diff --git a/config/default.py b/config/default.py
index a68e1fbe4..b3c99bbb8 100644
--- a/config/default.py
+++ b/config/default.py
@@ -47,6 +47,7 @@
 
 IIIF_ACTIVATE = False
 IIIF_DIR = ''
+IIIF_PREFIX = ''
 
 # For system checks
 WRITABLE_DIRS = [
diff --git a/openatlas/display/util.py b/openatlas/display/util.py
index bd67dc883..e197c00b1 100644
--- a/openatlas/display/util.py
+++ b/openatlas/display/util.py
@@ -431,13 +431,11 @@ def system_warnings(_context: str, _unneeded_string: str) -> str:
         warnings.append(
             f"Database version {app.config['DATABASE_VERSION']} is needed but "
             f"current version is {g.settings['database_version']}")
-    if app.config['IIIF_ACTIVATE']:
-        app.config['WRITABLE_DIRS'].append(app.config['IIIF_DIR'])
+    if app.config['IIIF_ACTIVATE'] and app.config['IIIF_DIR']:
+        path = Path(app.config['IIIF_DIR']) / app.config['IIIF_PREFIX']
+        check_write_access(path, warnings)
     for path in app.config['WRITABLE_DIRS']:
-        if not os.access(path, os.W_OK):
-            warnings.append(
-                '<p class="uc-first">' + _('directory not writable') +
-                f" {str(path).replace(app.root_path, '')}</p>")
+        check_write_access(path, warnings)
     if is_authorized('admin'):
         from openatlas.models.user import User
         user = User.get_by_username('OpenAtlas')
@@ -455,6 +453,14 @@ def system_warnings(_context: str, _unneeded_string: str) -> str:
         f'{"<br>".join(warnings)}</div>' if warnings else ''
 
 
+def check_write_access(path, warnings):
+    if not os.access(path, os.W_OK):
+        warnings.append(
+            '<p class="uc-first">' + _('directory not writable') +
+            f" {str(path).replace(app.root_path, '')}</p>")
+    return warnings
+
+
 @app.template_filter()
 def tooltip(text: str) -> str:
     if not text:
diff --git a/openatlas/templates/admin/data.html b/openatlas/templates/admin/data.html
index c2c1d269e..e062e735d 100644
--- a/openatlas/templates/admin/data.html
+++ b/openatlas/templates/admin/data.html
@@ -32,6 +32,7 @@ <h1 class="mb-1">{{ _('image processing')|uc_first }}</h1>
     <div class="col-auto">{{ 'admin/file'|manual|safe }}</div>
     <div class="col-auto">{{ _('create resized images')|button(url_for('admin_resize_images'))|safe }}</div>
     <div class="col-auto">{{ _('delete orphaned resized images')|button(url_for('admin_delete_orphaned_resized_images'))|safe }}</div>
+    <div class="col-auto">{{ _('convert all images to iiif')|button(url_for('admin_convert_all_to_iiif'))|safe }}</div>
   </div>
 {% endif %}
 {% if 'manager'|is_authorized %}
diff --git a/openatlas/views/admin.py b/openatlas/views/admin.py
index 39a4be31f..1240d7914 100644
--- a/openatlas/views/admin.py
+++ b/openatlas/views/admin.py
@@ -38,6 +38,7 @@
 from openatlas.models.settings import Settings
 from openatlas.models.type import Type
 from openatlas.models.user import User
+from openatlas.views.file import convert_image_to_iiif
 
 
 @app.route('/admin', methods=['GET', 'POST'], strict_slashes=False)
@@ -777,3 +778,14 @@ def get_disk_space_info() -> Optional[dict[str, Any]]:
         'percent_used': percent_free,
         'percent_project': percent_files,
         'percent_other': 100 - (percent_files + percent_free)}
+
+
+@app.route('/admin/admin_convert_all_to_iiif')
+@required_group('admin')
+def admin_convert_all_to_iiif() -> Response:
+    for entity in Entity.get_by_class('file'):
+        if entity.id in g.file_stats \
+                and g.file_stats[entity.id]['ext'] \
+                in app.config['ALLOWED_IMAGE_EXT']:
+            convert_image_to_iiif(entity.id)
+    return redirect(url_for('admin_index') + '#tab-data')
diff --git a/openatlas/views/file.py b/openatlas/views/file.py
index ea310a172..15d230d2a 100644
--- a/openatlas/views/file.py
+++ b/openatlas/views/file.py
@@ -1,6 +1,5 @@
 import subprocess
 from pathlib import Path
-from subprocess import call, run
 from typing import Any, Union
 
 from flask import g, render_template, request, send_from_directory, url_for
@@ -74,18 +73,20 @@ def file_add(id_: int, view: str) -> Union[str, Response]:
 @app.route('/file/iiif/<int:id_>', methods=['GET'])
 @required_group('contributor')
 def make_iiif_available(id_: int):
+    convert_image_to_iiif(id_)
+    return redirect(url_for('view', id_=id_))
+
+
+def convert_image_to_iiif(id_):
+    path = Path(app.config['IIIF_DIR']) / app.config['IIIF_PREFIX'] / str(id_)
     command = \
-        (f"vips.exe tiffsave "
-         f"{get_file_path(id_)} {Path(app.config['IIIF_DIR']) / str(id_)} "
+        (f"vips.exe tiffsave {get_file_path(id_)} {path} "
          f"--tile --pyramid --compression deflate "
          f"--tile-width 256 --tile-height 256")
     subprocess.Popen(command, shell=True)
-    return redirect(url_for('view', id_=id_))
 
 
 @app.route('/iiif/<int:id_>', methods=['GET'])
 @required_group('contributor')
 def view_iiif(id_: int):
     return redirect(url_for('view', id_=id_))
-
-