diff --git a/photoapp/daemon.py b/photoapp/daemon.py
index eed48ce..ed63579 100644
--- a/photoapp/daemon.py
+++ b/photoapp/daemon.py
@@ -5,12 +5,12 @@ import cherrypy
 from urllib.parse import urlparse
 from datetime import datetime, timedelta
 from photoapp.thumb import ThumbGenerator
-from photoapp.types import Photo, PhotoSet, Tag, TagItem, PhotoStatus, User
+from photoapp.types import Photo, PhotoSet, Tag, TagItem, PhotoStatus, User, mime2ext
 from photoapp.dbsession import DatabaseSession
 from photoapp.common import pwhash
 from photoapp.api import PhotosApi, LibraryManager
 from photoapp.dbutils import SAEnginePlugin, SATool, db, get_db_engine, date_format
-from photoapp.utils import mime2ext, auth, require_auth, photoset_auth_filter, slugify
+from photoapp.utils import auth, require_auth, photoset_auth_filter, slugify
 from photoapp.storage import uri_to_storage
 from jinja2 import Environment, FileSystemLoader, select_autoescape
 from sqlalchemy import desc, func, and_, or_
diff --git a/photoapp/types.py b/photoapp/types.py
index 236de0c..e5e2a92 100644
--- a/photoapp/types.py
+++ b/photoapp/types.py
@@ -3,31 +3,79 @@ from sqlalchemy.orm import relationship
 from sqlalchemy.schema import UniqueConstraint
 from photoapp.dbutils import Base
 from datetime import datetime
+import enum as py_enum
 import uuid
 import enum
 
 
+class fcategory(py_enum.Enum):
+    image = 0
+    raw = 1
+    video = 2
+
+
+ftypes = dict(jpg=dict(category=fcategory.image,
+                       extensions={"jpeg"},
+                       mimes={"image/jpeg"}),
+              png=dict(category=fcategory.image,
+                       mimes={"image/png"}),
+              gif=dict(category=fcategory.image,
+                       mimes={"image/gif"}),
+              cr2=dict(category=fcategory.raw,
+                       mimes={"image/x-canon-cr2"}),
+              xmp=dict(category=fcategory.raw,
+                       mimes={"application/octet-stream-xmp"}),
+              psd=dict(category=fcategory.raw,
+                       mimes={"image/vnd.adobe.photoshop"}),
+              mp4=dict(category=fcategory.video,
+                       mimes={"audio/mp4",
+                              "video/mp4"}),
+              mov=dict(category=fcategory.video,
+                       mimes={"video/quicktime"}))
+
+# set various defaults in ftypes
+# it should look like:
+# ftypes = {
+#     <default_extension>: {
+#         "category": <fcategory key>,                               # required, fcategory type
+#         "extensions": {<*default_extension|optional extensions>},  # optional, defaults to set([<default_extension>])
+#         "mimes": {                                                 # required, mimes mapped to this type
+#             <mime string>
+#         },
+#         "type": <str(*image|video)>,                               # optional, defaults to str("image")
+#     },
+# }
+for extension, entry in ftypes.items():
+    entry["extensions"] = entry.get("extensions", set()) | set([extension])
+    entry["type"] = entry.get("type", "image")
+
+
 # file extensions we allow
-known_extensions = ["jpg", "png", "cr2", "xmp", "mp4", "mov"]
-
-# categorizaiton of media type based on extension
-regular_images = ["jpg", "png"]  # we can pull metadata out of these
-files_raw = ["cr2", "xmp"]  # treated as black boxes
-files_video = ["mp4", "mov"]
-
-# extensions with well-known aliases
-mapped_extensions = {"jpg": {"jpeg", }}   # target: aliases
+known_extensions = set.union(*[i["extensions"] for i in ftypes.values()])
 
 # allowed file types (based on magic identification)
-# TODO enforce this
-known_mimes = {"image/png",
-               "image/jpeg",
-               "image/gif",
-               "application/octet-stream-xmp",
-               "image/x-canon-cr2",
-               "audio/mp4",
-               "video/mp4",
-               "video/quicktime"}
+known_mimes = set.union(*[i["mimes"] for i in ftypes.values()])
+
+# categorizaiton of media type based on extension
+# we can pull metadata out of these
+# jpg, png, gif etc
+regular_images = set([extension for extension, ftype in ftypes.items() if ftype["category"] == fcategory.image])
+# "derived" files, treated as black boxes, we can't open them because proprietary
+# cr2, xmp, etc
+files_raw = set([extension for extension, ftype in ftypes.items() if ftype["category"] == fcategory.raw])
+# video types
+# mp4, mov, etc
+files_video = set([extension for extension, ftype in ftypes.items() if ftype["category"] == fcategory.video])
+
+
+def mime2ext(mime):
+    """
+    Given a mime type return the canonical file extension
+    """
+    for ext, ftype in ftypes.items():
+        if mime in ftype["mimes"]:
+            return ext
+    raise Exception(f"Unknown mime: '{mime}'")
 
 
 def genuuid():
@@ -35,10 +83,10 @@ def genuuid():
 
 
 def map_extension(ext):
-    for target, aliases in mapped_extensions.items():
-        if ext in aliases:
-            return target
-    return ext
+    for known_ext, ftype in ftypes.items():
+        if ext in ftype["extensions"]:
+            return known_ext
+    raise Exception(f"Unknown extension: '{ext}'")
 
 
 def generate_storage_path(timestamp, sha, extension):
diff --git a/photoapp/utils.py b/photoapp/utils.py
index 900eade..f71ee70 100644
--- a/photoapp/utils.py
+++ b/photoapp/utils.py
@@ -25,20 +25,6 @@ def shasum(fpin):
     return sha.hexdigest()
 
 
-def mime2ext(mime):
-    """
-    Given a mime type return the canonical file extension
-    """
-    return {"image/png": "png",
-            "image/jpeg": "jpg",
-            "image/gif": "gif",
-            "application/octet-stream-xmp": "xmp",
-            "image/x-canon-cr2": "cr2",
-            "audio/mp4": "mp4",
-            "video/mp4": "mp4",
-            "video/quicktime": "mov"}[mime]
-
-
 def get_extension(fname):
     parts = os.path.basename(fname).split(".")
     if len(parts) == 1: