From c67121fbc79218661545ec13e7ddfc51cfc1f05b Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Mon, 17 Nov 2025 17:14:24 +0100
Subject: [PATCH 01/11] draw box shape according to the model

---
 .../app_bricks/object_detection/__init__.py   | 22 +++++++++++++++++--
 src/arduino/app_utils/image.py                | 13 +++++++++--
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/arduino/app_bricks/object_detection/__init__.py b/src/arduino/app_bricks/object_detection/__init__.py
index 93f2e290..774a848d 100644
--- a/src/arduino/app_bricks/object_detection/__init__.py
+++ b/src/arduino/app_bricks/object_detection/__init__.py
@@ -1,6 +1,7 @@
 # SPDX-FileCopyrightText: Copyright (C) 2025 ARDUINO SA <http://www.arduino.cc>
 #
 # SPDX-License-Identifier: MPL-2.0
+from typing import Any
 
 from PIL import Image
 from arduino.app_utils import brick, Logger, draw_bounding_boxes
@@ -20,8 +21,19 @@ class ObjectDetection(EdgeImpulseRunnerFacade):
     """
 
     def __init__(self, confidence: float = 0.3):
+        """Initialize the ObjectDetection module.
+
+        Args:
+            confidence (float): Minimum confidence threshold for detections. Default is 0.3 (30%).
+
+        Raises:
+            ValueError: If model information cannot be retrieved.
+        """
         self.confidence = confidence
         super().__init__()
+        self._model_info = self.get_model_info()
+        if not self._model_info:
+            raise ValueError("Failed to retrieve model information. Ensure the Edge Impulse service is running.")
 
     def detect_from_file(self, image_path: str, confidence: float = None) -> dict | None:
         """Process a local image file to detect and identify objects.
@@ -38,7 +50,7 @@ def detect_from_file(self, image_path: str, confidence: float = None) -> dict |
         ret = super().infer_from_file(image_path)
         return self._extract_detection(ret, confidence)
 
-    def detect(self, image_bytes, image_type: str = "jpg", confidence: float = None) -> dict:
+    def detect(self, image_bytes, image_type: str = "jpg", confidence: float = None) -> dict[str, list[Any]] | None:
         """Process an in-memory image to detect and identify objects.
 
         Args:
@@ -65,7 +77,13 @@ def draw_bounding_boxes(self, image: Image.Image | bytes, detections: dict) -> I
             Image with bounding boxes and key points drawn.
             None if no detection or invalid image.
         """
-        return draw_bounding_boxes(image, detections)
+        if self._model_info.model_type == "object_detection":
+            return draw_bounding_boxes(image, detections)
+        elif self._model_info.model_type == "constrained_object_detection":
+            return draw_bounding_boxes(image, detections, draw_centroid=True)
+        else:
+            logger.error("Model type not supported for drawing bounding boxes.")
+            return None
 
     def _extract_detection(self, item, confidence: float = None):
         if not item:
diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 8870f9b1..32e7369f 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -94,7 +94,9 @@ def draw_colored_dot(draw, x, y, color, size):
     draw.ellipse(bounding_box, fill=color)
 
 
-def draw_bounding_boxes(image: Image.Image | bytes, detection: dict, draw: ImageDraw.ImageDraw = None) -> Image.Image | None:
+def draw_bounding_boxes(
+    image: Image.Image | bytes, detection: dict, draw: ImageDraw.ImageDraw = None, draw_centroid: bool = False
+) -> Image.Image | None:
     """Draw bounding boxes on an image using PIL.
 
     The thickness of the box and font size are scaled based on image size.
@@ -104,6 +106,8 @@ def draw_bounding_boxes(image: Image.Image | bytes, detection: dict, draw: Image
         detection (dict): A dictionary containing detection results with keys 'class_name', 'bounding_box_xyxy', and
             'confidence'.
         draw (ImageDraw.ImageDraw, optional): An existing ImageDraw object to use. If None, a new one is created.
+        draw_centroid (bool, optional): If True, draws a dot at the centroid of the bounding box instead of the box
+        itself. Defaults to False.
     """
     if isinstance(image, bytes):
         image_box = Image.open(io.BytesIO(image))
@@ -163,7 +167,12 @@ def draw_bounding_boxes(image: Image.Image | bytes, detection: dict, draw: Image
         x2_text = x1 + text_width + label_hpad * 2
 
