[svn] Switch from photologue to imagekit. Less bloat.

Copied from http://cucc@cucc.survex.com/svn/trunk/expoweb/troggle/, rev. 8338 by cucc @ 5/11/2009 3:08 AM

imagekit/__init__.py

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+"""
+
+Django ImageKit
+
+Author: Justin Driscoll <justin.driscoll@gmail.com>
+Version: 0.2
+
+"""
+VERSION = "0.2"
+
+
+
+        

imagekit/defaults.py

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+""" Default ImageKit configuration """
+
+from imagekit.specs import ImageSpec
+from imagekit import processors
+    
+class ResizeThumbnail(processors.Resize):
+    width = 100
+    height = 50
+    crop = True
+    
+class EnhanceSmall(processors.Adjustment):
+    contrast = 1.2
+    sharpness = 1.1
+    
+class SampleReflection(processors.Reflection):
+    size = 0.5
+    background_color = "#000000"
+    
+class DjangoAdminThumbnail(ImageSpec):
+    access_as = 'admin_thumbnail'
+    processors = [ResizeThumbnail, EnhanceSmall, SampleReflection]

imagekit/lib.py

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+# Required PIL classes may or may not be available from the root namespace
+# depending on the installation method used.
+try:
+    import Image
+    import ImageFile
+    import ImageFilter
+    import ImageEnhance
+    import ImageColor
+except ImportError:
+    try:
+        from PIL import Image
+        from PIL import ImageFile
+        from PIL import ImageFilter
+        from PIL import ImageEnhance
+        from PIL import ImageColor
+    except ImportError:
+        raise ImportError('ImageKit was unable to import the Python Imaging Library. Please confirm it`s installed and available on your current Python path.')

imagekit/management/__init__.py

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+

imagekit/management/commands/__init__.py

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+

imagekit/management/commands/ikflush.py

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+from django.db.models.loading import cache
+from django.core.management.base import BaseCommand, CommandError
+from optparse import make_option
+from imagekit.models import ImageModel
+from imagekit.specs import ImageSpec
+
+
+class Command(BaseCommand):
+    help = ('Clears all ImageKit cached files.')
+    args = '[apps]'
+    requires_model_validation = True
+    can_import_settings = True
+
+    def handle(self, *args, **options):
+        return flush_cache(args, options)
+
+def flush_cache(apps, options):
+    """ Clears the image cache
+    
+    """
+    apps = [a.strip(',') for a in apps]
+    if apps:
+        print 'Flushing cache for %s...' % ', '.join(apps)
+    else:
+        print 'Flushing caches...'
+        
+    for app_label in apps:
+        app = cache.get_app(app_label)
+        models = [m for m in cache.get_models(app) if issubclass(m, ImageModel)]
+
+    for model in models:
+        for obj in model.objects.all():
+            for spec in model._ik.specs:
+                prop = getattr(obj, spec.name(), None)
+                if prop is not None:
+                    prop._delete()
+                if spec.pre_cache:
+                    prop._create()            

