colorstamps.stamps module

Colormap by name

colorstamps.stamps.get_cmap() is a getter function that selects the correct function based on the name of the colormap. It is called when a colormap is requested by name in colorstamps.helpers.apply_stamp().

colorstamps.stamps.get_cmap(name, l=None, rot=None, J=None, sat=None, limit_sat=None, a=None, b=None)

getter function for named colormaps the ‘alt’ colormaps are rotated 45 degrees flat colormaps are: —————- ‘flat’, ‘disk’ colormaps with a bright center: —- ‘peak’, ‘cone’ colormaps with a dark center: —— ‘abyss’, ‘funnel’ alternate with a bright center: —- ‘hsv’, ‘fourCorners’, ‘fourEdges’, ‘teuling0w’ to ‘teuling3w’ colormaps with lighness on y axis: - ‘barrel’, ‘cut’, ‘blues’, ‘reds’, ‘greens’, ‘yellows’ teuling colormaps: ——— ‘teuling0f’, ‘teuling1f’, ‘teuling2f’, ‘teuling3f’, ‘teuling0w’, ‘teuling1w’, ‘teuling2w’, ‘teuling3w’

any matplotlib colormap can also be converted to a colormap with lighness on y-axis

Parameters

  • name – string For radial colormaps the name may have a postfix separated by a space, i.e. ‘cone tr’ the postfix must be some combination of (t,b) and/or (l,r) which defines the quadrant/side of the colormap to include t-> top, b-> bottom, r-> right, l-> left, and ‘tr’-> top right, etc.

  • l – int, the size of the colormap will be (l,l), defaults to 256 if None

  • rot – float, rotation of the colormap (where applicable)

  • J – array-like of length 2 (float,float), determins min and max luminocity where applicable

  • sat – float, maximum saturation where applicable

  • limit_sat – string, ‘individual’ or ‘shared’. How saturation is limited for relevant colormaps when colors outside sRGB are required ‘individual’: each combination J, hue in the colormap has an individual limit to saturation ‘shared’: for each J, all hues share a limit, the maximum where all hues can be represented

  • a – range along a-axis, array-like [min,max] Used to move the center of the colormap where applicable. Defaults to (-1,1) which is then multiplied internally with sat

  • b – range along b-axis, see a.

Returns

a (l,l,3) numpy array of rgb values

Functions for spesific colormaps

get_const_J

colorstamps.stamps.get_const_J() is used for the ‘flat’ and ‘disk’ colormaps

colorstamps.stamps.get_const_J(J=95, a=(- 1, 1), b=(- 1, 1), r=33.0, l=256, mask='no_mask', rot=0)

Generates am rgb colormap of (l,l,3) that attempts to keep a constant lightness in the CAM02-LCD colorspace The colormap is based on the a-b plane of the Jab colorspace for a constant J.

Parameters

  • J – float (lighness), default 95, range approximately 1->128,

  • a – tuple of 2 floats, default (-1,1). The limit along the a-axis will be (a[0]*r,a[1]*r)

  • b – tuple of 2 floats, default (-1,1). The limit along the b-axis will be (b[0]*r,b[1]*r)

  • r – float, default 33.0. The saturation where a or b is 1. (named ‘r’ for radius in the a-b plane)

  • l – int, default 256. Size of the colormap.

  • mask – string, default ‘no_mask’. If ‘circle’ makes a circular mask, and everything outside will be np.nan If ‘unavailable’ makes a colors that “should” have rgb<0 or rgb>1 when transformed to sRGB will be np.nan

