Simplify and generate PHP captcha code

based on this comment

the result you wanted is similar to the Google captcha text but more than that is to be able to integrate the array into the captcha system use the color array and the captcha font array as an optional note to be able to use a custom text in the captcha image through a file.txt

• To create an image using one arrayfor colors, another arrayfor fonts, and get a word from a file .txt, you can do the following:

  captcha.php file

  <?php
  session_start();
  
  $source = file('palabras.txt'); // Archivo con palabras
  $word = trim($source[rand(0, count($source) - 1)]); // Obtenemos una palabra
  $charsLength = strlen($word); // Cantidad de letras de la palabra
  $marginLeftRight = 10; // Margen izq derecho
  $marginTopBottom = 10; // Margen sup inf
  $fonts = array( // Arreglo de fuentes
      array('spacing' =>   -3, 'minSize' => 27, 'maxSize' => 30, 'font' => 'fonts/Quixley.ttf'),
      array('spacing' => -1.5, 'minSize' => 28, 'maxSize' => 31, 'font' => 'fonts/AntykwaBold.ttf'),
      array('spacing' =>   -2, 'minSize' => 24, 'maxSize' => 30, 'font' => 'fonts/Ding-DongDaddyO.ttf'),
      array('spacing' =>   -2, 'minSize' => 28, 'maxSize' => 30, 'font' => 'fonts/Duality.ttf')
  );
  
  $rgbs = array( // Arreglo de colores
    array(17,70,121),
    array(12,133,25),
    array(114,26,7),
    array(38,44,10),
    array(16,113,52),
    array(123,29,26)
  );
  
  // Generamos la palabra
  $_SESSION['captcha_secure'] = '';
  $chars = array();
  $imageWidth = 0;
  $imageHeight = 0;
  for ($i = 0; $i < $charsLength; $i++) {
  
      //
      $font = $fonts[mt_rand(0, count($fonts) - 1)];
      $char = array(
          'char'     => $word[$i],
          'font'     => $font['font'],
          'spacing'  => $font['spacing'],
          'size'     => rand($font['minSize'], $font['maxSize']),
          'angle'    => rand(-20, 20)
      );
      $coords = imagettfbbox ($char['size'], $char['angle'], $char['font'] , $char['char']);
      $imageWidth += ($coords[2] - $char['spacing']); // Sumamos el ancho del char actual
      $imageHeight = max($imageHeight, $char['size']);
  
      $_SESSION['captcha_secure'] .= $char['char']; // Concatenamos el char
      $chars[] = $char; // Guardamos la config del char
  }
  $imageWidth += $marginLeftRight * 2; // Sumamos el margen configurado
  $imageHeight += $marginTopBottom * 2; // Sumamos el margen configurado
  
  // Creamos la imagen
  $image = imagecreatetruecolor($imageWidth, $imageHeight); //Ancho y alto de la imagen
  
  // Fondo
  $white = imagecolorallocate($image, 255, 255, 255); // Color de fondo de la imagen
  imagecolortransparent($image, $white); // Transpartente
  imagefill($image, 0, 0, $white);
  
  // Color palabra
  list($r, $g, $b) = $rgbs[mt_rand(0, count($rgbs) - 1)];
  $wordColor = imagecolorallocate($image, $r, $g, $b);
  
  // Palabra
  $x = $marginLeftRight;
  $y = ($imageHeight / 2) + $marginTopBottom;
  foreach ($chars as $char) {
  
      // Color del char
      $coords = imagettftext($image, $char['size'], $char['angle'], $x, $y, $wordColor, $char['font'], $char['char']);
  
      $x += $coords[2] - $x - $char['spacing'];
  }
  
  header("content-type:image/png");
  imagepng($image);
  

  Words.txt file ( no blank lines )

   globo
   chapuza
   varar
   poisa
   follar
   gozar
   cochina
   barbado
  

  index.php file

  <div style="background: #ccc; display: inline-block;">
     <img src="captcha.php" />
  </div>
  

  Results:

  

• To make a Google -like image

  I recommend that you read inquire about the bookstore Imagen Magick. This article can give you a couple of ideas.

  Here's one snippetas an example:

  <?php
  
  /* Creamos un objeto Imagick */
  $image = new Imagick();
  
  /* Creamos un objeto ImagickPixel para el fondo */
  $bg = new ImagickPixel();
  $bg->setColor('white'); // Blanco
  
  /* Creamos un ImagickDraw para configurar la fuente, tamaño, color y posición */
  $draw = new ImagickDraw();
  $draw->setFont('fonts/Duality.ttf');
  $draw->setFontSize( 50 );
  $draw->setFillColor("navy");
  $draw->setGravity(Imagick::GRAVITY_CENTER);
  $fontWidth = 
  
  /* Texto */
  $string = 'gozar';
  
  /* Creamos la imagen */
  $image->newImage(120, 60, $bg); 
  
  /* Escribimos el texto en la imagen */
  $image->annotateImage($draw, 0, 0, 0, $string);
  
  /* Arremolinamos la imagen (swirl) */
  $image->swirlImage(45);
  
  /* Agregamos el dibujo. */
  $image->drawImage($draw);
  
  /* Seteamos el formato */
  $image->setImageFormat('png');
  
  
  header( "Content-Type: image/{$image->getImageFormat()}" );
  echo $image->getImageBlob();
  

  Result:

  

J. Doe, have you tried using imagefill()and filling it with the assigned color imagecolorallocatealpha()which can have a value between 0 and 127, ie 0 indicates completely opaque while 127 indicates completely transparent.

Note: imagecolorallocatealpha() behaves identically to imagecolorallocate() with the addition of the alpha transparency parameter.

It could be something like this:

$white = imagecolorallocatealpha($image,255,255,255,80); //Fondo imagen.
imagefill($image,0,0,$white);//Rellenar.

OS source code:

• https://stackoverflow.com/questions/8437665/how-to-create-an-image-with-transparent-background

Handbook imagecolorallocatealpha():

• http://php.net/manual/es/function.imagecolorallocatealpha.php

Handbook imagefill():

• http://php.net/manual/es/function.imagefill.php

if you use imagecolortransparent()?

Here I leave you an example:

<?php
// Crear una imagen de 55x30
$im = imagecreatetruecolor(55, 30);
$rojo = imagecolorallocate($im, 255, 0, 0);
$negro = imagecolorallocate($im, 0, 0, 0);

// Hacer el fondo transparente
imagecolortransparent($im, $negro);

// Dibujar un rectángulo rojo
imagefilledrectangle($im, 4, 4, 50, 25, $rojo);

// Guardar la imagen
imagepng($im, './imagecolortransparent.png');
imagedestroy($im);
?>