Index exceeds matrix dimensions.

Dear All,

Good Day to you.I am trying to crop an image using the following method.I want to subdivide an image into components.My code is as follows.| |

a=imread('E:\a1.jpg'); [col row]=size(a); col

col =

   119

row

row =

   345

croped=a(1:119,1:116,:);

• _??? Index exceeds matrix dimensions.

I get an error message shown above, when try to crop using the above values.And error message is not there for certain values. Please help me to solve this.

Thanks in advance.

[Mischa Kim]

Good one. Could you attach the jpg?

Answer 1

[Image Analyst]

Rows is the first index, columns is the second. You had them swapped when you did this:

croped=a(1:119,1:116,:); % col, row instead of row, col like it should be

In addition, you can read about the size function in Steve's blog http://blogs.mathworks.com/steve/2011/03/22/too-much-information-about-the-size-function/, which essentially say what Jan said.

Answer 2

[pushk dfd]

Dear All, Thank you very much.It worked really well.

thanks once again.

Answer 3

[Jan]

What do you get for:

[col, row, channel] = size(a)

If you specify less outputs than the array has, the last one is the product of the remaining dimensions. If a is an RGB image, its dimensions are:

[119 x 115 x 3]

Therefore [s1,s2] = size(a) replies s1=119, s2=115*3.

See doc size -> "Specify Different Number of Outputs than ndims(X)"

[Koteswar Rao Jerripothula]

good observation, thanks

[pushk dfd]

Thank you very much.It also helped a lot for me to gain a good understanding.