--- /dev/null	2018-03-28 12:32:01.581694000 +0530
+++ new/test/jdk/javax/imageio/plugins/png/Read16BitPNGWithTRNSChunk.java	2018-03-28 13:31:09.546900000 +0530
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug     6788458
+ * @summary Test verifies that PNGImageReader takes tRNS chunk values
+ *          into consideration while reading non-indexed 16 bit PNG image.
+ * @run     main Read16BitPNGWithTRNSChunk
+ */
+
+import java.awt.color.ColorSpace;
+import java.awt.image.BufferedImage;
+import java.awt.image.ColorModel;
+import java.awt.image.ComponentColorModel;
+import java.awt.image.DataBuffer;
+import java.awt.image.DataBufferUShort;
+import java.awt.image.WritableRaster;
+import java.awt.image.Raster;
+import java.awt.Color;
+import java.awt.Transparency;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.Iterator;
+import javax.imageio.ImageTypeSpecifier;
+import javax.imageio.ImageWriter;
+import javax.imageio.ImageIO;
+import javax.imageio.ImageWriteParam;
+import javax.imageio.metadata.IIOMetadata;
+import javax.imageio.metadata.IIOMetadataNode;
+import javax.imageio.stream.ImageOutputStream;
+import javax.imageio.IIOImage;
+
+public final class Read16BitPNGWithTRNSChunk {
+
+    public static void main(String[] args) throws IOException {
+        String dir = System.getProperty("test.src");
+        String sep = System.getProperty("file.separator");
+        String filePath = dir + sep;
+        File directory = new File(filePath);
+        File output = File.createTempFile("output", "png", directory);
+        directory.delete();
+        ImageOutputStream ios = ImageIO.createImageOutputStream(output);
+        try {
+            // Create 16 bit PNG image
+            int height = 1;
+            int width = 2;
+            int numBands = 3;
+            int shortArrayLength = width * height * numBands;
+            short[] pixelData = new short[shortArrayLength];
+            // transparent first pixel
+            pixelData[0] = (short)0xffff;
+            pixelData[1] = (short)0xffff;
+            pixelData[2] = (short)0xffff;
+            // non-transparent second pixel
+            pixelData[3] = (short)0xffff;
+            pixelData[4] = (short)0xffff;
+            pixelData[5] = (short)0xfffe;
+
+            DataBuffer buffer = new DataBufferUShort(pixelData, shortArrayLength);
+
+            int[] bandOffset = {0, 1 ,2};
+            WritableRaster ras =
+                Raster.createInterleavedRaster(buffer, width, height,
+                    width * numBands, numBands, bandOffset, null);
+
+            int nBits[] = {16, 16 ,16};
+            ColorModel colorModel = new
+            ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
+                nBits, false, false, Transparency.OPAQUE,
+                DataBuffer.TYPE_USHORT);
+            BufferedImage img = new BufferedImage(colorModel, ras,
+                false, null);
+
+            Iterator<ImageWriter> iterWriter =
+                ImageIO.getImageWritersBySuffix("png");
+            ImageWriter writer = iterWriter.next();
+
+            ImageWriteParam param = writer.getDefaultWriteParam();
+            ImageTypeSpecifier specifier =
+                ImageTypeSpecifier.
+                    createFromBufferedImageType(BufferedImage.TYPE_3BYTE_BGR);
+            IIOMetadata metadata =
+                writer.getDefaultImageMetadata(specifier, param);
+
+            // Create tRNS node and merge it with default metadata
+            IIOMetadataNode tRNS_rgb = new IIOMetadataNode("tRNS_RGB");
+            tRNS_rgb.setAttribute("red", "65535");
+            tRNS_rgb.setAttribute("green", "65535");
+            tRNS_rgb.setAttribute("blue", "65535");
+
+            IIOMetadataNode tRNS = new IIOMetadataNode("tRNS");
+            tRNS.appendChild(tRNS_rgb);
+            IIOMetadataNode root =
+                new IIOMetadataNode("javax_imageio_png_1.0");
+            root.appendChild(tRNS);
+
+            metadata.mergeTree("javax_imageio_png_1.0", root);
+
+            writer.setOutput(ios);
+
+            writer.write(metadata, new IIOImage(img, null, metadata), param);
+
+            // Read 16 bit PNG RGB image with tRNS chunk
+            BufferedImage display_img = ImageIO.read(output);
+            // Verify alpha values present in first & second pixel
+            Color firstPixel = new Color(display_img.getRGB(0, 0), true);
+            Color secondPixel = new Color(display_img.getRGB(1, 0), true);
+            if (firstPixel.getAlpha() != 0 ||
+                secondPixel.getAlpha() != 255)
+            {
+                throw new RuntimeException("PNGImageReader is not using" +
+                    " transparent pixel information from tRNS chunk properly");
+            }
+        } finally {
+            ios.close();
+            Files.delete(output.toPath());
+        }
+
+    }
+}
+