Interactive image workspace

Choose a drawing mode and click on the image. Rectangular ROI requires two opposite corners. Coordinates always refer to native image pixels.

Particle measurement table

Equivalent diameter is area-derived. Major/minor axes describe a moment-equivalent ellipse. Perimeter is a 4-neighbor pixel-edge estimate; circularity is resolution-dependent. Touching objects are not automatically separated.

Particle distributions

Intensity histogram & line profile

Histogram uses original selected-channel grayscale values within the ROI. The line profile uses bilinear interpolation along the selected line.

ImageLab workflow & methods

1. Import an image or use the labeled synthetic example.
2. Draw the scale bar as a line and calibrate using a known distance. Without calibration, lengths are pixels.
3. Draw a rectangular ROI to exclude labels and the scale bar from segmentation.
4. Select the channel, filtering, threshold, polarity and object filters. Analyze and inspect the overlay.
5. Review the measurement table, size distribution and intensity profile. Export settings with your measurements.

Transparent pixels are composited onto white for grayscale analysis. Thresholding uses filtered values; object intensity statistics use the original selected channel. Morphology uses a 3 × 3 square kernel. Adaptive threshold uses a 15 × 15 local mean. Connected-component masks measure segmented foreground pixels, not automatically identified material phases. Area fractions are descriptive 2D segmentation fractions, not bulk porosity or volume fraction.

Limitations: 8-bit displayed raster intensities (TIFF is converted to RGBA8); no calibrated detector counts, full TIFF stacks, DICOM, SEM proprietary formats, 3D volume analysis, watershed separation, neural segmentation, full ImageJ equivalence or medical diagnosis. Moment axes include a 1/12 pixel-area correction. Pixel-edge perimeters introduce discretization bias. Measurements require scientific validation of segmentation and scale.

Methods reference: ImageJ measurement and particle-analysis documentation.