Uncaught error call to undefined function gregwar captcha imagecreatetruecolor

Проблема с imagecreatetruecolor

Cramac

Новичок

Проблема с imagecreatetruecolor

Не работает функция imagecreatetruecolor. В чем дело?
Возможно надо ГД2, если да, то где скачать под винды?

Стоит ВинХП, ГД1.6.2.

Фанат

oncle terrible

Sapfir

Guest

Повторяй за мной:

1). Иди в папку где у тебя распакован php.

2). Там открой папку extensions. В ней найди файл php_gd2.dll. Копируй его

3). Иди в папку где УСТАНОВЛЕН РНР (предположительно C:php3 или С:php4) и вставляй туда файл.

4). Открой свой php.ini (в папке Windows) найди строчку ;extension=php_gd2.dll и убери знак «;» в начале.

5). Улыбайся, радуйся.

Cramac

Новичок

Фанат

oncle terrible

Cramac

Новичок

Одну проблему решил, теперь другая, перестал работать вот такой скриптик:

header («Content-type: image/JPEG»);
$org_h = imagesy($src );
$org_w = imagesx($src );
if($org_h > $org_w ) <
$x_img=»800″;
$x_k= ($x_img * 100) / $org_h;
> else <
$y_img=»800″;
$y_k= ($y_img * 100) / $org_w;
>
if ($x_img==»»)<$x_img= ($org_h * $y_k)/100;>
else <$y_img=($org_w * $x_k)/100;>

// height is bigger than width
$cfg[height] = $x_img;
$cfg[width]= floor($cfg[height] * $org_w / $org_h );
$cfg[dstX]= ($y_img — $cfg[width]) / 2;
$cfg[dstY]= 0;
> else <
// width is bigger than height
$cfg[width]= $y_img;
$cfg[height] = floor($cfg[width] * $org_h / $org_w );
$cfg[dstX]= 0;
$cfg[dstY]= ($x_img — $cfg[height]) / 2;
>

ImageCopyResized($img, $src, $cfg[dstX], $cfg[dstY], 0, 0, $cfg[width], $cfg[height], $org_w, $org_h );
##################
Imagejpeg($img);
##################
ImageDestroy($img );

при передаче всех данных ничего не происходит, а у хостера работает.
пытаюсь вот так открыть resize.php?name=selk001.jpg
а наме не передается.
Что не так?

ПС. Обновил то быстро, главное чтоб теперь не зря 6.5 мегов скачал.

Источник

Проблема с imagecreatetruecolor

c0dex

web.dev 2002-.

@Ulibka, Call to undefined function imagecreatetruecolor() дальше в гугол

PS: надо убедиться в том, что ты верную строчку нашел и раскомментил и в НУЖНОМ файле. Нету у тебя библиотеки GD

Фанат

oncle terrible

Ulibka

Новичок

Нашел еще параметр , установил
extension_dir = «C:xamppphpext»

Если extension_dir не выставить, то возникает ошибка
PHP Startup: Unable to load dynamic library ‘C:phpextphp_gd2.dll’

стоит строка
extension=php_gd2.dll

Ошибки пропали, но картинка все равно не появляется.
Может быть проблема в Xampp ?

P.S. apache я конечно перезагружал

c0dex

web.dev 2002-.

@Ulibka, тебя не смущает:

c0dex

web.dev 2002-.

Ulibka

Новичок

Смущает
Xampp поставил на SSD (диск F)
PHP стоит на F:xamppphp
В директории F:xamppphp лежит php.ini

Пробовал ставить
extension_dir = F:/xampp/php/ext

Программа не работает (картинки не видно)
Снес xampp, поставил на C: Apache (httpd-2.4.29-Win64-VC15 from Apache lounge)
Поставил на C: в директорию PHP сам php 7 (php-7.2.1-Win32-VC15-x64 thread safe.zip)
Выставил
extension_dir = c:/php/ext
та же фигня — не работает

Ulibka

Новичок

Может быть я все таки в пяти строках программы ошибся ?
Но ведь это я тупо записал пример (наверно даже из документации)

Источник

«вызов функции undefined function imagecreatetruecolor» в PHP и pChart

Я пытаюсь интегрировать «pChart» с моим PHP-кодом. Когда я пытаюсь запустить образцы, он дает мне сообщение об ошибке call to undefined function imagecreatetruecolor . Рекомендованным решением было загрузить эту dll «php_gd2.dll», поэтому я раскомментировал extension=php_gd2.dll в файле php.ini.

