easy-thumbnails watermark to right bottom corner of the image

processors.py

# custom/processors.py
from django.conf import settings
from django.core.files.storage import default_storage

try:
    from PIL import Image
except ImportError:
    import Image


def watermark(image, watermark=False, position=False, **kwargs):
    if watermark:
        watermark_conf = settings.THUMBNAIL_WATERMARK.get(watermark)
        name = watermark_conf['name']
        storage = watermark_conf.get('storage', default_storage)
        watermark_image = Image.open(storage.open(name))
        if image.mode != 'RGBA':
            image = image.convert('RGBA')
        layer = Image.new('RGBA', image.size, (0, 0, 0, 0))
        width, height = image.size
        x = width - watermark_image.size[0]
        y = height - watermark_image.size[1]
        layer.paste(watermark_image, (x, y))
        image = Image.composite(layer, image, layer)

    return image

settings.py

THUMBNAIL_ALIASES = {
    '': {
        'thumb': {
            'size': (320, 240),
            'watermark': 'logo',
        }
    }
}

THUMBNAIL_WATERMARK = {
    'logo': {
        'name': 'logo.png',
        # optional storage class
        # 'storage': mystorage,
        }
}

THUMBNAIL_PROCESSORS = (
    'easy_thumbnails.processors.colorspace',
    'easy_thumbnails.processors.autocrop',
    'easy_thumbnails.processors.scale_and_crop',
    'easy_thumbnails.processors.filters',
    'custom.processors.watermark',
)