight = ImageFontHeight($font);
if ($maxwidth != NULL) {
$maxcharsperline = floor($maxwidth / $fontwidth);
$text = wordwrap($text, $maxcharsperline, "\n", 1);
}
$lines = explode("\n", $text);
while (list($numl, $line) = each($lines)) {
ImageString($image, $font, $x, $y, $line, $color);
$y += $fontheight;
}
}
So, in particular, if you want to wrap a text with the edge of the Image, you may do:
ImageStringWrap($img, $font, 0, $y, $text, $color, ImageSX($img) );
aly at slo-igre dot net ¶
19 years ago
There is an error in "tjpoe at cableaz dot com" 's function ImageStringWrap. Instead of
else
$string = $text;
there should be
else
$string = array($text);
for function to work for strings with only one word. Otherwise it works like a charm, thanks.
sk89q ¶
16 years ago
Creates a box of text. Has horizontal and vertical alignment, box arguments, and custom leading. I submitted this to the manual in 2003 actually, but it disappeared after a year or so (not sure why). Here it is again.
<?php
define("ALIGN_LEFT", "left");
define("ALIGN_CENTER", "center");
define("ALIGN_RIGHT", "right");
define("VALIGN_TOP", "top");
define("VALIGN_MIDDLE", "middle");
define("VALIGN_BOTTOM", "bottom");
function imagestringbox(&$image, $font, $left, $top, $right, $bottom, $align, $valign, $leading, $text, $color)
{
// Get size of box
$height = $bottom - $top;
$width = $right - $left;
// Break the text into lines, and into an array
$lines = wordwrap($text, floor($width / imagefontwidth($font)), "\n", true);
$lines = explode("\n", $lines);
// Other important numbers
$line_height = imagefontheight($font) + $leading;
$line_count = floor($height / $line_height);
$line_count = ($line_count > count($lines)) ? (count($lines)) : ($line_count);
// Loop through lines
for ($i = 0; $i < $line_count; $i++)
{
// Vertical Align
switch($valign)
{
case VALIGN_TOP: // Top
$y = $top + ($i * $line_height);
break;
case VALIGN_MIDDLE: // Middle
$y = $top + (($height - ($line_count * $line_height)) / 2) + ($i * $line_height);
break;
case VALIGN_BOTTOM: // Bottom
$y = ($top + $height) - ($line_count * $line_height) + ($i * $line_height);
break;
default:
return false;
}
// Horizontal Align
$line_width = strlen($lines[$i]) * imagefontwidth($font);
switch($align)
{
case ALIGN_LEFT: // Left
$x = $left;
break;
case ALIGN_CENTER: // Center
$x = $left + (($width - $line_width) / 2);
break;
case ALIGN_RIGHT: // Right
$x = $left + ($width - $line_width);
break;
default:
return false;
}
// Draw
imagestring($image, $font, $x, $y, $lines[$i], $color);
}
return true;
}
?>
wheberson dot com dot br at gmail dot com ¶
5 years ago
// Convert e-mail to image (png)
function convertEmailToImg ($aValue, $aRed, $aGreen, $aBlue, $aAlphaF=0, $aAlphaB=127, $aFontSize=4)
{
$img= imagecreatetruecolor (imagefontwidth ($aFontSize) * strlen ($aValue), imagefontheight ($aFontSize));
imagesavealpha ($img, true);
imagefill ($img, 0, 0, imagecolorallocatealpha ($img, 0, 0, 0, $aAlphaB));
imagestring ($img, $aFontSize, 0, 0, $aValue, imagecolorallocatealpha ($img, $aRed, $aGreen, $aBlue, $aAlphaF));
ob_start ();
imagepng ($img);
imagedestroy ($img);
return base64_encode (ob_get_clean ());
}
// Example
$imgString= convertEmailToImg ('contact@example.com', 0, 0, 255, 0, 127, 4);
jlamer ¶
17 years ago
// Example of use...
