# CINJOF --- Convolution INternal with Jumps. Output and FILTER are conjugate.
#
subroutine cinjof( conj, add, jump,   n1,n2,xx, nb1,nb2,bb, yy)
integer            conj, add, jump,   n1,n2,    nb1,nb2	  # jump subsamples data
real                                  xx( n1,n2),  bb( nb1,nb2),  yy( n1,n2)
integer y1,y2, x1,x2, b1, b2, ny1, ny2
call conjnull( conj, add,                          bb, nb1*nb2,   yy, n1*n2)
ny1 = n1 - (nb1-1) * jump;		if( ny1<1 ) call erexit('cinjof: ny1<1')
ny2 = n2 - (nb2-1);			if( ny2<1 ) call erexit('cinjof: ny2<1')
if( conj == 0 )
	do b2=1,nb2 { do y2=1,ny2 {	x2 =  y2 - (b2-nb2)      
	do b1=1,nb1 { do y1=1,ny1 {	x1 =  y1 - (b1-nb1) * jump
				yy(y1,y2) = yy(y1,y2) + bb(b1,b2) * xx(x1,x2)
			}} }}
else
	do b2=1,nb2 { do y2=1,ny2 {	x2 =  y2 - (b2-nb2)      
	do b1=1,nb1 { do y1=1,ny1 {	x1 =  y1 - (b1-nb1) * jump
				bb(b1,b2) = bb(b1,b2) + yy(y1,y2) * xx(x1,x2)
			}} }}
return; end