macbeth problems

Hi everybody,

I have some problems applying macbeth correction to some images. These are raw files converted to tiff with GraphicConverter, and then to pic, using ra_tiff. When I use macbethcal, it looks like it is working fine, no message, nevertheless if I view the debug.pic image, the right part of the squares stay black, which means that the calculation of the new color is not done. Here is the cal file I obtain where we can see that the variables are not calculated.

{
  Color correction file computed by:
    macbethcal -d A1.debug2.pic -p 1791 489 1724 2087 2839 539 2753 2134 A1_M.pic2 A1_2.cal

  Usage: pcomb -f A1_2.cal uncorrected.pic > corrected.pic
}
rxa(i) : select(i,0.00243504,0.0188038,0.0882526,0.293579,0.800897,0.994141);
rya(i) : select(i,0.0309326,0.0889489,0.201031,0.361486,0.602564,0.919236);
rfi(n) = if(n-4.5, 5, if(rxa(n+1)-r, n, rfi(n+1)));
rndx = rfi(1);
rn = ((rxa(rndx+1)-r)*rya(rndx) + (r-rxa(rndx))*rya(rndx+1)) /
    (rxa(rndx+1) - rxa(rndx)) ;
gxa(i) : select(i,0.00234237,0.0200952,0.0949858,0.297096,0.832963,0.994141);
gya(i) : select(i,0.0308484,0.0876956,0.200415,0.366194,0.606247,0.919034);
gfi(n) = if(n-4.5, 5, if(gxa(n+1)-g, n, gfi(n+1)));
gndx = gfi(1);
gn = ((gxa(gndx+1)-g)*gya(gndx) + (g-gxa(gndx))*gya(gndx+1)) /
    (gxa(gndx+1) - gxa(gndx)) ;
bxa(i) : select(i,0.0040146,0.0385061,0.178308,0.545997,0.994141,0.994141);
bya(i) : select(i,0.0303486,0.0852925,0.19516,0.360336,0.597103,0.884932);
bfi(n) = if(n-4.5, 5, if(bxa(n+1)-b, n, bfi(n+1)));
bndx = bfi(1);
bn = ((bxa(bndx+1)-b)*bya(bndx) + (b-bxa(bndx))*bya(bndx+1)) /
    (bxa(bndx+1) - bxa(bndx)) ;
r = ri(1); g = gi(1); b = bi(1);
ro = nan*rn + nan*gn + nan*bn ;
go = nan*rn + nan*gn + nan*bn ;
bo = nan*rn + nan*gn + nan*bn ;

I have no idea of what happens there. I tryed with an another file and had the same result. I also tryed with a blur. Is it because of the original raw format? or because I have no color profile? What should I do?

genevieve lucet

Hi Genevieve,

I don't know where you got these primary values, but CIE (x,y) primaries must each be between 0.0 and 1.0, and they cannot add up to greater than 1.0 when combined. I suspect this is at least part of your problem.

-Greg

···

{
  Color correction file computed by:
    macbethcal -d A1.debug2.pic -p 1791 489 1724 2087 2839 539 2753 2134 A1_M.pic2 A1_2.cal

  Usage: pcomb -f A1_2.cal uncorrected.pic > corrected.pic
}