diff --git a/contrib/pngminim/decoder/gather.sh b/contrib/pngminim/decoder/gather.sh
index 915873d37fafc018cde9437571b94eddc65cf9e7..5006c537bcb3ef3b6b76335c1f7cfd609d92b2d5 100755
--- a/contrib/pngminim/decoder/gather.sh
+++ b/contrib/pngminim/decoder/gather.sh
@@ -1,23 +1,15 @@
-
-# Get the source for the pngminus application
-cp ../../pngminus/png2pnm.c pngm2pnm.c
-
-# Get the libpng sources
-cp ../../../*.h .
-cp ../../../*.c .
-
-# Get the libpng scripts for building pnglibconf.h
-cp ../../../scripts/options.awk .
-cp ../../../scripts/pnglibconf.dfa .
-sed -e "s:scripts/::g" ../../../scripts/pnglibconf.mak > pnglibconf.mak
-#14+%
-# Remove libpng sources we won't use
+test -n "${PNGSRC}" || PNGSRC=../../..
+cp ${PNGSRC}/contrib/pngminus/png2pnm.c pngm2pnm.c
+cp "${PNGSRC}"/*.h .
+cp "${PNGSRC}"/*.c .
 rm example.c pngtest.c pngpread.c pngw*.c
-
-# Get the zlib sources
-# Change the following 2 lines if zlib is somewhere else
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
-
-# Remove zlib sources we won't use
+rm -f pnglibconf.h
+test -d scripts || mkdir scripts
+cp "${PNGSRC}"/scripts/pnglibconf.mak scripts
+cp "${PNGSRC}"/scripts/pnglibconf.dfa scripts
+cp "${PNGSRC}"/scripts/options.awk scripts
+# change the following if zlib is somewhere else
+test -n "${ZLIBSRC}" || ZLIBSRC="${PNGSRC}"/../zlib
+cp "${ZLIBSRC}"/*.h .
+cp "${ZLIBSRC}"/*.c .
 rm minigzip.c example.c compress.c deflate.c gz*
diff --git a/contrib/pngminim/decoder/makefile b/contrib/pngminim/decoder/makefile
index 45ec4f26f113e56f6af2cd2f6ed2dcef7a15c9ec..49b91fea92987f59ada1e8aaef17ea4464da1f4b 100644
--- a/contrib/pngminim/decoder/makefile
+++ b/contrib/pngminim/decoder/makefile
@@ -4,9 +4,6 @@
 #CC=cc
 CC=gcc
 LD=$(CC)
-AWK=awk
-SED=sed
-CPP=cpp
 
 RM=rm -f
 
@@ -28,50 +25,33 @@ OBJS  = pngm2pnm$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
 
 # implicit make rules -------------------------------------------------------
 
-.c$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h  pngusr.h zlib.h
+# note: dependencies do not work on implicit rule lines
+.c$(O):
 	$(CC) -c $(CFLAGS) $<
 
 # dependencies
 
 all: pngm2pnm$(E)
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: pnglibconf.mak pnglibconf.dfn
-	make -f pnglibconf.mak pnglibconf.h
-
-# used on demand to regenerate the standard header, CPPFLAGS should
-# be empty - no non-standard defines
-
-.dfn.out:
-	rm -f $@ dfn.c dfn?.out
-	echo '#include "$<"' >dfn.c
-	$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) @LIBPNG_DEFINES@\
-	    $(CPPFLAGS) $(SYMBOL_CFLAGS) dfn.c >dfn1.out
-	$(SED) -n -e 's|^.*PNG_DEFN_MAGIC-\(.*\)-PNG_DEFN_END.*$$|\1|p'\
-	    dfn1.out >dfn2.out
-	$(SED) -e 's| *@@@ *||g' -e 's| *$$||' dfn2.out >dfn3.out
-	rm -f dfn.c dfn[12].out
-	mv dfn3.out $@
-
-pnglibconf.dfn: pnglibconf.dfa options.awk
-	rm -f $@ dfn?.out
-	test -z "$(CPPFLAGS)" 
-	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
-	$(AWK) -f options.awk pre=1 out=dfn1.out\
-	    logunsupported=1 - pnglibconf.dfa 1>&2
-	$(AWK) -f options.awk pre=0 out=dfn2.out\
-	    logunsupported=1 dfn1.out 1>&2
-	rm dfn1.out
-	mv dfn2.out $@
-
-
 pngm2pnm$(E): $(OBJS)
 	$(LD) -o pngm2pnm$(E) $(OBJS)
 	strip pngm2pnm$(E)
 