// This is a simple function to output text to an image
// which is centered (as much as I want to do by eye)
// and wrapped
// Just remember that all the sizes are guessed
// doesn't cut on the space (only on number of characters)
// or change color of text, but this isn't for that...
function imageCenterString( $imgw, $imgh,
$image_text = '', $text_size=5 )
{
$im = imagecreate( $imgw, $imgh );
// white background and blue text
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 0);
$t_h = $t_w = $t_x = $t_y = 0;
$base_w =9; $base_h = 16;
$m = 0.88;
switch ( $text_size )
{
case 1: $t_w = $base_w*pow(($m*.98),4);
$t_h = $base_h*pow(($m*.98),4);
break;
case 2: $t_w = $base_w*pow($m,3);
$t_h = $base_h*pow($m,3);
break;
case 3: $t_w = $base_w*pow($m,2);
$t_h = $base_h*pow($m,2);
break;
case 4: $t_w = $base_w*$m;
$t_h = $base_h*$m;
break;
case 5: $t_w = $base_w;
$t_h = $base_h;
break;
default:
if ( $text_size >= 5 ) // set to 5
{ $t_w = $base_w; $t_h = $base_h; }
if ( $text_size < 5 ) // set to 1
{
$t_w = $base_w*pow(($m*.98),4);
$t_h = $base_h*pow(($m*.98),4);
}
break;
}
$text_array = array();
$max = floor($imgw/$t_w);
for( $i=0; strlen($image_text) > 0; $i += $max)
{
array_push($text_array, substr($image_text,0,$max));
if ( strlen($image_text) >= $max )
{ $image_text = substr($image_text,$max); }
else
{ $image_text = ''; }
}
$t_y = ($imgh/2) - ($t_h*count($text_array)/2);
foreach ( $text_array as $text )
{
$t_x = ($imgw/2)-($t_w*strlen($text)/2);
imagestring($im, $text_size, $t_x, $t_y,
$text, $textcolor);
$t_y += $t_h;
}
// output the image
header("Content-type: image/gpeg");
imagejpeg($im);
}
cesargus at yahoo dot com ¶
20 years ago
//simple hello world
<?
header ("Content-type: image/png");
$img_handle = ImageCreate (200, 20) or die ("Cannot Create image");
$back_color = ImageColorAllocate ($img_handle, 0, 10, 10);
$txt_color = ImageColorAllocate ($img_handle, 235, 235, 51);
ImageString ($img_handle, 10, 25, 5, "Hello world!", $txt_color);
ImagePng ($img_handle);
?>
mustafa at hafunny dot info ¶
16 years ago
If you have any problem with CentralEurope's words, for example : ľščťžýáíéúäňôď, I am try this problem by iconv() function.
<?php
// create example image
$im = imagecreate(200, 20);
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);
$text = "ľščťžýáíéúäňôď...";
//simple convert string
$string = iconv("Windows-1250", "Latin2", $text);
// write converted string at the top left
imagestring($im, 4, 0, 0, $string, $textcolor);
// output the image
header("Content-type: image/png");
imagepng($im);
?>
iibm at free dot fr ¶
17 years ago
I've made a little modification of the (quite usefull) imagestringcutted function (when align=center, it doesn't work well for me if x1!=0) so juste replace the last line with :
<?php
[...]
else imagestring($img,$font,$x1+($x2-$x1)/ 2 - strlen($text) * $fontwidth / 2,$y,$text,$color);
}
?>
webmaster at acdrifter dot com ¶
19 years ago
If you are looking to center the text, use the following function; I'm not promising perfection...
function imagecenteredstring ( &$img, $font, $xMin, $xMax, $y, $str, $col ) {
$textWidth = imagefontwidth( $font ) * strlen( $str );
$xLoc = ( $xMax - $xMin - $textWidth ) / 2 + $xMin + $font;
imagestring( $img, $font, $xLoc, $y, $str, $col );
}
php dot net at mvoncken dot nl ¶
21 years ago
A simple example:
To make one line of text fit in the image.
