I would like to know the minimum and maximum intensity level in a grayscale picture? How do I find this?

I have used imfinfo and I have figured out the size of the image (256x256)

I would now like to know the intensity levels of each of the pixels.

In particular what is the highest and lowest value of the intensity levels.

Answer 1

[Image Analyst]

Try this:

impixelinfo; % Let's you mouse around and see gray levels.  Or you could use impixel().
% Extrac min and max from the image array
minGrayLevel = min(grayImage(:));
maxGrayLevel = max(grayImage(:));

[Image Analyst]

Victor - are you still there? Didn't that work?

[Victor Fletcher]

I tried running impixelinfo on a .tif file

At first the code ran for about 30 minutes with no results.

Now the code wont run, an error message appears.

The current error message comes up with...

Error using impixelinfo>parseInputs (line 174)

H is an invalid graphics handle.

Error in impixelinfo (line 62)

[h,parent] = parseInputs(varargin{:});

[Victor Fletcher]

Ahh it worked, I have the min and maximum gray levels.

[Image Analyst]

You have to have an image displayed for impixelinfo to work. It's instant, doesn't take 30 minutes. It will show you the results in a status bar in the lower left of your GUI if you mouse around above the image.