LONGER How to: Use the Trace Image Feature in LightBurn

LONGER How to ：Use the Trace Image Feature in LightBurn

ABSTRACT
LightBurn is a powerful and user-friendly software widely used in the field of laser cutting and engraving. One of its most practical tools is the Trace Image function, which allows users to convert bitmap images into vector graphics by tracing their outlines. This feature is particularly effective for images with clear edges, such as silhouettes or cartoons. With Trace Image, you can easily convert complex raster images into editable vector paths for engraving or cutting. This guide explains how to use the Trace Image tool in LightBurn.

CONTENTS

Step 1: Import and Select the Image

Step 2: Use the Trace Image Dialog

Step 3: Adjust Threshold and Cutoff

Step 4: Define the Trace Area (Optional)

Step 5: Fine-Tune Trace Settings

Step 6: Apply and Finalize the Trace

Conclusion

Step 1: Import and Select the Image
Import a bitmap image into LightBurn. Click to select the image, then either go to Tools > Trace Image, or press Alt+T on your keyboard. You can also right-click the selected image and choose Trace Image from the context menu.

Step 2: Use the Trace Image Dialog
The Trace Image dialog will appear, displaying your image along with a preview of the traced vector outlines (in purple).

To make the vector lines more visible, click the Fade Image button.
You can zoom in or out using the mouse scroll wheel, and drag the view with the left or middle mouse button.
Double-click the middle mouse button to reset the view.

Step 3: Adjust Threshold and Cutoff
Cutoff sets the minimum brightness value to be traced.
Threshold sets the maximum brightness value.
By default, values range from 0 to 128, meaning pixels with brightness values between 0 and 128 will be traced, while brighter pixels (129–255) will be ignored. You can adjust these sliders to focus on a specific range of image brightness.

Step 4: Define the Trace Area (Optional)

You can manually define a portion of the image to trace by clicking and dragging within the dialog. Once defined:
Drag a corner to resize the selection.
Click outside the area to reset it.

Step 5: Fine-Tune Trace Settings

Ignore Less Than:

This setting tells the trace tool to ignore shapes smaller than the specified number of pixels. Useful for noisy or pixelated images.

Smoothness:

Controls how aggressively LightBurn smooths the resulting shapes.
A value of 0.0 produces sharp, jagged lines.
A value of 1.333 yields very smooth curves.
The default value 1.0 provides a good balance between accuracy and smoothness.

Example:
The left shape traced with Smoothness = 0 shows jagged edges.
The right shape traced with Smoothness = 1.333 shows overly rounded corners.

Optimize:

After generating paths, this option merges similar lines and curves to reduce node count.

0 = No optimization

0.2 (default) = Balanced accuracy and performance

Sketch Trace:

Ideal for handwriting or hand-drawn images. When enabled, LightBurn uses neighboring pixel data to compensate for uneven lighting or image noise.

Step 6: Apply and Finalize the Trace

After adjusting all parameters, click OK to apply the trace.
The new vector will be placed directly over the original image.
You can manually move the original image aside or enable the Delete Image After Trace option before confirming.

Conclusion
The Trace Image feature in LightBurn is a robust tool that enables users to convert bitmap images into clean, editable vectors with just a few adjustments. Whether you're tracing logos, handwritten notes, or silhouettes, fine-tuning the settings like threshold, smoothness, and optimization allows for precise control over the output. By mastering this tool, you can significantly expand your creative possibilities for laser engraving and cutting projects.

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