Scale bar

Display a 3D volume and the scale bar

Tags: experimental

Python (.py)

Notebook (.ipynb)

/home/runner/work/docs/docs/.venv/lib/python3.12/site-packages/napari/_qt/qt_event_loop.py:50: UserWarning: System theme detection requires a Qt6 backend. Please switch to PyQt6 or PySide6 to use it.
  theme_type=get_system_theme(),
/home/runner/work/docs/docs/.venv/lib/python3.12/site-packages/napari/_qt/qt_event_loop.py:50: UserWarning: System theme detection requires a Qt6 backend. Please switch to PyQt6 or PySide6 to use it.
  theme_type=get_system_theme(),

from skimage import data

import napari

cells = data.cells3d()

viewer = napari.Viewer(ndisplay=3)

viewer.add_image(
    cells,
    name=('membrane', 'nuclei'),
    channel_axis=1,
    scale=(0.29, 0.26, 0.26),
    units='um',
)
viewer.scale_bar.visible = True

# Text options
viewer.scale_bar.length = 23  # length, in units, of the scale bar
viewer.scale_bar.font_size = 20  # default is 10

# Text color
viewer.scale_bar.colored = True  # default value is False
viewer.scale_bar.color = 'yellow'  # default value is magenta: (1,0,1,1)

# Background box
viewer.scale_bar.box = True  # add background box, default is False
viewer.scale_bar.box_color = (0, 1, 1, 0.2)  # cyan with alpha=0.2

# Scale bar position
viewer.scale_bar.position = 'bottom_left'  # default is 'bottom_right'

if __name__ == '__main__':
    napari.run()