diff --git a/OCRmyPDF.sh b/OCRmyPDF.sh
index 0134993a..4c5d36ce 100644
--- a/OCRmyPDF.sh
+++ b/OCRmyPDF.sh
@@ -93,13 +93,11 @@ while getopts ":hvgkdcil:C:" opt; do
 		l) LAN="$OPTARG" ;;
 		C) TESS_CFG_FILES="$OPTARG $TESS_CFG_FILES" ;;
 		\?)
-			echo "Invalid option: -$OPTARG"
-			echo
+			echo "Invalid option: -$OPTARG" >&2
 			usage
 			exit $EXIT_BAD_ARGS ;;
 		:)
-			echo "Option -$OPTARG requires an argument"
-			echo
+			echo "Option -$OPTARG requires an argument" >&2
 			usage
 			exit $EXIT_BAD_ARGS ;;
 	esac
@@ -111,15 +109,14 @@ shift $((OPTIND-1))
 # Check if the number of mandatory parameters
 # provided is as expected
 if [ "$#" -ne "2" ]; then
-	echo "Exactly one mandatory argument shall be provided"
-	echo
+	echo "Exactly one mandatory argument shall be provided" >&2
 	usage
 	exit $EXIT_BAD_ARGS
 fi
 
-! absolutePath "$1" && echo "The folder in which the input file should be located does not exist. Exiting..." && exit $EXIT_BAD_ARGS
+! absolutePath "$1" && echo "The folder in which the input file should be located does not exist. Exiting..." >&2 && exit $EXIT_BAD_ARGS
 FILE_INPUT_PDF="`absolutePath "$1"`"
-! absolutePath "$2" && echo "The folder in which the output file should be generated does not exist. Exiting..." && exit $EXIT_BAD_ARGS
+! absolutePath "$2" && echo "The folder in which the output file should be generated does not exist. Exiting..." >&2 && exit $EXIT_BAD_ARGS
 FILE_OUTPUT_PDFA="`absolutePath "$2"`"
 
 
@@ -131,15 +128,15 @@ cd "`dirname $0`"
 
 # check if the required utilities are installed
 [ $VERBOSITY -ge $LOG_DEBUG ] && echo "Checking if all dependencies are installed"
-! command -v identify > /dev/null && echo "Please install ImageMagick. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v pdfimages > /dev/null && echo "Please install xpdf. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v pdftoppm > /dev/null && echo "Please install xpdf. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v pdftk > /dev/null && echo "Please install pdftk. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-[ $PREPROCESS_CLEAN -eq 1 ] && ! command -v unpaper > /dev/null && echo "Please install unpaper. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v tesseract > /dev/null && echo "Please install tesseract and tesseract-data. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v python > /dev/null && echo "Please install python, as well as the following python libraries: reportlab, lxml. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v gs > /dev/null && echo "Please install ghostcript. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
-! command -v java > /dev/null && echo "Please install java. Exiting..." && exit $EXIT_MISSING_DEPENDENCY
+! command -v identify > /dev/null && echo "Please install ImageMagick. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v pdfimages > /dev/null && echo "Please install xpdf. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v pdftoppm > /dev/null && echo "Please install xpdf. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v pdftk > /dev/null && echo "Please install pdftk. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+[ $PREPROCESS_CLEAN -eq 1 ] && ! command -v unpaper > /dev/null && echo "Please install unpaper. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v tesseract > /dev/null && echo "Please install tesseract and tesseract-data. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v python > /dev/null && echo "Please install python, as well as the following python libraries: reportlab, lxml. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v gs > /dev/null && echo "Please install ghostcript. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
+! command -v java > /dev/null && echo "Please install java. Exiting..." >&2 && exit $EXIT_MISSING_DEPENDENCY
 
 
 
@@ -162,7 +159,7 @@ mkdir -p "${TMP_FLD}"
 # get the size of each pdf page (width / height) in pt (inch*72)
 [ $VERBOSITY -ge $LOG_DEBUG ] && echo "Input file: Extracting size of each page (in pt)"
 ! identify -format "%w %h\n" "$FILE_INPUT_PDF" > "$FILE_SIZE_PAGES" \
-	&& echo "Could not get size of PDF pages. Exiting..." && exit $EXIT_BAD_INPUT_FILE
+	&& echo "Could not get size of PDF pages. Exiting..." >&2 && exit $EXIT_BAD_INPUT_FILE
 sed -I "" '/^$/d' "$FILE_SIZE_PAGES"	# removing empty lines (last one should be)
 numpages=`cat "$FILE_SIZE_PAGES" | wc -l | sed 's/^ *//g'`
 [ $VERBOSITY -ge $LOG_INFO ] && echo "Input file: The file has $numpages pages"
@@ -192,7 +189,7 @@ while read pageSize ; do
 	pdfimages -f $page -l $page -j "$FILE_INPUT_PDF" "$curOrigImg" 1>&2	
 	# count number of extracted images
 	nbImg=`ls -1 "$curOrigImg"* | wc -l`
-	[ $nbImg -ne "1" ] && echo "Not exactly 1 image on page $page. Exiting..." && exit $EXIT_BAD_INPUT_FILE
+	[ $nbImg -ne "1" ] && echo "Expecting exactly 1 image on page $page (found $nbImg). Exiting..." >&2 && exit $EXIT_BAD_INPUT_FILE
 	
