|Object properties:||Enabled, Color|
|Supported by objects:||A, ACRONYM, ADDRESS, B, BDO, BIG BLOCKQUOTE, body, BUTTON, CAPTION, CENTER, CITE, CODE, custom, DD, DFN, DIR, DIV, DL, DT, EM, FIELDSET, FONT, FORM, FRAME, Hn, I, IFRAME, IMG, INPUT, INS, KBD, LABEL, LEGEND, LI, MARQUEE, MENU, NOBR, OL, P, PLAINTEXT, PRE, Q, RT, RUBY, runtimeStyle, S, SAMP, SMALL, SPAN, STRIKE, STRONG, style, SUB, SUP, TABLE, TD, TEXTAREA, TH, TT, U, UL, VAR, XMP|
This visual filter provides a way to define a particular color as being transparent. This is sometimes called chroma keying (a technique much used in the television industry).
The Color property defines a hex triplet value which is deemed to be transparent for this element.
Version 5.5 of the MSIE browser adds the Enabled property which controls whether the effect is applied by means of the true and false value.
The example makes black the transparent color for the image.
Filters are defined in style sheets as if they were a function call with its arguments expressed as name=value pairs. This is not the typical way to define arguments so you should be aware of this anomaly when working with filters.
This can display some unattractive visual artifacts with images that have been compressed or dithered to reduce the number of colors available. It also does not work very well round the edges of anti-aliased images.
<HTML> <HEAD> </HEAD> <BODY> Normal--> <IMG ID="NORMAL" SRC="./Logo150.gif"> Filtered--> <IMG ID="MYIMAGE" SRC="./Logo150.gif"> <BR> <SCRIPT> myFilter = "progid:DXImageTransform.Microsoft.Chroma(color=#000000)"; document.all.MYIMAGE.style.filter = myFilter; </SCRIPT> </BODY> </HTML>