  • rot – rotation of the hues on the a-b plane, in degrees

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
fig, axes = plt.subplots(3,4,figsize=(14,10), dpi = 50)

cmap = colorstamps.stamps.get_const_J()
axes[0,0].imshow(cmap, origin = 'lower')
axes[0,0].set_title('default')

cmap = colorstamps.stamps.get_const_J(J=25)
axes[0,1].imshow(cmap, origin = 'lower')
axes[0,1].set_title('J = 25')

cmap = colorstamps.stamps.get_const_J(J=120, a=(- 1, 1), b=(- 1, 1), r=33.0, l=256, mask='no_mask', rot=0)
axes[0,2].imshow(cmap, origin = 'lower')
axes[0,2].set_title('J = 120')

cmap = colorstamps.stamps.get_const_J(mask = 'circle')
axes[0,3].imshow(cmap, origin = 'lower')
axes[0,3].set_title("mask = 'circle'")

cmap = colorstamps.stamps.get_const_J(rot=125)
axes[1,0].imshow(cmap, origin = 'lower')
axes[1,0].set_title('rot = 125')

cmap = colorstamps.stamps.get_const_J(r=20)
axes[1,1].imshow(cmap, origin = 'lower')
axes[1,1].set_title('r = 20')

cmap = colorstamps.stamps.get_const_J(r=50)
axes[1,2].imshow(cmap, origin = 'lower')
axes[1,2].set_title('r = 50')

cmap = colorstamps.stamps.get_const_J(r=50, mask='unavailable')
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title("r = 50, mask='unavailable')")


cmap = colorstamps.stamps.get_const_J( a = (-1,0))
axes[2,0].imshow(cmap, origin = 'lower')
axes[2,0].set_title('a = (-1,0)')

cmap = colorstamps.stamps.get_const_J( a = (-1,0), b = (0,1))
axes[2,1].imshow(cmap, origin = 'lower')
axes[2,1].set_title('a = (-1,0), b = (0,1)')


cmap = colorstamps.stamps.get_const_J(a = (-1,0), b = (0,1), mask = 'circle')
axes[2,2].imshow(cmap, origin = 'lower')
axes[2,2].set_title('a = (-1,0), b = (0,1), '+"mask = 'circle'")

cmap = colorstamps.stamps.get_const_J(l = 8)
axes[2,3].imshow(cmap, origin = 'lower')
axes[2,3].set_title('l = 8')

for ax in axes.ravel():
        ax.set_xticks([])
        ax.set_yticks([])
fig.patch.set_facecolor('white')
_images/get_const_J.png

get_var_J

colorstamps.stamps.get_var_J() is used for the ‘peak’, ‘abyss’, ‘cone’, and ‘funnel’ colormaps

colorstamps.stamps.get_var_J(J=[95, 128.5], a=(- 1, 1), b=(- 1, 1), r=33.0, l=256, mask='no_mask', rot=0, limit_sat=None)

Generates am rgb colormap of (l,l,3) that attempts to keep a constant lightness in the CAM02-LCD colorspace The colormap is based on the a-b plane of the Jab colorspace for a constant J.

Parameters

  • J – (lighness) tuple of 2 floats, default [95,128.5] defining the range of lightness for the colormap, default 95, max range of J approximately 1 to 128.5

  • a – tuple of 2 floats, default (-1,1). The limit along the a-axis will be (a[0]*r,a[1]*r)

  • b – tuple of 2 floats, default (-1,1). The limit along the b-axis will be (b[0]*r,b[1]*r)

  • r – float, default 33.0. The saturation where a or b is 1. (named ‘r’ for radius in the a-b plane)

  • l – int, default 256. Size of the colormap.

  • mask – string, default ‘no_mask’. If ‘circle’ makes a circular mask, and everything outside will be np.nan If ‘unavailable’ makes a colors that “should” have rgb<0 or rgb>1 when transformed to sRGB will be np.nan

  • rot – rotation of the hues on the a-b plane, in degrees

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
fig, axes = plt.subplots(2,4,figsize=(14,7), dpi = 50)

cmap = colorstamps.stamps.get_var_J()
axes[0,0].imshow(cmap, origin = 'lower')
axes[0,0].set_title('default')

cmap = colorstamps.stamps.get_var_J(J = (95,1))
axes[0,1].imshow(cmap, origin = 'lower')
axes[0,1].set_title('J = (95,1)')

cmap = colorstamps.stamps.get_var_J(mask = 'circle')
axes[0,2].imshow(cmap, origin = 'lower')
axes[0,2].set_title("mask = 'circle'")

cmap = colorstamps.stamps.get_var_J(J = (95,1), mask = 'circle')
axes[0,3].imshow(cmap, origin = 'lower')
axes[0,3].set_title("J = (95,1), mask = 'circle'")

