Convert Image to CNC Relief

I already have a clean black-and-white PNG/JPEG that shows the outline of a faux stained-glass window: raised framework and borders with recessed “glass” cells. What I now need is a machinable 3D relief that will carve cleanly on a wood CNC.

Scope
• Translate the 2-D outline into a single-sided 3-D model where the borders stand proud of the background and each pane drops to a lower plane.
• Preserve line weight so edges stay crisp, yet keep the overall geometry practical for machining—medium detail is the sweet spot. Tiny undercuts or over-thin walls aren’t necessary.
• The working size I’m aiming for is roughly 12–24 in (300–600 mm) tall, but I want the file built in real scale so I can resize later without distortion.

File & workflow
I’m flexible on format—STL, OBJ, or STEP are all acceptable as long as the mesh is watertight and ready for tool-path generation in common CAM packages (Vectric, Fusion 360, Aspire, etc.). A quick shaded render or screenshot of the finished relief will help me verify depth and proportion before sign-off.

Acceptance
1. Model mirrors the supplied outline generally in accordance with the image (some deviation permitted/flexible).
2. Distinct Z-levels: background, pane recess, raised mullions/frame.
3. No non-manifold edges or flipped normals.
4. Scales cleanly up to at least 24 in without visible faceting.

Send any clarifying questions you need up front and let me know your estimated turnaround. Looking forward to carving this piece!