BilinearForward Mapping Equations: i = +0.666667*x -0.000000*y +0.003704*x*y +0.000000; j = +0.333333*x +1.000000*y -0.003704*x*y +0.000000; BilinearForward Distort, FX Equivelent: -fx 'ii=i+page.x+0.500000; jj=j+page.y+0.500000; bb=-0.003704*ii -0.003704*jj +0.666667; rt=bb*bb -0.014815*(0.333333*ii-0.666667*jj); yy=( -bb + sqrt(rt) ) / 0.007407; xx=(ii +0.000000*yy)/(0.666667 +0.003704*yy); (rt < 0 ) ? red : p{ xx-page.x-.5, yy-page.y-.5 }'