imagekit/models.py

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+import os
+from datetime import datetime
+from django.conf import settings
+from django.core.files.base import ContentFile
+from django.db import models
+from django.db.models.base import ModelBase
+from django.utils.translation import ugettext_lazy as _
+
+from imagekit import specs
+from imagekit.lib import *
+from imagekit.options import Options
+from imagekit.utils import img_to_fobj
+
+# Modify image file buffer size.
+ImageFile.MAXBLOCK = getattr(settings, 'PIL_IMAGEFILE_MAXBLOCK', 256 * 2 ** 10)
+
+# Choice tuples for specifying the crop origin.
+# These are provided for convenience.
+CROP_HORZ_CHOICES = (
+    (0, _('left')),
+    (1, _('center')),
+    (2, _('right')),
+)
+
+CROP_VERT_CHOICES = (
+    (0, _('top')),
+    (1, _('center')),
+    (2, _('bottom')),
+)
+
+
+class ImageModelBase(ModelBase):
+    """ ImageModel metaclass
+    
+    This metaclass parses IKOptions and loads the specified specification
+    module.
+    
+    """
+    def __init__(cls, name, bases, attrs):
+        parents = [b for b in bases if isinstance(b, ImageModelBase)]
+        if not parents:
+            return
+        user_opts = getattr(cls, 'IKOptions', None)
+        opts = Options(user_opts)
+        try:
+            module = __import__(opts.spec_module,  {}, {}, [''])
+        except ImportError:
+            raise ImportError('Unable to load imagekit config module: %s' % \
+                opts.spec_module)    
+        for spec in [spec for spec in module.__dict__.values() \
+                     if isinstance(spec, type) \
+                     and issubclass(spec, specs.ImageSpec) \
+                     and spec != specs.ImageSpec]:
+            setattr(cls, spec.name(), specs.Descriptor(spec))
+            opts.specs.append(spec)
+        setattr(cls, '_ik', opts)
+
+
+class ImageModel(models.Model):
+    """ Abstract base class implementing all core ImageKit functionality
+    
+    Subclasses of ImageModel are augmented with accessors for each defined
+    image specification and can override the inner IKOptions class to customize
+    storage locations and other options.
+    
+    """
+    __metaclass__ = ImageModelBase
+
+    class Meta:
+        abstract = True
+        
+    class IKOptions:
+        pass
+        
+    def admin_thumbnail_view(self):
+        if not self._imgfield:
+            return None
+        prop = getattr(self, self._ik.admin_thumbnail_spec, None)
+        if prop is None:
+            return 'An "%s" image spec has not been defined.' % \
+              self._ik.admin_thumbnail_spec
+        else:
+            if hasattr(self, 'get_absolute_url'):
+                return u'<a href="%s"><img src="%s"></a>' % \
+                    (self.get_absolute_url(), prop.url)
+            else:
+                return u'<a href="%s"><img src="%s"></a>' % \
+                    (self._imgfield.url, prop.url)
+    admin_thumbnail_view.short_description = _('Thumbnail')
+    admin_thumbnail_view.allow_tags = True
+    
+    @property
+    def _imgfield(self):
+        return getattr(self, self._ik.image_field)
+
+    def _clear_cache(self):
+        for spec in self._ik.specs:
+            prop = getattr(self, spec.name())
+            prop._delete()
+
+    def _pre_cache(self):
+        for spec in self._ik.specs:
+            if spec.pre_cache:
+                prop = getattr(self, spec.name())
+                prop._create()
+
+    def save(self, clear_cache=True, *args, **kwargs):
+        is_new_object = self._get_pk_val is None
+        super(ImageModel, self).save(*args, **kwargs)
+        if is_new_object:
+            clear_cache = False
+            spec = self._ik.preprocessor_spec
+            if spec is not None:
+                newfile = self._imgfield.storage.open(str(self._imgfield))
+                img = Image.open(newfile)
+                img = spec.process(img, None)
+                format = img.format or 'JPEG'
+                if format != 'JPEG':
+                    imgfile = img_to_fobj(img, format)
+                else:
+                    imgfile = img_to_fobj(img, format,
+                                          quality=int(spec.quality),
+                                          optimize=True)
+                content = ContentFile(imgfile.read())
+                newfile.close()
+                name = str(self._imgfield)
+                self._imgfield.storage.delete(name)
+                self._imgfield.storage.save(name, content)
+        if clear_cache and self._imgfield != '':
+            self._clear_cache()
+            self._pre_cache()
+
+    def delete(self):
+        assert self._get_pk_val() is not None, "%s object can't be deleted because its %s attribute is set to None." % (self._meta.object_name, self._meta.pk.attname)
+        self._clear_cache()
+        models.Model.delete(self)

imagekit/options.py

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+# Imagekit options
+from imagekit import processors
+from imagekit.specs import ImageSpec
+    
+
+class Options(object):
+    """ Class handling per-model imagekit options
+
+    """
+    image_field = 'image'
+    crop_horz_field = 'crop_horz'
+    crop_vert_field = 'crop_vert'
+    preprocessor_spec = None
+    cache_dir = 'cache'
+    save_count_as = None
+    cache_filename_format = "%(filename)s_%(specname)s.%(extension)s"
+    admin_thumbnail_spec = 'admin_thumbnail'
+    spec_module = 'imagekit.defaults'
+    
+    def __init__(self, opts):        
+        for key, value in opts.__dict__.iteritems():
+            setattr(self, key, value)
+            self.specs = []

