You can delete photos on iPhone manually or with iTunes. Just follow the below steps to complete this task.
How to Delete a Photo from iPod
When you use iPod touch to take photos, you must encounter that there are some pictures that you take may be not beautiful as you wish and you want to delete them for making more space to snap extra shots. I think this is a common problem because people are always agitated when there are no other space for them to take more beautiful photos. Now let's have a look at the details about how to delete photos from iPod touch.
1. Open Photos app on your iPod touch;
2. Choose photos you want to delete;
Tap "Camera Roll" or other folders to choose photos you want to delete. (Please remember that if you want to delete one photo, you can tap that one and then click a trash can icon to confirm "Delete Photo" to complete the process; and if you want to delete some photos selectively, you can go back to the camera overview, and then click the share button on the upper right corner to select photos then tap "Delete" in the bottom right corner to confirm "Delete Everywhere".)
This way is quite easy to solve the problem about how to delete photos from iPod touch but there is still a problem. When you delete a bunch of photos on your iPod touch, those selected photos from camera roll or other albums that may have histories will also be deleted. And of course if you don't mind, you can choose this way to delete photos on iPod.
How to Delete Photos from iPod with iTunes
If you are used to saving photos to your iPod nano, and sometimes you need to delete some old photos to spare more space to new photographs but you have no idea about the deletion, then what do you do? Please don't worry, here are the details about how to delete photos from iPod nano. Remember that you need to create a new folder to store those photos you want to delete on your iPod nano.
1. Connect your iPod nano to a computer;
Connect your iPod nano to a computer via a USB cable.
2. Open iTunes on your computer;
iTunes will detect your iPod nano automatically once you connect it to your computer. (Please remember that you installed the latest iTunes version.)
3. Find photos of your iPod nano;
Click iPod nano icon on the upper left to open the contents of it, and then choose "Photos" in the contents of iPod nano.
4. Delete photos on your iPod nano
On the right side of the "Photos" interface, please uncheck the "Sync Photos" and then click "Remove Photos" in the pop up interface to delete all your photos on iPod nano; and if you want to delete photos selectively, find folders which they are synced with iPod nano before and delete photos from those folders, and then go back to the "Photos" interface of iPod nano in iTunes and please check "Sync Photos" and then select "Selected folders" and choose the folders you want to retain and last click "Apply" to delete those photos from your iPod nano.
This way is quite complicated to operate if you don't want to delete all photos on your iPod nano, and you will easily delete all photos if you're careless.
For more details, check: How to Delete Photos from iPod