Даже после этого я получаю ту же ошибку. Я попытался перезапустить сервер и машину.

ОТВЕТЫ

Ответ 1

Используйте следующий код, чтобы проверить, есть ли расширение GD:

Если вы получили сообщение, которое оно не установлено, проверьте следующие шаги:

• phpinfo() и найдите путь php.ini
• edit php.ini : extension_dir =
• изменить php.ini : extension = php_gd2.dll//раскомментировать или добавить
• Перезапустить веб-сервер
• Запустите тест script снова

Ответ 2

В Ubuntu/Linux Mint Platform (под root) используйте следующую команду:

Ответ 3

Я встретил эту проблему только сейчас. Вы должны выполнить sudo apt install php7.0-gd или vim свой php.ini открыть расширение = php_gd2.dll

Ответ 4

У меня такая же ошибка:

и мое решение было следующим:

отредактировать файл php.ini и раскомментировать содержимое строки extension = gd.so «, сохранить и повторить попытку

Ответ 5

Ответ 6

Этот ответ является обновлением 9 лет спустя, но PHP сильно изменился. Пожалуйста, проголосуйте за Святой Воланд, из которого это происходит.

Используйте следующий код на своем веб-сервере, чтобы проверить, есть ли у вас расширение GD:

«; //display GD function list

Если вы получили сообщение о том, что оно не установлено, выполните следующие действия:

1. Посмотрите на вывод phpinfo(), чтобы определить ваш php.ini
2. Отредактируйте php.ini и включите расширение GD:
   • Более новый PHP (7.3, fg):
     • extension = gd2//раскомментируем
   • Более старый PHP (5.x, 7.0, вы должны обновить):
     • extension_dir = & lt; путь к вашим расширениям & gt;//раскомментируем или добавляем
     • extension = php_gd2.dll//раскомментируем или добавляем
3. GD для 7.x не может быть установлен
   • (для Ubuntu, таких как OS) sudo apt install php7.3-gd # заменить версию своей
4. Перезапустите веб-сервер
5. Запустите тестовый скрипт еще раз
6. (Удалите тестовый скрипт, когда все работает, это может быть дыра в безопасности)

Как видите, точный метод очень зависит от версии. Я надеюсь, что эта дополнительная информация поможет другим разобраться, какие именно шаги им могут понадобиться.

Источник

imagecreatetruecolor

(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP

imagecreatetruecolor — Создание нового полноцветного изображения

Описание

imagecreatetruecolor() возвращает объект, представляющий чёрное изображение заданного размера.

Список параметров

Возвращаемые значения

Возвращает объект изображения в случае успешного выполнения или false в случае возникновения ошибки.

Список изменений

Примеры

Пример #1 Создание нового потока GD изображения и вывод картинки.

Результатом выполнения данного примера будет что-то подобное:

Смотрите также

• imagedestroy() — Уничтожение изображения
• imagecreate() — Создание нового палитрового изображения

User Contributed Notes 37 notes

If you want to create a *transparent* PNG image, where the background is fully transparent, and all draw operations happen on-top of this, then do the following:

= imagecreatetruecolor ( 800 , 600 );
imagesavealpha ( $png , true );

$trans_colour = imagecolorallocatealpha ( $png , 0 , 0 , 0 , 127 );
imagefill ( $png , 0 , 0 , $trans_colour );

$red = imagecolorallocate ( $png , 255 , 0 , 0 );
imagefilledellipse ( $png , 400 , 300 , 400 , 300 , $red );

header ( «Content-type: image/png» );
imagepng ( $png );
?>

What you do is create a true colour image, make sure that the alpha save-state is on, then fill the image with a colour that has had its alpha level set to fully transparent (127).

