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Make comparsion of images more reliable #33

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Merged
judovana merged 1 commit into from
Oct 1, 2025
Merged

Make comparsion of images more reliable #33

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40 changes: 18 additions & 22 deletions tests/testlib.bash
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Original file line number Diff line number Diff line change
Expand Up @@ -215,7 +215,7 @@ function beforeBg() {
if [ "x$TTL" = "x" -o "x$TTL" = "x0" ] ; then
echo "manual mode!"
else
import -window root "$REPORT_DIR"/diff-01.png
import -window root "png24:$REPORT_DIR"/diff-01.png
fi
}

Expand All @@ -239,7 +239,7 @@ function resolveBg() {
wait "$pid"
else
sleep "$TTL"
import -window root "$REPORT_DIR"/$cname-02.png
import -window root "png24:$REPORT_DIR"/$cname-02.png
ps
#pstree
cpids="$( getDescendants "$pid" )"|| true # gets pids of descendant processes
Expand All @@ -249,20 +249,20 @@ function resolveBg() {
for cpid in $cpids ; do kill -9 "$cpid" ; done
fi
sleep 1
import -window root "$REPORT_DIR"/$cname-03.png
import -window root "png24:$REPORT_DIR"/$cname-03.png
if [ "$DIFF" == "true" ] ; then
d12=$(compareImagesSilently $cname 01 02)
d23=$(compareImagesSilently $cname 02 03)
d13=$(compareImagesSilently $cname 01 03 03-01)
if [ "$d12" -gt 15 ] ; then
echo "error! images 1+2 are same, should be not"
if [ "$d12" -lt 1 ] ; then
echo "error! images 1+2 are same (or too similar), should be not"
exit 1
fi
if [ "$d23" -gt 15 ] ; then
echo "error! images 2+3 are same, should be not"
if [ "$d23" -lt 1 ] ; then
echo "error! images 2+3 are same (or too similar), should be not"
exit 1
fi
if [ "$d13" -le 15 ] ; then
if [ "$d13" -gt 0 ] ; then
echo "warning! images 1+3 are different, should be not"
# exit 1 # The difference between first and last stage is probably not relevant, and may cause false-negatives
fi
Expand All @@ -286,20 +286,16 @@ function compareImagesSilently() {
if [ "x$idCompOverride" == "x" ] ; then
idCompOverride=$id1-$id2
fi
compare -metric PSNR "$REPORT_DIR"/"$name"-"$id1".png "$REPORT_DIR"/"$name"-"$id2".png "$REPORT_DIR"/"$name"-"$idCompOverride".png 2> "$REPORT_DIR"/res-"$idCompOverride" || r=$?
echo "40+ same, 10- different" 1>&2
# shellcheck disable=SC2155
# shellcheck disable=SC2002
local diff=$(cat "$REPORT_DIR"/res-"$idCompOverride" | sed "s;[. ].*;;")
# behavior of psnr has changed, zero is now reported instead of "inf":
# https://www.imagemagick.org/discourse-server/viewtopic.php?t=31487
# distinguish "inf" case using AE metric to emulate previous behavior
if [ "$diff" -eq 0 ] && compare -metric AE "$REPORT_DIR"/"$name"-"$id1".png "$REPORT_DIR"/"$name"-"$id2".png null: 2>&1 | grep -q '^0' ; then
diff="inf"
fi
if [ "$diff" == "inf" ] ; then
local diff=50 #same
fi
# create black and white mask of difference, which we can use later (to count different pixels)
compare -compose Src -highlight-color White -lowlight-color Black "$REPORT_DIR"/"$name"-"$id1".png "$REPORT_DIR"/"$name"-"$id2".png "$REPORT_DIR"/"$name"-"$idCompOverride".png
local pxTotal; local pxDiff; local diff;
# total pixels in image
pxTotal="$( convert "$REPORT_DIR"/"$name"-"$idCompOverride".png -format "%[fx:w*h]" info: )"
# different pixels
# see: https://www.imagemagick.org/discourse-server/viewtopic.php?t=32078
pxDiff="$( convert "$REPORT_DIR"/"$name"-"$idCompOverride".png -format "%[fx:int(w*h*mean+0.5)]" info: )"
# percent of different pixels (rounded down)
diff="$( LANG=C printf '100 * %f / %f\n' "${pxDiff}" "${pxTotal}" | bc )"
echo $diff
}

Expand Down