This tutorial guides you through using Virtual Stitching to align multi-tile datasets.

Overview

Virtual Stitching allows you to interactively reposition individual tiles within a tiled dataset. This is useful for: - Correcting tile alignment after acquisition - Fine-tuning overlap regions between tiles - Adjusting chromatic aberration offsets between channels

Accessing Virtual Stitching

  1. Open a scene containing a tiled image layer in the 3D viewer.
  2. Navigate to Quick Access > Virtual Stitching in the sidebar.
  3. The Virtual Stitching panel will open.

Multi-Layer Support

You can work with multiple layers simultaneously:

  1. Ctrl+Click (or Cmd+Click on Mac) layers in the sidebar to select multiple
  2. Shift+Click to select a range of layers
  3. A badge shows the number of selected layers
  4. Tile grids from all selected layers are combined

When multiple layers share the same tile positions, selecting a grid cell selects tiles from all layers at that position.

Using the Tile Grid

Selecting Tiles

The tile grid displays all tiles arranged by their spatial positions:

  • Click on a tile to select it (centers viewer on that tile)
  • Drag across multiple tiles for freehand region selection
  • Ctrl+Click (or Cmd+Click on Mac) to toggle individual tiles
  • Shift+Click to select a rectangular range of tiles
  • Click row/column headers to select entire rows or columns
  • Use Select All / Deselect All buttons for bulk selection

Auto-Select Mode

The Auto-select toggle (green when active) automatically selects the tile at your current viewer position:

  • When enabled, navigating in the viewer automatically highlights the corresponding tile
  • Useful for quickly finding and adjusting tiles as you browse the dataset
  • Disable when you want manual tile selection to persist while navigating

Visual Indicators

  • Blue tiles are selected
  • Orange dot indicates tiles with unsaved changes
  • Light blue shows tiles in the current drag selection

Adjusting Tile Positions

Channel Selection

For multi-channel datasets, colored channel chips appear below the tile grid:

  1. Each chip shows the channel name and a color swatch matching the viewer display
  2. Click a channel chip to toggle selection (highlighted in blue when selected)
  3. Shift+Click to select a range of channels
  4. Use Select All / Deselect All for bulk channel selection

Only selected channels will be adjusted when you move the sliders.

Position Controls

Once tiles and channels are selected, use the position controls:

  • X, Y, Z Sliders: Drag to adjust offset in each dimension (real-time preview)
  • Input Fields: Type exact offset values for precise positioning
  • Changes are applied immediately to the viewer

The delta indicator (Δ) shows the current offset change from the original position.

Saving Changes

  • Save All: Commits all pending changes permanently
  • Discard: Reverts all changes to original positions
  • Closing the dialog without saving will also discard changes

Tips

  • Use Auto-select to quickly navigate to problem areas and select tiles
  • Start with coarse adjustments using sliders, then fine-tune with input fields
  • Use the viewer to verify alignment at tile boundaries
  • For chromatic aberration correction, select only the channel that needs adjustment
  • Changes are previewed live but not permanent until you click Save All

Troubleshooting

  • Tiles not loading: Ensure the layer is an IMAGE type with SISF tile metadata
  • Changes not visible: Try refreshing the viewer or wait for cache invalidation to complete
  • Multiple channels not moving together: Ensure all desired channels are selected (highlighted in blue)
  • Auto-select not working: Check that Auto-select toggle is green (enabled)
  • Layers not appearing: Click layers in the sidebar to add them to the selection
  • If issues persist, contact the site administrator for assistance.