Overlay images on web pages

[Xenophule]

I'm looking to create a little web app where one of the features is to display a graphic--based on what a specific user has decided--that looks as if it has been spray-painted over the page itself.

For example: AgentQ and MattMoney are using this; AgentQ wants to have a penguin on the main page of Ubuntu. So he "boots up" the service, heads on over to ubuntu.com, hits the "apply picture" button, picks out the penguin pic, rotates it a little, and hits "Save." Matt boots up the service and when he hits up ubuntu.com he sees Tux.

I was thinking it'd be possible with PHP+Javascript+mySQL or even a Firefox add-on, but I will admit I'm WAY behind the times when it comes to Web 2.0.

Feel free to barrage me with questions as I'm sure I'm being vague here.

[PeejAvery]

Well, doing it the exact way you described would be impossible for any combination of web programming. You would have to use some plugin for whatever browser with which you worked.

Using HTML/PHP you would upload an image. However, PHP's image library (GD (http://us3.php.net/gd)) is limited in its ability to edit images with free reign. You would have to make a couple of presets and only be able to apply those.

[Xenophule]

I expected as much. This was really a best-case scenereo anyway.

Would it be possible to just do that without the editing bits?

[PeejAvery]

Would it be possible to just do that without the editing bits?
To do just what?

[Xenophule]

To "place" the image on the site and have it "appear" to others, etc.

[PeejAvery]

I'm sorry, but you are being very vague. To place an image, all you need is to output an <img> tag in HTML. To make it appear, all you need is to have the CSS style display and visibility set properly.

Now, if you mean that you want a file uploaded and then use the GD library to alter it, then you will want to look at the following.

http://www.php.net/features.file-upload
http://us2.php.net/manual/en/image.examples.php
http://us2.php.net/manual/en/ref.image.php

[Xenophule]

No, not exactly.

Let's take some examples.

There's a service that allows you to highlight websites and comment on them and when others go to that site they can see the highlights, read the comments, and leave their own comments.

There's also a passive MMO (PMOG.com) that uses a Firefox plugin to create popups that have content created by its users.

What I'm getting at is something similar--except an image appears on the page itself. If this requires a Firefox extension, how would I go about doing such?

[PeejAvery]

Since you aren't provided visible examples, it is hard to figure out exactly what you want.

Basically, are you looking for a mini online image editor/creator? If so, you are going to have to use a browser plugin as you mentioned. Or you can use Flash, Silverlight, or Java. Just JavaScript and PHP will not be able to accomplish that for you.

[Xenophule]

Since you aren't provided visible examples
http://i74.photobucket.com/albums/i259/stealthy-kitten/picpage.png

[PeejAvery]

Haha. Nice drawing.

Since this is a cross website implementation, you will have to use a toolbar.

[Xenophule]

Awesome!

Could you point me in the direction of what I should look up?

[PeejAvery]

Sorry, I don't do toolbars because of having to write one for each browser. Then, the client has to install them.

But, stick around. Perhaps someone else here does.