 	# Get characteristics of the extracted image
 	curImg=`ls -1 "$curOrigImg"*`
@@ -210,7 +207,7 @@ while read pageSize ; do
 	# compute the resolution of the image in the page
 	dpi_x=$(($widthCurImg*72/$widthPDF))
 	dpi_y=$(($heightCurImg*72/$heightPDF))
-	[ "$dpi_x" -ne "$dpi_y" ] && echo "X/Y Resolutions not equal. Exiting..." && exit $EXIT_BAD_INPUT_FILE
+	[ "$dpi_x" -ne "$dpi_y" ] && echo "X/Y Resolutions not equal ($dpi_x/$dpi_y). Exiting..." >&2 && exit $EXIT_BAD_INPUT_FILE
 	dpi="$dpi_x"
 	
 	# Identify if page image should be saved as ppm (color) or pgm (gray)
@@ -227,13 +224,13 @@ while read pageSize ; do
 	# extract current page as image with right orientation and resoltution
 	[ $VERBOSITY -ge $LOG_DEBUG ] && echo "Page $page: Extracting image as $ext file (${dpi} dpi)"
 	! pdftoppm -f $page -l $page -r $dpi $opt "$FILE_INPUT_PDF" > "$curImgPixmap" \
-		&& echo "Could not extract page $page as $ext from $FILE_INPUT_PDF. Exiting..." && exit $EXIT_OTHER_ERROR
+		&& echo "Could not extract page $page as $ext from $FILE_INPUT_PDF. Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 
 	# if requested deskew image (without changing its size in pixel)
 	if [ "$PREPROCESS_DESKEW" -eq "1" ]; then
 		[ $VERBOSITY -ge $LOG_DEBUG ] && echo "Page $page: Deskewing image"
 		! convert "$curImgPixmap" -deskew 40% -gravity center -extent ${heightCurImg}x${widthCurImg} "$curImgPixmapDeskewed" \
-			&& echo "Could not deskew \"$curImgPixmap\". Exiting..." && exit $EXIT_OTHER_ERROR
+			&& echo "Could not deskew \"$curImgPixmap\". Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 	else
 		cp "$curImgPixmap" "$curImgPixmapDeskewed"
 	fi
@@ -244,7 +241,7 @@ while read pageSize ; do
 		! unpaper --dpi $dpi --mask-scan-size 100 \
 			--no-deskew --no-grayfilter --no-blackfilter --no-mask-center --no-border-align \
 			"$curImgPixmapDeskewed" "$curImgPixmapClean" 1> /dev/null \
-			&& echo "Could not clean \"$curImgPixmapDeskewed\". Exiting..." && exit $EXIT_OTHER_ERROR
+			&& echo "Could not clean \"$curImgPixmapDeskewed\". Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 	else
 		cp "$curImgPixmapDeskewed" "$curImgPixmapClean"
 	fi
@@ -252,7 +249,7 @@ while read pageSize ; do
 	# perform OCR
 	[ $VERBOSITY -ge $LOG_DEBUG ] && echo "Page $page: Performing OCR"
 	! tesseract -l "$LAN" "$curImgPixmapClean" "$curHocr" hocr $TESS_CFG_FILES 1> /dev/null 2> /dev/null \
-		&& echo "Could not OCR file \"$curImgPixmapClean\". Exiting..." && exit $EXIT_OTHER_ERROR
+		&& echo "Could not OCR file \"$curImgPixmapClean\". Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 	mv "$curHocr.html" "$curHocr"
 
