I have a PNG image, that has free form (non square).
I need to apply drop-shadow effect to this image.
The standard approach ...
-o-box-shadow: 12px 12px 29px #555;
-icab-box-shadow: 12px 12px 29px #555;
-khtml-box-shadow: 12px 12px 29px #555;
-moz-box-shadow: 12px 12px 29px #555;
-webkit-box-shadow: 12px 12px 29px #555;
box-shadow: 12px 12px 29px #555;
... displays shadows for this image, like it is a square. So, I see my image and square shadow, that doesn't follows the form of object, displayed in image.
Is there any way to do it properly?
A little late to the party, but yes, it is totally possible to create "true" dynamic drop shadows around alpha masked PNGs, using a combination of dropshadow-filter (for Webkit), SVG (for Firefox) and DX filters for IE.
.shadowed {
-webkit-filter: drop-shadow(12px 12px 25px rgba(0,0,0,0.5));
filter: url(#drop-shadow);
-ms-filter: "progid:DXImageTransform.Microsoft.Dropshadow(OffX=12, OffY=12, Color='#444')";
filter: "progid:DXImageTransform.Microsoft.Dropshadow(OffX=12, OffY=12, Color='#444')";
}
<!-- HTML elements here -->
<svg height="0" xmlns="http://www.w3.org/2000/svg">
<filter id="drop-shadow">
<feGaussianBlur in="SourceAlpha" stdDeviation="4"/>
<feOffset dx="12" dy="12" result="offsetblur"/>
<feFlood flood-color="rgba(0,0,0,0.5)"/>
<feComposite in2="offsetblur" operator="in"/>
<feMerge>
<feMergeNode/>
<feMergeNode in="SourceGraphic"/>
</feMerge>
</filter>
</svg>
Some comparisons between true drop-shadow and box-shadow and an article on the technique I've just described.
I hope this helps!