         # Draw bounding box
-        draw.rectangle([x1, y1, x2, y2], outline=box_color, width=box_thickness)
+        if draw_centroid:
+            centroid_x = int((x1 + x2) / 2)
+            centroid_y = int((y1 + y2) / 2)
+            draw_colored_dot(draw, centroid_x, centroid_y, box_color, size=max(3, box_thickness * 2))
+        else:
+            draw.rectangle([x1, y1, x2, y2], outline=box_color, width=box_thickness)
         # Draw label background (dark gray, semi-transparent) on overlay
         label_bg_color = (0, 0, 0, 128)
         overlay = Image.new("RGBA", image_box.size, (0, 0, 0, 0))

From 46af52ecdb5605ad3c7bf757bd3c3c20383afb53 Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 11:21:16 +0100
Subject: [PATCH 02/11] add hollow dot

---
 src/arduino/app_utils/image.py | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 32e7369f..7e0e49b1 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -94,6 +94,21 @@ def draw_colored_dot(draw, x, y, color, size):
     draw.ellipse(bounding_box, fill=color)
 
 
+def draw_hollow_dot(draw, x, y, size):
+    """Draws a hollow dot (circle) on a PIL Image at the specified coordinate.
+
+    Args:
+        draw: An ImageDraw object from PIL.
+        x: The x-coordinate of the center of the dot.
+        y: The y-coordinate of the center of the dot.
+        size: The radius of the dot (in pixels).
+    """
+    # Calculate the bounding box for the outer circle
+    inner_size = int(size * 0.5)
+    bounding_box_inner = (x - inner_size, y - inner_size, x + inner_size, y + inner_size)
+    draw.ellipse(bounding_box_inner, fill=(0, 0, 0, 0))
+
+
 def draw_bounding_boxes(
     image: Image.Image | bytes, detection: dict, draw: ImageDraw.ImageDraw = None, draw_centroid: bool = False
 ) -> Image.Image | None:
@@ -170,7 +185,7 @@ def draw_bounding_boxes(
         if draw_centroid:
             centroid_x = int((x1 + x2) / 2)
             centroid_y = int((y1 + y2) / 2)
-            draw_colored_dot(draw, centroid_x, centroid_y, box_color, size=max(3, box_thickness * 2))
+            draw_hollow_dot(draw, centroid_x, centroid_y, size=max(3, box_thickness * 2))
         else:
             draw.rectangle([x1, y1, x2, y2], outline=box_color, width=box_thickness)
         # Draw label background (dark gray, semi-transparent) on overlay

From 7d2b399ef3459e2fcfb59f857ee5360522eb4823 Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 11:36:30 +0100
Subject: [PATCH 03/11] remove fill

---
 src/arduino/app_utils/image.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 7e0e49b1..b3fa24b2 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -106,7 +106,7 @@ def draw_hollow_dot(draw, x, y, size):
     # Calculate the bounding box for the outer circle
     inner_size = int(size * 0.5)
     bounding_box_inner = (x - inner_size, y - inner_size, x + inner_size, y + inner_size)
-    draw.ellipse(bounding_box_inner, fill=(0, 0, 0, 0))
+    draw.ellipse(bounding_box_inner)
 
 
 def draw_bounding_boxes(

From 9f98df8fbc64bb5d1dd52a69601ddfc63de71d3a Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 11:48:45 +0100
Subject: [PATCH 04/11] outline color

---
 src/arduino/app_utils/image.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index b3fa24b2..42e42c8b 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -94,19 +94,20 @@ def draw_colored_dot(draw, x, y, color, size):
     draw.ellipse(bounding_box, fill=color)
 
 
-def draw_hollow_dot(draw, x, y, size):
+def draw_hollow_dot(draw, x, y, color, size):
     """Draws a hollow dot (circle) on a PIL Image at the specified coordinate.
 
