FlowCam Quantitative Metrics and Camera Settings

The effect of background intensity on particle image analysis

Background intensity affects segmentation, sizing, and counts—even at fixed context settings. This technical note profiles four particle types across a range of background intensity values to show how much it matters and why keeping it consistent protects your data quality.

What's inside:

• How background intensity mean (BIM) drives image segmentation in VisualSpreadsheet, and where to set it
• A controlled study across beads, phytoplankton, and a protein surrogate on both color and B&W cameras
• Why sizing stayed relatively stable while counts of sub-10 µm particles peaked at a BIM of 160
• How edge gradient rises with background intensity—and why the effect differs for opaque vs. translucent particles
• The practical takeaway: lock in an optimal BIM and capture settings, then keep them consistent to avoid bias