Image & Video Viewer
Overview
The Image & Video Viewer displays 2D and 2Dts signals - single images and image series (videos). It supports interactive pan, zoom, scalebar overlays, colour maps, and data value annotations.
Pan and Zoom
| Action | Control |
|---|---|
| Pan | Click and drag |
| Zoom | Mouse wheel (centred on cursor) |
| Selection zoom | Hold Shift + drag to draw a rectangle |
| Reset view | Double-click |
Sync Zoom & Pan
Enable Sync Zoom & Pan in the panel settings (Frame Navigation section) to tie a panel’s view to the other panels that have it enabled. They then share one zoom level and pan position: zoom or pan any of them and the rest follow, whichever one you drive.
Switching the toggle on snaps the panel to whatever the group is currently showing. Panels with it off keep their own view and are unaffected.
Synced panels match the zoom factor, not the physical field of view. If two signals were acquired at different pixel sizes, the same zoom factor covers a different area in each - and because pan is tracked in screen pixels, panels of different sizes will not frame exactly the same region.
Scalebar
The scalebar is rendered automatically when the signal contains spatial axis metadata. It adapts its colour (black or white) based on the brightness of the pixels behind it to stay readable on any image.
Supported units
Real-space - m, µm, nm, pm, Å. Values are displayed in the most readable unit (e.g. values ≥ 1000 nm are shown in µm).
Reciprocal-space - 1/nm, 1/Å, 1/m. Displayed directly with the original unit.
Scale values
The bar length is chosen from a series of “nice” values (1, 2, 5, 10, 20, 50, 100, …) so that it is approximately 150 pixels wide at the current zoom level. The label shows the exact length and unit.
Colour Maps
Select a colour map from the Color Scale dropdown in the panel settings (cog icon → Selection tab → Display Options).
| Map | Description |
|---|---|
| Grayscale | Linear black-to-white (default) |
| Viridis | Perceptually uniform, colour-blind friendly |
| Plasma | Purple → yellow gradient |
| Inferno | Dark → bright, perceptually uniform |
| Magma | Dark purple → cyan |
| Jet | Classic blue → red rainbow |
| Turbo | Improved rainbow with more detail |
Annotations Overlay
The image viewer can overlay live values from other signals (e.g. temperature, pressure) directly on the image. These update in real time as you scrub the timeline.
Adding annotations
Drag a 0Dts signal from the Data tab onto an existing Image Viewer panel. The signal appears as a coloured badge in the top-left corner of the image showing the signal name, current value, and unit.
Annotation display
- Each annotation uses the signal’s workspace colour as its accent.
- Values are formatted with automatic precision based on the data range.
- The signal name is shown alongside the value. You can hide signal names via the Annotation Labels toggle in the panel settings.
- To hide all annotations, use the Annotations toggle in the panel settings.
Removing annotations
Hover over the panel and click the × button on the annotation badge to remove it. The signal remains in the workspace - only the overlay is removed.
Copying and Saving a Frame
Right-click anywhere on an Image Viewer for a menu with two options - a quick way to get an image out of a project and into a message, a document, or an AI chat, without opening the export dialog.
| Option | Result |
|---|---|
| Copy Frame | Puts the frame on the clipboard as a PNG, ready to paste |
| Save Frame… | Opens a save dialog and writes a PNG |
You get what you see, cropped to the data: the capture is taken from the viewer at its displayed size and at the current zoom and pan, but trimmed to the image itself so the panel background and its alignment grid are left out. It includes the colour map and image adjustments, the signal overlay if one is configured, the scalebar, the annotation value badges, and the shape annotations - unless those are hidden with the Annotations toggle, in which case they are absent from the capture too.
Zoomed in far enough that the image overflows the panel, you get the visible portion - the part you are actually looking at.
For an image series, the frame captured is the one currently displayed.
The capture is as big as the image is on screen, so enlarging the panel before you copy gives you a higher-resolution image, and zooming in gives you a close-up of a detail.
For the frame at its full sensor resolution, or for control over cropping, format and overlays, use Export → Image from 2D Viewer instead. Right-click is the quick share, not a replacement.
Signal Overlay
A second 2D or 2Dts signal can be drawn on top of the one a panel is showing - for example a mask, a script output, or a second detector channel over a survey image.
Choose the signal from Overlay Signal in the panel settings (Selection tab → Signal Overlay). The panel’s own signal is not offered, and picking None removes the overlay.
| Setting | Effect |
|---|---|
| Opacity | How strongly the overlay covers the image beneath, 0-100% |
| Colour Scale | Colour map for the overlay, independent of the base image |
| Blend Mode | Colour (tints the image), Normal (alpha blend), Additive (brightens) or Multiply (darkens) |
| Transparent Zero | Hides pixels whose value is exactly zero, so only the non-zero part is drawn |
The overlay is normalised over its own value range and coloured with its own colour map, because it is usually a different measurement to the base image - sharing the base image’s contrast limits would generally render it black or saturated.
Colour is usually the blend mode you want when the point is to see where something is on top of the underlying image. It takes only the hue and saturation from the overlay and keeps the base image’s brightness, so the structure and texture of the image stay fully visible and simply become tinted. The other modes replace the base image’s brightness with the overlay’s, which darkens or washes out the detail underneath.
For a 2Dts overlay the frame follows the timeline alongside the base image. If the overlay has fewer frames it holds on its last one rather than disappearing.
Positioning
Overlays are placed using their spatial axis metadata, so a cropped or differently-sampled overlay lands where it physically belongs within the base image rather than being stretched over the whole panel. When either signal lacks spatial axes the overlay is drawn from the top-left at the base image’s scale.
Transparent Zero is what you usually want for masks and thresholded script outputs. Without it, the zero-valued background is painted in the colour map’s lowest colour and hides the image underneath.
This is separate from the Annotations Overlay above, which shows live scalar (0Dts) values as badges. Signal Overlay draws image data over image data.
Frame Navigation
For image series (2Dts), the viewer shows the frame corresponding to the current timeline position. Scrubbing the timeline automatically updates the displayed frame.
Lock Frame
Enable Lock Frame in the panel settings (Frame Navigation section) to freeze the displayed frame. When locked, scrubbing the timeline changes the time position but the viewer keeps showing the same frame.
The Sync Zoom & Pan toggle lives in the same section - see Sync Zoom & Pan above.
Smart frame loading
When you drop an image series onto the canvas, Nexus displays the first frame immediately - there is no need to wait for the entire series to finish loading. Additional frames are loaded automatically in the background and on-demand as you navigate the timeline, so playback stays smooth even for large datasets.
The cache indicator on the timeline sparkline shows which frames are ready - taller bars indicate cached frames.