imagekit/processors.py

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+""" Imagekit Image "ImageProcessors"
+
+A processor defines a set of class variables (optional) and a 
+class method named "process" which processes the supplied image using
+the class properties as settings. The process method can be overridden as well allowing user to define their
+own effects/processes entirely.
+
+"""
+from imagekit.lib import *
+
+class ImageProcessor(object):
+    """ Base image processor class """
+    @classmethod
+    def process(cls, image, obj=None):
+        return image
+
+
+class Adjustment(ImageProcessor):
+    color = 1.0
+    brightness = 1.0
+    contrast = 1.0
+    sharpness = 1.0
+
+    @classmethod
+    def process(cls, image, obj=None):
+        for name in ['Color', 'Brightness', 'Contrast', 'Sharpness']:
+            factor = getattr(cls, name.lower())
+            if factor != 1.0:
+                image = getattr(ImageEnhance, name)(image).enhance(factor)
+        return image
+
+
+class Reflection(ImageProcessor):
+    background_color = '#FFFFFF'
+    size = 0.0
+    opacity = 0.6
+    
+    @classmethod
+    def process(cls, image, obj=None):
+        # convert bgcolor string to rgb value
+        background_color = ImageColor.getrgb(cls.background_color)
+        # copy orignial image and flip the orientation
+        reflection = image.copy().transpose(Image.FLIP_TOP_BOTTOM)
+        # create a new image filled with the bgcolor the same size
+        background = Image.new("RGB", image.size, background_color)
+        # calculate our alpha mask
+        start = int(255 - (255 * cls.opacity)) # The start of our gradient
+        steps = int(255 * cls.size) # the number of intermedite values
+        increment = (255 - start) / float(steps)
+        mask = Image.new('L', (1, 255))
+        for y in range(255):
+            if y < steps:
+                val = int(y * increment + start)
+            else:
+                val = 255
+            mask.putpixel((0, y), val)
+        alpha_mask = mask.resize(image.size)
+        # merge the reflection onto our background color using the alpha mask
+        reflection = Image.composite(background, reflection, alpha_mask)
+        # crop the reflection
+        reflection_height = int(image.size[1] * cls.size)
+        reflection = reflection.crop((0, 0, image.size[0], reflection_height))
+        # create new image sized to hold both the original image and the reflection
+        composite = Image.new("RGB", (image.size[0], image.size[1]+reflection_height), background_color)
+        # paste the orignal image and the reflection into the composite image
+        composite.paste(image, (0, 0))
+        composite.paste(reflection, (0, image.size[1]))
+        # return the image complete with reflection effect
+        return composite
+
+
+class Resize(ImageProcessor):
+    width = None
+    height = None
+    crop = False
+    upscale = False
+    
+    @classmethod
+    def process(cls, image, obj=None):
+        cur_width, cur_height = image.size
+        if cls.crop:
+            crop_horz = getattr(obj, obj._ik.crop_horz_field, 1)
+            crop_vert = getattr(obj, obj._ik.crop_vert_field, 1)
+            ratio = max(float(cls.width)/cur_width, float(cls.height)/cur_height)
+            resize_x, resize_y = ((cur_width * ratio), (cur_height * ratio))
+            crop_x, crop_y = (abs(cls.width - resize_x), abs(cls.height - resize_y))
+            x_diff, y_diff = (int(crop_x / 2), int(crop_y / 2))
+            box_left, box_right = {
+                0: (0, cls.width),
+                1: (int(x_diff), int(x_diff + cls.width)),
+                2: (int(crop_x), int(resize_x)),
+            }[crop_horz]
+            box_upper, box_lower = {
+                0: (0, cls.height),
+                1: (int(y_diff), int(y_diff + cls.height)),
+                2: (int(crop_y), int(resize_y)),
+            }[crop_vert]
+            box = (box_left, box_upper, box_right, box_lower)
+            image = image.resize((int(resize_x), int(resize_y)), Image.ANTIALIAS).crop(box)
+        else:
+            if not cls.width is None and not cls.height is None:
+                ratio = min(float(cls.width)/cur_width,
+                            float(cls.height)/cur_height)
+            else:
+                if cls.width is None:
+                    ratio = float(cls.height)/cur_height
+                else:
+                    ratio = float(cls.width)/cur_width
+            new_dimensions = (int(round(cur_width*ratio)),
+                              int(round(cur_height*ratio)))
+            if new_dimensions[0] > cur_width or \
+               new_dimensions[1] > cur_height:
+                if not cls.upscale:
+                    return image
+            image = image.resize(new_dimensions, Image.ANTIALIAS)
+        return image
+
+    
+class Transpose(ImageProcessor):
+    """ Rotates or flips the image
+    
+    Method should be one of the following strings:
+        - FLIP_LEFT RIGHT
+        - FLIP_TOP_BOTTOM
+        - ROTATE_90
+        - ROTATE_270
+        - ROTATE_180
+        
+    """
+    method = 'FLIP_LEFT_RIGHT'
+    
+    @classmethod
+    def process(cls, image, obj=None):
+        return image.transpose(getattr(Image, cls.method))

