how to find pixel coordinate?

Hi all, can help how to fing the max pixel coordinate? image as attached.

i try below command, row and column is 1. not correct answer. and the slice is 2823 that is max pixel value.

i = dicomread('MLEMITR2SUB24.dcm');
m = max(max(max(i)));
[r, c, slice] = find (m)
 
 
r =

     1


c =

     1


slice =

  uint16

   2823

anyone can help me?

Answer 1

[KALYAN ACHARJYA]

Note: Suggested to avoid "i" as a vaiable name, as it may conflict with inbuilt "i"

>> i
ans =
   0.0000 + 1.0000i

Lets consider image_data as input data, in 2D case, you can directly used the find function, as

[r,c]=find(image_data==max(image_data));

In 3D or higher multidimentional case (Add more variable in LHS, as per dimension of the array), you may use ind2sub to get the desired result

idx=find(image_data==max(image_data(:)));
[rows,colm,sl_num]=ind2sub(size(image_data),idx)

It gives the indices of rows, columns and slice numbers of all maximum pixels elements.

[mohd akmal masud]

tq sir. it work.

[mohd akmal masud]

sir,

if i have the coordinat, how to get the pixel value?

let say i want to know the pixel value of coordinate (58,79), how to write the command?

is it like this?

idx=find(image_data==[58, 79](image_data(:)));
[rows,colm,sl_num]=ind2sub(size(image_data),idx)

[KALYAN ACHARJYA]

pix_val=image_data(58,79)

[mohd akmal masud]

if i want to pixel value in slice number 50, is it like below the command?

pix_val=image_data(58,79, 50)

[mohd akmal masud]

yes, it work