Fix Bug 695904, Transparency with non-identity transfer functions.

This does _not_ yet implement the arcane transfer function handling of
section 7.6.4 of the PDF 1.7 Reference Manual, but it fixes a problem
detected by customer 532 who uses a transfer function set by PS before
the PDF file runs. This was causing bands in part of the image.

The problem was that the pdf14 compositor was not applying the transfer
function for monochrome or indexed color images, and did apply it for
color images or when the halftone thresholding was done during image
processing. The transfer function was then applied during pdf14_put_image
only when the default method of passing the image to the device was
used (not when the device implemented a put_image proc, as the customer's
code does for efficiency). If color images had the transfer function
applied, then the put_image would apply it a second time.

For bands that had the pdf14 compositor skipped because transparency
was not needed, the transfer function was applied correctly, causing
differences on transitions to bands that used the pdf14 compositor.

The fix applies the transfer function in the pdf14 cmap procs and does
_not_ apply it during pdf14_put_image, which also makes it consistent
with devices that implement a put_image proc and do not have the pis
or any way to get the transfer function.

1 files changed, 25 insertions, 60 deletions

diff --git a/gs/base/gdevp14.c b/gs/base/gdevp14.c
index d1fccce5f..fd86ae049 100644
--- a/gs/base/gdevp14.c
+++ b/gs/base/gdevp14.c
@@ -5080,7 +5080,7 @@ pdf14_cmap_gray_direct(frac gray, gx_device_color * pdc, const gs_imager_state *
     /* map to the color model */
     dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_gray(trans_device, gray, cm_comps);
     for (i = 0; i < ncomps; i++)
-        cv[i] = frac2cv(cm_comps[i]);
+        cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
     /* encode as a color index */
     color = dev_proc(trans_device, encode_color)(trans_device, cv);
     /* check if the encoding was successful; we presume failure is rare */
@@ -5108,7 +5108,7 @@ pdf14_cmap_rgb_direct(frac r, frac g, frac b, gx_device_color *	pdc,
     /* map to the color model */
     dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_rgb(trans_device, pis, r, g, b, cm_comps);
     for (i = 0; i < ncomps; i++)
-        cv[i] = frac2cv(cm_comps[i]);
+        cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
     /* encode as a color index */
     color = dev_proc(trans_device, encode_color)(trans_device, cv);
     /* check if the encoding was successful; we presume failure is rare */
@@ -5137,7 +5137,7 @@ pdf14_cmap_cmyk_direct(frac c, frac m, frac y, frac k, gx_device_color * pdc,
     /* map to the color model */
     dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_cmyk(trans_device, c, m, y, k, cm_comps);
     for (i = 0; i < ncomps; i++)
-        cv[i] = frac2cv(cm_comps[i]);
+        cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
     /* if output device supports devn, we need to make sure we send it the
        proper color type */
     if (dev_proc(trans_device, dev_spec_op)(trans_device, gxdso_supports_devn, NULL, 0)) {
@@ -5181,7 +5181,7 @@ pdf14_cmap_gray_direct_group(frac gray, gx_device_color * pdc, const gs_imager_s
    /* If we are doing concretization of colors in an SMask or isolated group
        then just return the color as is */
    if (ncomps == 1 ) {
-        cv[0] = frac2cv(gray);
+        cv[0] = frac2cv(gx_map_color_frac(pis, gray, effective_transfer[0]));
         /* encode as a color index */
         color = dev_proc(trans_device, encode_color)(trans_device, cv);
         /* check if the encoding was successful; we presume failure is rare */
@@ -5191,7 +5191,7 @@ pdf14_cmap_gray_direct_group(frac gray, gx_device_color * pdc, const gs_imager_s
         /* map to the color model */
         dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_gray(trans_device, gray, cm_comps);
         for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(cm_comps[i]);
+            cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
         /* encode as a color index */
         color = dev_proc(trans_device, encode_color)(trans_device, cv);
         /* check if the encoding was successful; we presume failure is rare */
@@ -5222,34 +5222,15 @@ pdf14_cmap_rgb_direct_group(frac r, frac g, frac b, gx_device_color *	pdc,
         trans_device = dev;
     }
     ncomps = trans_device->color_info.num_components;
-    if ( ncomps == 3 ){
-        cv[0] = frac2cv(r);
-        cv[1] = frac2cv(g);
-        cv[2] = frac2cv(b);
-        /* encode as a color index */
-        color = dev_proc(trans_device, encode_color)(trans_device, cv);
-       /* check if the encoding was successful; we presume failure is rare */
-         if (color != gx_no_color_index)
+    /* map to the device color model */
+    dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_rgb(trans_device, pis, r, g, b, cm_comps);
+    for (i = 0; i < ncomps; i++)
+        cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
+    /* encode as a color index */
+    color = dev_proc(trans_device, encode_color)(trans_device, cv);
+    /* check if the encoding was successful; we presume failure is rare */
+    if (color != gx_no_color_index)
         color_set_pure(pdc, color);
-    } else {
-        /* map to the device color model */
-        /* We can end up here, if for example we had a DeviceN color space with a
-           CIE based alternate space and a output device that was  RGB but a
-           blending space that was CMYK.  The proper way to solve this is to
-           introduce another color space for the graphic state that has its own
-           Joint CIE Cache between the source and a CMYK CRD (the transparency
-           color space). The problem is that we can only have one CRD, which is
-           defined by the output device.  We will fix these issues with the ICC
-           based color architecture. */
-        dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_rgb(trans_device, pis, r, g, b, cm_comps);
-        for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(cm_comps[i]);
-        /* encode as a color index */
-        color = dev_proc(trans_device, encode_color)(trans_device, cv);
-        /* check if the encoding was successful; we presume failure is rare */
-        if (color != gx_no_color_index)
-            color_set_pure(pdc, color);
-    }
 }
 
