+# Set all transparent pixels in a PAM image to black. This assumes (fine for
+# LBX images) that all pixels are either fully-transparent or fully-opaque.
+dx_pam_normalize() {
+ dx_pam_header "$1" > "$1.sh" || return
+ ( . "./$1.sh" || exit
+ case $TUPLTYPE in
+ GRAYSCALE_ALPHA) $PAMCHANNEL -infile "$1" 1 > "$1.alpha" ;;
+ RGB_ALPHA) $PAMCHANNEL -infile "$1" 3 > "$1.alpha" ;;
+ *) rm -f "$1.alpha" ;;
+ esac
+ ) || return
+
+ if test -e "$1.alpha"; then
+ $PAMARITH -and "$1" "$1.alpha"
+ else
+ cat "$1"
+ fi
+}
+
+dx_check_pam_md5_() {
+ ( dx_pam_header "$1" > "$1.sh" || exit
+ . "./$1.sh" || exit
+ tail -n +"$ENDHDR" "$1" > "$1.px"
+ ) || return 55
+
+ $MD5SUM -c <<EOF
+$2 $1.px
+EOF
+}
+
+dx_check_pam_md5() {
+ if $HAVE_MD5SUM; then
+ if dx_pam_normalize "$1" > "$1.tmp"; then
+ mv -f "$1.tmp" "$1"
+ dx_md5_reliable=true
+ else
+ dx_md5_reliable=false
+ fi
+
+ dx_check_pam_md5_ "$1" "$2"
+ case $? in
+ 0) ok_ "$1" ;;
+ 55) not_ok_ "$1" ;;
+ *) if $dx_md5_reliable; then
+ not_ok_ "$1"
+ else
+ skip_ -r "netpbm unavailable or broken" "$1"
+ fi ;;
+ esac
+ else
+ skip_ -r "md5sum unavailable or broken" "$1"
+ fi
+}
+