how to get back my lost photos which were automatically deleted by the phone

[AC Question]

I first realise this problem yesterday. Firstly, I clicked and intended to view the photo, there was a prompt up message stating that there is no enough space, and I was required to delete some files. I turned off my phone and turned it on back, the camera folder appear empty, and all my photo cannot be found in DCIM-camera, Gallery.

I am sure that my phone has enough USB storage memory, and it is not fully used.

my phone model: Samsung Galaxy Note 1