Templatetags for thumbnail generation, with automatic rotation based on EXIF.Orientation.
Project description
Version : 0.2.0 Author : Thomas Weholt <thomas@weholt.org> License : GPL v3.0 WWW : https://bitbucket.org/weholt/django-photofile Status : Experimental/Alpha
About
Templatetags for thumbnail generation, supports automatic rotation based on EXIF.Orientation.
An abstract model for photos, handling extraction of EXIF-metadata.
Next planned feature: tagging - reading and writing tags to and from photo metadata (IPTC/XMP).
How
<img src=”{% generate_thumbnail imagefile 100x100 crop %}”/>
Provides a templatetag called generate_thumbnail which takes two or three parameters:
Param #1 : an object (imagefile), like a model instance, with a property/field called unique_filename, complete_filename or filename. Photofile will check in that order.
Param #2: resolution, specified as <width>x<height>, like 320x280.
Param #3: optional “crop” - which will enforce cropping of the photo.
The thumbnail will be written in a dir called “thumbs” in your STATICFILES_DIRS or STATIC_ROOT. If no dir exists called thumbs, it will be created.
The generated thumbnail will be named <filename>_<width>x<height>.<extension>. When cropping is used it will be named <filename>_<width>x<height>_crop.<extension>. For instance, thumbnail for test.jpg in resolution 200x300 will be named test_200x300.jpg.
Photofile will try to use caching if enabled, but it caches the url to the thumbnail, not the image itself so it’s not very efficient yet.
NB! It’s highly recommended to have some way of ensuring that the filename given to photofile is unique. That’s why it will look for a property called unique_filename first.
To use the abstract model, do something like this:
from django.db import models from photofile.models import PhotoMetadata class Photo(PhotoMetadata): image = models.ImageField(upload_to=settings.STATIC_DATA) title = models.CharField(max_length=100) def __unicode__(self): if self.width and self.height: return "%s (%sx%s)" % (self.title, self.width, self.height) else: return self.title
STATIC_DATA mentioned above is for testing only and can be defined in settings.py like so:
import tempfile import os STATIC_DATA = os.path.join(tempfile.gettempdir(), 'staticdata') if not os.path.exists(STATIC_DATA): os.makedirs(STATIC_DATA) MEDIA_ROOT = STATIC_DATA STATICFILES_DIRS = ( STATIC_DATA, )
When uploading a photo and saving it for the first time EXIF-metadata will be extracted and stored in the db. These EXIF-properties are currently available, but longitude, latitude and altitude is not implemented yet:
width
height
longitude
latitude
altitude
exif_date
camera_model
orientation
exposure_time
fnumber
exposure_program
iso_speed
metering_mode
light_source
flash_used
focal_length
exposure_mode
whitebalance
focal_length_in_35mm
The source contains an example project with more details on how to implement a suitable admin.py, some templates etc.
Why another thumbnail app for django?
I’ve looked at sorl-thumbnail and others, and initially I wanted to use an existing project, but none of them supported automatic rotation based on EXIF.Orientation.
Installation
Alternative a) pip install django-photofile.
Alternative b) download source, unpack and do python setup.py install.
Alternative c) hg clone https://bitbucket.org/weholt/django-photofile and do python setup.py install.
Usage
In settings.py: * Add ‘photofile’ to your INSTALLED_APPS. * Set up caching if you want. * Add a dir to your STATICFILES_DIRS or set STATIC_ROOT.
- In your template:
{% load photofile_tags %}
<img src=”{% generate_thumbnail imagefile 200x300 %}”/>
- or
<img src=”{% generate_thumbnail imagefile 100x100 crop %}”/>
Where imagefile is an object with at a property/field called: * unique_filename or * complete_filename or * filename
Resolution is specified as <width>x<height>, for instance 640x480 and if you want to crop the photo add crop as shown in the example over.
Requirements
django
PIL
pyexiv2
Project details
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