+pnglibconf.h: scripts/pnglibconf.mak scripts/pnglibconf.dfa \
+	scripts/options.awk pngusr.h
+
+	rm -f pnglibconf.h
+
+	$(MAKE) $(MAKEFLAGS) -f scripts/pnglibconf.mak\
+	 CPPFLAGS=-DPNG_USER_CONFIG $@
+
 clean:
+	$(MAKE) $(MAKEFLAGS) -f scripts/pnglibconf.mak clean
 	$(RM) pngm2pnm$(O)
 	$(RM) pngm2pnm$(E)
 	$(RM) $(OBJS)
 
+$(OBJS): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h\
+	 pnginfo.h pngdebug.h zlib.h
+
 # End of makefile for pngm2pnm
diff --git a/contrib/pngminim/decoder/pngusr.h b/contrib/pngminim/decoder/pngusr.h
index ebda3f2807525fd84db8fde53654559b23d98d9b..73e454067db26434547103cd80f1d91d8c22e65d 100644
--- a/contrib/pngminim/decoder/pngusr.h
+++ b/contrib/pngminim/decoder/pngusr.h
@@ -12,12 +12,15 @@
 #ifndef MINRDPNGCONF_H
 #define MINRDPNGCONF_H
 
+#ifdef NJET
+  /* No 16-bit support beyond reading with strip_16 */
+#endif
+
+#define PNG_USER_PRIVATEBUILD "PNG minimal build"
+#define PNG_USER_DLLFNAME_POSTFIX "MN"
+
 #define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
 #define PNG_NO_ERROR_TEXT
-#define png_error(s1,s2) png_err(s1)
-#define png_chunk_error(s1,s2) png_err(s1)
 
 #define PNG_NO_READ_GAMMA
 #define PNG_NO_READ_BACKGROUND
diff --git a/contrib/pngminim/encoder/gather.sh b/contrib/pngminim/encoder/gather.sh
index 2a6529a5a51f2be74413f6bac460ec6a0addd108..04f227c0c6c27b875d167c4f4bfa1d046b7996af 100755
--- a/contrib/pngminim/encoder/gather.sh
+++ b/contrib/pngminim/encoder/gather.sh
@@ -1,23 +1,17 @@
-
-# Get the source for the pngminus application
-cp ../../pngminus/pnm2png.c pnm2pngm.c
-
-# Get the libpng sources
-cp ../../../*.h .
-cp ../../../*.c .
-
-# Get the libpng scripts for building pnglibconf.h
-cp ../../../scripts/options.awk .
-cp ../../../scripts/pnglibconf.dfa .
-sed -e "s:scripts/::g" ../../../scripts/pnglibconf.mak > pnglibconf.mak
-#14+%
-# Remove libpng sources we won't use
+test -n "${PNGSRC}" || PNGSRC=../../..
+cp ${PNGSRC}/contrib/pngminus/pnm2png.c pnm2pngm.c
+cp "${PNGSRC}"/*.h .
+cp "${PNGSRC}"/*.c .
 rm example.c pngtest.c pngr*.c pngpread.c
+rm -f pnglibconf.h
+test -d scripts || mkdir scripts
+cp "${PNGSRC}"/scripts/pnglibconf.mak scripts
+cp "${PNGSRC}"/scripts/pnglibconf.dfa scripts
+cp "${PNGSRC}"/scripts/options.awk scripts
+# change the following if zlib is somewhere else
+test -n "${ZLIBSRC}" || ZLIBSRC="${PNGSRC}"/../zlib
+cp "${ZLIBSRC}"/*.h .
+cp "${ZLIBSRC}"/*.c .
+rm inf*.[ch]
+rm minigzip.c example.c gz*
 
-# Get the zlib sources
-# Change the following 2 lines if zlib is somewhere else
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
-
-# Remove zlib sources we won't use
-rm minigzip.c example.c inf*.[ch] gz*
diff --git a/contrib/pngminim/encoder/makefile b/contrib/pngminim/encoder/makefile
index 8c38c452cd1247058c29e097c6cc2e8a40279fe6..ef71f8a8ecccc526784c4696dce741d16051a65e 100644
--- a/contrib/pngminim/encoder/makefile
+++ b/contrib/pngminim/encoder/makefile
@@ -1,17 +1,13 @@
-
 # Makefile for PngMinus (pnm2pngm)
 # Linux / Unix
 
