[SOLVED] Simple doubt in MATLAB- Matrix elements

[Shweta_S]

Simple doubt in MATLAB- Product of two matrix elements

I read an image (gray scale) using imread function of MATLAB ( 'camerman.tif').
I got a matrix ( say F) of size 256x256.

I have another matrix, say A=[-1 0
. . . . . . . . . . . . .. . . . . . . . 0 1] ... (2x2 matrix)

In my program, at one point of the time I have to multiply A(1,1) and F(1,1)



I display the value of F(1,1) : I get 156 ......
I display the value of A (1,1): I get -1...

But when I display the value of A(1,1)*F(1,1), I get 0!!! NOT -156 Why is this so?

To be precise, disp(F(1,1)*A(1,1));




P.S. I tried the same thing out by having two simple matrices ( not with image), I'm getting the value correctly. Why is it not working when one of the i/p is an image? Am I missing something?

I am new to MATLAB. Please help.

Thanks in advance.

 

[Mityan]

This is because of imread result format - uint8. Try to change - F=double(F); for example

 

[Shweta_S]

Yep thank you... I got it!!!:smile: