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diff --git a/tensorflow/core/lib/png/png_io.h b/tensorflow/core/lib/png/png_io.h
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+++ b/tensorflow/core/lib/png/png_io.h
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+// Functions to read and write images in PNG format.
+//
+// The advantage over image/codec/png{enc,dec}ocder.h is that this library
+// supports both 8 and 16 bit images.
+//
+// The decoding routine accepts binary image data as a StringPiece.  These are
+// implicitly constructed from strings or char* so they're completely
+// transparent to the caller.  They're also very cheap to construct so this
+// doesn't introduce any additional overhead.
+//
+// The primary benefit of StringPieces being, in this case, that APIs already
+// returning StringPieces (e.g., Bigtable Scanner) or Cords (e.g., IOBuffer;
+// only when they're flat, though) or protocol buffer fields typed to either of
+// these can be decoded without copying the data into a C++ string.
+
+#ifndef TENSORFLOW_LIB_PNG_PNG_IO_H_
+#define TENSORFLOW_LIB_PNG_PNG_IO_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "tensorflow/core/lib/core/stringpiece.h"
+#include "external/png_archive/libpng-1.2.53/png.h"
+
+namespace tensorflow {
+namespace png {
+
+// Handy container for decoding informations and struct pointers
+struct DecodeContext {
+  const uint8* data;
+  int         data_left;
+  png_structp png_ptr;
+  png_infop   info_ptr;
+  png_uint_32 width, height;
+  int         num_passes;
+  int         color_type;
+  int         bit_depth;
+  int channels;
+  bool need_to_synthesize_16;
+  bool error_condition;
+  DecodeContext() : png_ptr(NULL), info_ptr(NULL) {}
+};
+
+bool DecodeHeader(StringPiece png_string, int* width, int* height,
+                  int* components, int* channel_bit_depth,
+                  std::vector<std::pair<string, string> >* metadata);
+
+// Sample usage for reading PNG:
+//
+// string png_string;  /* fill with input PNG format data */
+// DecodeContext context;
+// CHECK(CommonInitDecode(png_string, 3 /*RGB*/, 8 /*uint8*/, &context));
+// char* image_buffer = new char[3*context.width*context.height];
+// CHECK(CommonFinishDecode(bit_cast<png_byte*>(image_buffer),
+//       3*context.width /*stride*/, &context));
+//
+// desired_channels may be 0 to detected it from the input.
+
+bool CommonInitDecode(StringPiece png_string, int desired_channels,
+                      int desired_channel_bits, DecodeContext* context);
+
+bool CommonFinishDecode(png_bytep data, int row_bytes, DecodeContext* context);
+
+// Normally called automatically from CommonFinishDecode.  If CommonInitDecode
+// is called but not CommonFinishDecode, call this to clean up.  Safe to call
+// extra times.
+void CommonFreeDecode(DecodeContext* context);
+
+// Sample usage for writing PNG:
+//
+// uint16* image_buffer = new uint16[width*height];  /* fill with pixels */
+// string png_string;
+// CHECK(WriteImageToBuffer(image_buffer, width, height, 2*width /*stride*/,
+//       1 /*gray*/, 16 /*uint16*/, &png_string, NULL));
+//
+// compression is in [-1,9], where 0 is fast and weak compression, 9 is slow
+// and strong, and -1 is the zlib default.
+
+bool WriteImageToBuffer(
+    const void* image, int width, int height, int row_bytes, int num_channels,
+    int channel_bits, int compression, string* png_string,
+    const std::vector<std::pair<string, string> >* metadata);
+
+}  // namespace png
+}  // namespace tensorflow
+
+#endif  // TENSORFLOW_LIB_PNG_PNG_IO_H_