[求助]一个 apply to AOI的问题

<P> 我在一张QUICKBIRD影像上用AOI工具画了三个AOI,然后在RASTER的TOOLS里选择Convolve..,为什么不能选择apply to AOI呢.?apply to whole image 和on demand都能选择.</P>
<P>    帮助里面说"If the bands of the truecolor layer are not all from the same file, this radio button will be disabled and you will only be allowed to apply the convolution filter <B>On Demand</B>."那就应该不是这个问题了吧?</P>