 #CC=cc
 CC=gcc
 LD=$(CC)
-AWK=awk
-SED=sed
-CPP=cpp
 
 RM=rm -f
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. -O1
+CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
 
 C=.c
 O=.o
@@ -28,49 +24,27 @@ OBJS  = pnm2pngm$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
 
 # implicit make rules -------------------------------------------------------
 
-.c$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h  pngusr.h zlib.h
+.c$(O):
 	$(CC) -c $(CFLAGS) $<
 
 # dependencies
 
 all: pnm2pngm$(E)
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: pnglibconf.mak pnglibconf.dfn
-	make -f pnglibconf.mak pnglibconf.h
-
-# used on demand to regenerate the standard header, CPPFLAGS should
-# be empty - no non-standard defines
-
-.dfn.out:
-	rm -f $@ dfn.c dfn?.out
-	echo '#include "$<"' >dfn.c
-	$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) @LIBPNG_DEFINES@\
-	    $(CPPFLAGS) $(SYMBOL_CFLAGS) dfn.c >dfn1.out
-	$(SED) -n -e 's|^.*PNG_DEFN_MAGIC-\(.*\)-PNG_DEFN_END.*$$|\1|p'\
-	    dfn1.out >dfn2.out
-	$(SED) -e 's| *@@@ *||g' -e 's| *$$||' dfn2.out >dfn3.out
-	rm -f dfn.c dfn[12].out
-	mv dfn3.out $@
-
-pnglibconf.dfn: pnglibconf.dfa options.awk
-	rm -f $@ dfn?.out
-	test -z "$(CPPFLAGS)" 
-	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
-	$(AWK) -f options.awk pre=1 out=dfn1.out\
-	    logunsupported=1 - pnglibconf.dfa 1>&2
-	$(AWK) -f options.awk pre=0 out=dfn2.out\
-	    logunsupported=1 dfn1.out 1>&2
-	rm dfn1.out
-	mv dfn2.out $@
-
 pnm2pngm$(E): $(OBJS)
 	$(LD) -o pnm2pngm$(E) $(OBJS)
 	strip pnm2pngm$(E)
 
+pnglibconf.h: scripts/pnglibconf.mak scripts/pnglibconf.dfa scripts/options.awk pngusr.h
+	rm -f pnglibconf.h
+	$(MAKE) $(MAKEFLAGS) -f scripts/pnglibconf.mak CPPFLAGS=-DPNG_USER_CONFIG $@
+
 clean:
+	$(MAKE) $(MAKEFLAGS) -f scripts/pnglibconf.mak clean
 	$(RM) pnm2pngm$(O)
 	$(RM) pnm2pngm$(E)
 	$(RM) $(OBJS)
 
-# End of makefile for pngm2pnm
+$(OBJS): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h  pngusr.h zlib.h
+
+# End of makefile for pnm2pngm
diff --git a/contrib/pngminim/encoder/pngusr.h b/contrib/pngminim/encoder/pngusr.h
index 02eeaa8c7f2492142f4a8793493592c13585f0a2..089c41a419ef3382b88869275aaaac8fff85c003 100644
--- a/contrib/pngminim/encoder/pngusr.h
+++ b/contrib/pngminim/encoder/pngusr.h
@@ -12,14 +12,13 @@
 #ifndef MINWRPNGCONF_H
 #define MINWRPNGCONF_H
 
+#define PNG_USER_PRIVATEBUILD "PNG minimal build"
+#define PNG_USER_DLLFNAME_POSTFIX "MN"
+
 #define PNG_NO_READ_SUPPORTED
 
 #define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
 #define PNG_NO_ERROR_TEXT
-#define png_error(s1,s2) png_err(s1)
-#define png_chunk_error(s1,s2) png_err(s1)
 
