colorgram.py

colorgram.py is a Python library that lets you extract colors from images. Compared to other libraries, the colorgram algorithm's results are more intense.

colorgram.py is a port of colorgram.js, a JavaScript library written by GitHub user @darosh. The goal is to have 100% accuracy to the results of the original library (a goal that is met). I decided to port it since I much prefer the results the colorgram algorithm gets over those of alternative libraries - have a look in the next section.

Results

Time-wise, an extraction of a 512x512 image takes about 0.66s (another popular color extraction library, Color Thief, takes about 1.05s).

Installation

You can install colorgram.py with pip, as following:

pip install colorgram.py

How to use

Using colorgram.py is simple. Mainly there's only one function you'll need to use - colorgram.extract.

Example

import colorgram

# Extract 6 colors from an image.
colors = colorgram.extract('sweet_pic.jpg', 6)

# colorgram.extract returns Color objects, which let you access
# RGB, HSL, and what proportion of the image was that color.
first_color = colors[0]
rgb = first_color.rgb # e.g. (255, 151, 210)
hsl = first_color.hsl # e.g. (230, 255, 203)
proportion  = first_color.proportion # e.g. 0.34

# RGB and HSL are named tuples, so values can be accessed as properties.
# These all work just as well:
red = rgb[0]
red = rgb.r
saturation = hsl[1]
saturation = hsl.s

colorgram.extract(image, number_of_colors)

Extract colors from an image. image may be either a path to a file, or a file-like object. The function will return a list of number_of_colors Color objects.

colorgram.Color

A color extracted from an image. Its properties are:

• Color.rgb - The color represented as a namedtuple of RGB from 0 to 255, e.g. (r=255, g=151, b=210).
• Color.hsl - The color represented as a namedtuple of HSL from 0 to 255, e.g. (h=230, s=255, l=203).
• Color.proportion - The proportion of the image that is in the extracted color from 0 to 1, e.g. 0.34.

Sorting by HSL

Something the original library lets you do is sort the colors you get by HSL. In actuality, though, the colors are only sorted by hue (as of colorgram.js 0.1.5), while saturation and lightness are ignored. To get the corresponding result in colorgram.py, simply do:

colors.sort(key=lambda c: c.hsl.h)
# or...
sorted(colors, key=lambda c: c.hsl.h)

Contact

If you find a bug in the colorgram.py, or if there's a feature you would like to be added, please open an issue on GitHub.

If you have a question about the library, or if you'd just like to talk about, well, anything, that's no problem at all. You can reach me in any of these ways:

• Tweet @obskyr
• E-mail me

To get a quick answer, Twitter is your best bet.

Enjoy!