Description
Captures a single frame from a browser screen, window, or application tab share stream.
When the node appears in the workflow, a “Start capture” button is shown in the frontend. Clicking it opens the browser’s screen‑share permission dialog; after picking a source, a live preview appears directly in the node.
The node supports interactive cropping:
- Drag on the preview to draw a crop box.
- Drag inside the box to move it.
- Drag edges or corners to resize.
- Shift + drag to lock the aspect ratio.
- Right‑click or double‑click inside the preview to clear the crop.
The final output image is the selected crop area, resized to the dimensions given by the crop_width and crop_height inputs.
Works with auto‑queue – when queued repeatedly, the node re‑captures the same screen source on each run (useful for real‑time processing).
Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
frame_data | STRING | Yes | "" | Internal placeholder for the captured frame data. Leave as empty string – the node handles capture automatically. |
crop_width | INT | Yes | (none) | Width (in pixels) of the output image after cropping. |
crop_height | INT | Yes | (none) | Height (in pixels) of the output image after cropping. |
The crop dimensions define the final output resolution. The interactive crop box is drawn at free proportions on the preview; the captured region is then scaled (if needed) to match crop_width × crop_height.
Outputs
| Name | Type | Description |
|---|---|---|
IMAGE | torch.Tensor | The captured and cropped frame. Shape: (1, H, W, 3) in RGB order, values 0.0–1.0. |
Usage Notes
- Browser permission – The first time “Start capture” is clicked, the browser will ask permission to share a screen, window, or tab. The node can only access the source you explicitly select. If permission is denied, an error will be shown in the workflow.
- Auto‑queue – When the workflow is set to auto‑queue, the node captures a new frame on every execution. To stop, either disable auto‑queue or remove the node.
- Cropping behaviour – The crop box is drawn interactively on the preview. If the drawn region does not match
crop_width×crop_heightin aspect ratio, the final output will be resized to those exact dimensions (stretching or letterboxing as needed). - No crop – If you never draw a crop box (or clear it with right‑click / double‑click), the full captured frame is used. In that case, the output is still resized to
crop_width×crop_height. - Output dimensions – Best performance and quality are obtained when
crop_widthandcrop_heightapproximately match the resolution of the source content. Very large values may cause slowdowns or memory issues.
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