Orthomosaic Processing Fails with "MemoryError: bad allocation"

📌Orthomosaic Processing Fails with "MemoryError: bad allocation"

During orthomosaic generation in LP360 Drone, the processing may terminate unexpectedly with the following error:

MemoryError: bad allocation

This error indicates that the system has run out of available memory (RAM) during processing. It is most commonly encountered when generating orthomosaics from large datasets or high-resolution outputs.

💡 Note: You may also see messages such as SyntaxWarning or DeprecationWarning in the log. These are informational Python warnings and are not responsible for the processing failure.

🔍Symptoms

Users may observe one or more of the following:

• You may experience one or more of the following:

• ❌ Orthomosaic processing stops before completion.

• ⚠️ The log ends with: MemoryError: bad allocation

• 🐢 Processing becomes significantly slower before failing.
• ✅ The generated Metashape project still opens successfully.

⚠️Cause

This error occurs when the orthomosaic workflow requires more system memory than is available.

Common scenarios include:

• Very large projects with thousands of images.
• High-resolution DEMs.
• Small GSD (high output resolution).
• Large processing extents.
• Limited available RAM due to other applications running simultaneously.

✅Resolution

1. Reduce the Processing Load

The most effective way to resolve this issue is to reduce memory usage during orthomosaic generation.

Possible approaches include:

• Divide the project into smaller processing regions.
• Reduce the processing extent.
• Increase the output GSD if full resolution is not required.

2. Optimize Your Workstation

Before processing:

• Close unnecessary applications.
• Ensure the temporary (scratch) directory is located on a fast SSD.
• Verify sufficient free disk space.
• If possible, process the project on a workstation with more RAM.

3. Review Workflow Settings

If applicable:

• Process the project in smaller chunks.
• Temporarily disable optional processing features that increase memory usage (such as advanced roof edge refinement) to determine whether they contribute to the issue.

📝Additional Notes and Summary

If processing becomes extremely slow before failing, the operating system is likely using virtual memory (disk paging) because physical RAM has been exhausted. While this allows processing to continue temporarily, it significantly reduces performance.