diff --git a/piwigo_thumbgen.sh b/piwigo_thumbgen.sh
index 57575f3..716308f 100755
--- a/piwigo_thumbgen.sh
+++ b/piwigo_thumbgen.sh
@@ -22,7 +22,7 @@ STARTTIME=$(date +%s)
 # drop CIFS cache in case target files existed before 
 #sync; echo 3 > /proc/sys/vm/drop_caches;
 
-for file in "$sourceDir"/**/*.{jpg,JPG,jpeg,JPEG}
+for file in "$sourceDir"/**/*.{jpg,JPG,jpeg,JPEG,png,PNG}
 do
   if [[ ! -f "$file" ]]
   then
@@ -52,11 +52,15 @@ do
 
     mkdir -p "${destDir}${fnPath}"
 
-    #Error checking
-    result=$(jpeginfo -c "$file")
-    if [[ $result != *"[OK]"* ]]
-    then
-      echo $result
+    # image format specific checks to display warnings
+    exp='\.(png|PNG)$'
+    if [[ ! "$file" =~ $exp ]] ; then
+      #Error checking
+      result=$(jpeginfo -c "$file")
+      if [[ $result != *"[OK]"* ]]
+      then
+        echo $result
+      fi
     fi
 
     #auto rotate source image according to exif orientation information
@@ -66,6 +70,7 @@ do
       if [ "$quali" -le "0" ]; then
         quali=94
       fi
+
       echo "rotate with quality $quali preserving timestamp: $file"
       TIMESTAMP="$( ls -l --time-style='+%Y%m%d%H%M.%S' "${file}" | cut  --delimiter=' ' --fields=6 )"
       mogrify -auto-orient -quality ${quali} "${file}"