pdfwrite : A simplified implementation for ColorConversionStrategy, continued 2.

DETAILS :

This implements color conversion for images.

1. make_device_color_space is factored out from psdf_setup_image_colors_filter,
because the substituted color spase is needed for pdf_begin_write_image,
which works before installing the image colors filter.

2. In pdf_begin_typed_image the new variables pcs_device and pcs_orig
provide a right logics for the color space substitution.

EXPECTED DIFFERENCES :

None.

git-svn-id: http://svn.ghostscript.com/ghostscript/trunk@6640 a1074d23-0009-0410-80fe-cf8c14f379e6

4 files changed, 101 insertions, 48 deletions

diff --git a/gs/doc/Ps2pdf.htm b/gs/doc/Ps2pdf.htm
index 875005891..f19c0b19c 100644
--- a/gs/doc/Ps2pdf.htm
+++ b/gs/doc/Ps2pdf.htm
@@ -582,7 +582,7 @@ The value <tt><b>CMYK</tt></b> works with any <tt><b>CompatibilityLevel</tt></b>
 requires the device parameter <tt><b>ProcessColorModel</tt></b> to be set to <tt><b>DeviceCMYK</tt></b>.
 The value <tt><b>sRGB</tt></b>
 requires the device parameter <tt><b>ProcessColorModel</tt></b> to be set to <tt><b>DeviceRGB</tt></b>,
-and actually converts to RBG with the default Ghostscript conversion.
+and actually converts to RGB with the default Ghostscript conversion.
 The new Ghostscript-specific value <tt><b>Gray</tt></b>
 requires the device parameter <tt><b>ProcessColorModel</tt></b> to be set to <tt><b>DeviceGray</tt></b>,
 and converts all colors to DeviceGray.
diff --git a/gs/src/gdevpdfi.c b/gs/src/gdevpdfi.c
index 862c6a570..76beca8d3 100644
--- a/gs/src/gdevpdfi.c
+++ b/gs/src/gdevpdfi.c
@@ -238,6 +238,51 @@ pdf_begin_image_data_decoded(gx_device_pdf *pdev, int num_components, const gs_r
     return pdf_begin_image_data(pdev, &pie->writer, pi, cs_value, i);
 }
 
+private int
+make_device_color_space(gx_device_pdf *pdev, 
+			gs_color_space_index output_cspace_index, 
+			gs_color_space **ppcs)
+{
+    gs_color_space *cs;
+    gs_memory_t *mem = pdev->v_memory;
+
+    cs = gs_alloc_struct(mem, gs_color_space, &st_color_space, 
+			    "psdf_setup_image_colors_filter");
+    if (cs == NULL)
+	return_error(gs_error_VMerror);
+    switch (output_cspace_index) {
+	case gs_color_space_index_DeviceGray:
+	    gs_cspace_init_DeviceGray(mem, cs);
+	    break;
+	case gs_color_space_index_DeviceRGB:
+	    gs_cspace_init_DeviceRGB(mem, cs); 
+	    break;
+	case gs_color_space_index_DeviceCMYK:
+	    gs_cspace_init_DeviceCMYK(mem, cs); 
+	    break;
+	default:
+	    /* Notify the user and terminate.
+	       Don't emit rangecheck becuause it would fall back
+	       to a default implementation (rasterisation). 
+	     */
+	    eprintf("Unsupported ProcessColorModel");
+	    return_error(gs_error_undefined);
+    }
+    *ppcs = cs;
+    return 0;
+}
+
+private bool
+check_image_color_space(gs_pixel_image_t * pim, gs_color_space_index index)
+{
+    if (pim->ColorSpace->type->index == index)
+	return true;
+    if (pim->ColorSpace->type->index == gs_color_space_index_Indexed)
+	if (pim->ColorSpace->params.indexed.base_space.type->index == index)
+	    return true;
+    return false;
+}
+
 /*
  * Start processing an image.  This procedure takes extra arguments because
  * it has to do something slightly different for the parts of an ImageType 3
@@ -284,6 +329,8 @@ pdf_begin_typed_image(gx_device_pdf *pdev, const gs_imager_state * pis,
     const gs_range_t *pranges = 0;
     const pdf_color_space_names_t *names;
     bool convert_to_process_colors = false;
+    gs_color_space *pcs_device = NULL;
+    const gs_color_space *pcs_orig = NULL;
     pdf_lcvd_t *cvd = NULL;
 
