Collect luminance information

  Use Collect luminance to record luminance information for closed contours drawn over acquired images.

The Collect luminance tool is in the Luminance section of the Image ribbon.

Note that data are reported for the current Z position of the image within the closed contour, not the Z position of the contour.

In addition, luminance data are reported only for the current zoom position of the image and only for the portion of the image enclosed in the contour that is displayed on screen. Note that:

  • If you are zoomed out to see the entire image, the luminance will be collected on a compressed/downsampled version of the image.

  • Luminance data are collected only for the portion of the contour that is displayed on screen.

Procedure

To record luminance information:

  1. Click Image > Luminance > Collect luminance.
  2. Open the Contour Measurements window to view the results.

To turn off luminance recording:

Click Image > Luminance > Collect luminance again.

Visualizing luminance values

To see a thumbnail of the image and a histogram of the luminance values for the current Z position of the image within a contour:

  1. Go to File > Preferences > Images > Luminance options.
  2. In the Luminance panel, check the Save Image Histogram and Save Image check boxes. The image of the contour and the luminance histogram can be copied to the clipboard and pasted into other programs for further analysis.