If you backed up your phone to your PC/Lap then you can go and get them there.
If you you have an SD card then they typically would be duplicated there (depending on your settings and features)
If, none of these apply then I am afraid that you cannot retrieve them.
I suggest that when you take a pic that you either save to your SIM/SD card (some phone models allow you to save contacts, pics to your SIM) or use a social media to keep them safe.
Sorry, losing pics is always upsetting