cmap = colorstamps.stamps.get_var_J(J = (50,128))
axes[1,0].imshow(cmap, origin = 'lower')
axes[1,0].set_title('J = (50,128)')

cmap = colorstamps.stamps.get_var_J(J = (50,128), limit_sat = 'shared')
axes[1,1].imshow(cmap, origin = 'lower')
axes[1,1].set_title("J = (50,128), limit_sat = 'shared'")

cmap = colorstamps.stamps.get_var_J(J = (50,128), mask = 'circle')
axes[1,2].imshow(cmap, origin = 'lower')
axes[1,2].set_title("J = (50,128), mask = 'circle'")

cmap = colorstamps.stamps.get_var_J(J = (1,128), mask = 'circle', limit_sat = 'shared')
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title("J = (1,128), mask = 'circle',\n limit_sat = 'shared'")

for ax in axes.ravel():
        ax.set_xticks([])
        ax.set_yticks([])
fig.patch.set_facecolor('white')
_images/get_var_J.png

four_edges

colorstamps.stamps.four_edges() is used for the ‘fourEdges’ and ‘fourCorners’ colormaps

colorstamps.stamps.four_edges(a=(- 1, 1), b=(- 1, 1), r_exp=- 0.5, f0_exp=1.7, f1_exp=1.7, yellow_exp=0.75, l=256, rot=0)

Generates a 2d colormap with four colors (r,g,b,y) on the edges (or corners if rot = 45) based on the sRGB colorspace, with exponentials

Parameters

  • a – limits the range of the y,x plane to use for the colormap. Both default to (-1,1), changing this will zoom in/out on different parts of the colormap

  • b – limits the range of the y,x plane to use for the colormap. Both default to (-1,1), changing this will zoom in/out on different parts of the colormap

  • r_exp – float, radial exponent to the lighness, defaults -0.5. Increasing this makes a big white spot in the middle

  • f0_exp – floats, exponent for the color along the a and b axes, both default 1.7

  • f1_exp – floats, exponent for the color along the a and b axes, both default 1.7

  • yellow_exp – additioal exponent for yellow, defaults 0.75

  • l – size of the colormap, defaults to 256

  • rot – rotation of the colormap, in degrees

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
fig, axes = plt.subplots(2,4,figsize=(14,7), dpi = 50)

cmap = colorstamps.stamps.four_edges()
axes[0,0].imshow(cmap, origin = 'lower')
axes[0,0].set_title('default')

cmap = colorstamps.stamps.four_edges(rot = 45)
axes[0,1].imshow(cmap, origin = 'lower')
axes[0,1].set_title('rot = 45')

cmap = colorstamps.stamps.four_edges(f0_exp = 0.5, f1_exp = 0.5)
axes[0,2].imshow(cmap, origin = 'lower')
axes[0,2].set_title('f0_exp, f1_exp = 0.5')

cmap = colorstamps.stamps.four_edges(f0_exp = 2.5, f1_exp = 2.5)
axes[0,3].imshow(cmap, origin = 'lower')
axes[0,3].set_title('f0_exp, f1_exp = 2.5')

cmap = colorstamps.stamps.four_edges(f0_exp = 2.5)
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title('f0_exp = 3')

cmap = colorstamps.stamps.four_edges(f1_exp = 0.5)
axes[1,0].imshow(cmap, origin = 'lower')
axes[1,0].set_title('f1_exp = 0.5')

cmap = colorstamps.stamps.four_edges(f0_exp = 0.5)
axes[1,1].imshow(cmap, origin = 'lower')
axes[1,1].set_title('f0_exp = 0.5')

cmap = colorstamps.stamps.four_edges(a = (-1,0), rot = 180)
axes[1,2].imshow(cmap, origin = 'lower')
axes[1,2].set_title('a = (0,1), rot = 180')

cmap = colorstamps.stamps.four_edges(a = (-1,0), b = (0,1), rot = 180)
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title('a = (0,1), b = (0,1), rot = 180')

for ax in axes.ravel():
        ax.set_xticks([])
        ax.set_yticks([])
fig.patch.set_facecolor('white')
_images/four_edges.png

barrel

colorstamps.stamps.barrel() is used for the ‘barrel’ colormap

colorstamps.stamps.barrel(sat=33, phi=[- 180, 180], J=[15, 120], l=256, limit_sat='shared')

