What Stage 1 is for
Stage 1 is the input stage of the detection workflow. You're telling ZeroCount where to look on the drawing (Areas of Interest, or AOIs) and what to look for (the legend). Press Submit, the detection pipeline runs, and you arrive in Stage 2 with a tree of marker groups to review.
"Amend the auto-detected areas of interest (AOIs) and legends, or create new ones. Submit to detect any legend symbols found within the AOIs."
That sentence — from the Stage 1 indicator tooltip — captures the job: amend what ZeroCount has guessed, or build from scratch if there's nothing to amend.
What ZeroCount has already done
When you first open a drawing it runs a quick OCR pass and tries to place AOIs and a legend marker for you. Three possible outcomes:
- Both placed correctly — common on clean drawings with a standard legend layout. Skim, sanity-check, press Submit.
- Placed but wrong — the AOI is too small, too large, or it covers the legend. Resize the polygon corners to fix.
- Nothing placed — the OCR couldn't make sense of the drawing. Draw an AOI and a legend marker manually.
The auto-detected AOIs are visible immediately. Each AOI is a polygon overlay with a configurable colour and opacity.
The Zones & AOIs panel
AOIs and zones live in the same sidebar dropdown — open it from the Zones & AOIs button in the marker list toolbar.
Inside the dropdown you'll see two sections:
- AOIs — the regions of the drawing where ZeroCount will search for symbols.
- Zones — for Stage 3 work, not Stage 1.
Each AOI in the list is labelled AOI 1, AOI 2, etc., with a colour swatch and a delete button .
For full detail on each part of Stage 1:
The Submit flow
Once your AOIs and legend marker are in place, press Submit in the bottom-right corner of the canvas.
ZeroCount sends the AOI polygons and the legend region to the backend detection pipeline. The pipeline runs three stages of its own — symbol extraction from the legend, template matching against the AOI, and group clustering — and returns marker groups when it finishes.
Full detail on what happens behind the scenes: Running detection.
Tips for a clean Stage 1
- One AOI per working area, not many small ones. ZeroCount handles complex polygons fine — better one large AOI hugging the working drawing than several small ones.
- Always exclude the legend from the AOI. If your AOI covers the legend, ZeroCount finds the legend symbols as well as the real ones, inflating counts.
- Lock AOIs before you hand the drawing to a colleague. Locking prevents accidental moves; you can unlock to delete.
When to skip Stage 1 entirely
If the drawing has no legend at all (a hand-marked-up sketch, for example), there's nothing useful for Stage 1 to do. Turn on Skip Stage 1 in your user preferences and new files open straight into Stage 2 for manual takeoff.