Bug fix: handle ColorSpace lookup for inline images (fixes #392)

If the value of /CS in the inline image dictionary was is key in the
page's /Resource -> /ColorSpace dictionary, properly resolve it by
referencing the proper colorspace, and not just the name, in the
external image dictionary.

1 files changed, 16 insertions, 0 deletions

diff --git a/libqpdf/QPDFPageObjectHelper.cc b/libqpdf/QPDFPageObjectHelper.cc
index d588c322..01f1d662 100644
--- a/libqpdf/QPDFPageObjectHelper.cc
+++ b/libqpdf/QPDFPageObjectHelper.cc
@@ -141,6 +141,22 @@ InlineImageTracker::convertIIDict(QPDFObjectHandle odict)
                 }
                 else
                 {
+                    // This is a key in the page's /Resources ->
+                    // /ColorSpace dictionary. We need to look it up
+                    // and use its value as the color space for the
+                    // image.
+                    QPDFObjectHandle colorspace =
+                        resources.getKey("/ColorSpace");
+                    if (colorspace.isDictionary() && colorspace.hasKey(name))
+                    {
+                        QTC::TC("qpdf", "QPDFPageObjectHelper colorspace lookup");
+                        value = colorspace.getKey(name);
+                    }
+                    else
+                    {
+                        resources.warnIfPossible(
+                            "unable to resolve colorspace " + name);
+                    }
                     name.clear();
                 }
                 if (! name.empty())