<?php
header ("Content-type: image/png");
$string = "spam@mvoncken.nl";
$font = 4;
$width = ImageFontWidth($font) * strlen($string);
$height = ImageFontHeight($font);
$im = @imagecreate ($width,$height);
$background_color = imagecolorallocate ($im, 255, 255, 255); //white background
$text_color = imagecolorallocate ($im, 0, 0,0);//black text
imagestring ($im, $font, 0, 0, $string, $text_color);
imagepng ($im);
?>
I use something like this for spamprotection of my visitors (pass userid as an url-parameter for this php)
mike at mike-griffiths dot co dot uk ¶
15 years ago
I created an alternative using the function imagechar to create a string of an image. The below function below was used to create an image the same height and width of the text string. It is used on my website to mask users email addresses.
<?PHP
// Set your string somehow
$string = 'your@example.com';
// Set font size
$font_size = 4;
// Create image width dependant on width of the string
$width = imagefontwidth($font_size)*strlen($string);
// Set height to that of the font
$height = imagefontheight($font_size);
// Create the image pallette
$img = imagecreate($width,$height);
// Grey background
$bg = imagecolorallocate($img, 25, 25, 25);
// White font color
$color = imagecolorallocate($img, 255, 255, 255);
// Length of the string
$len = strlen($string);
// Y-coordinate of character, X changes, Y is static
$ypos = 0;
// Loop through the string
for($i=0;$i<$len;$i++){
// Position of the character horizontally
$xpos = $i * imagefontwidth($font_size);
// Draw character
imagechar($img, $font_size, $xpos, $ypos, $string, $color);
// Remove character from string
$string = substr($string, 1);
}
// Return the image
header("Content-Type: image/gif");
imagegif($img);
// Remove image
imagedestroy($img);
?>
Epidemiah ¶
16 years ago
Its just an easy function to write an string in the middle of a picture.
<?php
function imageCenterString(&$img, $font, $text, $color)
{
if($font < 0 || $font > 5){ $font = 0; }
$num = array(array(4.6, 6),
array(4.6, 6),
array(5.6, 12),
array(6.5, 12),
array(7.6, 16),
array(8.5, 16));
$width = ceil(strlen($text) * $num[$font][0]);
$x = imagesx($img) - $width - 8;
$y = Imagesy($img) - ($num[$font][1] + 2);
imagestring($img, $font, $x/2, $y/2, $text, $color);
}
?>
god at in-heaven dot org ¶
18 years ago
Here's a simple function for creating an aligned string which is cutted to match the space between $x1 and $x2
<?php
function imagestringcutted($img,$font,$y,$x1,$x2,$text,$color,$align="center") {
$fontwidth = imagefontwidth($font);
$fullwidth = strlen($text) * $fontwidth;
$maxwidth = $x2-$x1;
$targetwidth = $fullwidth-(4*$fontwidth);
if($fullwidth > $maxwidth) {
for($i = 0; $i < strlen($text) AND ((strlen($text)-($i-4))*$fontwidth) > $targetwidth ;$i++) { }
$text = substr($text,0,(strlen($text)-$i)-4)."...";
}
if($align == "left") imagestring($img,$font,$x1,$y,$text,$color);
elseif($align == "right") imagestring($img,$font,$x2 - ((strlen($text) * $fontwidth)),$y,$text,$color);
else imagestring($img,$font,($x2-$x1)/ 2 - strlen($text) * $fontwidth / 2,$y,$text,$color);
}
?>
Usage:
<?php
imagestringcutted($img,$font,$y,$x1,$x2,$text,$color,$align);
?>
Will create a string $text, which is cutted if it's too long to match between $x1 and $2, on $img with font $font and color $color at height $y and with align to $align.
Hope it will help some people.
Sorry for my bad English.
shadikka at gmail dot com ¶
19 years ago
My version of the centered string, it decreases the font number (since I've noticed smaller numbers are smaller fonts) until 1 if the string won't fit. Then it will give up.
