add opencv-plot node for dora dataflows

A display sink that overlays bounding boxes and text on an image input and shows it in an OpenCV window. Based on opencv-plot from dora-hub, brought up to the dora 1.0 node contract and packaged with uv. Python rather than Rust: the opencv Rust crate generates its bindings from the OpenCV headers on the build machine, so it needs libopencv-dev and libclang-dev per machine and per architecture and does not cross-compile. Every dependency here ships prebuilt wheels for linux-x86_64, linux-aarch64 and macos-arm64. Covers every encoding the upstream node did — bgr8, rgb8, jpeg/jpg/jpe/bmp/ webp/png, yuv420 and avif — plus both bbox formats, the text overlay, PLOT_WIDTH/PLOT_HEIGHT and headless operation under CI=true.
2026-09-10 18:55:28 -03:00
parent f043beec21
commit 43cb1ff01c
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+# The repository's own example: a webcam and a fixed caption feeding the viewer.
+# The plot node is built from this checkout with `path:` + `build:`, so
+# `dora validate` picks up the typed contract in dora-node.yml next to it.
+#
+# Run it with `--uv` so every Python node gets its own managed environment.
+# A consumer wires the node from a tag instead — see README.md.
+#
+# `bbox` is left unwired: every bbox source is a detector, and pulling one in
+# would put a model download in the way of a webcam preview. README.md shows
+# the wiring.
+strict_types: true
+
+nodes:
+  - id: camera
+    git: https://github.com/dora-rs/dora-hub.git
+    build: pip install ./node-hub/opencv-video-capture
+    path: opencv-video-capture
+    inputs:
+      tick: dora/timer/millis/100
+    outputs:
+      - image
+    output_types:
+      image: std/core/v1/UInt8
+
+  - id: caption
+    git: https://github.com/dora-rs/dora-hub.git
+    build: pip install ./node-hub/pyarrow-sender
+    path: pyarrow-sender
+    env:
+      DATA: "'dora-plot'"
+    outputs:
+      - data
+    output_types:
+      data: std/core/v1/String
+
+  - id: plot
+    path: opencv-plot
+    build: pip install .
+    inputs:
+      image: camera/image
+      text: caption/data