FUNCTION split_image, im, pdf

    sz=size(im)
    
    total_im=total(im)
    
    ;print,total_im
    ;prob_dist_den = fltarr(10000)
    ;j=0
    
    ;FOR i=0.01,0.5,0.01 DO BEGIN & $
    ;	prob_dist_den(j:(j-1+4*i*100)) = i & $
    ;	j=max(where(prob_dist_den NE 0.))+1 & $
    ;ENDFOR
    
    ;FOR i=0.51,0.99,0.01 DO BEGIN & $
    ;	prob_dist_den(j:(j-1+4*(1-i)*100)) = i & $
    ;	j=max(where(prob_dist_den NE 0.))+1 & $
    ;ENDFOR
    
    ;plot_hist,prob_dist_den,bin=0.01,x,h
    ;plot,x,h/sqrt(N_ELEMENTS(prob_dist_den))
    
    recalc:
    m2n=get_rid()
    m1n=get_rid()
    
    IF m1n EQ 10000. OR m2n EQ 10000. OR m1n EQ 0. OR m2n EQ 0. THEN GOTO, recalc
    m1=pdf(m1n)
    m2=pdf(m2n)
    
    im( 0:sz(1)/2.-1, 0:sz(2)/2.-1) = (m1*m2)*total_im/(sz(1)*sz(2)/4.)
    im( sz(1)/2.:*, 0:sz(2)/2.-1)   = (m1*(1-m2))*total_im/(sz(1)*sz(2)/4.)
    im( 0:sz(1)/2.-1, sz(2)/2:*)    = ((1-m1)*m2)*total_im/(sz(1)*sz(2)/4.)
    im( sz(1)/2.:*, sz(2)/2:*)      = ((1-m1)*(1-m2))*total_im/(sz(1)*sz(2)/4.)
    ;tvim,im
    ;print,total_im
    RETURN,im
END