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Image Browser

Browse large collections of georeferenced seafloor images spatially and by index, with the map and the imagery kept in sync.

Image Browser dock

A HabCam frame in the Image Browser — coarse shell hash grading into sand — with the display histogram alongside.

What it does

  • Loads a per-image metadata table (Parquet) and builds a spatial index (KD-tree) over the image positions, so the nearest image to any location is found instantly.
  • Displays the current image in a fast pyqtgraph viewer with an LRU cache for smooth back-and-forth navigation.
  • Shows a metadata panel listing every column of the metadata table for the current image (position, depth, altimeter, field-of-view, mm/pixel, salinity/temperature, …) plus its acquisition time — so extra columns of your own appear automatically.
  • Overlays bounding-box annotations (e.g. detector output) with a tunable confidence threshold.

How to use

  • Navigate with the forward/back buttons, the index slider, or the index spin-box; the step control sets how many images each press advances.

The slider is in its own panel, behind its own toolbar button

The index slider, spin-box, step and zoom-to controls live in a separate QGIS panel titled Image Index, which starts hidden. It has its own toolbar button — Show / hide the Image Index navigator — next to the Image Browser one, and the two are independent: showing the browser does not show the navigator. If the image is displayed but you cannot find the controls to move between images, that second button is what you want.

  • Click the map (image-query tool) to jump to the image nearest that point.
  • Enable Zoom-to so the map recenters on each image as you browse. The zoom control is a map scale (1:N) — larger numbers zoom out — so it behaves the same whether your project is in metres or degrees.
  • Adjust the annotation confidence spin-box to show/hide detections below a threshold.

Annotations over an image

Bounding-box annotations with a confidence threshold.

Inputs (Settings → HabCam)

Setting What it is
imagepath Folder of image files (JPEG).
imagemetadata Per-image metadata table (Parquet) — must include image name, longitude, latitude (plus depth, FOV, etc.).
imageannotation Optional CSV mapping image names to bounding boxes + species + confidence.

Column-by-column: Image metadata · Annotation CSV.

Which position the marker uses

The marker sits on the calibrated USBL fix (Xutm + dx / Yutm + dy, reprojected to WGS-84 at load), falling back to habcam_lon / habcam_lat when those columns are absent. The same position drives the nearest-image lookup, the KMZ export and the query builder's sampling centre, so all four always coincide — see Positioning.