Uploading images on a stateless form or importing bulk images

Uploading images on a stateless form or importing bulk images

I am working on a creator app that will function as a survey, so the user interface will be public.
There is an option to upload an image file on the survey.  Ultimately, I want to display a sample of the images on a future survey. 

I see that on a form, I can select "Local Computer" as the browse option, but I would prefer not to make the form itself public.  The "Local Computer" option is not available on a stateless form, so it appears I cannot make a public stateless form with the same field.  Likewise, File Upload is not available on a stateless form.

A second option is to collect images using a different survey platform.  However, I would then need to import bulk images into my form.  I have tried a few options (listing URL or local address in a csv file), but these have not worked.

Can anyone suggest a way to allow an upload of a local computer image to a stateless form, and/or a way to upload bulk images to the form using a data import (csv or spreadsheet)?

Thanks.