What Is the third value when reading an image

When using imread() we get a matrix of the size [r,c,x] what does x stand for?

[Adam]

doc imread

tells you this!

Answer 1

[madhan ravi]

https://www.mathworks.com/help/matlab/ref/imread.html#btv1pto-1

Answer 2

[Image Analyst]

When used with an image, the third output of the size() function represents how many color channels there are: 1 for a gray scale image and 3 for an RGB image. There are some watchouts if you only accept two size() outputs and you actually really have an RGB image and not a gray scale image. See the link below.

See Steve's blog discussion about this: Too much information about the size function.