     /*
@@ -583,22 +630,52 @@ pdf_begin_typed_image(gx_device_pdf *pdev, const gs_imager_state * pis,
 	    code = pdf_color_space(pdev, &cs_value, &pranges,
 				     pcs,
 				     names, in_line);
-	    if (code < 0) {
-	        const char *sname;
-
+	    if (code < 0)
 	        convert_to_process_colors = true;
-	        switch (pdev->pcm_color_info_index) {
-		    case gs_color_space_index_DeviceGray: sname = names->DeviceGray; break;
-		    case gs_color_space_index_DeviceRGB:  sname = names->DeviceRGB;  break;
-		    case gs_color_space_index_DeviceCMYK: sname = names->DeviceCMYK; break;
-		    default:
-		        eprintf("Unsupported ProcessColorModel.");
-		        return_error(gs_error_undefined);
-	        }
-	        cos_c_string_value(&cs_value, sname);
-	    }
         }
     }
+    if ((pdev->params.ColorConversionStrategy == ccs_Gray &&
+	 !check_image_color_space(&image[0].pixel, gs_color_space_index_DeviceGray)) ||
+	(pdev->params.ColorConversionStrategy == ccs_sRGB &&
+	 !psdf_is_converting_image_to_RGB((const gx_device_psdf *)pdev, pis, &image[0].pixel) &&
+	 !check_image_color_space(&image[0].pixel, gs_color_space_index_DeviceGray) &&
+	 !check_image_color_space(&image[0].pixel, gs_color_space_index_DeviceRGB)) ||
+	(pdev->params.ColorConversionStrategy == ccs_CMYK &&
+	 !check_image_color_space(&image[0].pixel, gs_color_space_index_DeviceGray) &&
+	 !check_image_color_space(&image[0].pixel, gs_color_space_index_DeviceCMYK))) {
+	/* fixme : as a rudiment of old code, 
+	   the case psdf_is_converting_image_to_RGB 
+	   is handled with the 'cmyk_to_rgb' branch 
+	   in psdf_setup_image_filters. */
+	if ((pdev->params.ColorConversionStrategy == ccs_CMYK && 
+	     strcmp(pdev->color_info.cm_name, "DeviceCMYK")) ||
+	    (pdev->params.ColorConversionStrategy == ccs_sRGB && 
+	     strcmp(pdev->color_info.cm_name, "DeviceRGB")) ||
+	    (pdev->params.ColorConversionStrategy == ccs_Gray && 
+	     strcmp(pdev->color_info.cm_name, "DeviceGray"))) {
+	    eprintf("ColorConversionStrategy isn't compatible to ProcessColorModel.");
+	    return_error(gs_error_rangecheck);
+	}
+	convert_to_process_colors = true;
+    }
+    if (convert_to_process_colors) {
+        const char *sname;
+
+	switch (pdev->pcm_color_info_index) {
+	    case gs_color_space_index_DeviceGray: sname = names->DeviceGray; break;
+	    case gs_color_space_index_DeviceRGB:  sname = names->DeviceRGB;  break;
+	    case gs_color_space_index_DeviceCMYK: sname = names->DeviceCMYK; break;
+	    default:
+		eprintf("Unsupported ProcessColorModel.");
+		return_error(gs_error_undefined);
+	}
+	cos_c_string_value(&cs_value, sname);
+	pcs_orig = image[0].pixel.ColorSpace;
+	code = make_device_color_space(pdev, pdev->pcm_color_info_index, &pcs_device);
+	if (code < 0)
+  	    goto fail;
+	image[0].pixel.ColorSpace = pcs_device;
+    }
     if ((code = pdf_begin_write_image(pdev, &pie->writer, gs_no_id, width,
 		    height, pnamed, in_line)) < 0 ||
 	/*
@@ -620,16 +697,19 @@ pdf_begin_typed_image(gx_device_pdf *pdev, const gs_imager_state * pis,
 	)
 	goto fail;
     if (convert_to_process_colors) {
+	image[0].pixel.ColorSpace = pcs_orig;
 	code = psdf_setup_image_colors_filter(&pie->writer.binary[0], 
-		    (gx_device_psdf *)pdev, &image[0].pixel, pis,
-		    pdev->pcm_color_info_index);
+		    (gx_device_psdf *)pdev, &image[0].pixel, pis);
 	if (code < 0)
   	    goto fail;
+	image[0].pixel.ColorSpace = pcs_device;
     }
     if (pie->writer.alt_writer_count > 1) {
         code = pdf_make_alt_stream(pdev, &pie->writer.binary[1]);
         if (code)
             goto fail;
+	if (convert_to_process_colors)
+	    image[1].pixel.ColorSpace = pcs_device;
 	code = psdf_setup_image_filters((gx_device_psdf *) pdev,
 				  &pie->writer.binary[1], &image[1].pixel,
 				  pmat, pis, false);
@@ -641,11 +721,12 @@ pdf_begin_typed_image(gx_device_pdf *pdev, const gs_imager_state * pis,
 	} else if (code)
 	    goto fail;
 	else if (convert_to_process_colors) {
+	    image[1].pixel.ColorSpace = pcs_orig;
 	    code = psdf_setup_image_colors_filter(&pie->writer.binary[1], 
-		    (gx_device_psdf *)pdev, &image[1].pixel, pis,
-		    pdev->pcm_color_info_index);
+		    (gx_device_psdf *)pdev, &image[1].pixel, pis);
 	    if (code < 0)
   		goto fail;
+	    image[1].pixel.ColorSpace = pcs_device;
 	}
     }
     for (i = 0; i < pie->writer.alt_writer_count; i++) {
diff --git a/gs/src/gdevpsdf.h b/gs/src/gdevpsdf.h
index d2c3517c1..d04b8c7bd 100644
--- a/gs/src/gdevpsdf.h
+++ b/gs/src/gdevpsdf.h
@@ -368,8 +368,7 @@ int psdf_setup_image_to_mask_filter(psdf_binary_writer *pbw, gx_device_psdf *pde
 /* Set up an image colors filter. */
 int psdf_setup_image_colors_filter(psdf_binary_writer *pbw, 
 	gx_device_psdf *pdev, gs_pixel_image_t * pim,
-	const gs_imager_state *pis,
-	gs_color_space_index output_cspace_index);
+	const gs_imager_state *pis);
 
