Graphics Library

1. GD Library
Jigar Makhija

2. Introduction
• It is used to create and manipulate image files in a variety of different
image formats, including GIF, PNG, JPEG, WBMP, and XPM.
• Fonts in GD are identified by numbers.
For Reference: https://www.php.net/manual/en/book.image.php

3. GD supports a varity of formats, below is a list of
formats supported by GD.

4. Functions
• // Create the size of image or blank image
$image = imagecreate(500, 300);
or
$image=imagecreatetruecolor($w,$h);
• // Set the background color of image and Setting the text color of
image
• $color = imagecolorallocate($image, 255, 255, 255);

5. Functions
// Function to create image which contains string.
//bool imagestring( $image, $font, $x, $y, $string, $color )
• imagestring($image, 5, 50, 100, " A computer portal", $text_color);
or
• imagettftext($image,40,0,50,50,$blacktext,$font,$text);
• header("content-type: image/png");
• imagepng($image);
• imagedestroy($image);

6. Code to implement <?php
//Set the Content Type
header('content-type:image/png');
$w=730;
$h=450;
//imagecreatefromjpeg(string $filename): GdImage|false
$image=imagecreatefrompng("img.png");
$text='hello world';
$whitebackground=imagecolorallocate($image,255,200,255);
$blacktext=imagecolorallocate($image,0,255,0);
$font =$font_path = dirname(__FILE__) . '/font.ttf';
imagettftext($image,40,0,50,50,$blacktext,$font,$text);
imagepng($image);
imagedestroy($image);
?>
<?php
$w=730;
$h=450;
$image=imagecreatetruecolor($w,$h);
$bg = imagecolorallocate($image, 0, 0, 0);
$col_ellipse = imagecolorallocate($image, 255, 255, 255);
imageellipse($image, 200, 150, 300, 200, $col_ellipse);
Header('content-type:image/jpeg');
imagejpeg($image);
?>