Matlab code (JPEG image file structure)

I have Matlab code for detection JPEG image file from a dataset. (The problem) The code detects all JPEG file image even the JPEG file embedded with another file such as pdf , video, Microsoft word, .... etc. (The solution) I want the code to detect JPEG image without embedded JPEG image. Note: I have the images which are needed. after solving this problem put this code in my GUI code