 /* color mapping for when we have an smask or a isolated transparency group with another color space */
@@ -5275,25 +5256,13 @@ pdf14_cmap_cmyk_direct_group(frac c, frac m, frac y, frac k, gx_device_color * p
         trans_device = dev;
     }
     ncomps = trans_device->color_info.num_components;
-    if (ncomps == 4 ){
-        cv[0] = frac2cv(c);
-        cv[1] = frac2cv(m);
-        cv[2] = frac2cv(y);
-        cv[3] = frac2cv(k);
-         /* encode as a color index */
-        color = dev_proc(trans_device, encode_color)(trans_device, cv);
-        /* check if the encoding was successful; we presume failure is rare */
-        if (color != gx_no_color_index)
-            color_set_pure(pdc, color);
-    } else {
-        /* map to the color model */
-        dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_cmyk(trans_device, c, m, y, k, cm_comps);
-        for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(cm_comps[i]);
-        color = dev_proc(trans_device, encode_color)(trans_device, cv);
-        if (color != gx_no_color_index)
-            color_set_pure(pdc, color);
-    }
+    /* map to the color model */
+    dev_proc(trans_device, get_color_mapping_procs)(trans_device)->map_cmyk(trans_device, c, m, y, k, cm_comps);
+    for (i = 0; i < ncomps; i++)
+        cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
+    color = dev_proc(trans_device, encode_color)(trans_device, cv);
+    if (color != gx_no_color_index)
+        color_set_pure(pdc, color);
 }
 
 static	void
@@ -5330,7 +5299,7 @@ pdf14_cmap_rgb_alpha_direct(frac r, frac g, frac b, frac alpha,	gx_device_color
     }
 
     for (i = 0; i < ncomps; i++)
-        cv[i] = frac2cv(cm_comps[i]);
+        cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
     color = dev_proc(trans_device, encode_color)(trans_device, cv);
     /* check if the encoding was successful; we presume failure is rare */
     if (color != gx_no_color_index)
@@ -5367,12 +5336,10 @@ pdf14_cmap_separation_direct(frac all, gx_device_color * pdc, const gs_imager_st
     /* apply the transfer function(s); convert to color values */
     if (additive)
         for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(gx_map_color_frac(pis,
-                                cm_comps[i], effective_transfer[i]));
+            cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
     else
         for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(frac_1 - gx_map_color_frac(pis,
-                        (frac)(frac_1 - cm_comps[i]), effective_transfer[i]));
+            cv[i] = frac2cv(frac_1 - gx_map_color_frac(pis, (frac)(frac_1 - cm_comps[i]), effective_transfer[i]));
 
     /* if output device supports devn, we need to make sure we send it the
        proper color type */
@@ -5416,12 +5383,10 @@ pdf14_cmap_devicen_direct(const	frac * pcc,
     /* apply the transfer function(s); convert to color values */
     if (trans_device->color_info.polarity == GX_CINFO_POLARITY_ADDITIVE)
         for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(gx_map_color_frac(pis,
-                                cm_comps[i], effective_transfer[i]));
+            cv[i] = frac2cv(gx_map_color_frac(pis, cm_comps[i], effective_transfer[i]));
     else
         for (i = 0; i < ncomps; i++)
-            cv[i] = frac2cv(frac_1 - gx_map_color_frac(pis,
-                        (frac)(frac_1 - cm_comps[i]), effective_transfer[i]));
+            cv[i] = frac2cv(frac_1 - gx_map_color_frac(pis, (frac)(frac_1 - cm_comps[i]), effective_transfer[i]));
     /* if output device supports devn, we need to make sure we send it the
        proper color type */
     if (dev_proc(trans_device, dev_spec_op)(trans_device, gxdso_supports_devn, NULL, 0)) {