Get color palette from App Engine image (Blobstore, Python)

Question

Is it possible to get a set of dominant colors from an App Engine Image (stored as a blob)?

With PIL, I can do this:

import Image
im = Image.open('image.jpg')
out = im.convert('P', palette=Image.ADAPTIVE, colors=5)

In App Engine, I get hold of the image like so:

image = images.Image(blob_key=blob_key)

Is it possible to get a palette from here?

Answer 1

The GAE images.Image class doesn't appear to offer a similar/pallette-based functionality.

But PIL is one of the GAE Built-in Third-party Libraries which you can use instead. You'd need to:

• request the library in your app.yaml:

  libraries:
  - name: PIL
    version: "1.1.7"
  

• explicitly use the Image class from PIL (may need to import it as a different name if you're also importing/using the Image class from GAE's images, to avoid a naming conflict):

  from PIL import Image
  im = Image.open('image.jpg')
  out = im.convert('P', palette=Image.ADAPTIVE, colors=5)