From 0dd52ae391d01284543210e5a00bf0856721bc79 Mon Sep 17 00:00:00 2001
From: Frank Warmerdam <warmerdam@pobox.com>
Date: Fri, 1 Jun 2012 00:38:39 +0000
Subject: [PATCH] Add alpha grayscale image support to TIFFReadRGBAImage

---
 ChangeLog              |  6 ++++++
 libtiff/tif_getimage.c | 27 +++++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ac20efab..c3f55963 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2012-05-31  Frank Warmerdam  <warmerdam@google.com>
+
+	* libtiff/tif_getimage.c: Add support for greyscale+alpha c/o Jérémie Laval.
+	http://bugzilla.maptools.org/show_bug.cgi?id=2398
+
 2012-05-29  Frank Warmerdam  <warmerdam@google.com>
 
 	* libtiff/tif_dir.c: avoid using specific set/get logic to process fields in custom directories,
@@ -72,6 +77,7 @@
 2011-12-22  Bob Friesenhahn  <bfriesen@simple.dallas.tx.us>
 
 	* libtiff/tif_win32.c: Eliminate some minor 64-bit warnings in
+
 	tif_win32.c.  Patch by Edward Lam.
 
 	* configure.ac: Add libtiff private dependency on -llzma for
diff --git a/libtiff/tif_getimage.c b/libtiff/tif_getimage.c
index c897f5af..88adf1dc 100644
--- a/libtiff/tif_getimage.c
+++ b/libtiff/tif_getimage.c
@@ -1,4 +1,4 @@
-/* $Id: tif_getimage.c,v 1.79 2012-04-06 16:46:46 fwarmerdam Exp $ */
+/* $Id: tif_getimage.c,v 1.80 2012-06-01 00:38:39 fwarmerdam Exp $ */
 
 /*
  * Copyright (c) 1991-1997 Sam Leffler
@@ -1208,6 +1208,26 @@ DECLAREContigPutFunc(putgreytile)
     }
 }
 
+/*
+ * 8-bit greyscale with associated alpha => colormap/RGBA
+ */
+DECLAREContigPutFunc(putagreytile)
+{
+    int samplesperpixel = img->samplesperpixel;
+    uint32** BWmap = img->BWmap;
+
+    (void) y;
+    while (h-- > 0) {
+	for (x = w; x-- > 0;)
+        {
+            *cp++ = BWmap[*pp][0] & (*(pp+1) << 24 | ~A1);
+            pp += samplesperpixel;
+        }
+	cp += toskew;
+	pp += fromskew;
+    }
+}
+
 /*
  * 16-bit greyscale => colormap/RGB
  */
@@ -2473,7 +2493,10 @@ PickContigCase(TIFFRGBAImage* img)
 						img->put.contig = put16bitbwtile;
 						break;
 					case 8:
-						img->put.contig = putgreytile;
+						if (img->alpha && img->samplesperpixel == 2)
+							img->put.contig = putagreytile;
+						else
+							img->put.contig = putgreytile;
 						break;
 					case 4:
 						img->put.contig = put4bitbwtile;