i read the
http://www.imagemagick.org/Usage/layers/#layer_calc
and saw :
convert {balloon,castle,eye,eyeguy,ghost,hand_point,medical}.gif \
{news,noseguy,paint_brush,pencil,present,recycle}.gif \
{shading,skull,snowman,storm,terminal,tree}.gif \
\
-set page '+%[fx:80*cos((t/n)*2*pi)]+%[fx:80*sin((t/n)*2*pi)]' \
\
-background none -layers merge +repage image_circle.png
i change it to :
exec("convert 1.png 2.png 3.png ((((N.png)))) -set page '+%[fx:80*cos((t/n)*2*pi)]+%[fx:80*sin((t/n)*2*pi)]' -background none -layers merge +repage image_circle.png");
but the result is :

any help please?