Quadrat Cropper

＋ Add photos ▾

Drop photos, folders or a Drive-exported .zip here — or click to choose a folder (all its subfolders are included; their names fill the metadata) — or paste a Drive link above.

Each photo is scanned for the PVC quadrat frame (mint-green or yellow); the square opening is auto-cropped. auto-accepted review suggested needs manual corners cropped by hand

Whole Drive folder

Google only lets a signed-in app list everything in a folder, so pick whichever of these is easiest:

In Drive: right-click the folder → Download. When it finishes, drop the .zip anywhere on this page.

Welcome 👋

This app finds the PVC quadrat frame (mint-green or yellow) in each photo and crops the square opening (25 × 25 cm) automatically. Low-confidence crops are flagged so you can drag the corner markers yourself.

It is built for the MBON Pole to Pole network's standardized rocky-shore photo-quadrat protocol — see marinebon.org/p2p.

Getting images in — any one of:

  1. Drag & drop image files onto the page.
  2. Paste a Drive link to a single photo (shared as “Anyone with the link”) — works instantly, no sign-in.
  3. Bulk from Drive: either right-click the folder in Drive → Download and drop the .zip here (no sign-in), or do a one-time Google sign-in (⚙ button) and paste the folder link.

Optionally drop in the trip .csv files — their columns get merged into the export spreadsheet.

How to use

  1. Add images: drop files / a Drive-exported .zip, or paste a Drive link. Single-photo links work with no setup; whole folders need the .zip trick or a one-time sign-in (⚙).
  2. Wait for the scan: green ring = confident auto-crop (confidence ≥ 0.80), amber = review suggested (0.55–0.80), red = needs manual corners (< 0.55 or detection failed), blue = you cropped it by hand in the editor. The suggested crop is always a square inside the photo; if the detected outline was not square, ran off the photo or is much smaller/larger than the rest of the batch, it is flagged amber/red for review.
  3. Review: click any thumbnail to open the full photo with the crop's corner markers and a live crop preview alongside. Drag the markers onto the inner corners of the frame, then Apply & re-crop (failed detections open the same page so you can place the markers by hand).
  4. Export ZIP — no ticking needed: every crop with ≥ 80% confidence is included automatically, plus any you adjusted manually (adjusting a red/amber one always includes it). Images without a usable frame are skipped but listed in manifest.csv so nothing is silently lost.

Best results follow the P2P protocol as-designed: the camera 42 cm above the surface, whole quadrat inside the photo, the frame shaded for even lighting, and no tide pools in shot. Pre-cropped images (no green frame) are rejected rather than guessed.

These photo-quadrats follow the MBON Pole to Pole protocol

Your crops feed directly into the network's standardized rocky-shores monitoring: a 20 mm PVC frame with an OM System Tough TG-7 camera mounted 42 cm above the surface photographs a 25 × 25 cm opening; 40–60 photo-quadrats are taken per intertidal level (3 levels per site, 3 sites > 1 km apart per locality).

Protocol & network: marinebon.org/p2p — field manual (EN) · manual de campo (ES) · DOI 10.25607/OBP-2014.3.

This tool is open source — view the code on GitHub or report an image that fails (wrong crop, missed frame, crash… the more detail the better). The detector is being actively improved with real-world shots like yours.

Google Drive sign-in (one-time)

This is only needed to list a whole Drive folder automatically. Single-photo links and .zip drops never need it.

  1. Open Google Cloud → Credentials (free Google account) and Create credentials → OAuth client ID.
  2. Application type: Web application. Under “Authorized JavaScript origins” add exactly this (click to copy):
  3. Copy the resulting Client ID (ends in .apps.googleusercontent.com) and paste it below.

Stored only in this browser, sent only to Google. Scopes requested: drive.readonly (list + download the files you pick).

Crop

Keeps the yellow/green PVC rim out of the crop. Applies to photos processed after saving (default 5 %).

Adds high-resolution Esri World Imagery to the Map tab. Free key from an ArcGIS Location Platform account (privilege: basemaps). Without it the map uses Sentinel-2 cloudless (10 m) and OpenStreetMap.

Every crop shows the same 25 × 25 cm, so a common size in px means a common scale (px per cm) — crops become directly comparable. The px box is used with "fixed size".

Manual corner review

source image