image format independent of cs

app/forms.py

@@ -24,6 +24,8 @@ class DisplayEditFormImpl(FlaskForm):
         name = StringField('Display Name', validators=[DataRequired()])
         if current_app.config['ENABLE_DISPLAY_APPROVAL']:
             form_status = SelectField("Status", choices=[(k, v) for k, v in DISP_STATUS.items()], validators=[DataRequired()])
+        image_format = SelectField("Image Format", choices=[('BMP', 'BMP'), ('JPEG', 'JPEG'), ('PNG', 'PNG')], validators=[DataRequired()])
+        image_bit_depth = SelectField("Image Bit Depth", choices=[(None, 'Default'), (1, '1 bit (monochrome)'), (16, '16 bit'), (24, '24 bit')], validators=[Optional()])
         playlist = QuerySelectField('Playlist',
             validators=[Optional()],
             query_factory=lambda: Playlist.query.order_by(Playlist.name.asc()),

app/lib/image.py

@@ -1,4 +1,4 @@
-from typing import List, Tuple
+from typing import List, Tuple, Optional
 
 from PIL import Image
 
@@ -19,11 +19,10 @@ def convert_palette(palette: List[int]) -> List[int]:
     return out
 
 
-def convert_colors(color_spec: str, input_path: str):
+def convert_colors__cs(color_spec: str, in_im):
+    """Initial conversion to what's specified in color_spec"""
     cs = COLOR_SPEC.get(color_spec, COLOR_SPEC['1b'])
 
-    in_im = Image.open(input_path).convert('RGB')
-
     if cs['bits'] == 1:
         mode = '1'
     elif cs['bits'] < 16:
@@ -52,3 +51,25 @@ def convert_colors(color_spec: str, input_path: str):
         out_im.paste(in_im, tuple([0, 0] + list(in_im.size)))
 
     return out_im
+
+
+def convert_colors__bits(bit_depth: Optional[int], in_im):
+    """Second conversion to actual bit depth"""
+    if bit_depth:
+        if bit_depth >= 16:
+            return in_im.convert('RGB')
+        else:
+            # must be 1, 16, 24 - this case would be 1 bit
+            out_im = Image.new('1', in_im.size)
+            in_im = in_im.convert('L')
+            in_im = in_im.point(lambda p: 255 if p >= 170 else 0)
+            out_im.paste(in_im, tuple([0, 0] + list(in_im.size)))
+            return out_im
+    return in_im
+
+
+def convert_colors(bit_depth: Optional[int], color_spec: str, input_path: str):
+    im = Image.open(input_path).convert('RGB')
+    im = convert_colors__cs(color_spec, im)
+    im = convert_colors__bits(bit_depth, im)
+    return im

app/lib/jinja.py

@@ -122,6 +122,31 @@ def color_spec(value):
         return label(cs['name'], level='default')
 
 
+@jfilter()
+def image_format(value):
+    level = 'default'
+    if value == 'BMP':
+        level = 'info'
+    if value == 'JPEG':
+        level = 'primary'
+    if value == 'PNG':
+        level = 'success'
+    return label(value, level=level)
+
+
+@jfilter()
+def image_bit_depth(value):
+    level = 'default'
+    if value is not None:
+        if value >= 24:
+            level = 'success'
+        elif value >= 16:
+            level = 'info'
+        elif value >= 1:
+            level = 'primary'
+    return label(value or 'Default', level=level)
+
+
 @jfilter()
 def fixed(value, d=2):
     if value is not None:

app/models.py

@@ -319,6 +319,8 @@ class Display(Base):
     last_seen_at = db.Column(sau.ArrowType(), nullable=False, default=arrow.utcnow)
     display_spec = db.Column(sau.ChoiceType(choices=[(k, v['name']) for k, v in DISPLAY_SPEC.items()]), nullable=False)
     color_spec = db.Column(sau.ChoiceType(choices=[(k, v['name']) for k, v in COLOR_SPEC.items()]), nullable=False)
+    image_format = db.Column(sau.ChoiceType(choices=[('BMP', 'BMP'), ('JPEG', 'JPEG'), ('PNG', 'PNG')]), nullable=False, default='BMP', server_default='BMP')
+    image_bit_depth = db.Column(db.Integer())
     width = db.Column(db.Integer(), nullable=False, default=0)
     height = db.Column(db.Integer(), nullable=False, default=0)
     playlist_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"), db.ForeignKey(Playlist.id, onupdate='CASCADE', ondelete='SET NULL', name='fk_display_playlist'))
@@ -365,6 +367,9 @@ def sync(cls):
                 'name': key,
                 'status': 'pending' if current_app.config['ENABLE_DISPLAY_APPROVAL'] else 'active',
                 'approval_code': cls.generate_approval_code(),
+                # Set image details on create only; this allows for editing later
+                'image_format': request.args.get('i', 'BMP'),
+                'image_bit_depth': request.args.get('ib'),
             })
             display = cls.query.filter(cls.key == key).first()
             if display:

app/templates/display/list.html.j2

@@ -18,6 +18,7 @@
                             <th>Last Seen</th>
                             <th>Type</th>
                             <th>Colors</th>
+                            <th>Image</th>
                             <th>Dimensions</th>
                             {% if config['ENABLE_DISPLAY_APPROVAL'] %}
                                 <th>Status</th>
@@ -38,6 +39,10 @@
                                 <td>{{ d.last_seen_at |dt |typed_label }}</td>
                                 <td>{{ d.display_spec |display_spec }}</td>
                                 <td>{{ d.color_spec |color_spec }}</td>
+                                <td style="white-space: nowrap;">
+                                    {{ d.image_format |image_format }}
+                                    {{ d.image_bit_depth |image_bit_depth }}
+                                </td>
                                 <td>{{ d.width }}x{{ d.height }}</td>
                                 {% if config['ENABLE_DISPLAY_APPROVAL'] %}
                                     <td>

app/views/display.py

@@ -65,13 +65,14 @@ def render():
                 '--path', path,
                 '--browser', current_app.config['BROWSER'],
             ])
-            im = convert_colors(screen.display.color_spec, path)
+            im = convert_colors(screen.display.image_bit_depth, screen.display.color_spec, path)
             out = BytesIO()
-            im.save(out, 'bmp')
+            fmt = screen.display.image_format.code.lower()
+            im.save(out, fmt)
             l = out.tell()
             out.seek(0)
             payload = out
-            headers.update({'Content-length': l, 'Content-type': 'image/bmp'})
+            headers.update({'Content-length': l, 'Content-type': f'image/{fmt}'})
         finally:
             if os.path.exists(path):
                 os.unlink(path)

migrations/versions/2026_01_23_1414-84a28e9fdbb7_image_format.py

@@ -0,0 +1,35 @@
+"""image format
+
+Revision ID: 84a28e9fdbb7
+Revises: 6bda9090d0d3
+Create Date: 2026-01-23 14:14:40.125158
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+import sqlalchemy_utils
+
+# revision identifiers, used by Alembic.
+revision = '84a28e9fdbb7'
+down_revision = '6bda9090d0d3'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('display', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('image_format', sa.String(length=8), server_default='BMP', nullable=False))
+        batch_op.add_column(sa.Column('image_bit_depth', sa.Integer(), nullable=True))
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('display', schema=None) as batch_op:
+        batch_op.drop_column('image_bit_depth')
+        batch_op.drop_column('image_format')
+
+    # ### end Alembic commands ###