There are three type of sourceType to pick images:

- Use this to pick image from Camera:

imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;

 - Use this to pick image from all folders in the gallery:

 imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

 - Use this to pick image from PhotosAlbum(camera roll):

imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;