public byte[] getPaletteTransparency() {
            if (!transparencySet) {
                throw new IllegalStateException(PropertyUtil.getString("PNGEncodeParam5"));
            }
            byte[] alpha = new byte[transparency.length];
            for (int i = 0; i < alpha.length; i++) {
                alpha[i] = (byte)transparency[i];
            }
            return alpha;
        }
Returns the alpha values associated with each palette entry.

<p> If the palette transparency has not previously been
set, or has been unset, an
<code>IllegalStateException</code> will be thrown.

@throws IllegalStateException if the palette transparency is
       not set.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/png/PNGEncodeParam.java