Orthomosaic generation

What is an orthomosaic?

An orthomosaic is a front-facing composite image generated from multiple obliquely captured photos. It lets you view an entire building wall as a single image, which is ideal for understanding accurate spatial relationships and for inclusion in reports.

CRITIR can generate visible and infrared orthomosaics at the same time.

Launching the wizard

Launch image linking / orthomosaic generation from either of the following:

• Process menu on the toolbar → Image Linking / Orthomosaic Generation
• Orthomosaic generation button at the bottom right of the main viewer (shown when no orthomosaic has been generated yet)

Wizard steps

Step 1: Output settings

Quality presets

Infrared orthomosaic

If infrared images are available, an infrared orthomosaic can be generated together with the visible orthomosaic (enabled by default).

Advanced settings

The defaults are recommended in most cases, but you can adjust the advanced settings if you run into problems.

Step 2: Set selection

If the project has multiple sets, select the target set for orthomosaic generation. This step is skipped automatically when there is only one set.

Step 3: Target plane selection

Candidate planes automatically detected from the SfM result are shown in a grid. Select the candidate that corresponds to the target wall surface.

• The most suitable candidate is marked with a "Recommended" badge
• If no candidate fits, click "Find More" to search for additional candidates
• Newly found candidates are marked with a "NEW" badge

Specifying a plane manually

Automatic detection looks for planes based on point-cloud density, so the plane you want may not appear among the candidates — the candidate list may be empty, the structure may be slender, or you may want only part of a wall. In that case, click "Specify Plane Manually..." and draw the target plane on an image to create a candidate.

1. Pick an image from the thumbnails where the target plane is clearly visible
2. Click the start point, move the mouse, and click the end point to enclose the target plane
3. Click Add Area and Preview to generate a combined orthomosaic preview
4. If needed, enclose the same plane on other images and repeat step 3 (selections across images are merged)
5. When the preview looks right, click Save This Preview

Orientation adjustment (optional)

When you select a candidate, the orientation of the orthomosaic is estimated automatically. If needed, fine-tune it with the rotation buttons (±180° / ±90° / ±10° / ±1°). Click "Restore Auto Orientation" to reset to the initial state.

Step 4: Scale settings (optional)

You can calibrate the real-world scale of the orthomosaic by specifying two points with a known distance between them. This step can be skipped.

1. Click two points with a known distance on the image (e.g. a door height or window width)
2. Enter the actual distance and unit (m / cm / mm)
3. Click "Add Measurement"

Registering 2–4 measurements is recommended for better accuracy. Because the median of the measurements is used, the calibration is robust against outliers.

Starting generation

Once all settings are complete, click "Start Generation" and the orthomosaic is generated automatically.