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The Ultimate Guide to swfIR Image Replacement

[ Screenshot: Example Photo Styled with swfIR ] In this ultimate guide to swfIR, you will learn how to use swfIR to replace your ordinary images with richer, stylized graphics. swfIR enables efficient, practical and scalable application of drop-shadows, rounded corners, and even image rotation to any number of specified images throughout your site. From concept and application to examples and recipes, this guide covers everything you need for successful swfIR implementation.

The Challenge..

There are many ways to enhance the visual presentation of your images. Popular visual effects include rounded corners, drop shadows, and image rotation. To achieve these effects, designers often use either CSS, direct image manipulation, or some combination thereof. CSS may possess limited ability to round image borders in certain browsers, but for drop shadows and image rotation, designers must either modify each image individually, or rely upon convoluted techniques employing additional graphics and CSS to get the job done. This may be suitable for a single header graphic, but for any significant number of images, hand-editing each one in Photoshop with the desired visual effect is neither efficient, practical, nor scalable.

The Solution..

Fortunately, JavaScript provides a far better solution via the outstanding >swfIR method. Thanks to the work of Jon Aldinger, Mark Huot, and Dan Mall, swfIR (swf Image replacement) provides designers an efficient, practical and scalable method of applying a flexible assortment of visual effects to any number of images. swfIR works by uniting the magical powers of JavaScript and Flash to dynamically stylize all specified images within all associated web pages. The JavaScript relies upon a modified, integrated version of Geoff Stearns’ SWFObject and is completely unobtrusive in its application. swfIR enables strict compliance with standards-based web design through progressive enhancement and graceful degradation.

The Process..

Once implemented, swfIR performs the following actions:

  • Identifies all specified/targeted images on the web page
  • Applies specified styles to all targeted images via Flash
  • Replaces original <img> elements with processed graphics

Each replaced image is enclosed within a dynamically applied <span> element. Further, the id or class attribute associated with each replaced image is replicated on the corresponding <span> element, thereby providing hooks for additional CSS styles. To demonstrate this transformation, here is an example showing the image markup before swfIR processing:

<img id="season" src="http://domain.tld/path/image.png" alt="Winter Scene" />

..and here is how the markup looks after swfIR processing:

<span id="season" class="swfir">
	[ replaced image; code varies by browser ]

As you can see, the code within the <span> element will vary according to specific browser types. Also notice the how the id is transferred to the <span> element itself; for replaced images identified via class attribute, the class name is transferred instead.


One of the great things about swfIR is the ease of typical implementations, and the flexibility of more elaborate, custom applications. Although knowledge of JavaScript and Flash is certainly beneficial, it is by no means necessary to get swfIR up and running on your site. Here’s how to do it in four easy steps (well, okay, three easy steps and one step that requires a little thought):

1. Download swfIR!
Go to the official swfIR website and download a copy of swfIR.
2. Upload swfIR!
Upload the two files, swfir.js and swfir.swf, into the same directory on your server (save the readme file for future reference). If these two files aren’t in the same directory, you will need to edit the src parameter, as described in the “Important Notes” section (below).
3. Include the JavaScript
Place the following code within the <head> region of your (X)HTML document (remember to specify the correct path!):
<script type="text/javascript" src="http://domain.tld/path/swfir.js"></script>
4. Specify the Styles
In this step, you specify the various styles that are applied to your target images. This step requires a bit of explaining, so we will go ahead and discuss it in detail in the next section. For those of you already familiar with this process, here is a quick, “copy-&-paste” example:
<script type="text/javascript">
	// applies a big fat white border 
	window.onload = function() {
		var sir = new swfir();
		sir.specify("border-width", "25");
		sir.specify("border-color", "fff");


Once you have uploaded the swfIR files to your server and included them as described in the previous section, you are ready to custom the script by specifying the various image styles. Begin by placing the following code just before the closing </body> tag of your web page1:

<script type="text/javascript">
	window.onload = function() {
		var sir = new swfir();


Then, the desired style parameters are inserted between the var sir = new swfir(); and the closing bracket. Here is the general format for each of the currently available parameters (listed below):

sir.specify([parameter], [value]);