The resulting PNG from the code above will have a red circle on a fully transparent background (drag the image into Photoshop to see for yourself)

HOW THE CHECK THE MEMORY BEFORE CREATING AN IMAGE?

I worked on a script where I delt with large images. Very often the error «out of memory» occured. So I had to figure out, how to check the memory BEFORE creating an image. I didn’t find a solution on the web, so I ran my own test script. It built lots of images to compute the needed memory. I found out, that the formula mem = x * y * channel was not enough. There was an additional multiplier that varied. As a result 1.7 worked best. So the formula is: mem = x * y * channel * 1.7.

I post this script here hoping it is useful to someone who will run into the same problems.

//————————————————— ENOUGH MEMORY ?
function enoughmem ( $x , $y , $rgb = 3 ) <
return ( $x * $y * $rgb * 1.7 MAXMEM — memory_get_usage () );
>

//————————————————— SIMPLE EXAMPLE
list ( $x , $y ) = @ getimagesize ( ‘your_img.jpg’ ); //— get size of img —
if ( enoughmem ( $x , $y )) <
$img = @ imagecreatefromjpeg ( ‘your_img.jpg’ ); //— open img file —
$thumb = 200 ; //— max. size of thumb —
if ( $x > $y ) <
$tx = $thumb ; //— landscape —
$ty = round ( $thumb / $x * $y );
> else <
$tx = round ( $thumb / $y * $x ); //— portrait —
$ty = $thumb ;
>
if ( enoughmem ( $tx , $ty )) <
$thb = imagecreatetruecolor ( $tx , $ty ); //— create thumbnail —
imagecopyresampled ( $thb , $img , 0 , 0 , 0 , 0 , $tx , $ty , $x , $y );
imagejpeg ( $thb , ‘your_thumbnail.jpg’ , 80 );
imagedestroy ( $thb );
>
imagedestroy ( $img );
>

//—————————————————
//— to check the memory working with —
//— b/w-image or gif use: —
//—————————————————
$check = enoughmem ( $x , $y , 1 );
?>

Taking the opportunity, I thank everyone here at php.net for the great manual and the useful user scripts.

There is no need to allocate colors with imagecreatetruecolor. All [256 x 256 x 256 x 128] true colors are already allocated, and you can use the color indexes directly.

Examples :
Blue => color index 255.
White => color index 16777215 (= 255*256² + 255*256+255).
Full transparent => color index 2130706432 (= 127*256^3).

using imagecolorallocate to specify the image’s background color does not work with truecolor-image.

instead you have to use imagefill to force flood-filling the image with the backgorund-color previously allocated:

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

If you want to place an image on a larger canvas you’ve previously created with imagecreatetruecolor(), but you don’t want the default black background to surround it: use imagefill() AFTER imagecopyresampled().

I have no idea why this should be the case, but it works!

A note to post by Justin Greer @ 18-Nov-2003 10:40:

While this information has already been posted by php at REMOVEreallynicejerk dot com @ 16-Sep-2002 12:01, I feel it neccesary to notice ’cause Justin’s post is in the top and it can make people go the wrong way: Justin’s way of detecting which imagecreate function to use is too complicated, while there’s an easy standard way:

if ( function_exists ( ‘imagecreatetruecolor’ ) <
// use imagecreatetruecolor
> else <
// use imagecreate
>

If you want a simple way to mirror images, use the function I’ve included below.

function image_mirror ( $input_image_resource )
<
$width = imagesx ( $input_image_resource );
$height = imagesy ( $input_image_resource );
$output_image_resource = imagecreatetruecolor ( $width , $height );
$y = 1 ;

while ( $y $height )
<
for ( $i = 1 ; $i $width ; $i ++ )
imagesetpixel ( $output_image_resource , $i , $y , imagecolorat ( $input_image_resource , ( $i ), ( $height — $y ) ) );
$y = $y + 1 ;
>

return $output_image_resource ;
>
?>
Example Usage:
// A good use of this is when a user uploads a TGA file,
// on the completion screen show the image and have a link
// that asks if the image appears mirrored, and if so
// that link will execute these commands below.

