The Note is: DO NOT put more files (any kind) into your iPhone before recover the deleted photos. Or the lost ones would be overwritten by the latest one and you will lose the photos forever.
There are four iPhones most use nowadays: iPhone 3GS, iPhone 4, iPhone 4S, iPhone 5. For recovering iPhone data, they can be divided into two groups. iPhone 3GS & iPhone 4 which need you to enter the EPU mode for iPhone Photo Recovery; iPhone 4S & iPhone 5 needn't.
This tutorial today I gonna to show you how to recover photos from iPhone 4 and iPhone 4S as an example.
First Part: Recover iPhone 4 photos
Download iPhone Data Recovery for iPhone 4 on Goshareware.com
Step 1. Install Hodo iPhone 4 Data Recovery into your computer. Run it and connect your iPhone 4 with your computer. You will see the interface like this.
Step 2. Enter DFU mode for recovering. Just follow the guide in the image below. Afeter entering, it will start to scan for the recoverable files.
Step 3. After scaning, you will see this interface, Select the files you want to get back and click recover button.
Step 4. Save the files recovered in your computer.
Part 2: How to Recover iPhone 4s photos?
Step 1. The same as iPhone 4 Photo recovery gudie.
Step 2. Click "Start iDevice Recovery" button, and it will start analyzing and scanning your device for your lost data.
Step 3. The same as iPhone 4 Photo Recovery, Choosing the files you need and click "Recover" icon.
Step 4. Save the photos.