--- a/sat/core/sat_main.py	Sun Mar 01 18:47:05 2020 +0100
+++ b/sat/core/sat_main.py	Sun Mar 01 18:48:06 2020 +0100
@@ -20,6 +20,8 @@
 import sys
 import os.path
 import uuid
+import hashlib
+from pathlib import Path
 import sat
 from sat.core.i18n import _, D_, languageSwitch
 from sat.core import patches
@@ -173,6 +175,7 @@
         self.bridge.register_method("namespacesGet", self.getNamespaces)
         self.bridge.register_method("imageCheck", self._imageCheck)
         self.bridge.register_method("imageResize", self._imageResize)
+        self.bridge.register_method("imageGeneratePreview", self._imageGeneratePreview)
 
         self.memory.initialized.addCallback(lambda __: defer.ensureDeferred(self._postMemoryInit()))
 
@@ -684,6 +687,45 @@
         d.addCallback(lambda new_image_path: str(new_image_path))
         return d
 
+    def _imageGeneratePreview(self, path, profile_key):
+        client = self.getClient(profile_key)
+        d = defer.ensureDeferred(self.imageGeneratePreview(client, Path(path)))
+        d.addCallback(lambda preview_path: str(preview_path))
+        return d
+
+    async def imageGeneratePreview(self, client, path):
+        """Helper method to generate in cache a preview of an image
+
+        @param path(Path): path to the image
+        @return (Path): path to the generated preview
+        """
+        report = images.checkImage(self, path, max_size=(300, 300))
+
+        if not report['too_large']:
+            # in the unlikely case that image is already smaller than a preview
+            preview_path = path
+        else:
+            # we use hash as id, to re-use potentially existing preview
+            path_hash = hashlib.sha256(str(path).encode()).hexdigest()
+            uid = f"{path.stem}_{path_hash}_preview"
+            filename = f"{uid}{path.suffix.lower()}"
+            metadata = client.cache.getMetadata(uid=uid)
+            if metadata is not None:
+                preview_path = metadata['path']
+            else:
+                with client.cache.cacheData(
+                    source='HOST_PREVIEW',
+                    uid=uid,
+                    filename=filename) as cache_f:
+
+                    preview_path = await images.resizeImage(
+                        path,
+                        new_size=report['recommended_size'],
+                        dest=cache_f
+                    )
+
+        return preview_path
+
     # local dirs
 
     def getLocalPath(self, client, dir_name, *extra_path, **kwargs):