Question

I’m trying to find all elements that have a filter style applied to them from a CSS file.

For instance

.fourty {

    filter:alpha(opacity=40);
}
.fifty {

    filter:alpha(opacity=50);
}
.sixty {

    filter:alpha(opacity=60);
}

How would I capture those elements?

Answer 1

How about add class to the elements which has filter ?
Then you can do the following:

var $elements = $('.yourClass');

Or you can do the following if you don’t want to add a class.

var $elements = $('*').filter(function() {
    return $(this).css('filter') != 'auto';
});

I suggest you to add opacity to the css, because filter isn’t crossbrowser. So your code should be the following.

var $elements = $('*').filter(function() {
    var $element = $(this);
    return $element.css('filter') != 'auto' || $element.css('opacity') != 1;
});

demo