chromatose

---

A package for storing and visualizing palettes, and constructing new ones via polynomial interpolation and image extraction. Now pippable!

*This package borrows inspiration from @jmaasch's scatterplots in her package [`sanzo`](https://github.com/jmaasch/sanzo), and uses extraction algorithms from @qTipTip's package [`Pylette`](https://github.com/qTipTip/Pylette).*

Palettes 🎨

frieda	plath	selah	blonde	honeycombe
crepuscule	leather	gucci	sandbar	fiestaware
chilaquiles	eleven	splenda	gremlin	pollen
medium	juniper	polya	ostrich	fraiche
cheshire	carmine	joan*	pinot	addams
minuit	fugazi	clementine	leda	pugsley
bellhooks	wes	lysergic	pepo	reese
lufte	oolong	pitaya	alice	neko
belle	spiff	yoshi	phoebe	pam
menthol	dwight	riley	mona	eeyore
rory	pudding	marmalade	polaris	trefoil
harmon	abed	shirley	surely	annie
pierce	britta	strogatz	lutz	writhe
perl*	roosh	seafare	heliotrope	moonbow
peanuts	naval	indomie	maggie	rainbow
???	quinone	quinoline	diverging	orb*
warble*	waitomo*	vylette*	pom*	lava*
pumpkin*	pinctada*	nacre*	moxxi*	salvia*
bluefish	BuPu*	holst	joker*	rach*
blink*	betan*	rue*	otterpop*	gummi*
emporium	paired	category20a	category20b	category20c

* available as xxx256

[discrete] [monochrome continuous] [polychromatic continuous] [bokeh]

Viz 👀

ct.palplot( )

Visualizations include swatches, pies, points, lines, scatters. Somewhat helpful for seeing how colors behave on a plot, in dense or scattered visuals. Sometimes colors look great together on a swatch, but not so great in their pointillistic forms.

• palette : list or iterable any combination of hex strings or rgb tuples or HTML
• bg_color : HTML or hex string background fill color
• alpha : fraction between 0.0 and 1.0 alpha transparency of entire palette
• shuffle : boolean shuffles palette

ct.palpicker( )

Testing out panel's new colorpicker widget! Useful for adjusting palettes to personal taste.

• n : list or integer

Color mapping

map_palette( )

Given palette and 1D quantitative axis, returns list of mapped colors. Uses min and max to first and last of palette

• q : 1D quantitative axis, numpy array
• palette : color palette to map to
• Returns colors: list of mapped colors

map_palette_thresh( )

Given palette and 1D quantitative axis, returns list of mapped colors. Instead of min and max of dataset, uses customized end points.

For example, a dataset may range from (-1, 1), and you want extreme colors to reflect those bounds, not necessarily your dataset's range.

• q : 1D quantitative axis, numpy array
• palette : color palette to map to
• q_min_thresh : minimum threshold, default -infinity
• q_max_thresh : maximum threshold, default +infinity
• min_color : color to map minimum threshold to (otherwise set to first color in palette)
• max_color : color to map maximum threshold to (otherwise set to last color in palette)
• nan_color : color to map nan values to
• Returns colors: list of mapped colors

map_palette_diverging( )

For customizing diverging palettes with variable breakpoints and thresholds.

For example, a dataset may range from (-x, +y), and you want zero to be the color/point at which the colors diverge.

This function assumes you pass in a balanced palette, but 'midpoint' can approximately adjust this.

• q : 1D quantitative axis, numpy array
• palette : color palette to map to
• q_dividing : dividing numeric value corresponding to divergence in palette
• q_min_thresh : minimum threshold, default -infinity
• q_max_thresh : maximum threshold, default -infinity
• nan_color : color to map nan values to, default black
• midpoint : fraction, where to set midpoint of colorbar to, default 0.5
• Returns colors: list of mapped colors

Interpolation

ct.palpolate( )

palpolate (pal-(ette inter)-polate): input lists of any size and user can control output size.

There are a multitude of beautiful gradients in packages like bokeh and colorcet that are, for the most part, static. The interpolation scheme here can be used to create entirely new ones given only a few endpoints. This part is still in development, but currently uses linear or polynomial fits in color space metrics RGB, HSL, or HSV. Heatmaps are a good way to visualize the results!

On the left are the input palettes, and on the right are the output palettes all approximately of size 256.

• palette : list or iterable any combination of hex strings or rgb tuples or HTML
• n_colors : integer approximate desired length of final palette
• method : string 'rgb' or 'hsv' or 'hsl' interpolation metric, default 'rgb'
• curve : boolean if True, fit t 2ndº polynomial if False, simple linear interpolation
• directions : list of 3 strings, 'up' or 'down' each entry corresponds to r, g, b 'up' pushes intermediate values higher (lighter) 'down' pushes intermediate values lower (darker)

Extraction 📷

Extract palette of size n_colors from image given image path using k-means or median cut algorithms.

ct.extract( )

• path : string of image path
• n_colors : integer number of colors to extract
• method : 'kmeans' or 'median' or 'both' algorithm of extraction either k-means clustering or median cut, default k-means
• resize : boolean, default True resizing samples a smaller image, speeds up extraction
• sort : boolean, default False amateur sort by luminance
• show : boolean, default True prints palette and returns panel object

Command line tools

Palettes can be retrieved from command line:

>>> chromatose leda
>>> ['#2c2f30', '#8fa7d7', '#afd7d6', '#aa3731', '#f5b3b8']

Palettes can be extracted from command line:

>>> extract egg.png
>>> K-Means:    ['#050002', '#0c1c7b', '#013adc', '#1b143a', '#294254']
>>> Median Cut: ['#040000', '#080006', '#1e1b3c', '#1e2d61', '#0330bd']

Palette extraction from image path using both k-means and median cut
algorithms. Defaults to 5 colors, resized, unsorted, and not displayed.

 path             path to image

 -n , --ncolors   length of palette (int, default 5)
 -r , --resize    resize for efficiency (bool, default True)
 -s , --show      display pillow swatches (bool, default False)

Gallery 🌈

discrete

frieda

plath

selah

blonde

honeycombe

lysergic

pepo

reese

rainbow

lufte

pitaya

spiff

leather

medium

addams

mona

leda

rory

pudding

polaris

trefoil

writhe

perl*

roosh

heliotrope

indomie

strogatz

juniper

quinone

minuit

alice

wes

pam

dwight

marmalade

harmon

shirley

annie

pierce

britta

abed

eeyore

neko

maggie

quinoline

peanuts

eleven

naval

fugazi

clementine

diverging

lutz

moonbow

chilaquiles

fiestaware

polya

splenda

pollen

fraiche

cheshire

bellhooks

belle

phoebe

ostrich

yoshi

monochrome continuous

salvia*

pom*

lava*

moxxi*

joan*

waitomo*

warble*

vylette*

pumpkin*

crest*

nacre*

salvia256

warble256

waitomo256

vylette256

pom256

moxxi256

lava256

pumpkin256

joan256

nacre256

crest256

polychromatic continuous

joker*

rach*

orb*

blink*

rue*

betan*

bluefish

otterpop*

gummi*

emporium*

perl256

orb256

blink256

otterpop256

gummi256

emporium256

betan256

rue256

rach256

joker256

bokeh

paired

category20a

category20b

category20c

"The last color she remembered was the indigo chips in the headstone. After that she became as color conscious as a hen."