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Check if page already contains a font

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fritz-hh
2014-01-04 18:05:21 +01:00
parent f8ccf42c06
commit 7d76c46731
2 changed files with 13 additions and 4 deletions
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src/ocrPage.sh
+11 -4
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@@ -39,8 +39,9 @@ TESS_CFG_FILES="${13}" # Specific configuration files to be used by Tesseract
# <dpi> <colorspace>
# Returns:
# - 0: if no error occurs
# - 1: in case the page contains more than one image
# - 2: in case the x,y resolutions are not equal
# - 1: in case the page already contains fonts (which should be the case for PDF generated from scanned pages)
# - 2: in case the page contains more than one image
# - 3: in case the x,y resolutions are not equal
##################################
imageCharacteristics() {
local page widthPDF heightPDF curImgCharacteristics nbImg curImg propCurImg widthCurImg heightCurImg colorspaceCurImg tmpval dpi_x dpi_y epsilon dpi
@@ -52,6 +53,10 @@ imageCharacteristics() {
heightPDF="$3"
# path of the file in which the output should be written
curImgCharacteristics="$4"
# check if the page already contains fonts (which should not be the case for PDF based on scanned files
[ `pdffonts -f $page -l $page ${FILE_INPUT_PDF} | wc -l` -gt 2 ] && echo "Page $page: This page already contains fonts !!!" && return 1
[ $VERBOSITY -ge $LOG_DEBUG ] && echo "Page $page: Size ${heightPDF}x${widthPDF} (h*w in pt)"
# extract raw image from pdf file to compute resolution
@@ -60,7 +65,7 @@ imageCharacteristics() {
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 "Page $page: Expecting exactly 1 image on page $page (found $nbImg). Page might not (only) contain a scanned image !!!" && return 1
[ $nbImg -ne "1" ] && echo "Page $page: Expecting exactly 1 image on page $page (found $nbImg). Cannot compute dpi value." && return 2
# Get characteristics of the extracted image
curImg=`ls -1 "$curOrigImg"*`
propCurImg=`identify -format "%w %h %[colorspace]" "$curImg"`
@@ -100,7 +105,7 @@ imageCharacteristics() {
# - the precision of dpi values computed above
epsilon=`echo "scale=5;($widthCurImg*72/$widthPDF^2)+($heightCurImg*72/$heightPDF^2)+0.00002" | bc` # max inaccuracy due to truncation of PDF size in pt
[ $VERBOSITY -ge $LOG_WARN ] && [ `echo "($dpi_x - $dpi_y) < $epsilon " | bc` -eq 0 -o `echo "($dpi_y - $dpi_x) < $epsilon " | bc` -eq 0 ] \
&& echo "Page $page: (x/y) resolution mismatch ($dpi_x/$dpi_y). Difference should be less than $epsilon. Taking biggest value" && return 2
&& echo "Page $page: (x/y) resolution mismatch ($dpi_x/$dpi_y). Difference should be less than $epsilon. Taking biggest value" && return 3
# everything went well!
return 0
@@ -127,6 +132,8 @@ curImgCharacteristics="$TMP_FLD/${page}-img-characteristics.txt" # Detected char
imageCharacteristics "$page" "$widthPDF" "$heightPDF" "$curImgCharacteristics"
#in case the page contains more than one image, warn the user but go on with default parameters
if [ "$?" -eq "1" ]; then
echo "Page $page: No need to OCR this file. Exiting..." && exit $EXIT_BAD_INPUT_FILE
elif [ "$?" -eq "2" ]; then
dpi=300
echo "Page $page: Continuing anyway, assuming a default resolution of $dpi dpi"
colorspaceCurImg="sRGB"