Here is a list of available swfIR parameters and their associated value types:

border-radius    = number
border-width     = number
border-color     = color   (e.g., #fff)

shadow-color     = color   (e.g., #fff)
shadow-quality   = number  (between 0 - 1)
shadow-alpha     = number  (between 0 - 100)
shadow-blur	 = number
shadow-blur-x    = number
shadow-blur-y    = number
shadow-strength  = number
shadow-offset    = number
shadow-angle     = number
shadow-inner     = boolean (true or false)
shadow-knockout  = boolean (true or false)
shadow-hide      = boolean (true or false)

rotate           = number  (between -359 - 359)
overflow         = string  ('expand-x', 'expand-y', or 'fit')
elasticity       = string  ('true'), number (pixel-to-em ratio)
src              = string  (path to your swf file, if not standard)
wmode            = string  ('opaque', 'transparent', etc.)
link             = string  (e.g., http://www.example.com/)

So, let’s say that we want to add a 25-pixel white border to an image with an id of #example. After determining the required parameters from the list, our style-specification code would now look like this:

<script type="text/javascript">
	window.onload = function() {
		var sir = new swfir();
		sir.specify("border-width", "25");
		sir.specify("border-color", "fff");

In addition to the two specified style parameters, we have also added the required swap() method to indicate exactly our target image(s), namely:


Here we are targeting an image with an id of “example”. Of course, we may also target an entire class of images by including a swap() method such as:


Technically, the swap() method accepts any valid CSS selector. So, for example, we could target all images withing some div marked with an id of “container”:

sir.swap("#container img");

We can even use attribute selectors to specify our target images. For example, we may target all images containing an alt attribute of “Pancakes”:


The possibilities for targeting images are virtually endless!

And that’s all there is to it! At this point, you should be up and running with swfIR. It may seem like a lot to read through, but once you get everything setup and configured properly, using swfIR is really quite straightforward, even fun! Now, before digging into some specific code examples and recipes, let’s cover a few important notes concerning the implementation and functionality of swfIR.

Important Notes

Some important things to consider..

Custom swf file location

As discussed in step 2 of the “Application” section above, you must explicitly define the location of the swfir.swf file only if it is located in a different directory than the swfir.js file. To do this, add the following line of code to your style parameters:

sir.specify("src", "http://domain.tld/different/path/swfir.swf");

As usual, edit the file path to reflect the actual location of the file on your web server. Here is how the code appears when placed correctly in our working example:

<script type="text/javascript">
	window.onload = function() {
		var sir = new swfir();
		sir.specify("border-width", "25");
		sir.specify("border-color", "fff");
		sir.specify("src", "http://domain.tld/different/path/swfir.swf");

Elasticity settings

When setting the elasticity parameter to “true”, swfIR will resize your image(s) using ems rather than pixels. This functionality enables your styled images to automatically resize along with text and other resizable elements. You may also specify an exact pixel-to-em ratio (such as 10 for a base-font size of 62.5%) to bypass the auto calculation and decrease rendering time.

Targeting all images

To target all images — i.e., all <img> elements — on the page, we would write our example like so:

<script type="text/javascript">
	window.onload = function() {
		var sir = new swfir();
		sir.specify("border-width", "25");
		sir.specify("border-color", "fff");
		sir.specify("src", "http://domain.tld/different/path/swfir.swf");

As you can see, we have simply replaced the id value in our swap() method with “img”.

Current issues

Unfortunately, there are several issues that may interfere with flawless swfIR functionality:

  • Resizing/zooming in Opera crashes the browser
  • Flash of unstyled content: images load before JavaScript replaces them
  • alt text is not preserved upon replacement
  • HTML right-click options are disabled
  • Incompatible with other JavaScript libraries like Prototype or MooTools
  • Doesn’t work with hot-linked images because of security restrictions in Flash

The swfIR team assures us that they are diligently working on solutions for these issues. ;) Now, with that out of the way, lets dive into some tasty little swfIR recipes!