<?php
function imagestringcentered ($img,$font,$cy,$text,$color) {
while (strlen($text) * imagefontwidth($font) > imagesx($img)) {
if ($font > 1) { $font--; }
else { break; }
}
imagestring($img,$font,imagesx($img) / 2 - strlen($text) * imagefontwidth($font) / 2,$cy,$text,$color);
}
?>
bob dot brown at opus dot co dot nz ¶
22 years ago
If you find that you are getting two characters on the end of your imageString that look like a Y and an upside down L then they're probably representations of CR/LF. Try trim()ing the string before outputting it. (I was sooo sure this was a bug <g>)
Abubaker dot shamlan at gmail dot com ¶
16 years ago
this is a function that is based on imagestring but it produces text in the center of an image i hope it helps :D
<?php
function ImageStringCenter($image_resource, $font_size, $line_number, $total_lines, $text, $color ) {
$center_x = ceil( ( imagesx($image_resource) - ( ImageFontWidth($font_size) * strlen($text) ) ) / 2 );
$center_y = ceil( ( ( imagesy($image_resource) - ( ImageFontHeight($font_size) * $total_lines ) ) / 2) + ( ($line_number-1) * ImageFontHeight($font_size) ) );
ImageString($image_resource, $font_size, $center_x, $center_y, $text, $color );
}
?>
tjpoe at cableaz dot com ¶
19 years ago
i modified the centering functions and created this which centers each word on it's own line. You can adjust the spacing with the $valign var. currently no implimentation if text is too large for image. strings are tokenized by space, but can obviously be changed.
function ImageStringWrap($image, $font, $text, $color)
{
$fontwidth = ImageFontWidth($font);
$fontheight = ImageFontHeight($font);
$words= str_word_count($text);
if ($words > 1){
$string=array(strtok($text,' '));
for ($i = 1 ; $i <= $words ; $i++){
$string=array_merge($string,array($i=>strtok(' ')));
}
}
else
$string=$text;
$vspace=4;
$y=((imagesy($image)-($fontheight*$words)-($words*$vspace))/2);
foreach($string as $st){
$x=((imagesx($image)-($fontwidth * strlen($st)))/2);
ImageString($image,$font,$x,$y,$st,$color);
$y+=($fontheight+$vspace);
}
}
hope this is helpful
brooks dot boyd at gmail dot com ¶
20 years ago
Drawing a string as an image is a handy way to disguise an eMail address so spam sniffers can't get it as easily. The only catch to creating a dynamic image with your eMail in it is the eMail to be displayed must be passed via the query string to enable static HTML to use it. So, the eMail must be encrypted slightly in order to not defeat the purpose of not typing your eMail address outright. I wrote the following script to do so:
Save the following as email.php
<?php
if ($_GET['addr'] != "") {
$msg = $_GET['addr'];
$msg = preg_replace("/\[dot]/",".",$msg);
$msg = preg_replace("/\[at]/","@",$msg);
$final = "";
for ($i=0; $i<=strlen($msg); $i++) {
$final .= substr($msg, strlen($msg)-$i, 1);
}
$msg = $final;
$char_width = 8;
$char_height = 17;
$padding = 3;
$width = $padding*2+strlen($msg)*$char_width;
$height = +$padding*2+$char_height;
$im = imagecreatetruecolor($width,$height);
imagealphablending($im, FALSE);
imagesavealpha($im, TRUE);
$bg = imagecolorallocatealpha($im, 255, 255, 0, 100);
$text = imagecolorallocatealpha($im, 0, 0, 0, 0);
imagefilledrectangle ($im, 0, 0, $width, $height, $bg); # Make transparent
imagestring($im, 4, $padding, $padding, $msg, $text);
} else {
$im = imagecreatetruecolor(1,1);
imagealphablending($im, FALSE);
imagesavealpha($im, TRUE);
$bg = imagecolorallocatealpha($im, 255, 0, 0, 125);
imagefilledrectangle ($im, 0, 0, 1, 1, $bg); # Make transparent
}
header('Content-type: image/jpg');
imagepng($im);
imagedestroy($im);
?>
If the script is called without an eMail address, it outputs a 2x2 transparent image.