     Args:
         draw: An ImageDraw object from PIL.
         x: The x-coordinate of the center of the dot.
         y: The y-coordinate of the center of the dot.
+        color: A color value that PIL understands (e.g., "red", (255, 0, 0), "#FF0000"). This is the outline color.
         size: The radius of the dot (in pixels).
     """
     # Calculate the bounding box for the outer circle
-    inner_size = int(size * 0.5)
+    inner_size = int(size * 1)
     bounding_box_inner = (x - inner_size, y - inner_size, x + inner_size, y + inner_size)
-    draw.ellipse(bounding_box_inner)
+    draw.ellipse(bounding_box_inner, outline=color)
 
 
 def draw_bounding_boxes(
@@ -185,7 +186,7 @@ def draw_bounding_boxes(
         if draw_centroid:
             centroid_x = int((x1 + x2) / 2)
             centroid_y = int((y1 + y2) / 2)
-            draw_hollow_dot(draw, centroid_x, centroid_y, size=max(3, box_thickness * 2))
+            draw_hollow_dot(draw, centroid_x, centroid_y, box_color, size=max(3, box_thickness * 2))
         else:
             draw.rectangle([x1, y1, x2, y2], outline=box_color, width=box_thickness)
         # Draw label background (dark gray, semi-transparent) on overlay

From b21da8ad63fb9268be370ac3358b7ee9e62107cb Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 12:04:05 +0100
Subject: [PATCH 05/11] improve

---
 src/arduino/app_utils/image.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 42e42c8b..42a4b3a8 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -104,10 +104,8 @@ def draw_hollow_dot(draw, x, y, color, size):
         color: A color value that PIL understands (e.g., "red", (255, 0, 0), "#FF0000"). This is the outline color.
         size: The radius of the dot (in pixels).
     """
-    # Calculate the bounding box for the outer circle
-    inner_size = int(size * 1)
-    bounding_box_inner = (x - inner_size, y - inner_size, x + inner_size, y + inner_size)
-    draw.ellipse(bounding_box_inner, outline=color)
+    bounding_box = (x - size, y - size, x + size, y + size)
+    draw.ellipse(bounding_box, outline=color, width=2)
 
 
 def draw_bounding_boxes(
@@ -186,7 +184,7 @@ def draw_bounding_boxes(
         if draw_centroid:
             centroid_x = int((x1 + x2) / 2)
             centroid_y = int((y1 + y2) / 2)
-            draw_hollow_dot(draw, centroid_x, centroid_y, box_color, size=max(3, box_thickness * 2))
+            draw_hollow_dot(draw, centroid_x, centroid_y, box_color, size=10)
         else:
             draw.rectangle([x1, y1, x2, y2], outline=box_color, width=box_thickness)
         # Draw label background (dark gray, semi-transparent) on overlay

From ed32f691aff5b1ad5f2384158b4f0682de45583c Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 14:34:34 +0100
Subject: [PATCH 06/11] refactor + fix tests

---
 .../app_bricks/object_detection/__init__.py   | 12 ++--
 src/arduino/app_utils/image.py                | 67 ++++++++-----------
 .../objectdetection/test_objectdetection.py   |  6 ++
 3 files changed, 38 insertions(+), 47 deletions(-)

diff --git a/src/arduino/app_bricks/object_detection/__init__.py b/src/arduino/app_bricks/object_detection/__init__.py
index 774a848d..09697afa 100644
--- a/src/arduino/app_bricks/object_detection/__init__.py
+++ b/src/arduino/app_bricks/object_detection/__init__.py
@@ -4,7 +4,7 @@
 from typing import Any
 
 from PIL import Image
-from arduino.app_utils import brick, Logger, draw_bounding_boxes
+from arduino.app_utils import brick, Logger, draw_bounding_boxes, Shape
 from arduino.app_internal.core import EdgeImpulseRunnerFacade
 
 logger = Logger("ObjectDetection")
@@ -75,15 +75,13 @@ def draw_bounding_boxes(self, image: Image.Image | bytes, detections: dict) -> I
 
