What a Detection marker is
A Detection marker represents one instance of a symbol that ZeroCount has matched against a template. Every Detection marker has:
- A position on the drawing.
- A parent group — the symbol type it represents.
- An image — the bitmap pattern it matched against.
They live in the Auto Count Symbol section of the sidebar.
Detection groups are the heart of a typical takeoff — most counts come through this route.
Where Detection markers come from
Two paths into a Detection group:
- Stage 1 auto-detection — when you press Submit, the pipeline produces one Detection group per template it could find. Each match becomes a marker. See Running detection.
- Auto Count Symbol in Stage 2/3 — drag a box around an example and ZeroCount finds more like it. See Manual symbol detection.
There's no third route — you can't place an individual Detection marker by clicking. For per-click manual counts, use Unit markers instead.
What you see on the canvas
Each Detection marker appears as a coloured overlay on its match position. The colour comes from the group's appearance settings. By default the marker is a small filled shape — you can switch to outline-only or hidden via the group's visibility settings.
When you hover a marker, panning is suspended so you can interact with it. Click to select. Multi-select with CTRL+drag.
What you see in the sidebar
Each Detection group shows:
- A colour swatch / thumbnail — the symbol image extracted from the legend or your Auto Count Symbol selection.
- The group label —
Group 1by default; click to edit. - The marker count — number of matches.
- A link icon ( or ) — whether the group is linked to a database item.
- An expand chevron — opens the marker list inside the group.
- A merge icon — to merge into another group.
- A + button — to add more markers via Auto Count Symbol scoped to this group.
- A dotted menu — for Visibility, Reimage Group, Delete Symbol Group, and Link Item.
In the Excel export
Detection groups appear in the Type = Detection rows. Each group's row shows:
- The group's label as the Takeoff Description.
- The linked product Code and Description (if linked).
- A count per zone, plus an Uncategorized column and a Total Quant.
See Exporting to Excel for the full column layout.
When detection misses
If a Detection group has fewer markers than you expect:
- Use the + button on the group's row, drag around a missed instance — Auto Count Symbol finds more.
- If matches are still partial, the group's symbol image may be a poor template — use Reimage Group to swap for a cleaner example.
- As a last resort, fall back to Unit markers for the missed instances — a few hand-clicks fill the gap.