To retrieve your deleted pictures is to use some picture recovery programs. One is Asoftech Photo Recovery, but there are more you can use. Here is the steps you may refer to with Asoftech to retrieve your deleted pictures from your phone memory.
1. Download and install this photo recovery program on your computer. http://www.asoftech.com/apr/
2. With your phone memory inserted, Under "My Computer", note the drive letter assigned to your phone's memory card (usually G: or H:).
3. Start the program and select the drive letter that assigned to the memory, click "Start".
4. Now the scanning process will start automatically to look for the deleted pictures. You will then get a list of all recoverable ones.
5. Select the pictures you want and click "Recover” and you can get back deleted pictures from your phone successfully.