// I suggest checking $HTTP_REFERER for security.

// $_GET[‘file’] in this case would be something along the lines
// of johndoe-img0001 (Basename is necessary to prevent
// abuse of this script!)

if ( isset( $_GET [ ‘file’ ] ) )
<
$filename = «./» . basename ( $_GET [ ‘file’ ] ) . «.jpg» ;
// Making the image resource that needs to be mirrored
// Taking it from a previously exported to JPEG file.
$output_resource_image = image_mirror ( imagecreatefromjpeg ( $filename ) );
if ( imagejpeg ( $output_resource_image , $filename , 75 ) )
echo «Image resaved successfully» ;
else
echo «Image couldn’t be written over (Check permissions)!» ;
>
?>

A very simple and efficient way to create RGB color from hexadecimal (HTML) notation:

function color_hex2dec ( $color ) <
return array ( hexdec ( substr ( $color , 0 , 2 )), hexdec ( substr ( $color , 2 , 2 )), hexdec ( substr ( $color , 4 , 2 )));
>

list ( $r , $g , $b ) = color_hex2dec ( ‘FFEECC’ );

I had a strange bug occurring under Debian Linux with PHP5.

In file B (where I create the image) I included a file (file A). The image that was produced was always corrupt. When I did not include file A, everything was fine.

After 2 hours of searching I found that there were some extra spaces and linefeeds after the PHP closing tag ?> in file A. After removing those chars, everything works fine again.

Obviously those extra bytes of file A were added to the image and corrupted it.

I know it’s not a discussion board, but when incorrect info is posted, it should be corrected.

The function_exists() check does not work correctly because if PHP is compiled with an older GD library, the imagecreatetruecolor() function still exists — it just gives a fatal error when called, stating that GD2 is required. Therefore, the function_exists() method will fail on any new-ish copy of PHP that only has GD 1.x. (That includes most of the 4.1.x and 4.2.x installs I’ve seen.)

Unfortunately the @imagecreatetruecolor() method doesn’t even work because php dies with a fatal error noting that GD 2 is required. You can’t even capture this error with a custom error handler.

I have come up with a function to get the GD version number that seems to work pretty well on every version of PHP and GD I’ve thrown at it (even CLI versions.) It’s obviously not the most efficient thing in the world, but it does cache the result in a static variable so calling it multiple times doesn’t slow down further.

function gd_version() <
static $gd_version_number = null;
if ($gd_version_number === null) <
// Use output buffering to get results from phpinfo()
// without disturbing the page we’re in. Output
// buffering is «stackable» so we don’t even have to
// worry about previous or encompassing buffering.
ob_start();
phpinfo(8);
$module_info = ob_get_contents();
ob_end_clean();
if (preg_match(«/bgds+versionb[^dnr]+?([d.]+)/i»,
$module_info,$matches)) <
$gd_version_number = $matches[1];
> else <
$gd_version_number = 0;
>
>
return $gd_version_number;
>

Then you can simply use it something like this:

if (gd_version() >= 2) <
$image = ImageCreateTrueColor($width, $height);
> else <
$image = ImageCreate($width, $height);
>

Regarding choosing the TrueColor or the plain version of imagecreate automatically, I’ve found that the following works for me:

=@ ImageCreateTrueColor ( $width , $height )
or $newImg = ImageCreate ( $width , $height );

I just fiddled around with Phpix, which had some problems using the GD lib
(washed out colours).
I changed the lines, which did the trick.
Just in case some of you are still having problems and
you can’t change the PHP-install
on the hosting side:

$im = ImageCreateFromJPEG($source);
$new_im = ImageCreate($new_width,$new_height);

$im = ImageCreateFromJPEG($source);
$new_im = ImageCreateTrueColor($new_width,$new_height);

Here is my solution for creating images with the same code for both GD 2:

$dst_img = @imageCreateTrueColor($width, $height);
if (!$dst_img)

Because imagecreatetruecolor exist both in gd and gd2,
you can’t use function_exists or get_extension_funcs to check for gd2 !
But . there is a difference in imagettfbbox between gd and gd2:
gd use pixels and gd2 use points.