To call the script to generate the eMail "user@home.com", the HTML tag would be:
<img src="email.php?addr=moc[dot]emoh[at]resu">
To 'encrypt' the eMail address to pass to the script, write the address backwards and replace "." with "[dot]" and "@" with "[at]". It's not the most ironclad protection, but it thwarts most casual eMail sniffers.
aholmes84 at hotmail dot com ¶
22 years ago
When setting the font, any integer less than 1 defaults to 1, and any integer greater than 5 defaults to 5.
rush at 507magazine dot com ¶
18 years ago
hello, I noticed that if you put a rand(3,5) it will put random sizes of font to each character put on the image. this is very useful when programming captchas for anti-spam form verification.
julien / at / theoconcept.com ¶
18 years ago
If you are looking for a way to generate a "CAPTCHA" image for a form verification (to verify it is not a robot), have a look at this : http://blog.theoconcept.com/static/distortion/
It gives an animated image with the parameter string, with distortion, here is an example :
http://blog.theoconcept.com/static/distortion/distortion.php
(*) You'll need GD + Freetype support
(**) You'll need ImageMagick on the machine
jurgen dot vanoosterwijck at pandora dot be ¶
19 years ago
Based on the previous example, here's how to center a string both horizontally and vertically...
<?php
function imagestringcentered ($img,$font,$text,$color) {
while (strlen($text) * imagefontwidth($font) > imagesx($img)) {
if ($font > 1) { $font--; }
else { break; }
}
$cy = (imagesy($img)/2) - (imagefontwidth($font)/2);
imagestring($img,$font,imagesx($img) / 2 - strlen($text) * imagefontwidth($font) / 2,$cy,$text,$color);
}
?>
eric dot brison at anakeen dot com ¶
15 years ago
Same function as above but it can display multi-line strings.
<?php
function sendimagetext($text) {
// Set font size
$font_size = 4;
$ts=explode("\n",$text);
$width=0;
foreach ($ts as $k=>$string) { //compute width
$width=max($width,strlen($string));
}
// Create image width dependant on width of the string
$width = imagefontwidth($font_size)*$width;
// Set height to that of the font
$height = imagefontheight($font_size)*count($ts);
$el=imagefontheight($font_size);
$em=imagefontwidth($font_size);
// Create the image pallette
$img = imagecreatetruecolor($width,$height);
// Dark red background
$bg = imagecolorallocate($img, 0xAA, 0x00, 0x00);
imagefilledrectangle($img, 0, 0,$width ,$height , $bg);
// White font color
$color = imagecolorallocate($img, 255, 255, 255);
foreach ($ts as $k=>$string) {
// Length of the string
$len = strlen($string);
// Y-coordinate of character, X changes, Y is static
$ypos = 0;
// Loop through the string
for($i=0;$i<$len;$i++){
// Position of the character horizontally
$xpos = $i * $em;
$ypos = $k * $el;
// Draw character
imagechar($img, $font_size, $xpos, $ypos, $string, $color);
// Remove character from string
$string = substr($string, 1);
}
}
// Return the image
header("Content-Type: image/png");
imagepng($img);
// Remove image
imagedestroy($img);
}
?>
bpgordon at gmail dot com ¶
19 years ago
This code produces a png image of the text within the query. It autofits to the length of the string.
Usage: http://yoursite.com/text.php?abcdefg+hijk
Use + to produce a space in the image. The + can be excaped with a carat (^). Most other symbols work fine in the query string, like the ?.
<?php
header ("Content-type: image/png");
$string = $_ENV["QUERY_STRING"];
$md5 = md5($string); //just so we don't convert valid text into a +
$string = str_replace("^+", $md5, $string); //replaces ^+ with long, unnatural string
$string = str_replace("+", " ", $string); //replaces + with space
$string = str_replace($md5, "+", $string); //replaces the long, unnatural string with +
$width = imagefontwidth($font) * strlen($string);
$height = imagefontheight($font);
$image = @imagecreate($width+2, $height+2);
$black = imagecolorallocate($image, 0, 0, 0); //background
$white = imagecolorallocate($image, 255, 255, 255);
imagestring($image, 2, 1, 1, $string, $white);
imagepng($image);
imagedestroy($image);
?>