Fix issue where entire physical pages would disappear.

diff --git a/scan2pages.sh b/scan2pages.sh
index cbfe52f..3013efe 100755 (executable)
--- a/scan2pages.sh
+++ b/scan2pages.sh
@@ -156,7 +156,7 @@ for scanpgnum in  `$my_seq 1 $pages`; do
                # ... get crop co-ords. They're off by ~2 as I don't know how to
                # properly correct for the border.
                cropcords=$(convert -border 1x1 -bordercolor '#000' -resize 1000% -trim -fuzz 90% -format "%wx%h%O" $outdir/scanpg-mask-${scanpgnum}.png info: || exit 1)
-               
+
                # ... crop and despeckle? the final pre-prepared image
                convert $convertflags -crop $cropcords $binscanpg  $cleanscanpg || exit 1
        fi;
@@ -190,13 +190,22 @@ for scanpgnum in  `$my_seq 1 $pages`; do
                        convert $convertflags -resize 10% -depth 8 -gamma 0.01 -median 2 $physpg $outdir/physpg-mask-${scanpgnum}-${physpgnum}.png ||exit 1
 
                        # Trim #-border 1x1 -bordercolor '#fff' -trim -fuzz 30% 
-                       cropcords=$(convert -trim -fuzz 90%\
+                       # binarise is so effective, try something << 90%
+                       cropcords=$(convert -trim -fuzz 50%\
                         -resize 1000% -format "%wx%h%O" $outdir/physpg-mask-${scanpgnum}-${physpgnum}.png info: || exit 1)
                
+                       [[ $verbose ]] && echo Crop co-ords: $cropcords
+
                        # ... crop and despeckle? the final pre-prepared image
                        convert $convertflags -crop $cropcords $physpg $cleanphyspg || exit 1
                fi;
-               
+
+               # check it hasn't mostly disappeared, warn viciously if it has!
+               if [[ $(convert  $cleanphyspg -format '%[fx:s.w*s.h>1000]' info:) = "0" ]]; then
+                       echo "Warning: discarding physical pg ${scanpgnum}-${physpgnum}: not enough remains after masking."
+                       continue;
+               fi;
+
                #detect if the page is 2-up
 
                if [[ $logperphys == 2 ]] || ( [[ $logperphys != 1 ]] && $(dirname $0)/detect2pages.sh ${cleanphyspg} ${scanpgnum} ${physpgnum} ); then