http://repos.archlinux.org/wsvn/packages/digikam/trunk/libpng14.patch

--- libs/dimg/loaders/pngloader.cpp
+++ libs/dimg/loaders/pngloader.cpp
@@ -105,7 +105,7 @@
     unsigned char buf[PNG_BYTES_TO_CHECK];
 
     size_t membersRead = fread(buf, 1, PNG_BYTES_TO_CHECK, f);
-    if ((membersRead != PNG_BYTES_TO_CHECK) || !png_check_sig(buf, PNG_BYTES_TO_CHECK))
+    if ((membersRead != PNG_BYTES_TO_CHECK) || png_sig_cmp(buf, 0, PNG_BYTES_TO_CHECK))
     {
         kDebug() << "Not a PNG image file.";
         fclose(f);
@@ -322,7 +322,7 @@
 #ifdef ENABLE_DEBUG_MESSAGES
                     kDebug() << "PNG in PNG_COLOR_TYPE_GRAY";
 #endif
-                    png_set_gray_1_2_4_to_8(png_ptr);
+                    png_set_expand_gray_1_2_4_to_8(png_ptr);
                     png_set_gray_to_rgb(png_ptr);
 
                     if (QSysInfo::ByteOrder == QSysInfo::LittleEndian)           // Intel
--- libs/threadimageio/thumbnailbasic.cpp
+++ libs/threadimageio/thumbnailbasic.cpp
@@ -137,7 +137,7 @@
     unsigned char buf[PNG_BYTES_TO_CHECK];
 
     size_t itemsRead = fread(buf, 1, PNG_BYTES_TO_CHECK, f);
-    if (itemsRead != 1 || !png_check_sig(buf, PNG_BYTES_TO_CHECK))
+    if (itemsRead != 1 || png_sig_cmp(buf, 0, PNG_BYTES_TO_CHECK))
     {
         fclose(f);
         return qimage;
@@ -232,7 +232,7 @@
     {
         png_set_gray_to_rgb(png_ptr);
         if (png_get_bit_depth(png_ptr, info_ptr) < 8)
-            png_set_gray_1_2_4_to_8(png_ptr);
+            png_set_expand_gray_1_2_4_to_8(png_ptr);
     }
 
     int sizeOfUint = sizeof(unsigned int);