Then you can check gd2 with this function:

$rep=false;
if(isset($GLOBALS[«gBGDVersion»]))
<
$rep=$GLOBALS[«gBGDVersion»];
>
else
<
if(function_exists(«gd_info»))
<
$gdver=gd_info();
if(strstr($gdver[«GD Version»],»1.»)!=false)
<
$rep=false;
>
else
<
$rep=true;
>
>
else
<
$size=40;
$font= your font file path here;
$b=imagettfbbox ($size,0,$font,»abcdefghijklmnopqrstuvwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ»);

Why not just use function_exists?

Just because they have version 2.0 GD doesn’t mean that they haven’t disabled that function.

Also instead of determining which one you have on your machine and then writing setup specific code, you can write a universal code usable on either setups.

if (function_exists(imagecreatetruecolor))<
use imagecreatetruecolor()
>else<
use imagecreate()
>

Here is answer for first question ‘why do I need true color images’.

True color images you need when you want to work with images such as photos (snapshots), video frames and so on.

When you need to combine some these images for user, or to send him only small part of your image, and you try to use 256 colors, image will be ugly (try it if you want). Some colors will change dramatically.

«Antialias» lines which you may see are probably the result of using JPEG compression. JPEG is not looseless compression so «small image details may be changed» in order to reduce image size dramatically. On really true-color images such as your snapshots of landscape and so on and using small compression level you will hardly see differences. But on exact objects, such as lines, circles, which you draw on solid background using single color, you can see that if you save and load this image that some details are changed.

This little function does it for you:

The .299 , .578 , .114 values are estimations, and add a gamma correction to the colors. For more or less luminace in the result, you can change these values.

Goodluck,
Eric Mulders, Netherlands

Thanks to OverFlow636 at gmail dot com and kuya1284 at techie dot com for their original coding which this function is based upon.

PHP lacks an imagecreatefromtga function, so I have prepared a simple function to include in your library if you deal with TGA images. In addition to creating an image from TGA, it also, optionally, will output an array with the dimensions of the image because getimagesize() does not function with TGA files.

Hopefully this function will eventually be unneeded if GD is ever updated to support the TGA format.

Please keep in mind that TGA’s come in many different compressions, color settings, and as a result this function will not work 100% of the time. Resulting images will fit the symptoms kuya1284 at techie dot com mentioned, and as a result you may need to create a second function. Keep in mind that using her code causes the «mirror» effect on images that load properly with the following function.

function imagecreatefromtga ( $filename , $return_array = 0 )
<
$handle = fopen ( $filename , ‘rb’ );
$data = fread ( $handle , filesize ( $filename ) );
fclose ( $handle );

$pointer = 18 ;
$x = 0 ;
$y = 0 ;
$w = base_convert ( bin2hex ( strrev ( substr ( $data , 12 , 2 ) ) ), 16 , 10 );
$h = base_convert ( bin2hex ( strrev ( substr ( $data , 14 , 2 ) ) ), 16 , 10 );
$img = imagecreatetruecolor ( $w , $h );

while ( $pointer strlen ( $data ) )
<
imagesetpixel ( $img , $x , $y , base_convert ( bin2hex ( strrev ( substr ( $data , $pointer , 3 ) ) ), 16 , 10 ) );
$x ++;

if ( $return_array )
return array ( $img , $w , $h );
else
return $img ;
>
?>

Example Usage

// the image ( resource image )
$image = $array [ 0 ];