imagekit/specs.py

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+""" ImageKit image specifications
+
+All imagekit specifications must inherit from the ImageSpec class. Models
+inheriting from ImageModel will be modified with a descriptor/accessor for each
+spec found.
+
+"""
+import os
+from StringIO import StringIO
+from imagekit.lib import *
+from imagekit.utils import img_to_fobj
+from django.core.files.base import ContentFile
+
+class ImageSpec(object):
+    pre_cache = False
+    quality = 70
+    increment_count = False
+    processors = []
+    
+    @classmethod
+    def name(cls):
+        return getattr(cls, 'access_as', cls.__name__.lower())
+        
+    @classmethod
+    def process(cls, image, obj):
+        processed_image = image.copy()
+        for proc in cls.processors:
+            processed_image = proc.process(processed_image, obj)
+        return processed_image
+        
+
+class Accessor(object):
+    def __init__(self, obj, spec):
+        self._img = None
+        self._obj = obj
+        self.spec = spec
+        
+    def _get_imgfile(self):
+        format = self._img.format or 'JPEG'
+        if format != 'JPEG':
+            imgfile = img_to_fobj(self._img, format)
+        else:
+            imgfile = img_to_fobj(self._img, format,
+                                  quality=int(self.spec.quality),
+                                  optimize=True)
+        return imgfile
+        
+    def _create(self):
+        if self._exists():
+            return
+        # process the original image file
+        fp = self._obj._imgfield.storage.open(self._obj._imgfield.name)
+        fp.seek(0)
+        fp = StringIO(fp.read())
+        try:
+            self._img = self.spec.process(Image.open(fp), self._obj)
+            # save the new image to the cache
+            content = ContentFile(self._get_imgfile().read())
+            self._obj._imgfield.storage.save(self.name, content)
+        except IOError:
+            pass
+        
+    def _delete(self):
+        self._obj._imgfield.storage.delete(self.name)
+
+    def _exists(self):
+        return self._obj._imgfield.storage.exists(self.name)
+
+    def _basename(self):
+        filename, extension =  \
+            os.path.splitext(os.path.basename(self._obj._imgfield.name))
+        return self._obj._ik.cache_filename_format % \
+            {'filename': filename,
+             'specname': self.spec.name(),
+             'extension': extension.lstrip('.')}
+
+    @property
+    def name(self):
+        return os.path.join(self._obj._ik.cache_dir, self._basename())
+
+    @property
+    def url(self):
+        self._create()
+        if self.spec.increment_count:
+            fieldname = self._obj._ik.save_count_as
+            if fieldname is not None:
+                current_count = getattr(self._obj, fieldname)
+                setattr(self._obj, fieldname, current_count + 1)
+                self._obj.save(clear_cache=False)
+        return self._obj._imgfield.storage.url(self.name)
+        
+    @property
+    def file(self):
+        self._create()
+        return self._obj._imgfield.storage.open(self.name)
+        
+    @property
+    def image(self):
+        if self._img is None:
+            self._create()
+            if self._img is None:
+                self._img = Image.open(self.file)
+        return self._img
+        
+    @property
+    def width(self):
+        return self.image.size[0]
+        
+    @property
+    def height(self):
+        return self.image.size[1]
+
+
+class Descriptor(object):
+    def __init__(self, spec):
+        self._spec = spec
+
+    def __get__(self, obj, type=None):
+        return Accessor(obj, self._spec)

