Image rotation (`tool_image_rotation`)

See also: Tools user guide · Developer reference

Image rotation is an interactive editor for straightening and reframing an image already attached to a record — it rotates and crops every web-sized copy while leaving the preserved master untouched.

What it's for

An image component keeps a preserved master plus several generated copies (a web-sized version, a small preview, a thumbnail). When a scan or photo comes out crooked or with an unwanted border, you do not want to re-scan and re-upload — you want to straighten it in place. Image rotation opens the picture in an editor, lets you pick a precise angle and draw a crop rectangle, and re-renders all the derived copies to match. The original master is always kept intact, so you can redo the transform later from the pristine file.

The same panel offers background removal: it can isolate the subject and drop the background using a neural network that runs in your browser.

Concrete scenario: a photo archivist uploads a scanned print that came off the scanner tilted and with a black edge. They open Image rotation, nudge the angle slider until the horizon is level (the alignment guides and "Expand" mode keep the corners from being clipped), draw a crop box to remove the edge, and apply. Every web and thumbnail copy is regenerated straight and trimmed; the archived master is unchanged.

When to use it

A derived image needs straightening or reframing without re-uploading.
You want to isolate an object on a transparent or plain background.

It works on images only. To manage the wider quality set — rebuild, delete, fix audiovisual headers, re-sync — use Media versions. To bring a new image into a component, use Upload.

Where to find it

Image rotation surfaces as a button on component_image components in the record's edit view. It opens as a modal containing the editor.

Using it, step by step

Open the record and click the Image rotation button on the image component. The editor opens showing the picture with alignment guides.
Set the angle: drag the Rotation slider (any angle, in fine steps) or type a value in the box next to it. The preview rotates live.
If the corners get clipped, tick Expand so the canvas grows to fit the whole rotated image.
Choose how exposed corners are filled: pick a Background colour, or tick Transparent for an alpha background (only meaningful for formats that support transparency).
To crop, click the crop button and draw a rectangle over the image; drag its handles or the box itself to adjust. The live readout shows the selection.
Press the apply button (labelled Create). Confirm when prompted. Dédalo re-renders every derived copy with the rotation and crop, then reloads the preview. The slider and crop reset.
To isolate the subject, press Remove background. If your browser lacks WebGPU you are warned it may be slow. The result is uploaded and processed into a new copy.

Options

Control	What it does
Rotation (slider / value)	Sets the rotation angle applied to every derived copy. Zero leaves the orientation unchanged.
Expand	Grows the canvas to the rotated bounding box so no corners are clipped; unchecked keeps the original frame and clips corners.
Background colour	The fill colour shown behind the rotated image where corners are exposed.
Transparent	Renders the background as transparent instead of a solid colour (needs an alpha-capable format).
Crop	Toggles the crop overlay; draw and adjust a rectangle to trim the image.
Create (apply)	Sends the rotation and crop to the server, which re-renders the derived copies.
Remove background	Runs in-browser background removal and files the cut-out as a new copy.

Tips and gotchas

Tip

Turn on Expand before rotating a rectangular image — otherwise the slider crops the corners as it turns, and you lose the parts you were trying to keep.

Warning

Applying a rotation or crop re-renders every derived copy and cannot be undone from within this tool. The preserved master (the original quality) is never overwritten, so if you need to start over, use Media versions to rebuild the copies from the master.

Info

Background removal runs the neural network entirely in your browser; a WebGPU-capable browser makes it practical, and you are prompted before it starts on an incompatible one.

Media versions — the broader quality manager; it also offers a simple per-quality rotate.
Upload — bring an image into the component in the first place.
Posterframe — the equivalent capture tool for audiovisual clips.
Developer reference — the apply_rotation action, options and internals. See also the media pipeline overview.

Image rotation (tool_image_rotation)