Grayscale in matlab

I'm trying to convert a 2D array to grayscale but using mat2gray doesn't do anything and imshow() appears to create a binary image that when I graph I cannot rotate it, e.g. the original array is 2d but maps in 3d. So, what is the best way to take a grayscale of 2d array in Matlab so if you have A=rand(5,10) or something and want to take a grayscale of that, what 开发者_JAVA技巧is the best way?

I would expect MAT2GRAY to work, but if it doesn't you can try this:

A = rand(5,10);     %# Make a random array of values between 0 and 1
B = uint8(255.*A);  %# Scale the values and convert them to uint8

If you use imshow on a 2D image, it is a good idea to use autoscaling.

img = randn(100);
imshow(img,[]);