         Returns:
             Image with bounding boxes and key points drawn.
-            None if no detection or invalid image.
         """
+        shape = None
         if self._model_info.model_type == "object_detection":
-            return draw_bounding_boxes(image, detections)
+            shape = Shape.RECTANGLE
         elif self._model_info.model_type == "constrained_object_detection":
-            return draw_bounding_boxes(image, detections, draw_centroid=True)
-        else:
-            logger.error("Model type not supported for drawing bounding boxes.")
-            return None
+            shape = Shape.CIRCLE
+        return draw_bounding_boxes(image, detections, shape=shape)
 
     def _extract_detection(self, item, confidence: float = None):
         if not item:
diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 42a4b3a8..0c7ccbb6 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -8,6 +8,12 @@
 
 logger = Logger(__name__)
 
+
+class Shape:
+    RECTANGLE = "rectangle"
+    CIRCLE = "circle"
+
+
 # Define a mapping of confidence ranges to colors for bounding boxes
 CONFIDENCE_MAP = {
     (0, 20): "#FF0976",  # Pink
@@ -40,7 +46,7 @@ def _read(file_path: str) -> bytes:
 
 
 def get_image_type(image_bytes: bytes | Image.Image) -> str | None:
-    """Detect the type of an image from bytes or a PIL Image object.
+    """Detect the type of image from bytes or a PIL Image object.
 
     Returns:
         str: The image type in lowercase (e.g., 'jpeg', 'png').
@@ -60,7 +66,7 @@ def get_image_type(image_bytes: bytes | Image.Image) -> str | None:
         return None
 
 
-def get_image_bytes(image: str | Image.Image | bytes) -> bytes:
+def get_image_bytes(image: str | Image.Image | bytes) -> bytes | None:
     """Convert different type of image objects to bytes."""
     if image is None:
         return None
@@ -78,38 +84,27 @@ def get_image_bytes(image: str | Image.Image | bytes) -> bytes:
         return None
 
 
-def draw_colored_dot(draw, x, y, color, size):
+def draw_dot(draw, x, y, size, fill_color=None, outline_color=None):
     """Draws a large colored dot on a PIL Image at the specified coordinate.
 
     Args:
         draw: An ImageDraw object from PIL.
         x: The x-coordinate of the center of the dot.
         y: The y-coordinate of the center of the dot.
-        color: A color value that PIL understands (e.g., "red", (255, 0, 0), "#FF0000").
         size: The radius of the dot (in pixels).
+        fill_color: The fill color of the dot. Default is None (no fill).
+        outline_color: The outline color of the dot. Default is None (no outline).
     """
     # Calculate the bounding box for the circle
     bounding_box = (x - size, y - size, x + size, y + size)
-    # Draw a filled ellipse (which looks like a circle if the bounding box is a square)
-    draw.ellipse(bounding_box, fill=color)
-
-
-def draw_hollow_dot(draw, x, y, color, size):
-    """Draws a hollow dot (circle) on a PIL Image at the specified coordinate.
-
-    Args:
-        draw: An ImageDraw object from PIL.
-        x: The x-coordinate of the center of the dot.
-        y: The y-coordinate of the center of the dot.
-        color: A color value that PIL understands (e.g., "red", (255, 0, 0), "#FF0000"). This is the outline color.
-        size: The radius of the dot (in pixels).
-    """
-    bounding_box = (x - size, y - size, x + size, y + size)
-    draw.ellipse(bounding_box, outline=color, width=2)
+    draw.ellipse(bounding_box, fill=fill_color, outline=outline_color)
 
 
 def draw_bounding_boxes(
-    image: Image.Image | bytes, detection: dict, draw: ImageDraw.ImageDraw = None, draw_centroid: bool = False
+    image: Image.Image | bytes,
+    detection: dict,
+    draw: ImageDraw.ImageDraw = None,
+    shape: Shape = Shape.RECTANGLE,
 ) -> Image.Image | None:
     """Draw bounding boxes on an image using PIL.
 