imagekit/tests.py

@@ -0,0 +1,86 @@
+import os
+import tempfile
+import unittest
+from django.conf import settings
+from django.core.files.base import ContentFile
+from django.db import models
+from django.test import TestCase
+
+from imagekit import processors
+from imagekit.models import ImageModel
+from imagekit.specs import ImageSpec
+from imagekit.lib import Image
+
+
+class ResizeToWidth(processors.Resize):
+    width = 100
+    
+class ResizeToHeight(processors.Resize):
+    height = 100
+    
+class ResizeToFit(processors.Resize):
+    width = 100
+    height = 100
+    
+class ResizeCropped(ResizeToFit):
+    crop = ('center', 'center')
+
+class TestResizeToWidth(ImageSpec):
+    access_as = 'to_width'
+    processors = [ResizeToWidth]
+
+class TestResizeToHeight(ImageSpec):
+    access_as = 'to_height'
+    processors = [ResizeToHeight]
+    
+class TestResizeCropped(ImageSpec):
+    access_as = 'cropped'
+    processors = [ResizeCropped]
+
+class TestPhoto(ImageModel):
+    """ Minimal ImageModel class for testing """
+    image = models.ImageField(upload_to='images')
+    
+    class IKOptions:
+        spec_module = 'imagekit.tests'
+    
+
+class IKTest(TestCase):
+    """ Base TestCase class """
+    def setUp(self):
+        # create a test image using tempfile and PIL
+        self.tmp = tempfile.TemporaryFile()
+        Image.new('RGB', (800, 600)).save(self.tmp, 'JPEG')
+        self.tmp.seek(0)
+        self.p = TestPhoto()
+        self.p.image.save(os.path.basename('test.jpg'),
+                           ContentFile(self.tmp.read()))
+        self.p.save()
+        # destroy temp file
+        self.tmp.close()
+        
+    def test_setup(self):
+        self.assertEqual(self.p.image.width, 800)
+        self.assertEqual(self.p.image.height, 600)
+        
+    def test_to_width(self):
+        self.assertEqual(self.p.to_width.width, 100)
+        self.assertEqual(self.p.to_width.height, 75)
+        
+    def test_to_height(self):
+        self.assertEqual(self.p.to_height.width, 133)
+        self.assertEqual(self.p.to_height.height, 100)
+        
+    def test_crop(self):
+        self.assertEqual(self.p.cropped.width, 100)
+        self.assertEqual(self.p.cropped.height, 100)
+
+    def test_url(self):
+        tup = (settings.MEDIA_URL, self.p._ik.cache_dir, 'test_to_width.jpg')
+        self.assertEqual(self.p.to_width.url, "%s%s/%s" % tup)
+ 
+    def tearDown(self):
+        # make sure image file is deleted
+        path = self.p.image.path
+        self.p.delete()
+        self.failIf(os.path.isfile(path))

imagekit/utils.py

@@ -0,0 +1,15 @@
+""" ImageKit utility functions """
+
+import tempfile
+
+def img_to_fobj(img, format, **kwargs):
+    tmp = tempfile.TemporaryFile()
+    if format != 'JPEG':
+        try:
+            img.save(tmp, format, **kwargs)
+            return
+        except KeyError:
+            pass
+    img.save(tmp, format, **kwargs)
+    tmp.seek(0)
+    return tmp