More attempts to fix DPX log/lin problems; see comments and #1123.

diff --git a/src/lib/magick_image_proxy.cc b/src/lib/magick_image_proxy.cc
index 4cefd9018ea6238d03fb7b5c5e5841ee72b90f33..55795910553f422564fe2656cdb76632aac247e9 100644 (file)
--- a/src/lib/magick_image_proxy.cc
+++ b/src/lib/magick_image_proxy.cc
@@ -102,17 +102,17 @@ MagickImageProxy::image (optional<dcp::NoteHandler>, optional<dcp::Size>) const
                throw DecodeError (String::compose (_("Could not decode image file (%1)"), error));
        }
 
-#ifdef DCPOMATIC_IMAGE_MAGICK
-       if (magick_image->colorSpace() == Magick::LogColorspace) {
-               magick_image->colorSpace(Magick::RGBColorspace);
-       }
-#endif
-#ifdef DCPOMATIC_GRAPHICS_MAGICK
-       if (magick_image->colorSpace() == Magick::CineonLogRGBColorspace) {
-               magick_image->colorSpace(Magick::RGBColorspace);
+       unsigned char const * data = static_cast<unsigned char const *>(_blob.data());
+       if (data[801] == 1) {
+               /* The transfer characteristic in this file is "printing density"; in this case ImageMagick sets the colour space
+                  to LogColorspace.  Empirically we find that if we subsequently call colorSpace(Magick::RGBColorspace) the colours
+                  are very wrong.  To prevent this, set the image colour space to RGB to stop the ::colorSpace call below doing
+                  anything.  See #1123 and others.
+               */
+               SetImageColorspace(magick_image->image(), Magick::RGBColorspace);
        }
 
-#endif
+       magick_image->colorSpace(Magick::RGBColorspace);
 
        dcp::Size size (magick_image->columns(), magick_image->rows());