To get information about a graphic file using imread( ) function of MATLAB

1. First of all you have to set directory path in matlab, which is shown when you start the matlalb. That means when you save any file in matlab the first location which is open.
2. Now you can write commands directly in command windows or in script file.

     3.  >>i=imread('filename.jpg'); %to read the image%

          >>imshow(i); %you can see image in figure window%

          >>imfinfo('filename.jpg')%you can view the image information%

     4.  >>imwrite(i,'newfilename.png')% your old jpg file formate image change into png file%