Examples and Recipes

With an understanding of swfIR and how it works, we are now ready to dig into some tasty little code recipes — simply copy, paste, and edit to suit your specific needs! If you have other handy swfIR recipes that you would like to see here, drop a comment and I’ll post it along with a credit link to your site! :)

Rounded Corners

Complete recipe for white, rounded borders applied to all <img> elements. Edit paths and values, delete any extraneous lines, and/or add additional parameters as needed:

<script type="text/javascript" src="http://domain.tld/path/swfir.js"></script>
<script type="text/javascript">
	window.onload = function() {	
		round = new swfir();
		round.specify('src', 'http://domain.tld/path/swfir.swf');
		round.specify('border-color', 'ffffff');
		round.specify('border-radius', '10');

Rotated Images

Complete recipe for slight image rotation applied to all <img> elements. Edit paths and values, delete any extraneous lines, and/or add additional parameters as needed:

<script type="text/javascript" src="http://domain.tld/path/swfir.js"></script>
<script type="text/javascript">
	window.onload = function() {	
		rotate = new swfir();
		rotate.specify('src', 'http://domain.tld/path/swfir.swf');
		rotate.specify('rotate', '-5');

Elastic Images

Complete recipe for elasticity applied to all <img> elements. Edit paths and values, delete any extraneous lines, and/or add additional parameters as needed:

<script type="text/javascript" src="http://domain.tld/path/swfir.js"></script>
<script type="text/javascript">
	window.onload = function() {
		var elastic = new swfir();
		elastic.specify('src', 'http://domain.tld/path/swfir.swf');
		elastic.specify('elasticity', 'true');

Multiple Images

Complete recipe for slight image rotation applied to two different <img> elements, identified via right and left, respectively. Edit paths and values, delete any extraneous lines, and/or add additional parameters as needed:

<script type="text/javascript" src="http://domain.tld/path/swfir.js"></script>
<script type="text/javascript">
	window.onload = function() {	
		rotate_01 = new swfir();
		rotate_01.specify('src', 'http://domain.tld/path/swfir.swf');
		rotate_01.specify('rotate', '-5');

		rotate_02 = new swfir();
		rotate_02.specify('src', 'http://domain.tld/path/swfir.swf');
		rotate_02.specify('rotate', '5');

Multiple Styles

Complete recipe for multiple styles applied to all images within a div marked with an id of “targeted”. Edit paths and values, delete any extraneous lines, and/or add additional parameters as needed:

<script type="text/javascript" src="http://domain.tld/path/swfir.js"></script>
<script type="text/javascript">
	window.onload = function() {
		sir = new swfir();
		sir.specify("shadow-blur", "15");
		sir.specify("border-width", "20");
		sir.specify("border-radius", "15");
		sir.specify("border-color", "fff");
		sir.specify("background-color", "000");
		sir.specify('src', 'http://domain.tld/path/swfir.swf');
		sir.swap("#targeted img");

A Specific Implementation..

Here is a specific implementation that I used recently on a client’s site. The trick for this setup involves styling multiple images with multiple styles, and also placing all of the stylistic parameters in an external JavaScript file to keep things 100% unobtrusive and sweet. At this point, all of the style parameters should speak for themselves, so I will forego another elaborate discussion concerning the intrinsic mechanics of this specific application. Note that, in order to get this technique to work, the <script> call to the external swfir.js JavaScript file must be placed in the document <head>; the script will not work when called from the bottom of the <body> element. Here is the code that was included at the bottom of the swfir.js JavaScript file itself:

// set swfir variables
function set_variables() {	
	kel = new swfir();
	kel.specify("shadow-blur", "10");
	kel.specify("border-width", "7");
	kel.specify("shadow-angle", "60");
	kel.specify("shadow-offset", "5");
	kel.specify("border-radius", "10");
	kel.specify("border-color", "cccccc");
	kel.specify('src', 'http://domain.tld/javascript/swfir.swf');
	hat = new swfir();
	hat.specify("shadow-blur", "10");
	hat.specify("border-width", "5");
	hat.specify("shadow-angle", "60");
	hat.specify("shadow-offset", "5");
	hat.specify("border-radius", "10");
	hat.specify("border-color", "cccccc");
	hat.specify('src', 'http://domain.tld/javascript/swfir.swf');
// onload event function
function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function() {
			if (oldonload) {

Also note that the onload event function can be anything you wish; no need to use this exact method, especially if you have an existing onload event function available elsewhere.

Hit the lights..

