How many gray levels Matlab can show?

Question

Let's say I have a Matrix Image of uint16.

Where basically each pixel can range from 0 to 65535.

If I display this image with imshow(Image) How many levels of gray Matlab will render?

The standard 255 levels (thus implicitly converting the image to uint8)?
(Please note I know I can change the colormap, but I would like to know only the number of gray levels )

Answer 1

The size of the colormap tells you how many colors (or gray levels, in this case) Matlab is trying to display.

numGrayLevels = size(get(gcf,'Colormap'),1)

Note that most monitors only support 8-bits of gray. And depending on the quality and calibration of the display you may be seeing far less than that.