1hew-ComfyUI-1hewNodes/web/docs/1hew_ImageBBoxOverlayByMask/en.md

Image BBox Overlay by Mask - Draw bboxes from mask

Node Purpose: Image BBox Overlay by Mask draws bounding boxes on images using connected components from the input mask or a single merged bbox. Supports color, stroke width, optional fill, and extra padding.

Inputs

Name	Port	Type	Default	Range	Description
image	-	IMAGE	-	-	Input image batch (B×H×W×3).
mask	-	MASK	-	-	Mask batch (B×H×W). Automatically aligned and broadcast to image batch.
bbox_color	-	COMBO	green	options	red/green/blue/yellow/cyan/magenta/white/black.
stroke_width	-	INT	4	1–100	Line width for outline mode.
fill	-	BOOLEAN	True	-	When True, fill bbox region; otherwise draw outline.
padding	-	INT	0	0–1000	Expand bbox outward by this many pixels.
output_mode	-	COMBO	separate	separate/merge	Multiple bboxes per component or a single merged bbox for the whole mask.

Outputs

Name	Type	Description
image	IMAGE	Image batch with drawn bboxes.

Features

• Batch alignment: broadcasts mask to match image batch length and aligns size by LANCZOS.
• Modes: separate finds connected components via regionprops; merge uses min/max over all positive mask pixels.
• Padding: expands each bbox by padding in all directions, clamped to image bounds.
• Async per-frame: processes each sample in worker threads for responsiveness.

Typical Usage

• Visualize detection masks: set output_mode=separate to draw bboxes for each component.
• Generate a single ROI: set output_mode=merge and tune padding to include context.
• Choose display style: switch fill to fill the rectangle or use outline with stroke_width.

Notes & Tips

• Mask thresholding uses >128 on 8-bit representation when computing components and merged bbox.
• Color options are mapped to fixed RGB values; defaults to green if not found.