APIs and tests for extracting bitmaps from image objects

Added FPDFImageObj_GetBitmap() that returns the bitmap of an image
object, and a FPDFBitmap_GetFormat() that returns the format of a
bitmap.
    * Fixed a small bitmap conversion bug in cfx_dibsource.cpp.
    * Enabled EmbedderTest::CompareBitmap() to support different formats
      of bitmaps.
    * Added an embedder test and a test PDF file with images of many
      different formats.

Bug=pdfium:677

Change-Id: I6a72f9d969cf5f3577db9400ca33197c213622ed
Reviewed-on: https://pdfium-review.googlesource.com/9690
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Jane Liu <janeliulwq@google.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/fpdfsdk/fpdfview.cpp b/fpdfsdk/fpdfview.cpp
index 355fcb3f8f..5aa80139ae 100644
--- a/fpdfsdk/fpdfview.cpp
+++ b/fpdfsdk/fpdfview.cpp
@@ -1126,6 +1126,26 @@ DLLEXPORT FPDF_BITMAP STDCALL FPDFBitmap_CreateEx(int width,
   return pBitmap.Leak();
 }
 
+DLLEXPORT int STDCALL FPDFBitmap_GetFormat(FPDF_BITMAP bitmap) {
+  if (!bitmap)
+    return FPDFBitmap_Unknown;
+
+  FXDIB_Format format = CFXBitmapFromFPDFBitmap(bitmap)->GetFormat();
+  switch (format) {
+    case FXDIB_8bppRgb:
+    case FXDIB_8bppMask:
+      return FPDFBitmap_Gray;
+    case FXDIB_Rgb:
+      return FPDFBitmap_BGR;
+    case FXDIB_Rgb32:
+      return FPDFBitmap_BGRx;
+    case FXDIB_Argb:
+      return FPDFBitmap_BGRA;
+    default:
+      return FPDFBitmap_Unknown;
+  }
+}
+
 DLLEXPORT void STDCALL FPDFBitmap_FillRect(FPDF_BITMAP bitmap,
                                            int left,
                                            int top,