// its dimensions ( integers )
$dimensions [ ‘width’ ] = $array [ 1 ];
$dimensions [ ‘height’ ] = $array [ 2 ];

// Delete the image resource array entry to free memory
imagedestroy ( $array [ 0 ]);
?>

The second variable, $return_array is optional. If you simply want to load a TGA, leave the variable off the function’s call as such:

imagecreatetruecolor() returns not only image identifier representing a black image of size x_size by y_size.

imagecreatetruecolor() is called to create truecolor images, with an essentially unlimited number of colors (also not only 256 colors).

kai wrote:
//using imagecolorallocate to specify the image’s background
//color does not work with truecolor-image.
//
//instead you have to use imagefill to force flood-filling the
//image with the backgorund-color previously allocated:
//
//$bgColor = imagecolorallocate($img, 255,255,255);
//imagefill($img , 0,0 , $bgColor);

even this doesn’t work for my configuration — fedora core2, php 4.3.8 + gd bundled (2.0.23 compatible) and I have to do this:
$img = imagecreatetruecolor($x, $y);
$bgColor = imagecolorallocate($img, 255,255,255);
imagefilledrectangle($img, 0, 0, $x-1, $y-1, $bgColor);

I put this together — combining two of the examples and then generated the text dynamically. but, with this set up, i was able to get the transparent background working as well.

// Set the content-type

header ( ‘Content-type: image/png’ );

// Create the image
$im = imagecreatetruecolor ( 175 , 15 );
imagesavealpha ( $im , true );

// Create some colors
$white = imagecolorallocate ( $im , 255 , 255 , 255 );
$grey = imagecolorallocate ( $im , 128 , 128 , 128 );
$black = imagecolorallocate ( $im , 0 , 0 , 0 );
imagefilledrectangle ( $im , 0 , 0 , 150 , 25 , $black );
$trans_colour = imagecolorallocatealpha ( $im , 0 , 0 , 0 , 127 );
imagefill ( $im , 0 , 0 , $trans_colour );

// The text to draw
$text = $_GET [ ‘text’ ];
// Replace path by your own font path
$font = ‘catriel regular.ttf’ ;

// Add some shadow to the text
imagettftext ( $im , 9 , 0 , 13 , 16 , $black , $font , $text );

// Add the text
imagettftext ( $im , 9 , 0 , 12 , 15 , $white , $font , $text );

// Using imagepng() results in clearer text compared with imagejpeg()
imagepng ( $im );
imagedestroy ( $im );
?>

Источник

Hello there again, i’m using a shopping cart called plaincart, everything works perfectly but the image upload, i was told it has something to do with GD not being enabled, i’m running wamp on a local machine, using PHP version : 5.2.4 and the error message is get is:

Fatal error: Call to undefined function imagecreatetruecolor() in Z:wampwwwplaincartadminlibraryfunctions.php on line 223

the php code is:

<?php

/*
Check if a session user id exist or not. If not set redirect
to login page. If the user session id exist and there's found
$_GET['logout'] in the query string logout the user
*/
function checkUser()
{
// if the session id is not set, redirect to login page
if (!isset($_SESSION['plaincart_user_id'])) {
	header('Location: ' . WEB_ROOT . 'admin/login.php');
	exit;
}

// the user want to logout
if (isset($_GET['logout'])) {
	doLogout();
}
}

/*

*/
function doLogin()
{
// if we found an error save the error message in this variable
$errorMessage = '';

$userName = $_POST['txtUserName'];
$password = $_POST['txtPassword'];

// first, make sure the username & password are not empty
if ($userName == '') {
	$errorMessage = 'You must enter your username';
} else if ($password == '') {
	$errorMessage = 'You must enter the password';
} else {
	// check the database and see if the username and password combo do match
	$sql = "SELECT user_id
	        FROM tbl_user 
			WHERE user_name = '$userName' AND user_password = md5('$password')";
	$result = dbQuery($sql);

	if (dbNumRows($result) == 1) {
		$row = dbFetchAssoc($result);
		$_SESSION['plaincart_user_id'] = $row['user_id'];

