*e.g. filecaptcha.py:*

    CAPTCHA_SOLUTIONS = {'01.png': ['alfa romeo', 'alfa-romeo', 'alfaromeo'],
                         '02.png': ['audi'],
                         ...
---

*urls.py:*

    extra_context = {'contact_form': MessageForm(), 'captcha_choices': CAPTCHA_SOLUTIONS.keys()}
---

*forms.py:*

    class MessageForm(forms.Form):
        captcha = forms.CharField(label='Spam protection')
        captcha_img = forms.CharField(required=False)
    
        def clean(self):
            if not self.data['captcha']:
                raise forms.ValidationError('This field is required.')
            if self.data['captcha'].lower() in CAPTCHA_SOLUTIONS.get(self.data['captcha_img']):
                return self.cleaned_data
            raise forms.ValidationError('Wrong solution')
---

*base.html:*

    {% if contact_form %}
    {% with captcha=captcha_choices|random %}
    <tr>
        <th><label for="id_captcha">{{contact_form.captcha.label}}</label></th>
        <td>{% if contact_form.non_field_errors %}
            {{contact_form.non_field_errors}}
            {% endif %}
            <input type="text" id="id_captcha" name="captcha">
            <input type="hidden" name="captcha_img" value="{{captcha}}"></td>
    </tr>
    <tr>
        <td></td>
        <td>
            <img src="{{MEDIA_URL}}image/captcha/{{captcha}}" alt="captcha" title="Spam protection image" width="107" height="70" />
        </td>
    </tr>
    {% endwith %}
    {% endif %}
---

*views.py (contact_form POST target):*

        form = MessageForm(request.POST or None)
        if form.is_valid():
            #save and redirect
        return render_to_response('contact.html',
                                  {'form': form,
                                   'captcha': random.choice(CAPTCHA_SOLUTIONS.keys()),
                                   },
                                  context_instance=RequestContext(request))