Generates a 2d colormap that cycles different hues on the x-axis and has lighness on the y-axis

Parameters

  • sat – float, default 33. Desired saturation

  • phi – range for the hues on the x-axis in degrees, array like of length 2, default [-180,180]

  • J – limits to lighness on the y-axis, array like of length 2, default [15,120]

  • l – desired size (l,l,3) of the colormap

  • limit_sat – string, how to limit the saturation to say within the limits of the RGB colorspace ‘shared’: all hues share same limits ‘individual’: different hues have different limits

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
fig, axes = plt.subplots(2,4,figsize=(14,7), dpi = 50)

cmap = colorstamps.stamps.barrel()
axes[0,0].imshow(cmap, origin = 'lower')
axes[0,0].set_title('default')

cmap = colorstamps.stamps.barrel(sat = 10)
axes[0,1].imshow(cmap, origin = 'lower')
axes[0,1].set_title('sat = 10')

cmap = colorstamps.stamps.barrel(sat = 70)
axes[0,2].imshow(cmap, origin = 'lower')
axes[0,2].set_title('sat = 70')

cmap = colorstamps.stamps.barrel(sat = 70, limit_sat = 'individual')
axes[0,3].imshow(cmap, origin = 'lower')
axes[0,3].set_title("sat = 70, limit_sat = 'individual'")

cmap = colorstamps.stamps.barrel(phi = [0,360])
axes[1,0].imshow(cmap, origin = 'lower')
axes[1,0].set_title("phi = [0,360]")

cmap = colorstamps.stamps.barrel(phi = [0,180])
axes[1,1].imshow(cmap, origin = 'lower')
axes[1,1].set_title("phi = [0,180]")


cmap = colorstamps.stamps.barrel(J = (20,110))
axes[1,2].imshow(cmap, origin = 'lower')
axes[1,2].set_title("J = (20,110)")

cmap = colorstamps.stamps.barrel(phi = [0,180], J = (20,110))
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title("phi = [0,180], J = (20,110)")

for ax in axes.ravel():
        ax.set_xticks([])
        ax.set_yticks([])
fig.patch.set_facecolor('white')
_images/barrel.png

cut

colorstamps.stamps.cut() is used for the ‘cut’, ‘blues’, ‘reds’, ‘greens’, and ‘yellows’ colormaps

colorstamps.stamps.cut(a=(- 1, 1), sat=33, rot=0, J=[15, 120], l=256, limit_sat='shared')

Generates a 2d colormap that is bilinear with saturation along the x-axis and lighness on the y-axis effectivly the cross-section of the Jab colorspace at some angle rot

Parameters

  • sat – float, default 33. Desired saturation

  • rot – the hue, or rotation in the a-b plane to make the cut

  • J – limits to lighness on the y-axis, array like of length 2, default [15,120]

  • l – desired size (l,l,3) of the colormap

  • limit_sat – string, how to limit the saturation to say within the limits of the RGB colorspace ‘shared’: all hues share same limits ‘individual’: different hues have different limits

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
fig, axes = plt.subplots(2,4,figsize=(14,7), dpi = 50)

cmap = colorstamps.stamps.cut()
axes[0,0].imshow(cmap, origin = 'lower')
axes[0,0].set_title("default")

cmap = colorstamps.stamps.cut(rot = 45)
axes[0,1].imshow(cmap, origin = 'lower')
axes[0,1].set_title("rot = 45")

cmap = colorstamps.stamps.cut(rot = 90)
axes[0,2].imshow(cmap, origin = 'lower')
axes[0,2].set_title("rot = 90")

cmap = colorstamps.stamps.cut(rot = 135)
axes[0,3].imshow(cmap, origin = 'lower')
axes[0,3].set_title("rot = 135")