		// log the time when the user last login
		$sql = "UPDATE tbl_user 
		        SET user_last_login = NOW() 
				WHERE user_id = '{$row['user_id']}'";
		dbQuery($sql);

		// now that the user is verified we move on to the next page
            // if the user had been in the admin pages before we move to
		// the last page visited
		if (isset($_SESSION['login_return_url'])) {
			header('Location: ' . $_SESSION['login_return_url']);
			exit;
		} else {
			header('Location: index.php');
			exit;
		}
	} else {
		$errorMessage = 'Wrong username or password';
	}		

}

return $errorMessage;
}

/*
Logout a user
*/
function doLogout()
{
if (isset($_SESSION['plaincart_user_id'])) {
	unset($_SESSION['plaincart_user_id']);
	session_unregister('plaincart_user_id');
}

header('Location: login.php');
exit;
}


/*
Generate combo box options containing the categories we have.
if $catId is set then that category is selected
*/
function buildCategoryOptions($catId = 0)
{
$sql = "SELECT cat_id, cat_parent_id, cat_name
		FROM tbl_category
		ORDER BY cat_id";
$result = dbQuery($sql) or die('Cannot get Product. ' . mysql_error());

$categories = array();
while($row = dbFetchArray($result)) {
	list($id, $parentId, $name) = $row;

	if ($parentId == 0) {
		// we create a new array for each top level categories
		$categories[$id] = array('name' => $name, 'children' => array());
	} else {
		// the child categories are put int the parent category's array
		$categories[$parentId]['children'][] = array('id' => $id, 'name' => $name);	
	}
}	

// build combo box options
$list = '';
foreach ($categories as $key => $value) {
	$name     = $value['name'];
	$children = $value['children'];

	$list .= "<optgroup label="$name">"; 

	foreach ($children as $child) {
		$list .= "<option value="{$child['id']}"";
		if ($child['id'] == $catId) {
			$list.= " selected";
		}

		$list .= ">{$child['name']}</option>rn";
	}

	$list .= "</optgroup>";
}

return $list;
}

/*
If you want to be able to add products to the first level category
replace the above function with the one below
*/
/*

function buildCategoryOptions($catId = 0)
{
$sql = "SELECT cat_id, cat_parent_id, cat_name
		FROM tbl_category
		ORDER BY cat_id";
$result = dbQuery($sql) or die('Cannot get Product. ' . mysql_error());

$categories = array();
while($row = dbFetchArray($result)) {
	list($id, $parentId, $name) = $row;

	if ($parentId == 0) {
		// we create a new array for each top level categories
		$categories[$id] = array('name' => $name, 'children' => array());
	} else {
		// the child categories are put int the parent category's array
		$categories[$parentId]['children'][] = array('id' => $id, 'name' => $name);	
	}
}	

// build combo box options
$list = '';
foreach ($categories as $key => $value) {
	$name     = $value['name'];
	$children = $value['children'];

	$list .= "<option value="$key"";
	if ($key == $catId) {
		$list.= " selected";
	}

	$list .= ">$name</option>rn";

	foreach ($children as $child) {
		$list .= "<option value="{$child['id']}"";
		if ($child['id'] == $catId) {
			$list.= " selected";
		}

		$list .= ">  {$child['name']}</option>rn";
	}
}

return $list;
}
*/

/*
Create a thumbnail of $srcFile and save it to $destFile.
The thumbnail will be $width pixels.
*/
function createThumbnail($srcFile, $destFile, $width, $quality = 75)
{
$thumbnail = '';

if (file_exists($srcFile)  && isset($destFile))
{
	$size        = getimagesize($srcFile);
	$w           = number_format($width, 0, ',', '');
	$h           = number_format(($size[1] / $size[0]) * $width, 0, ',', '');

	$thumbnail =  copyImage($srcFile, $destFile, $w, $h, $quality);
}

// return the thumbnail file name on sucess or blank on fail
return basename($thumbnail);
}

