src/java.desktop/share/classes/com/sun/imageio/plugins/png/PNGMetadata.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -2257,10 +2257,16 @@
             }
         }
         return retVal;
     }
 
+    boolean hasTransparentColor() {
+        return tRNS_present &&
+               (tRNS_colorType == PNGImageReader.PNG_COLOR_RGB ||
+               tRNS_colorType == PNGImageReader.PNG_COLOR_GRAY);
+    }
+
     // Reset all instance variables to their initial state
     public void reset() {
         IHDR_present = false;
         PLTE_present = false;
         bKGD_present = false;

@@ -2292,5 +2298,6 @@
         zTXt_text = new ArrayList<String>();
         unknownChunkType = new ArrayList<String>();
         unknownChunkData = new ArrayList<byte[]>();
     }
 }
+