I read an rgb image i wanted the histogram of the image but when i gave the command imhist('xyz.jpg') it gave me error by plotting just the x -y axis and not the graph in it.It was totally white.The image is already in uint8 type ,how do i solve it ?

I=imread('v.jpg'); imshow(i) figure; imhist(i)

[Jan]

In the title your mention imhist('xyz.jpg'), which interprets the char vector 'xyz.jpg' as image with 1 row and 7 columns. In the body of question, you use I=imread('v.jpg') with an upper-case 'I', but display i in lower-case. This is at least confusing.

"It gave me error" does not help to understand, which problem you get. Please post a copy of the code and of the complete error message.