/*
Copy an image to a destination file. The destination
image size will be $w X $h pixels
*/
function copyImage($srcFile, $destFile, $w, $h, $quality = 75)
{
    $tmpSrc     = pathinfo(strtolower($srcFile));
    $tmpDest    = pathinfo(strtolower($destFile));
    $size       = getimagesize($srcFile);

    if ($tmpDest['extension'] == "gif" || $tmpDest['extension'] == "jpg")
    {
       $destFile  = substr_replace($destFile, 'jpg', -3);
       $dest      = imagecreatetruecolor($w, $h);
       imageantialias($dest, TRUE);
    } elseif ($tmpDest['extension'] == "png") {
       $dest = imagecreatetruecolor($w, $h);
       imageantialias($dest, TRUE);
    } else {
      return false;
    }

    switch($size[2])
    {
       case 1:       //GIF
           $src = imagecreatefromgif($srcFile);
           break;
       case 2:       //JPEG
           $src = imagecreatefromjpeg($srcFile);
           break;
       case 3:       //PNG
           $src = imagecreatefrompng($srcFile);
           break;
       default:
           return false;
           break;
    }

    imagecopyresampled($dest, $src, 0, 0, 0, 0, $w, $h, $size[0], $size[1]);

    switch($size[2])
    {
       case 1:
       case 2:
           imagejpeg($dest,$destFile, $quality);
           break;
       case 3:
           imagepng($dest,$destFile);
    }
    return $destFile;

}

/*
Create the paging links
*/
function getPagingNav($sql, $pageNum, $rowsPerPage, $queryString = '')
{
$result  = mysql_query($sql) or die('Error, query failed. ' . mysql_error());
$row     = mysql_fetch_array($result, MYSQL_ASSOC);
$numrows = $row['numrows'];

// how many pages we have when using paging?
$maxPage = ceil($numrows/$rowsPerPage);

$self = $_SERVER['PHP_SELF'];

// creating 'previous' and 'next' link
// plus 'first page' and 'last page' link

// print 'previous' link only if we're not
// on page one
if ($pageNum > 1)
{
	$page = $pageNum - 1;
	$prev = " <a href="$self?page=$page{$queryString}">[Prev]</a> ";

	$first = " <a href="$self?page=1{$queryString}">[First Page]</a> ";
}
else
{
	$prev  = ' [Prev] ';       // we're on page one, don't enable 'previous' link
	$first = ' [First Page] '; // nor 'first page' link
}

// print 'next' link only if we're not
// on the last page
if ($pageNum < $maxPage)
{
	$page = $pageNum + 1;
	$next = " <a href="$self?page=$page{$queryString}">[Next]</a> ";

	$last = " <a href="$self?page=$maxPage{$queryString}{$queryString}">[Last Page]</a> ";
}
else
{
	$next = ' [Next] ';      // we're on the last page, don't enable 'next' link
	$last = ' [Last Page] '; // nor 'last page' link
}

// return the page navigation link
return $first . $prev . " Showing page <strong>$pageNum</strong> of <strong>$maxPage</strong> pages " . $next . $last; 
}
?>

7 Answers

<?php
$testGD = get_extension_funcs("gd"); // Grab function list 
if (!$testGD){ echo "GD not even installed."; exit; }
echo"<pre>".print_r($testGD,true)."</pre>";

apt-get update && apt-get -y install php5-gd

sudo apt-get install php7.2-gd

<?php
    $testGD = get_extension_funcs("gd"); // Grab function list 
    if (!$testGD){
        echo "GD not even installed.";
        phpinfo();  // Display the php configuration for the web server
        exit;
    }
    echo"<pre>".print_r($testGD,true)."</pre>";  //display GD function list

PHP Fatal error:  Call to undefined function imagecreatetruecolor() in /var/www/webphp/php/captcha.php on line 251

$ locate php.ini
    /etc/php56/php.ini