> For the complete documentation index, see [llms.txt](https://docs.augelab.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.augelab.com/function-blocks/blocks-reference/detections-shapes/draw/draw-detections.md).

# Draw Detections

This function block overlays detection results on an image by drawing rectangles and a textual verdict (OK / Nok) for each detected object. It is intended as a final visualization or inspection step in a vision pipeline.

## 📥 Inputs <a href="#inputs" id="inputs"></a>

`Image` Primary image to draw overlays on. (input socket)

`Coordinate_List` List of rectangle coordinates to draw. Each item should be a pair of points defining a rectangle. (input socket)

`Object_Count` List of counts/flags corresponding to each rectangle. Used to determine OK (green) or Nok (red) status. (input socket)

`Trigger` Boolean to enable drawing. When not active the block will output nothing. (input socket)

## 📤 Outputs <a href="#outputs" id="outputs"></a>

`Result Image` The image with drawn rectangles and status text. (output socket)

## 🕹️ Controls <a href="#controls" id="controls"></a>

This block has no internal UI controls. Behavior is controlled entirely via its input sockets.

## 🎨 Features <a href="#features" id="features"></a>

* Visual status overlay that draws colored rectangles and text labels on the input image.
* Color coding: green for OK, red for Nok — determined from the corresponding `Object_Count` values.
* Handles multiple detections at once by iterating through the lists of coordinates and counts.
* Emits warnings when list lengths mismatch or when coordinate data is invalid.
* Requires an active `Trigger` to produce an output; otherwise it produces no result.

## ⚙️ Running mechanism <a href="#running-mechanism" id="running-mechanism"></a>

* When the block receives data and the `Trigger` input is True, it copies the provided `Image` and draws one rectangle for each entry in `Coordinate_List`.
* For each rectangle, the block checks the corresponding value in `Object_Count`. If the value indicates presence (non-zero), the rectangle and the label are drawn in green with text "Ok". If the value is zero or missing, the rectangle and text are drawn in red with text "Nok".
* If the number of coordinates and counts differ, the block will warn and pair items using the shortest length. Invalid coordinate entries are skipped with a warning.
* The final annotated image is sent through the `Result Image` output socket.

## 📝 Usage instructions <a href="#usage" id="usage"></a>

1. Feed a source image into `Image`.
2. Provide matching lists into `Coordinate_List` and `Object_Count` (same length recommended).
3. Activate `Trigger` to generate the annotated result image.
4. Connect the `Result Image` to a viewer or saver block to inspect or store the annotated frames.

## 💡 Tips and Tricks <a href="#tips-and-tricks" id="tips-and-tricks"></a>

* Use `Object Detection` or `Object Detection - Custom` (or `Object Detection (D-FINE)`) to produce rectangle lists and counts, then connect their rectangle and count outputs into `Coordinate_List` and `Object_Count`.
* Combine with `Object_Detection_Tracker` to draw tracked rectangles with consistent positions; feed tracked rectangle outputs into this block for per-object OK/Nok overlays.
* Use `Rectangles in Rectangle` or `Check Area` to filter detections before drawing (exclude detections outside a region of interest).
* Preview results with `Show Image` and save with `Image Logger` or `Image Write` for record keeping.
* Control when annotations appear using `Logic Input` or edge detectors like `Rising Edge` so you only draw on selected frames.
* If you need to draw single rectangles directly, consider `Draw Rectangle`; use this block when you have multiple detections and want automated OK/Nok marking.

## 🛠️ Troubleshooting <a href="#troubleshooting" id="troubleshooting"></a>

* No output: ensure `Trigger` is True and valid image data is connected to `Image`.
* Mismatched lists: if `Coordinate_List` and `Object_Count` lengths differ you will see warnings and some items may be ignored — make sure your upstream block outputs aligned lists.
* Invalid coordinates: if coordinate entries are malformed the block will skip them and warn; verify the format coming from detection blocks.
* To persist results or inspect them frame-by-frame, connect `Result Image` to `Show Image` or to saving blocks like `Image Logger`.