PHP: imagecreate

Description

resource imagecreate ( int x_size, int y_size )

imagecreate() returns an image identifier representing a blank image of size x_size by y_size.

We recommend the use of imagecreatetruecolor().

Przykład 1. Creating a new GD image stream and outputting an image.


<?php

header("Content-type: image/png");

$im = @imagecreate(100, 50)

    or die("Cannot Initialize new GD image stream");

$background_color = imagecolorallocate($im, 255, 255, 255);

$text_color = imagecolorallocate($im, 233, 14, 91);

imagestring($im, 1, 5, 5,  "A Simple Text String", $text_color);

imagepng($im);

imagedestroy($im);

?>

User Contributed Notes


// 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>


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