 #define PNG_NO_WRITE_BACKGROUND
 #define PNG_NO_WRITE_GAMMA
diff --git a/contrib/pngminim/preader/gather.sh b/contrib/pngminim/preader/gather.sh
index 4fe4231bc7b6d6c24bc9866683abb7e5b8fd8f42..bfb948ec59480d90e30ecb8cc9ca220df26abcca 100755
--- a/contrib/pngminim/preader/gather.sh
+++ b/contrib/pngminim/preader/gather.sh
@@ -1,9 +1,18 @@
-cp ../../gregbook/rpng2-x.c ../../gregbook/readpng2.[ch] .
-cp ../../gregbook/COPYING ../../gregbook/LICENSE .
-cp ../../../*.h .
-cp ../../../*.c .
+test -n "${PNGSRC}" || PNGSRC=../../..
+cp "${PNGSRC}"/contrib/gregbook/rpng2-x.c .
+cp "${PNGSRC}"/contrib/gregbook/readpng2.[ch] .
+cp "${PNGSRC}"/contrib/gregbook/COPYING .
+cp "${PNGSRC}"/contrib/gregbook/LICENSE .
+cp "${PNGSRC}"/*.h .
+cp "${PNGSRC}"/*.c .
 rm example.c pngtest.c pngw*.c
-# change the following 2 lines if zlib is somewhere else
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
+rm -f pnglibconf.h
+test -d scripts || mkdir scripts
+cp "${PNGSRC}"/scripts/pnglibconf.mak scripts
+cp "${PNGSRC}"/scripts/pnglibconf.dfa scripts
+cp "${PNGSRC}"/scripts/options.awk scripts
+# change the following if zlib is somewhere else
+test -n "${ZLIBSRC}" || ZLIBSRC="${PNGSRC}"/../zlib
+cp "${ZLIBSRC}"/*.h .
+cp "${ZLIBSRC}"/*.c .
 rm minigzip.c example.c compress.c deflate.c gz*
diff --git a/contrib/pngminim/preader/makefile b/contrib/pngminim/preader/makefile
index 9b2ad253feaaa514c747c660adf61cb8921aa324..ecbfb0dfd3ca513cb4ed2adb1e8ad0fcac3e4841 100644
--- a/contrib/pngminim/preader/makefile
+++ b/contrib/pngminim/preader/makefile
@@ -41,7 +41,7 @@ OBJS  = rpng2-x$(O) readpng2$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
 
 # implicit make rules -------------------------------------------------------
 
-.c$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h  readpng2.h pngusr.h zlib.h
+.c$(O):
 	$(CC) -c $(CFLAGS) $<
 
 # dependencies
@@ -52,9 +52,16 @@ rpng2-x$(E): $(OBJS)
 	$(LD) -o rpng2-x$(E) $(OBJS) $(LIBS)
 	strip rpng2-x$(E)
 
+pnglibconf.h: scripts/pnglibconf.mak scripts/pnglibconf.dfa scripts/options.awk pngusr.h
+	rm -f pnglibconf.h
+	$(MAKE) $(MAKEFLAGS) -f scripts/pnglibconf.mak CPPFLAGS=-DPNG_USER_CONFIG $@
+
 clean:
+	$(MAKE) $(MAKEFLAGS) -f scripts/pnglibconf.mak clean
 	$(RM) rpng2-x$(O)
 	$(RM) rpng2-x$(E)
 	$(RM) $(OBJS)
 
+$(OBJS): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h  readpng2.h pngusr.h zlib.h
+
 # End of makefile for rpng2-x
diff --git a/contrib/pngminim/preader/pngusr.h b/contrib/pngminim/preader/pngusr.h
index 6f6d0ce19277d8153aa2bcdb71f3cc2220ad1ac6..a675a8fb37f5a16f045b2e905ce1322a08c95323 100644
--- a/contrib/pngminim/preader/pngusr.h
+++ b/contrib/pngminim/preader/pngusr.h
@@ -12,12 +12,11 @@
 #ifndef MINPRDPNGCONF_H
 #define MINPRDPNGCONF_H
 
+#define PNG_USER_PRIVATEBUILD "PNG minimal build"
+#define PNG_USER_DLLFNAME_POSTFIX "MN"
+
 #define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
 #define PNG_NO_ERROR_TEXT
-#define png_error(s1,s2) png_err(s1)
-#define png_chunk_error(s1,s2) png_err(s1)
 
 #define PNG_NO_READ_QUANTIZE
 #define PNG_NO_READ_INVERT