Use MATLAB to prompt user to select a image file -

i trying implement function starting prompting user select image , image operation. here code:

[filename, path] = uigetfile ('*.bmp; *.png; *.jpg','select secret image'); secretimg = filename;  r = secretimg(:,:,1); g = secretimg(:,:,2); b = secretimg(:,:,3); 

however, prompt me error:

index exceeds matrix dimensions.

error in main (line 16) g = secretimg(:,:,2);

it works traditional method specify filename inside code this:

%secretimg = imread('images/lena.bmp'); 

try this:

secretimg = imread(strcat(path,filename)); 

full code:

[filename, path] = uigetfile ('*.bmp; *.png; *.jpg','select secret image'); secretimg = imread(strcat(path,filename));  %// 1 alternative use `fullfile` rayryeng suggested,  %// secretimg = imread(fullfile(path,filename));  r = secretimg(:,:,1); g = secretimg(:,:,2); b = secretimg(:,:,3);