Imagecreatefromjpeg 和类似的函数在 PHP 中不能工作

Install GD Library

Which OS you are using?

http://php.net/manual/en/image.installation.php

Windows http://www.dmxzone.com/go/5001/how-do-i-install-gd-in-windows/

Linux http://www.cyberciti.biz/faq/ubuntu-linux-install-or-add-php-gd-support-to-apache/

You must enable the library GD2.

Find your (proper) php.ini file

Find the line: ;extension=php_gd2.dll and remove the semicolon in the front.

The line should look like this:

extension=php_gd2.dll

Then restart apache and you should be good to go.

In Ubuntu/Mint (Debian based)

$ sudo apt-get install php5-gd

After installing php5-gd apache restart is needed.

In CentOS, RedHat, etc. use below command. don't forget to restart the Apache. Because the PHP module has to be loaded.

yum -y install php-gd
service httpd restart

sudo apt-get install phpx.x-gd
sudo service apache2 restart

x.x is the versión php.

For php 7 on Ubuntu:

sudo apt-get install php7.0-gd

You can still get Fatal error: Call to undefined function imagecreatefromjpeg() even if GD is installed.

The solution is to install/enable jped lib:

On Ubuntu:

    apt-get install libjpeg-dev
apt-get install libfreetype6-dev

On CentOS:

    yum install libjpeg-devel
yum install freetype-devel

If compiling from source add --with-jpeg-dir --with-freetype-dir or --with-jpeg-dir=/usr --with-freetype-dir=/usr.

For more details check https://www.tectut.com/2015/10/solved-call-to-undefined-function-imagecreatefromjpeg/

after
systemctl restart php-fpm
the Gd library works.

As mentioned before, you might need GD library installed.

On a shell, check your php version first:
php -v

Then install accordingly. In my system (Linux-Ubuntu) it's php version 7.0:
sudo apt-get install php7.0-gd

Restart your webserver:
systemctl restart apache2

You should now have GD library installed and enabled.

If you are like me and you are using one of the PHP Docker images as your base, you need to add the gd extension using different instructions then what's discussed above.

For the php:7.4.1-apache image you need to add in your Dockerfile:

RUN apt-get update && \
apt-get install -y zlib1g-dev libpng-dev libjpeg-dev


RUN docker-php-ext-configure gd --with-jpeg && \
docker-php-ext-install gd

These dev packages are needed for compilation of the GD php extension. For me this resulted in activation of GD with PNG and JPEG support in PHP.

I spent so much time trying to figure this out on Windows after installing PHP Version 8.0.11.

I created this phpinfo.php file to check whether GD was loaded:

<?php
if (extension_loaded('gd')) {
print 'gd loaded';
} else {
print 'gd NOT loaded';
}


phpinfo(); ?>

If it returns gd NOT loaded then ensure that in your php.ini file you have the following unchecked:

; - Many DLL files are located in the extensions/ (PHP 4) or ext/ (PHP 5+)
;   extension folders as well as the separate PECL DLL download (PHP 5+).
;   Be sure to appropriately set the extension_dir directive.
;
extension=gd

Further down they'll be a section for extension_dir on Windows you need to uncheck the following:

; Directory in which the loadable extensions (modules) reside.
; http://php.net/extension-dir
;extension_dir = "./"
; On windows:
extension_dir = "ext"

You should now see gd loaded when running the phpinfo.php file and any function calls (like imagecreatefromjpeg()) should now work as intended.

I am replying in 2022, anyone still facing this problem may my answer helpful. If your PHP version,n is 8+ you can add the below line to your php.ini file which is located in the PHP folder.

extension=php_gd.dll