In this extensive tutorial, we have covered everything you need to know to successfully deploy swfIR on your own sites. If you have any questions, concerns, or improvements, please share them via them comments below. And, again, if you have any keen swfIR code recipes, drop them in a comment or email me directly (Jeff at this domain) and I will put those up (along with a link to your site) as well. Alright, that’s gonna do it for this mind-boggling article! I think I’ll take a little break.. ;)


  • 1 Note that, although it isn’t recommended on the swfIR site, it is possible to place this code at the bottom of the external swfir.js document, thereby achieving a more “unobtrusive” implementation. This external placement may not work for all configurations, and is known to fail when the call to the JavaScript file is made from the bottom of the <body> element (as recommended for performance optimization).

About the Author
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19 responses to “The Ultimate Guide to swfIR Image Replacement”

  1. Not to be confused with sIFR : http://www.mikeindustries.com/blog/sifr/

  2. Jeff Starr 2008/11/09 9:41 am

    Correct, swfIR is for styling images, while sIFR is used for replacing text with images. Thanks for the reminder!

  3. Wow this is definitely some awesome stuff. I guess what makes swfIR very appealing is that if you have basic knowledge of CSS, the possibilities of image styling is almost infinite. I love the fact that it allows CSS selectors, which allows us to style images selectively across the page.

    It is tragic that it is incompatible with other javascript libraries like MooTools and Prototype – I hope they can fix the incompatibility issue soon. But if I really wan to use it I wouldn’t mind forgoing the javascript libraries for simple websites.

    This is a really comprehensive guide you’ve written about swfIR! Excellent stuff over here ;) thanks for sharing!

  4. Jeff Starr 2008/11/09 5:10 pm

    Hi teddY! Great to see you again! Thanks for the feedback on the article — hopefully it will serve the web-design community well. As for the incompatibility, I wonder if the conflict is with swfobject (which is included in the script), or with the swfIR script itself.. seems like a workaround should be possible. Hopefully they are working on it! In any case, thanks for dropping by, and I am glad you enjoyed the article! :)

  5. Absolutely amazing site, love the design.

  6. And I thought my job was complicated!

  7. Geld Lening 2008/11/16 9:40 am

    Wow, this is really something I’m going to check out tomorrow! The options seem endless! Thanks for the article!

  8. Jeff Starr 2008/11/16 4:42 pm

    My pleasure! Glad you find the article useful! :)

  9. Elliot Geno 2009/02/09 10:08 am

    @Geld Lening
    Not totally endless though… I would like to see all the traditional flash filters made available through this. Including Bevel, Glow, Blur, and adjust color. Plus it is unclear if you can

    They don’t provide you with the source FLA and AS classes. So you can’t create your own unique take on it.

    All you get is a compiled SWF.

    I just would like take a crack at it and see what I can do!

    Also… in the documentation about drop shadow quality. It says its a number between 0 and 1 which is inaccurate. Flash accepts a number between 1 and 3 for quality for rendering of filters. So set that to 3 for the highest quality rendering of shadows! 2 even looks way better than 1!

  10. Elliot Geno 2009/02/09 10:12 am

    Sorry, it was unclear if you can add multiple filters to mix and match, or whether or not you can apply multiple filters in specific orders… which is kind of a nice feature in flash.

  11. Elliot Geno 2009/02/09 10:20 am

    OOOOHHH! I just thought of something really cool for this!

    With Flash 10 there is the new ability to rotate flat objects in 3D space. It would be cool to add this functionality to a picture!

    So you could say something like this…
    sir.specify(“rotation-x”, “15”);

    And it would rotate your image 15 degrees along the x axis! I am going to email them!

  12. I am a university lecturer in Sri Lanka and we have a learning Management system operating on Moodle Platform.

    We have a local server and the reading materials are uploaded to the server for the access of the students.

    I tried this Swfir tools with few images and uploaded to the local server. But it doesn’t work there. Initially the images download to the browser and when the swf functioning start images become invisible though the flash player is running on the desktop.

    when the java is disabled in the browser it shows only the jpeg images.

    Can anyone help me to solve this , Is this a problem with the Moodle or with our local server?

    It works perfectly in other free web hosting servers.

    Any reply is appreciated.


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