where are the code that handle image file upload in Django admin page?

[Chuck22]

I have three ImageField in my form and model, I want to know how to
upload the three image files in the form processing code. I found
Django Admin page handles the image file upload nicely. And I want to
do the exactly same work. But I can not find the piece of code that
does the job when searching the Django source code. Can anyone point
to me where these code are located? Or share some code snippets
related to this.

in my model:
image1 = models.ImageField(upload_to='img/bk', blank=True)
image2 = models.ImageField(upload_to='img/bk', blank=True)
image3 = models.ImageField(upload_to='img/bk', blank=True)

in my form processing:

if request.method == 'POST':
f = MyForm(request.POST, request.FILES)
if f.is_valid():
email = f.cleaned_data['email']
title = f.cleaned_data['title']
...

# save the uploaded images
for v in request.FILES:
save_upload_file(v) <---- this is where i am stuck

[Chuck22]

Anyone can help on this? I get stuck with image file upload.

[krylatij]

http://docs.djangoproject.com/en/dev/topics/http/file-uploads/
here is a sample how to handle file upload

And have tried:
MyForm.save()?