aperio: use main image ICC profile for thumbnail if profile names match

The thumbnail's TIFF directory doesn't have an ICC profile, but both it
and level 0's directory have properties including an ICC profile name.
If the two profile names exist and are equal, use the main image's ICC
profile for the thumbnail.

Fixes: openslide#637
Signed-off-by: Benjamin Gilbert <[email protected]>

Author: bgilbert

src/openslide-vendor-aperio.c

@@ -349,6 +349,7 @@ static bool add_properties(openslide_t *osr, TIFF *tiff, GError **err) {
 // true does not necessarily imply an image was added
 static bool add_associated_image(openslide_t *osr,
                                  const char *name_if_available,
+                                 tdir_t *icc_dir_if_available,
                                  struct _openslide_tiffcache *tc,
                                  TIFF *tiff,
                                  GError **err) {
@@ -384,7 +385,7 @@ static bool add_associated_image(openslide_t *osr,
 
   return _openslide_tiff_add_associated_image(osr, name, tc,
                                               TIFFCurrentDirectory(tiff),
-                                              NULL, err);
+                                              icc_dir_if_available, err);
 }
 
 static void propagate_missing_tile(void *key, void *value G_GNUC_UNUSED,
@@ -424,6 +425,12 @@ static bool aperio_open(openslide_t *osr,
     return false;
   }
 
+  // add properties early, since we'll need them for the thumbnail ICC
+  // profile
+  if (!add_properties(osr, ct.tiff, err)) {
+    return false;
+  }
+
   /*
    * http://www.aperio.com/documents/api/Aperio_Digital_Slides_and_Third-party_data_interchange.pdf
    * page 14:
@@ -523,8 +530,27 @@ static bool aperio_open(openslide_t *osr,
       }
     } else {
       // associated image
-      const char *name = (dir == 1) ? "thumbnail" : NULL;
-      if (!add_associated_image(osr, name, tc, ct.tiff, err)) {
+      const char *name = NULL;
+      g_autofree tdir_t *icc_dir = NULL;
+      if (dir == 1) {
+        name = "thumbnail";
+
+        g_autoptr(GHashTable) thumbnail_props = read_properties(ct.tiff, err);
+        if (!thumbnail_props) {
+          g_prefix_error(err, "Reading thumbnail properties: ");
+          return false;
+        }
+        const char *main_icc_name =
+          g_hash_table_lookup(osr->properties, "aperio.ICC Profile");
+        const char *thumbnail_icc_name =
+          g_hash_table_lookup(thumbnail_props, "ICC Profile");
+        if (main_icc_name && thumbnail_icc_name &&
+            g_str_equal(main_icc_name, thumbnail_icc_name)) {
+          // use ICC profile from first directory
+          icc_dir = g_new0(tdir_t, 1);
+        }
+      }
+      if (!add_associated_image(osr, name, icc_dir, tc, ct.tiff, err)) {
 	return false;
       }
       //g_debug("associated image: %d", dir);
@@ -539,14 +565,6 @@ static bool aperio_open(openslide_t *osr,
                          level_array->pdata[i + 1]);
   }
 
-  // read properties
-  if (!_openslide_tiff_set_dir(ct.tiff, 0, err)) {
-    return false;
-  }
-  if (!add_properties(osr, ct.tiff, err)) {
-    return false;
-  }
-
   // get icc profile size, if present
   struct level *base_level = level_array->pdata[0];
   if (!_openslide_tiff_get_icc_profile_size(ct.tiff, base_level->tiffl.dir,

test/cases/aperio-thumbnail-empty-imagedescription/CMU-1.svs.xdelta

@@ -0,0 +1,7 @@
+# thumbnail ImageDescription is zero-length string
+base: Aperio/CMU-1.svs
+slide: CMU-1.svs
+success: true
+vendor: aperio
+properties:
+  openslide.associated.thumbnail.icc-size: ""

test/cases/aperio-thumbnail-empty-imagedescription/config.yaml

@@ -0,0 +1,7 @@
+# thumbnail ICC Profile name doesn't match main image
+base: Aperio/CMU-1.svs
+slide: CMU-1.svs
+success: true
+vendor: aperio
+properties:
+  openslide.associated.thumbnail.icc-size: ""

test/cases/aperio-thumbnail-mismatched-icc-profile/CMU-1.svs.xdelta

@@ -4,6 +4,7 @@ success: true
 vendor: aperio
 primary: true
 properties:
+  openslide.associated.thumbnail.icc-size: "141992"
   openslide.icc-size: "141992"
   openslide.quickhash-1: 30f1a38031fc0e21d81f9d01435ac4af848f6fe2bbf8f7768184336ee5d7e796
   openslide.vendor: aperio