 /* ---------------- Symbolic data printing ---------------- */
 
diff --git a/gs/src/gdevpsdi.c b/gs/src/gdevpsdi.c
index 8c14e1406..c4cf2d814 100644
--- a/gs/src/gdevpsdi.c
+++ b/gs/src/gdevpsdi.c
@@ -622,15 +622,11 @@ psdf_setup_image_to_mask_filter(psdf_binary_writer *pbw, gx_device_psdf *pdev,
 int
 psdf_setup_image_colors_filter(psdf_binary_writer *pbw, 
 			       gx_device_psdf *pdev, gs_pixel_image_t * pim, 
-			       const gs_imager_state *pis,
-			       gs_color_space_index output_cspace_index)
+			       const gs_imager_state *pis)
 {   /* fixme: currently it's a stub convertion to mask. */
     int code;
-    extern_st(st_color_space);
-    gs_memory_t *mem = pdev->v_memory;
     stream_state *ss = s_alloc_state(pdev->memory, s__image_colors_template.stype, 
 	"psdf_setup_image_colors_filter");
-    gs_color_space *cs;
     int i;
 
     if (ss == 0)
@@ -640,10 +636,6 @@ psdf_setup_image_colors_filter(psdf_binary_writer *pbw,
     code = psdf_encode_binary(pbw, &s__image_colors_template, ss);
     if (code < 0)
 	return code;
-    cs = gs_alloc_struct(mem, gs_color_space, &st_color_space, 
-			    "psdf_setup_image_colors_filter");
-    if (cs == NULL)
-	return_error(gs_error_VMerror);
     s_image_colors_set_dimensions((stream_image_colors_state *)ss, 
 		    pim->Width, pim->Height, 
 		    gs_color_space_num_components(pim->ColorSpace), 
@@ -655,24 +647,5 @@ psdf_setup_image_colors_filter(psdf_binary_writer *pbw,
 	pim->Decode[i * 2 + 0] = 0;
 	pim->Decode[i * 2 + 1] = 1;
     }
-    switch (output_cspace_index) {
-	case gs_color_space_index_DeviceGray:
-	    gs_cspace_init_DeviceGray(mem, cs);
-	    break;
-	case gs_color_space_index_DeviceRGB:
-	    gs_cspace_init_DeviceRGB(mem, cs); 
-	    break;
-	case gs_color_space_index_DeviceCMYK:
-	    gs_cspace_init_DeviceCMYK(mem, cs); 
-	    break;
-	default:
-	    /* Notify the user and terminate.
-	       Don't emit rangecheck becuause it would fall back
-	       to a default implementation (rasterisation). 
-	     */
-	    eprintf("Unsupported ProcessColorModel");
-	    return_error(gs_error_undefined);
-    }
-    pim->ColorSpace = cs;
     return 0;
 }