X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?a=blobdiff_plain;ds=sidebyside;f=pctb%2Fstructure.c;fp=pctb%2Fstructure.c;h=c54f89a13c35aa3a4b8bc7ef4dda73b1bc665fb3;hb=41ac8cfeadd4eac0927b8fce086c805c2753ba77;hp=139180878012d92ae6b0589c19d262c370a02a21;hpb=710699382b7be70ce8fb067a7d64102fa5153754;p=ypp-sc-tools.db-live.git

diff --git a/pctb/structure.c b/pctb/structure.c
index 1391808..c54f89a 100644
--- a/pctb/structure.c
+++ b/pctb/structure.c
@@ -486,11 +486,16 @@ static double find_aa_density(const RgbImage *ri, Point p, long background,
   double alpha_max= alpha_mean + thresh;
   for (i=0; i<3; i++)
     MUST( alpha_min <= alpha[i] && alpha[i] <= alpha_max,
+	  MP(p);
 	  MRGB(here);MRGB(background);MRGB(foreground);MI(fg_extra);
 	  MF(alpha_min); MI(i);MF(alpha[i]);MF(alpha_max) );
 
+  if (   -1e-5 <  alpha_mean && alpha_mean <= 0.0     ) alpha_mean= 0.0;
+  if (1.0      <= alpha_mean && alpha_mean <= 1.0+1e-5) alpha_mean= 1.0;
+
   MUST( 0 <= alpha_mean &&
-	(fg_extra ? alpha_mean < 0.999 : alpha_mean >= 1.0),
+	(fg_extra ? (alpha_mean < 0.999) : (alpha_mean <= 1.0)),
+	MP(p);
 	MRGB(here);MRGB(background);MRGB(foreground);MI(fg_extra);
 	MF(alpha_mean); MF(alpha[0]);MF(alpha[1]);MF(alpha[2]); );