PNG transparency issue in IE8

FIXED!

I've been wrestling with the same issue, and just had a breakthrough! We've established that if you give the image a background color or image, the png displays properly on top of it. The black border is gone, but now you've got an opaque background, and that pretty much defeats the purpose.

Then I remembered a rgba to ie filter converter I came across. (Thanks be to Michael Bester). So I wondered what would happen if I gave my problem pngs an ie filtered background emulating rgba(255,255,255,0), fully expecting it not to work, but lets try it anyway...

.item img {
    background: transparent;
    -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#00FFFFFF,endColorstr=#00FFFFFF)"; /* IE8 */   
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=#00FFFFFF,endColorstr=#00FFFFFF);   /* IE6 & 7 */      
    zoom: 1;

}

Presto! Goodbye black, and hello working alpha channels in ie7 and 8. Fade your pngs in and out, or animate them across the screen - it's all good.

I put this into a jQuery plugin to make it more modular (you supply the transparent gif):

$.fn.pngFix = function() {
  if (!$.browser.msie || $.browser.version >= 9) { return $(this); }

  return $(this).each(function() {
    var img = $(this),
        src = img.attr('src');

    img.attr('src', '/images/general/transparent.gif')
        .css('filter', "progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true',sizingMethod='crop',src='" + src + "')");
  });
};

Usage:

$('.my-selector').pngFix();

Note: It works also if your images are background images. Just apply the function on the div.

I know this thread has been dead some time, but here is another answer to the old ie8 png background issue.

You can do it in CSS by using IE's proprietary filtering system like this as well:

filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true',sizingMethod='scale',src='pathToYourPNG');

DEMO

you will need to use a blank.gif for the 'first' image in your background declaration. This is simply to confuse ie8 and prevent it from using both the filter and the background you have set, and only use the filter. Other browsers support multiple background images and will understand the background declaration and not understand the filter, hence using the background only.

You may also need to play with the sizingMethod in the filter to get it to work the way you want.

I had the same thing happen to a PNG with transparency that was set as the background-image of an <A> element with opacity applied.

The fix was to set the background-color of the <A> element.

So, the following:

filter: alpha(opacity=40);
-moz-opacity: 0.4;
-khtml-opacity: 0.4;
opacity: 0.4;
background-image: ...;

Turns into:

/* "Overwritten" by the background-image. However this fixes the IE7 and IE8 PNG-transparency-plus-opacity bug. */
background-color: #FFFFFF; 

filter: alpha(opacity=40);
-moz-opacity: 0.4;
-khtml-opacity: 0.4;
opacity: 0.4;
background-image: ...;