@@ -120,7 +115,7 @@ def draw_bounding_boxes(
         detection (dict): A dictionary containing detection results with keys 'class_name', 'bounding_box_xyxy', and
             'confidence'.
         draw (ImageDraw.ImageDraw, optional): An existing ImageDraw object to use. If None, a new one is created.
-        draw_centroid (bool, optional): If True, draws a dot at the centroid of the bounding box instead of the box
+        shape (Shape, optional): Shape of the bounding box. Defaults to rectangle.
         itself. Defaults to False.
     """
     if isinstance(image, bytes):
@@ -134,6 +129,10 @@ def draw_bounding_boxes(
     if not detection or "detection" not in detection:
         return None
 
+    if shape not in (Shape.RECTANGLE, Shape.CIRCLE):
+        logger.warning(f"Unsupported shape '{shape}'. Defaulting to rectangle.")
+        shape = Shape.RECTANGLE
+
     detection = detection["detection"]
 
     # Scale font size and box thickness based on image size and number of detections
@@ -181,17 +180,15 @@ def draw_bounding_boxes(
         x2_text = x1 + text_width + label_hpad * 2
 
         # Draw bounding box
-        if draw_centroid:
-            centroid_x = int((x1 + x2) / 2)
-            centroid_y = int((y1 + y2) / 2)
-            draw_hollow_dot(draw, centroid_x, centroid_y, box_color, size=10)
+        if shape == Shape.CIRCLE:
+            draw_dot(draw, int((x1 + x2) / 2), int((y1 + y2) / 2), 10, outline_color=box_color)
         else:
-            draw.rectangle([x1, y1, x2, y2], outline=box_color, width=box_thickness)
+            draw.rectangle((x1, y1, x2, y2), outline=box_color, width=box_thickness)
         # Draw label background (dark gray, semi-transparent) on overlay
         label_bg_color = (0, 0, 0, 128)
         overlay = Image.new("RGBA", image_box.size, (0, 0, 0, 0))
         overlay_draw = ImageDraw.Draw(overlay)
-        overlay_draw.rectangle([x1, y1_text, x2_text, y2_text], fill=label_bg_color, outline=None)
+        overlay_draw.rectangle((x1, y1_text, x2_text, y2_text), fill=label_bg_color, outline=None)
         image_box = image_box.convert("RGBA")
         image_box = Image.alpha_composite(image_box, overlay)
         draw = ImageDraw.Draw(image_box)
@@ -204,7 +201,6 @@ def draw_bounding_boxes(
 def draw_anomaly_markers(
     image: Image.Image | bytes,
     detection: dict,
-    draw: ImageDraw.ImageDraw = None,
 ) -> Image.Image | None:
     """Draw bounding boxes on an image using PIL.
 
@@ -214,10 +210,6 @@ def draw_anomaly_markers(
         image (Image.Image|bytes): The image to draw on, can be a PIL Image or bytes.
         detection (dict): A dictionary containing detection results with keys 'class_name', 'bounding_box_xyxy', and
             'score'.
-        draw (ImageDraw.ImageDraw, optional): An existing ImageDraw object to use. If None, a new one is created.
-        label_above_box (bool, optional): If True, labels are drawn above the bounding box. Defaults to False.
-        colours (list, optional): List of colors to use for bounding boxes. Defaults to a predefined palette.
-        text_color (str, optional): Color of the text labels. Defaults to "white".
     """
     if isinstance(image, bytes):
         image_box = Image.open(io.BytesIO(image))
@@ -227,9 +219,6 @@ def draw_anomaly_markers(
     if image_box.mode != "RGBA":
         image_box = image_box.convert("RGBA")
 
-    if draw is None:
-        draw = ImageDraw.Draw(image_box)
-
     max_anomaly_score = detection.get("anomaly_max_score", 0.0)
 
     if not detection or "detection" not in detection:
@@ -262,10 +251,8 @@ def draw_anomaly_markers(
         temp_layer = Image.new("RGBA", image_box.size, (0, 0, 0, 0))
         temp_draw = ImageDraw.Draw(temp_layer)
 
-        temp_draw.rectangle([x1, y1, x2, y2], fill=fill_color_with_alpha)
-        temp_draw.rectangle([x1, y1, x2, y2], outline=outline_color, width=box_thickness)
+        temp_draw.rectangle((x1, y1, x2, y2), fill=fill_color_with_alpha)
+        temp_draw.rectangle((x1, y1, x2, y2), outline=outline_color, width=box_thickness)
         image_box = Image.alpha_composite(image_box, temp_layer)
 
