PHP image and graphics processing introductory tutorial (1/3)_PHP tutorial

Introduction to PHP image and graphics processing tutorial This PHP image generation tutorial is a PHP tutorial from generating a simple image to generating complex graphics. It has 12 examples of image generation for people who are simple and complex. 1 Generate a simple image.

php tutorial image graphics processing introductory tutorial
This PHP image generation tutorial is a PHP tutorial from generating a simple image to generating complex graphics. It has 12 examples of image generation for people who are simple and complex.

1 Generate a simple image.
2 Set the color of the image.
3 Draw a straight line on the image.
4 Display text on the image.
5 Display Chinese characters in the image.
6 Open an existing picture.
7 Get the relevant attributes of the image.
8 Usage of function getimagesize().
9 Add watermark effect to uploaded pictures.
10 Generate thumbnails of existing images.
11 Use the function imagecopyresampled().
12 PHP program that generates digital verification code images with shading.

*/

//1 Generate a simple image.

$width = 200;
$height =200;

$img = imagecreatetruecolor($width,$height) or die("gd image processing is not supported");
imagepng($img);
imagedestroy($img);

//2 Set the color of the image.

$width = 200;
$height =200;

$img = imagecreatetruecolor($width,$height) or die("gd image processing is not supported");

$bg_color = imagecolorallocate($img, 255, 0, 0);
imagefill($img, 0, 0, $bg_color);

imagepng($img);
imagedestroy($img);

//3 Draw a straight line on the image.

$width = 200;
$height =300;

$img = imagecreatetruecolor($width,$height) or die("gd image processing is not supported");

$line_color = imagecolorallocate($img, 255, 255, 255);
imageline($img,0,40,200,40,$line_color);
imageline($img,0,260,200,260,$line_color);

imagepng($img);
imagedestroy($img);

//4 Display text on the image.

$width = 200;
$height =300;

$img = imagecreatetruecolor($width,$height) or die("gd image processing is not supported");
$line_color = imagecolorallocate($img, 255, 255, 255);

imageline($img, 0, 40, 200, 40, $line_color);
imageline($img, 0, 260, 200, 260, $line_color);
imagestring($img, 5, 0, 60, "it's time to learn php!", $line_color);

imagepng($img);
imagedestroy($img);

//5 Display Chinese characters in the image.

$width = 200;
$height =300;

$img = imagecreatetruecolor($width,$height) or die("gd image processing is not supported");
$line_color = imagecolorallocate($img, 255, 255, 255);
$font_type ="c://windows//fonts//simli.ttf"; //Get truetype font, using official script font

//"Journey to the West" 3 hexadecimal characters
$cn_char1 = chr(0xe8).chr(0xa5).chr(0xbf);
$cn_char2 = chr(0xe6).chr(0xb8).chr(0xb8);
$cn_char3 = chr(0xe8).chr(0xae).chr(0xb0);

//"Wu Cheng'en" 4-character hexadecimal characters
$cn_str = chr(0xe5).chr(0x90).chr(0xb4).chr(0xe6).chr(0x89).chr(0xbf).chr(0xe6).chr(0x81).chr(0xa9);
$cn_str .= " ".chr(0xe8).chr(0x91).chr(0x97);

imageline($img, 0, 40, 200, 40, $line_color);
imageline($img, 0, 260, 200, 260, $line_color);

//Display the 3 words "Journey to the West" vertically
imagettftext($img, 30, 0, 10, 80, $line_color, $font_type,$cn_char1);
imagettftext($img, 30, 0, 10, 120, $line_color, $font_type,$cn_char2);
imagettftext($img, 30, 0, 10, 160, $line_color, $font_type,$cn_char3);

//Display the 4 words "Wu Cheng'en" horizontally
imagettftext($img, 15, 0, 90, 254, $line_color, $font_type,$cn_str);

imagepng($img);
imagedestroy($img);

//6 Open an existing picture.
$img=imagecreatefromjpeg("tower.jpg");

imagejpeg($img);
imagedestroy($img);

///7 Get the relevant attributes of the image.
$img=imagecreatefromjpeg("tower.jpg");

$x = imagesx($img);
$y = imagesy($img);
echo "The width of the image tower.jpg is: $x pixels";
echo "
";
echo "
";
echo "The height of the picture tower.jpg is: $y pixels";

//8 Usage of function getimagesize().
$img_info=getimagesize("tower.jpg");

for($i=0; $i<4; ++$i)
{
echo $img_info[$i];
echo "
";
}

?>
1 2 3