Convert to 16-bit Intensity
The Convert to 16-bit Intensity command converts an RGB image to a 16-bit Grayscale image with pixel values between 0 and 65535. The R, G, and B channels are combined to a single value using the standard Grayscale conversion weights (0.292, 0.594, 0.114). If you wish to convert an RGB image to a 16-bit image using any other weight values, use Convert to Grayscale prior to the present command. If the RGB image is already in grayscale form, then this command will weight R, G, and B equally.
The Convert to 16-bit Intensity command opens from the Image Window > Process > RGB Images menu when an image or image set is displayed in the top-most window.
Working with RGB Images, Convert to 8-bit Intensity, Convert to Grayscale