Improved border artifact work; dealing with blank scans; 2up page detection

diff --git a/detect2pages.sh b/detect2pages.sh
new file mode 100755 (executable)
index 0000000..4b8c189
--- /dev/null
+++ b/detect2pages.sh
@@ -0,0 +1,45 @@
+#!/bin/bash
+
+#should probably have given up on shell and gone over to python.
+
+
+infile=$1
+pg=$2
+subpg=$3
+
+dir=$(dirname $infile)
+
+convert -blur 10 -gamma 0.00001 -median 1 $infile -resize 1x601\! -gamma 0.3 $dir/strip-${pg}-${subpg}.png
+
+#There seems to be a definte bias in my reader scans for things to be in the top part rather than the bottom part
+testpoints=`jot - 270 320`
+
+sum=0
+prev=0
+longestrun=0
+
+
+for testpoint in $testpoints; do
+       #convert -verbose strip-${pg}-${subpg}.png[1x1+0+${testpoint}] -format "%[fx:s.intensity]" info:
+       value=$(convert $dir/strip-${pg}-${subpg}.png[1x1+0+${testpoint}] -format "%[fx:s.intensity>0.3]" info:)
+       sum=$(expr $value + $sum)
+
+       if [[ $prev = 1 && $value = 0 ]]; then
+               if [[ $sum > $longestrun ]]; then
+                       longestrun=$sum;
+               fi;
+               sum=0
+       fi;
+
+       prev=$value
+
+       #echo "$testpoint: $value ($sum, $longestrun)"
+done;
+
+if [[ $sum > $longestrun ]]; then
+       longestrun=$sum;
+fi
+
+echo $longestrun
+
+exit $( expr $longestrun "<=" 10 )

diff --git a/scan2pages.sh b/scan2pages.sh
index 321d31c..b129963 100755 (executable)
--- a/scan2pages.sh
+++ b/scan2pages.sh
@@ -160,21 +160,46 @@ for pg in `$my_seq 1 $pages`; do
                cp $origpnm $preppnm
        fi;
        
+       # check it hasn't mostly disappeared - e.g. if the scan was all black
+       # (e.g. forgot to put the book down when you first hit scan)
+       # ... not sure why such a convoluted form is required. expr doesn't like
+       # processing a convert -format "%w * %h" or any variant thereof
+       if [[ $(convert  $preppnm -format '%[fx:s.w*s.h>1000]' info:) = "0" ]]; then
+               [[ $verbose == 1 ]] && echo "Discarding pg ${pgn}: not enough remains after masking."
+               continue; 
+       fi;
+       
        #unpaper it
        #names go a bit funny here
        #also, ignore flags starting here
        unppnm=$dir/upg-${pgn}-%01d.pnm
        unpaper $unpaperflags --layout double --overwrite --no-blackfilter -ni 10 -op 2 $preppnm $unppnm || exit 1
 
+       #detect if the page is 2-up
+       for subpg in $($my_seq 1 2); do
+               echo Processing subpg ${subpg}.
+               if $(dirname $0)/detect2pages.sh $dir/upg-${pgn}-${subpg}.pnm ${pgn} ${subpg}; then
+                       if [[ $verbose == 1 ]]; then
+                               echo "Resplitting subpg ${subpg}."
+                       fi
+                       unpaper $unpaperflags --pre-rotate 90 --layout double --overwrite --no-blackfilter -op 2 $dir/upg-${pgn}-${subpg}.pnm $dir/upg-${pgn}-${subpg}-%01d.pnm
+               else
+                       cp $dir/upg-${pgn}-${subpg}.pnm $dir/upg-${pgn}-${subpg}-1.pnm
+               fi;
+
+       done;
+
        #final convert and clean w/ bebook optimisation
        if [[ $bebook ]]; then
-               convert $convertflags -colorspace Gray -median 1 $dir/upg-${pgn}-?.pnm -resize 1200x1600 $dir/final-${pgn}-%01d.${extension} || exit 1
+               convert $convertflags -colorspace Gray -median 1 $dir/upg-${pgn}-1-?.pnm -trim -resize 1800x2400 $dir/final-${pgn}-1-%01d.${extension} || exit 1
+               convert $convertflags -colorspace Gray -median 1 $dir/upg-${pgn}-2-?.pnm -trim -resize 1800x2400 $dir/final-${pgn}-2-%01d.${extension} || exit 1
        else
-               convert $convertflags $dir/upg-${pgn}-?.pnm $dir/final-${pgn}-%01d.${extension} || exit 1
+               convert $convertflags $dir/upg-${pgn}-1-?.pnm $dir/final-${pgn}-1-%01d.${extension} || exit 1
+               convert $convertflags $dir/upg-${pgn}-2-?.pnm $dir/final-${pgn}-2-%01d.${extension} || exit 1
        fi
        
 done
 
-mkdir $dir/pages
+mkdir -p $dir/pages
 mv $dir/final-*.${extension} $dir/pages