Added testing flag --save-images that saves embedded images

1. Added --save-images flag in pdfium_test to save embedded images using
FPDFImageObj_GetBitmap() API and the bitmap-to-png conversion tool.
    * Added support for bitmaps of other common color spaces in the
    bitmap-to-png conversion tool.

Bug=pdfium:677

Change-Id: Ide29f51021695af0a1afb5205355f4b78b918d35
Reviewed-on: https://pdfium-review.googlesource.com/9710
Commit-Queue: Jane Liu <janeliulwq@google.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/testing/image_diff/image_diff_png.h b/testing/image_diff/image_diff_png.h
index 4d87aa1cc0..b334b20453 100644
--- a/testing/image_diff/image_diff_png.h
+++ b/testing/image_diff/image_diff_png.h
@@ -18,6 +18,13 @@ bool DecodePNG(const unsigned char* input,
                int* width,
                int* height);
 
+// Encode a BGR pixel array into a PNG.
+bool EncodeBGRPNG(const unsigned char* input,
+                  int width,
+                  int height,
+                  int row_byte_width,
+                  std::vector<unsigned char>* output);
+
 // Encode an RGBA pixel array into a PNG.
 bool EncodeRGBAPNG(const unsigned char* input,
                    int width,
@@ -33,6 +40,13 @@ bool EncodeBGRAPNG(const unsigned char* input,
                    bool discard_transparency,
                    std::vector<unsigned char>* output);
 
+// Encode a grayscale pixel array into a PNG.
+bool EncodeGrayPNG(const unsigned char* input,
+                   int width,
+                   int height,
+                   int row_byte_width,
+                   std::vector<unsigned char>* output);
+
 }  // namespace image_diff_png
 
 #endif  // TESTING_IMAGE_DIFF_IMAGE_DIFF_PNG_H_