How to Build Orthomosaics in Agisoft Metashape: Step-by-Step Guide for Beginners

Creating orthomosaics is one of the most powerful features of Agisoft Metashape. An orthomosaic is a geometrically corrected image composed from multiple aerial photos, where distortions from camera angle and terrain have been removed. This tutorial walks beginners through the full workflow—from importing images to exporting the final orthophoto.

What is an Orthomosaic?

An orthomosaic (or orthophoto) is a 2D image that’s been corrected to remove distortion and scale differences. Unlike a simple stitched panorama, an orthomosaic maintains real-world measurements, making it ideal for surveying, mapping, construction, and agriculture.

What You Need Before Starting

Aerial photos with high overlap (minimum 70% front, 60% side)
Agisoft Metashape Standard or Professional installed
Optional: GPS metadata or Ground Control Points (GCPs)

Step-by-Step: How to Build an Orthomosaic in Metashape

Step 1: Create a New Project

Open Metashape and start a new project by going to File → New. Save your project file right away to avoid data loss.

Step 2: Import Your Images

Go to Workflow → Add Photos and select your images. Make sure all images are properly geotagged or have been taken in a well-planned flight grid.

Step 3: Align Photos

Go to Workflow → Align Photos. In the dialog:

Accuracy: Medium (for fast preview) or High
Key Point Limit: 40,000
Tie Point Limit: 4,000

Metashape will now detect image features and generate a sparse point cloud and camera positions. This is the foundation for the orthomosaic.

Step 4: Build Dense Cloud (Optional but Recommended)

Navigate to Workflow → Build Dense Cloud. Use:

Quality: Medium or High
Depth filtering: Moderate

This step creates a detailed point cloud that will improve the model’s geometry for more accurate orthorectification.

Step 5: Build DEM (Digital Elevation Model)

Go to Workflow → Build DEM and choose source data as Dense Cloud. This generates the terrain model that corrects the image geometry.

Step 6: Build Orthomosaic

Now the key step: go to Workflow → Build Orthomosaic. In the dialog:

Surface: DEM
Blending mode: Mosaic (or Average for consistent lighting)
Image projection: Planar
Projection: Use a coordinate system (e.g. WGS 84 / UTM zone)

This process generates a flat, true-scale image based on your original photos and the terrain surface model.

Step 7: Export the Orthomosaic

Once the orthomosaic is generated, export it by clicking File → Export → Export Orthomosaic.

Format: GeoTIFF (.tif) or JPG/PNG (non-georeferenced)
Resolution: Choose based on project needs (e.g. 2–10 cm/pixel)
Projection: Match your mapping standard (EPSG code)

Tips for Better Orthomosaic Results

Use high-quality images with good lighting and sharp focus
Ensure proper image overlap and flight planning
Add GCPs for survey-grade accuracy (Pro version)
Use a consistent coordinate system across the workflow
Avoid strong shadows, glare, or water surfaces

When to Use Orthomosaics

Orthomosaics are commonly used in:

Agriculture (crop monitoring)
Construction and infrastructure
Archaeology and cultural heritage
Urban planning and land use
Disaster response and damage mapping

Conclusion

Creating orthomosaics in Metashape may sound complex, but the workflow becomes intuitive with practice. This guide gives you the essential steps to generate accurate, georeferenced orthophotos even as a beginner. With the right photos, overlap, and settings, you’ll be able to turn raw images into actionable map data—ready for analysis, sharing, or integration into GIS software.