 	# embed text and image to new pdf file
@@ -263,13 +260,13 @@ while read pageSize ; do
 	fi
 	[ $VERBOSITY -ge $LOG_DEBUG ] && echo "Page $page: Embedding text in PDF"
 	! python hocrTransform.py -r $dpi -i "$image4finalPDF" "$curHocr" "$curOCRedPDF" \
-		&& echo "Could not create PDF file from \"$curHocr\". Exiting..." && exit $EXIT_OTHER_ERROR
+		&& echo "Could not create PDF file from \"$curHocr\". Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 	
 	# if requested generate special debug PDF page with visible OCR text
 	if [ $DEBUG_MODE -eq "1" ] ; then
 		[ $VERBOSITY -ge $LOG_DEBUG ] && echo "Page $page: Embedding text in PDF (debug page)"
 		! python hocrTransform.py -b -r $dpi "$curHocr" "$curOCRedPDFDebug" \
-			&& echo "Could not create PDF file from \"$curHocr\". Exiting..." && exit $EXIT_OTHER_ERROR	
+			&& echo "Could not create PDF file from \"$curHocr\". Exiting..." >&2 && exit $EXIT_OTHER_ERROR	
 	fi
 	
 	# delete temporary files created for the current page
@@ -293,7 +290,7 @@ done < "$FILE_SIZE_PAGES"
 # concatenate all pages
 [ $VERBOSITY -ge $LOG_DEBUG ] && echo "Output file: Concatenating all pages"
 ! pdftk $FILES_OCRed_PDFS cat output "$FILE_OUTPUT_PDF" \
-	&& echo "Could not concatenate individual PDF pages (\"$FILES_OCRed_PDFS\") to one file. Exiting..." && exit $EXIT_OTHER_ERROR
+	&& echo "Could not concatenate individual PDF pages (\"$FILES_OCRed_PDFS\") to one file. Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 
 # insert metadata (copy metadata from input file)
 #echo "Output file: Inserting metadata"
@@ -305,20 +302,19 @@ done < "$FILE_SIZE_PAGES"
 ! gs -dQUIET -dPDFA -dBATCH -dNOPAUSE -dUseCIEColor \
 	-sProcessColorModel=DeviceCMYK -sDEVICE=pdfwrite -sPDFACompatibilityPolicy=2 \
 	-sOutputFile=$FILE_OUTPUT_PDFA "$FILE_OUTPUT_PDF" 1> /dev/null 2> /dev/null \
-	&& echo "Could not convert PDF file \"$FILE_OUTPUT_PDF\" to PDF/A. Exiting..." && exit $EXIT_OTHER_ERROR
+	&& echo "Could not convert PDF file \"$FILE_OUTPUT_PDF\" to PDF/A. Exiting..." >&2 && exit $EXIT_OTHER_ERROR
 
 # validate generated pdf file (compliance to PDF/A)
 [ $VERBOSITY -ge $LOG_DEBUG ] && echo "Output file: Checking compliance to PDF/A standard" 
 java -jar /root/jhove-1_9/jhove/bin/JhoveApp.jar -m PDF-hul "$FILE_OUTPUT_PDFA" > "$FILE_VALIDATION_LOG"
 grep -i "Status|Message" "$FILE_VALIDATION_LOG" # summary of the validation
-# check if the validation was successful
-pdf_valid=1
-grep -i "ErrorMessage" "$FILE_VALIDATION_LOG" && pdf_valid=0
-grep -i "Status.*not valid" "$FILE_VALIDATION_LOG" && pdf_valid=0
-grep -i "Status.*Not well-formed" "$FILE_VALIDATION_LOG" && pdf_valid=0
-[ $VERBOSITY -ge $LOG_INFO ] && [ $pdf_valid -eq 1 ] && echo "Output file: The generated PDF/A file is VALID"
-[ $pdf_valid -ne 1 ] && echo "Output file: The generated PDF/A file is INVALID"
 [ $VERBOSITY -ge $LOG_DEBUG ] && cat "$FILE_VALIDATION_LOG"
+# check the validation results
+pdf_valid=1
+grep -i 'ErrorMessage' "$FILE_VALIDATION_LOG" && pdf_valid=0
+grep -i 'Status.*not valid' "$FILE_VALIDATION_LOG" && pdf_valid=0
+grep -i 'Status.*Not well-formed' "$FILE_VALIDATION_LOG" && pdf_valid=0
+! grep -i 'Profile:.*PDF/A-1' "$FILE_VALIDATION_LOG" && pdf_valid=0
 
 
 
@@ -327,4 +323,9 @@ if [ $KEEP_TMP -eq 0 ]; then
 	rm -r -f "${TMP_FLD}"
 fi
 
+
+
+[ $pdf_valid -ne 1 ] && echo "Output file: The generated PDF/A file is INVALID" >&2 && exit $EXIT_INVALID_OUPUT_PDFA
+
+[ $VERBOSITY -ge $LOG_INFO ] && echo "Output file: The generated PDF/A file is VALID"
 exit 0