imagecreatefromjpeg and similar functions are not working in PHP

问题

I’ve searched for this and the solutions provided in past questions are completely incomprehensible to me. Whenever I run functions like imagecreatefromjpeg, I get this:

Fatal error: Call to undefined function imagecreatefromjpeg() ...

I’m working on a new install of PHP; my last installation never had this problem. I don’t get what’s going on.

回答1:

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/

回答2:

In Ubuntu/Mint (Debian based)

$ sudo apt-get install php5-gd

回答3:

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.

回答4:

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

x.x is the versión php.

回答5:

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/

回答6:

After installing php5-gd apache restart is needed.

回答7:

For php 7 on Ubuntu:

sudo apt-get install php7.0-gd

回答8:

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

来源：https://stackoverflow.com/questions/13338339/imagecreatefromjpeg-and-similar-functions-are-not-working-in-php