imagestring()

(PHP 4, PHP 5, PHP 7)

水平地画一行字符串

说明

imagestring()用$col颜色将字符串$s画到$image所代表的图像的$x，$y坐标处（这是字符串左上角坐标，整幅图像的左上角为 0，0）。如果$font是 1，2，3，4 或 5，则使用内置字体。

imagestring()例子

参见imageloadfont()和imagettftext()。

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.

Have fun :)

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 

// 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);

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));
}

A simple example:
To make one line of text fit in the image.

I use something like this for spamprotection of my visitors (pass userid as an url-parameter for this php)

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 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

//simple hello world 

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) );

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. 

Simple script to convert a string (such as an email addresses) to a transparent image.
Usage: 
">
From a spambot's point of view, they see:

Optional parameters:
  font_size: 1 to 5, with the default at 3
  R/G/B: the font color, in hex.
Usage:
&font_size=4&R=FF&G=FF&B=00"> 

// 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  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);
}

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 );
}

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.

Here is a small bit I made for writing to a image from right to left when you are limited to imagestring() 

Its just an easy function to write an string in the middle of a picture. 

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.

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 )

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. 

If you have any problem with CentralEurope's words, for example : ľščťžýáíéúäňôď, I am try this problem by iconv() function. 

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 : 

Here's a simple function for creating an aligned string which is cutted to match the space between $x1 and $x2

Usage:

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.

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. 

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

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:

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.

this is a function that is based on imagestring but it produces text in the center of an image i hope it helps :D 

When setting the font, any integer less than 1 defaults to 1, and any integer greater than 5 defaults to 5.

Same function as above but it can display multi-line strings. 

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.

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

There is a small error in the function for horizontal and vertical centering by "jurgen dot vanoosterwijck at pandora dot be"
the line 
 $cy = (imagesy($img)/2) - (imagefontwidth($font)/2);
should be
 $cy = (imagesy($img)/2) - (imagefontheight($font)/2);

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 ?.

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