Writing images

You can write an Image object into a file or a byte string buffer (blob) as format what you want.

Convert images to JPEG

If you wonder what is image’s format, use format property.

>>> image.format
'JPEG'

The format property is writable, so you can convert images by setting this property.

from wand.image import Image

with Image(filename='pikachu.png') as img:
    img.format = 'jpeg'
    # operations to a jpeg image...

If you want to convert an image without any changes of the original, use convert() method instead:

from wand.image import Image

with Image(filename='pikachu.png') as original:
    with original.convert('jpeg') as converted:
        # operations to a jpeg image...
        pass

Note

Support for some of the formats are delegated to libraries or external programs. To get a complete listing of which image formats are supported on your system, use identify command provided by ImageMagick:

$ identify -list format

Save to file

In order to save an image to a file, use save() method with the keyword argument filename:

from wand.image import Image

with Image(filename='pikachu.png') as img:
    img.format = 'jpeg'
    img.save(filename='pikachu.jpg')

Save to stream

You can write an image into a output stream (file-like object which implements write() method) as well. The parameter file takes a such object (it also is the first positional parameter of save() method).

For example, the following code converts pikachu.png image into JPEG, gzips it, and then saves it to pikachu.jpg.gz:

import gzip
from wand.image import Image

gz = gzip.open('pikachu.jpg.gz')
with Image(filename='pikachu.png') as img:
    img.format = 'jpeg'
    img.save(file=gz)
gz.close()

Get binary string

Want just a binary string of the image? Use make_blob() method so:

from wand.image import Image

with image(filename='pikachu.png') as img:
    img.format = 'jpeg'
    jpeg_bin = img.make_blob()

There’s the optional format parameter as well. So the above example code can be simpler:

from wand.image import Image

with Image(filename='pikachu.png') as img:
    jpeg_bin = img.make_blob('jpeg')