From fd26a220c69e0942e12c2f3a21b7193225f74a50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zdenko=20Podobn=C3=BD?= <zdenop@gmail.com>
Date: Fri, 5 Aug 2016 22:37:58 +0200
Subject: [PATCH] fix #369 - pdf output with transparent background image

---
 api/pdfrenderer.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/api/pdfrenderer.cpp b/api/pdfrenderer.cpp
index 3b969fe7e8..4708300492 100644
--- a/api/pdfrenderer.cpp
+++ b/api/pdfrenderer.cpp
@@ -711,8 +711,9 @@ bool TessPDFRenderer::imageToPDFObj(Pix *pix,
   int format, sad;
   findFileFormat(filename, &format);
   if (pixGetSpp(pix) == 4 && format == IFF_PNG) {
-    pixSetSpp(pix, 3);
-    sad = pixGenerateCIData(pix, L_FLATE_ENCODE, 0, 0, &cid);
+    Pix *p1 = pixAlphaBlendUniform(pix, 0xffffff00);
+    sad = pixGenerateCIData(p1, L_FLATE_ENCODE, 0, 0, &cid);
+    pixDestroy(&p1);
   } else {
     sad = l_generateCIDataForPdf(filename, pix, kJpegQuality, &cid);
   }