-        draw = ImageDraw.Draw(image_box)
-
     return image_box
diff --git a/tests/arduino/app_bricks/objectdetection/test_objectdetection.py b/tests/arduino/app_bricks/objectdetection/test_objectdetection.py
index f98f779f..da041ab6 100644
--- a/tests/arduino/app_bricks/objectdetection/test_objectdetection.py
+++ b/tests/arduino/app_bricks/objectdetection/test_objectdetection.py
@@ -9,6 +9,11 @@
 from arduino.app_bricks.object_detection import ObjectDetection
 
 
+class ModelInfo:
+    def __init__(self, model_type: str):
+        self.model_type = model_type
+
+
 @pytest.fixture(autouse=True)
 def mock_dependencies(monkeypatch: pytest.MonkeyPatch):
     """Mock external dependencies in __init__.
@@ -19,6 +24,7 @@ def mock_dependencies(monkeypatch: pytest.MonkeyPatch):
     monkeypatch.setattr("arduino.app_internal.core.load_brick_compose_file", lambda cls: fake_compose)
     monkeypatch.setattr("arduino.app_internal.core.resolve_address", lambda host: "127.0.0.1")
     monkeypatch.setattr("arduino.app_internal.core.parse_docker_compose_variable", lambda x: [(None, None), (None, "8100")])
+    monkeypatch.setattr("arduino.app_bricks.object_detection.ObjectDetection.get_model_info", lambda self: ModelInfo("object-detection"))
 
 
 @pytest.fixture

From f9eaaefd06a3eb29db9200f1d284cb231af9a73d Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 14:49:04 +0100
Subject: [PATCH 07/11] set width

---
 src/arduino/app_utils/image.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 0c7ccbb6..4fcc32ce 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -97,7 +97,7 @@ def draw_dot(draw, x, y, size, fill_color=None, outline_color=None):
     """
     # Calculate the bounding box for the circle
     bounding_box = (x - size, y - size, x + size, y + size)
-    draw.ellipse(bounding_box, fill=fill_color, outline=outline_color)
+    draw.ellipse(bounding_box, fill=fill_color, outline=outline_color, width=2)
 
 
 def draw_bounding_boxes(

From 77a2c649d1383d630a16354ebcfd6cbc011a44ec Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 15:14:41 +0100
Subject: [PATCH 08/11] remove method

---
 src/arduino/app_utils/image.py | 21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 4fcc32ce..3f5b21a2 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -84,22 +84,6 @@ def get_image_bytes(image: str | Image.Image | bytes) -> bytes | None:
         return None
 
 
-def draw_dot(draw, x, y, size, fill_color=None, outline_color=None):
-    """Draws a large colored dot on a PIL Image at the specified coordinate.
-
-    Args:
-        draw: An ImageDraw object from PIL.
-        x: The x-coordinate of the center of the dot.
-        y: The y-coordinate of the center of the dot.
-        size: The radius of the dot (in pixels).
-        fill_color: The fill color of the dot. Default is None (no fill).
-        outline_color: The outline color of the dot. Default is None (no outline).
-    """
-    # Calculate the bounding box for the circle
-    bounding_box = (x - size, y - size, x + size, y + size)
-    draw.ellipse(bounding_box, fill=fill_color, outline=outline_color, width=2)
-
-
 def draw_bounding_boxes(
     image: Image.Image | bytes,
     detection: dict,
@@ -181,7 +165,10 @@ def draw_bounding_boxes(
 
         # Draw bounding box
         if shape == Shape.CIRCLE:
-            draw_dot(draw, int((x1 + x2) / 2), int((y1 + y2) / 2), 10, outline_color=box_color)
+            center_x = int((x1 + x2) / 2)
+            center_y = int((y1 + y2) / 2)
+            bounding_box = (center_x - 10, center_y - 10, center_x + 10, center_y + 10)
+            draw.ellipse(bounding_box, outline=box_color, width=2)
         else:
             draw.rectangle((x1, y1, x2, y2), outline=box_color, width=box_thickness)
         # Draw label background (dark gray, semi-transparent) on overlay

From 018cc6835009a9cbc506f47e496e5791a63d492e Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 15:30:13 +0100
Subject: [PATCH 09/11] set radius

