poppler/PSOutputDev.cc | 24 +++++++++++++++---------
 poppler/PSOutputDev.h  |  4 ++++
 utils/pdftops.cc       |  4 ++++
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/poppler/PSOutputDev.cc b/poppler/PSOutputDev.cc
index f69eb86..ba252a2 100644
--- a/poppler/PSOutputDev.cc
+++ b/poppler/PSOutputDev.cc
@@ -3312,16 +3312,20 @@ GBool PSOutputDev::checkPageSlice(Page *page, double /*hDPI*/, double /*vDPI*/,
     case psLevel1Sep:
       p = bitmap->getDataPtr();
       // Check for an all gray image
-      isGray = gTrue;
-      for (y = 0; y < h; ++y) {
-	for (x = 0; x < w; ++x) {
-	  if (p[4*x] != p[4*x + 1] || p[4*x] != p[4*x + 2]) {
-	    isGray = gFalse;
-	    y = h;
-	    break;
+      if (getOptimizeColorSpace()) {
+        isGray = gTrue;
+        for (y = 0; y < h; ++y) {
+	  for (x = 0; x < w; ++x) {
+	    if (p[4*x] != p[4*x + 1] || p[4*x] != p[4*x + 2]) {
+	      isGray = gFalse;
+	      y = h;
+	      break;
+	    }
 	  }
+	  p += bitmap->getRowSize();
 	}
-	p += bitmap->getRowSize();
+      } else {
+	isGray = gFalse;
       }
       writePSFmt("{0:d} {1:d} 8 [{2:d} 0 0 {3:d} 0 {4:d}] pdfIm1{5:s}{6:s}\n",
 		 w, h, w, -h, h,
@@ -3468,7 +3472,9 @@ GBool PSOutputDev::checkPageSlice(Page *page, double /*hDPI*/, double /*vDPI*/,
       p = bitmap->getDataPtr() + (h - 1) * bitmap->getRowSize();
       str0 = new MemStream((char *)p, 0, w * h * numComps, &obj);
       // Check for a color image that uses only gray
-      if (numComps == 4) {
+      if (!getOptimizeColorSpace()) {
+	isGray = gFalse;
+      } else if (numComps == 4) {
         int compCyan;
         isGray = gTrue;
         while ((compCyan = str0->getChar()) != EOF) {
diff --git a/poppler/PSOutputDev.h b/poppler/PSOutputDev.h
index 128ff7c..6c14cef 100644
--- a/poppler/PSOutputDev.h
+++ b/poppler/PSOutputDev.h
@@ -319,11 +319,13 @@ public:
   GBool getEmbedCIDPostScript() const { return embedCIDPostScript; }
   GBool getEmbedCIDTrueType() const { return embedCIDTrueType; }
   GBool getFontPassthrough() const { return fontPassthrough; }
+  GBool getOptimizeColorSpace() const { return optimizeColorSpace; }
   void setEmbedType1(GBool b) { embedType1 = b; }
   void setEmbedTrueType(GBool b) { embedTrueType = b; }
   void setEmbedCIDPostScript(GBool b) { embedCIDPostScript = b; }
   void setEmbedCIDTrueType(GBool b) { embedCIDTrueType = b; }
   void setFontPassthrough(GBool b) { fontPassthrough = b; }
+  void setOptimizeColorSpace(GBool b) { optimizeColorSpace = b; }
   void setPreloadImagesForms(GBool b) { preloadImagesForms = b; }
   void setGenerateOPI(GBool b) { generateOPI = b; }
   void setUseASCIIHex(GBool b) { useASCIIHex = b; }
@@ -518,6 +520,8 @@ private:
   GBool embedCIDPostScript;	// embed CID PostScript fonts?
   GBool embedCIDTrueType;	// embed CID TrueType fonts?
   GBool fontPassthrough;	// pass all fonts through as-is?
+  GBool optimizeColorSpace;	// false to keep gray RGB images in their original color space
+				// true to optimize gray images to DeviceGray color space
   GBool preloadImagesForms;	// preload PostScript images and forms into
 				//   memory
   GBool generateOPI;		// generate PostScript OPI comments?
diff --git a/utils/pdftops.cc b/utils/pdftops.cc
index b85d96e..dfeaa14 100644
--- a/utils/pdftops.cc
+++ b/utils/pdftops.cc
@@ -95,6 +95,7 @@ static GBool noEmbedTTFonts = gFalse;
 static GBool noEmbedCIDPSFonts = gFalse;
 static GBool noEmbedCIDTTFonts = gFalse;
 static GBool fontPassthrough = gFalse;
+static GBool optimizeColorSpace = gFalse;
 static char rasterAntialiasStr[16] = "";
 static GBool preload = gFalse;
 static char paperSize[15] = "";
@@ -157,6 +158,8 @@ static const ArgDesc argDesc[] = {
    "don't substitute missing fonts"},
   {"-aaRaster",   argString,   rasterAntialiasStr, sizeof(rasterAntialiasStr),
    "enable anti-aliasing on rasterization: yes, no"},
+  {"-optimizecolorspace",  argFlag,        &optimizeColorSpace,0,
+   "convert gray RGB images to gray color space"},
   {"-preload",    argFlag,     &preload,        0,
    "preload images and forms"},
   {"-paper",      argString,   paperSize,       sizeof(paperSize),
@@ -403,6 +406,7 @@ int main(int argc, char *argv[]) {
   psOut->setEmbedCIDTrueType(!noEmbedCIDTTFonts);
   psOut->setFontPassthrough(fontPassthrough);
   psOut->setPreloadImagesForms(preload);
+  psOut->setOptimizeColorSpace(optimizeColorSpace);
 #if OPI_SUPPORT
   psOut->setGenerateOPI(doOPI);
 #endif