Library tutorials & articles

Image Generation on the FLY using PHP

By Divyesh Jariwala, published on 23 Feb 2002
Page 2 of 6
  1. Introduction
  2. Getting Started
  3. Creating our image
  4. Displaying our image
  5. Generating the random number
  6. Changing the font

Getting Started

Note
To handle the code described in this article, you should feel comfortable with the PHP scripting language at an intermediate level. Also, if you haven't got the necessary libraries to generate images installed (explained in a minute), then you should be able to modify the php.ini file. In our example, we will be using PHP on a Windows 2000 machine running Apache.

To generate images in real-time using PHP, we need to have the GD library installed. To make sure you have the GD library installed, create a new PHP page named checkgd.php in a directory on your web server. Enter the following code into checkgd.php:

<?php
phpinfo(INFO_MODULES);
?>

Run the checkgd.php page on your web server. If you can find a section for the GD library (like in the sample shown below), then you have the GD library installed and ready to go:

On the other hand, if you don't see a section for the GD library, then you will need to download and install the GD library. If you are running windows, then installation instructions are available here. If you are running Linux, installation instructions are available here.

Both of the links to installation instructions shown above use an older version of the GD library. This is because with the newer versions, any support for GIF images has been removed due to copyright infringements.

As mentioned at the beginning of this article, we will be creating an image that contains a random number, similar to the methods used by yahoo.com and paypal.com when you register to become a member.

So, now that we have the GD library installed as part of our PHP distribution, let's jump right in and create our first image.

Comments

  1. Babul Gogoi
    02 Apr 2005 at 04:12

    Hi


    I saw them using a image-on-the-fly script as (at www.worldspaceasia.com):
    <a href="modules.php?name=Content&pa=listpagescategories&cid=2"><img src="includes/img.php?title=Western Classical/Jazz&textsize=8&border=1&imgype=randomTTF" border="0" alt="Western Classical/Jazz"></a>


    The :
    title=
    imgype=randomTTF


    are crucial!


    So whts the secret of the img.php?


    Regards

  2. Leonard Anukam
    06 Nov 2004 at 04:32

    Very good tutorial and useful. But am wondering, if it can be converted to be used as a counter in a website, to get the number of visitors to the site. It will then start from a certain number and count sequencially upwards. It could start from 1 or 10.


    Thanks

  3. charles fletcher
    03 Sep 2004 at 14:58
    after installing the gd.dll am i suppose to uncomment it in the php.ini file and if so do i restart my server to get it to load??? after putting it in my php.ini file and uncommenting it nothing came up? can you give me more detial instructions on fixing this  problem or installing this gd.dll? i am using windows xp iis5 and php5 just got it all working and jumping in for soome more, lol, well hope you can help .... altimastr
  4. Anil Kumar Reddy
    18 Aug 2004 at 02:09

    I used the script it was good. The random script is accessed as an image in another script, then how to access the number displayed on the image so that i can check that the user entered the correct displayed number.

  5. Idea_Rat
    05 Aug 2004 at 13:58

    very well-written & useful javascript:smilie('')

  6. scoobedoo
    23 Jul 2003 at 12:49
    want to display an image on a  form when an item is selected from a ComboBox. the image will be stored on the a:\drive (floppy). there will be multiple items in the combobox, each 1 relating to a specific picture. i just need the  basic code to get the img to appear after selecting the item from the combobox. if n e 1 could email me the  code or tell me where to  get  it, that would be  great! oz_utester@hotmail.com

    thanx 4 ur time!
  7. scoobedoo
    23 Jul 2003 at 12:47
    want to display an image on a  form when an item is selected from a ComboBox. the image will be stored on the a:\drive (floppy). there will be multiple items in the combobox, each 1 relating to a specific picture. i just need the  basic code to get the img to appear after selecting the item from the combobox. if n e 1 could email me the  code or tell me where to  get  it, that would be  great! shb53@hotmail.com

    thanx 4 ur time!
  8. Charles Wang
    30 May 2003 at 13:09

    hi:


    I copied your code to my PHP4.3.x+Windows2000Server+Apache2, The picture does not show at a browser, only white page.  I checked the sapce befor the "<?php"  carefully.


    In fact, befor I have a similar bad experience that I can't show picture at my machine. But If I put the code to a linux machine , it works. The situation is all my other php codes, including session,mysql, work fine. Only for this method, header(header("Content-type:image/jpeg"), the send out a image, it does not work.


    I guess there must be some setting parameters problem at apache2. Does anyone have any idea?


    Thanks



  9. Mark Rawson
    17 Apr 2003 at 04:51

    I think your posting in the wrong place buddy! this is for creating and showing PHP images on-the-fly not VB! If you DO really want to take a PHP created image and put it in a VB form you can either post back here or email me at webmaster@isgeeky.com

  10. Mark Rawson
    17 Apr 2003 at 04:48

    To my knowledge it is not possible to send an image created on-the-fly using PHP without the content-type header being modified. Why do you not want to use the "Header("Content-Type: Image/jpg")" code?

  11. sshri123
    31 Jan 2003 at 06:17
    Hi,
       Actually I have seen your image generation on the fly and i have used it on my project. But i facing a problem is i don't want to use a Header("Content-Type: Image/jpg") . So if you have link please send me on sshti123@hotmail.com.

    Vivek
  12. sshri123
    31 Jan 2003 at 06:16
    Hi,
       Actually I have seen your image generation on the fly and i have used it on my project. But i facing a problem is i do want to use a Header("Content-Type: Image/jpg") . So if you have link please send me on sshti123@hotmail.com.

    Vivek
  13. sshri123
    31 Jan 2003 at 06:15
    Hi,
       Actually I have seen your image generation f\on the fly and i have used it on my project. But i facing a problem is i do want to use a Header("Content-Type: Image/jpg") . So if you have link please send me on sshti123@hotmail.com.

    Vivek
  14. oz_utester
    09 Aug 2002 at 01:47

    i want to display an image on a  form when an item is selected from a ComboBox. the image will be stored on the a:\drive (floppy). there will be multiple items in the combobox, each 1 relating to a specific picture. i just need the  basic code to get the img to appear after selecting the item from the combobox. if n e 1 could email me the  code or tell me where to  get  it, that would be  great! oz_utester@hotmail.com


    thanx 4 ur time!

  15. Developer Fusion Bot
    01 Jan 1999 at 00:00

    This thread is for discussions of Image Generation on the FLY using PHP.

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