---
 src/arduino/app_utils/image.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index 3f5b21a2..e02663fb 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -167,7 +167,8 @@ def draw_bounding_boxes(
         if shape == Shape.CIRCLE:
             center_x = int((x1 + x2) / 2)
             center_y = int((y1 + y2) / 2)
-            bounding_box = (center_x - 10, center_y - 10, center_x + 10, center_y + 10)
+            radius = 10
+            bounding_box = (center_x - radius, center_y - radius, center_x + radius, center_y + radius)
             draw.ellipse(bounding_box, outline=box_color, width=2)
         else:
             draw.rectangle((x1, y1, x2, y2), outline=box_color, width=box_thickness)

From 167ec20d113065688718bbfaba864ca235bb2bf3 Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 15:36:48 +0100
Subject: [PATCH 10/11] add check

---
 src/arduino/app_bricks/object_detection/__init__.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/arduino/app_bricks/object_detection/__init__.py b/src/arduino/app_bricks/object_detection/__init__.py
index 09697afa..04fb018a 100644
--- a/src/arduino/app_bricks/object_detection/__init__.py
+++ b/src/arduino/app_bricks/object_detection/__init__.py
@@ -75,7 +75,11 @@ def draw_bounding_boxes(self, image: Image.Image | bytes, detections: dict) -> I
 
         Returns:
             Image with bounding boxes and key points drawn.
+            None if input image or detections are invalid.
         """
+        if not image or not detections:
+            return None
+
         shape = None
         if self._model_info.model_type == "object_detection":
             shape = Shape.RECTANGLE

From e89639a1cec748ec213af24c83d73ec5c7be619f Mon Sep 17 00:00:00 2001
From: Stefano Torneo <s.torneo@arduino.cc>
Date: Tue, 18 Nov 2025 17:15:43 +0100
Subject: [PATCH 11/11] revert change

---
 src/arduino/app_utils/image.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/arduino/app_utils/image.py b/src/arduino/app_utils/image.py
index e02663fb..48f2f25c 100644
--- a/src/arduino/app_utils/image.py
+++ b/src/arduino/app_utils/image.py
@@ -189,6 +189,7 @@ def draw_bounding_boxes(
 def draw_anomaly_markers(
     image: Image.Image | bytes,
     detection: dict,
+    draw: ImageDraw.ImageDraw = None,
 ) -> Image.Image | None:
     """Draw bounding boxes on an image using PIL.
 
@@ -198,6 +199,10 @@ def draw_anomaly_markers(
         image (Image.Image|bytes): The image to draw on, can be a PIL Image or bytes.
         detection (dict): A dictionary containing detection results with keys 'class_name', 'bounding_box_xyxy', and
             'score'.
+        draw (ImageDraw.ImageDraw, optional): An existing ImageDraw object to use. If None, a new one is created.
+        label_above_box (bool, optional): If True, labels are drawn above the bounding box. Defaults to False.
+        colours (list, optional): List of colors to use for bounding boxes. Defaults to a predefined palette.
+        text_color (str, optional): Color of the text labels. Defaults to "white".
     """
     if isinstance(image, bytes):
         image_box = Image.open(io.BytesIO(image))
@@ -207,6 +212,9 @@ def draw_anomaly_markers(
     if image_box.mode != "RGBA":
         image_box = image_box.convert("RGBA")
 
+    if draw is None:
+        draw = ImageDraw.Draw(image_box)
+
     max_anomaly_score = detection.get("anomaly_max_score", 0.0)
 
     if not detection or "detection" not in detection:
@@ -239,8 +247,10 @@ def draw_anomaly_markers(
         temp_layer = Image.new("RGBA", image_box.size, (0, 0, 0, 0))
         temp_draw = ImageDraw.Draw(temp_layer)
 
-        temp_draw.rectangle((x1, y1, x2, y2), fill=fill_color_with_alpha)
-        temp_draw.rectangle((x1, y1, x2, y2), outline=outline_color, width=box_thickness)
+        temp_draw.rectangle([x1, y1, x2, y2], fill=fill_color_with_alpha)
+        temp_draw.rectangle([x1, y1, x2, y2], outline=outline_color, width=box_thickness)
         image_box = Image.alpha_composite(image_box, temp_layer)
 
+        draw = ImageDraw.Draw(image_box)
+
     return image_box