cmap = colorstamps.stamps.cut(J = (1,128))
axes[1,0].imshow(cmap, origin = 'lower')
axes[1,0].set_title("J = (1,128)")

cmap = colorstamps.stamps.cut(J = (50,128))
axes[1,1].imshow(cmap, origin = 'lower')
axes[1,1].set_title("J = (50,128)")

cmap = colorstamps.stamps.cut(a = (0,1))
axes[1,2].imshow(cmap, origin = 'lower')
axes[1,2].set_title("a = (0,1)")

cmap = colorstamps.stamps.cut(a = (0,1), rot = 225)
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title("a = (0,1), rot = 225")

for ax in axes.ravel():
        ax.set_xticks([])
        ax.set_yticks([])
fig.patch.set_facecolor('white')
_images/cut.png

teuling

colorstamps.stamps.teuling() is here shown with the parameters that generate the named colormaps

colorstamps.stamps.teuling(l=256, a=0.32, order=[1, 0, 2], white_center=False, green_multiplier=1.0)

Generates a 2d colormap based on:

Teuling, A. J., R. Stöckli, and Sonia I. Seneviratne. “Bivariate colour maps for visualizing climate data.” International journal of climatology 31.9 (2011): 1408-1412.

Parameters

  • l – size of the colormap, defaults to 256

  • a – float between 0 and 1, determines how the second and third color scales along the x and y axis

  • order – The order in which colors are applied. Should be an array of lenght three with the values 0, 1 and 2, corresponding to red, green and blue. The color at the first index scales equally (0.5) in both x and y, the two others scale according to a and (1-a) along x and y, and y and x

  • white_center – bool, default False. If true, the center will be colored white

  • green_multiplier – float, default 1.0. The green part component of the colormap multipled by this value. Can help reduce the luminocity of the green corner to produec a more homogeneous-looking map

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
import numpy as np

fig, axes = plt.subplots(2,4, figsize = (12,7), dpi = 75)

cmap = colorstamps.stamps.teuling(a = 0.32, order = [0,1,2])
axes[0,0].imshow(cmap, origin = 'lower')
axes[0,0].set_title('a = 0.32, order = [0,1,2]')
cmap = colorstamps.stamps.teuling(a = 0.72, order = [1,0,2])
axes[0,1].imshow(cmap, origin = 'lower')
axes[0,1].set_title('a = 0.72, order = [1,0,2]')
cmap = colorstamps.stamps.teuling(a = 0.32, order = [1,0,2])
axes[0,2].imshow(cmap, origin = 'lower')
axes[0,2].set_title('a = 0.32, order = [1,0,2]')
cmap = colorstamps.stamps.teuling(a = 0.32, order = [1,0,2], green_multiplier = 0.75)
axes[0,3].imshow(cmap, origin = 'lower')
axes[0,3].set_title('a = 0.32, order = [1,0,2],\ngreen_multiplier = 0.75')

cmap = colorstamps.stamps.teuling(a = 0.32, order = [0,1,2], white_center = True)
axes[1,0].imshow(cmap, origin = 'lower')
axes[1,0].set_title('a = 0.32, order = [0,1,2],\nwhite_center = True')
cmap = colorstamps.stamps.teuling(a = 0.72, order = [1,0,2], white_center = True)
axes[1,1].imshow(cmap, origin = 'lower')
axes[1,1].set_title('a = 0.72, order = [1,0,2],\nwhite_center = True')
cmap = colorstamps.stamps.teuling(a = 0.32, order = [1,0,2], )
axes[1,2].imshow(cmap, origin = 'lower')
axes[1,2].set_title('a = 0.32, order = [1,0,2],\nwhite_center = True')
cmap = colorstamps.stamps.teuling(a = 0.32, order = [1,0,2], green_multiplier = 0.75, white_center = True)
axes[1,3].imshow(cmap, origin = 'lower')
axes[1,3].set_title('a = 0.32, order = [1,0,2],\ngreen_multiplier = 0.75,\nwhite_center = True')

for ax in axes.ravel():
    ax.set_xticks([])
    ax.set_yticks([])

fig.patch.set_facecolor('white')
_images/teuling.png

bilinear

colorstamps.stamps.bilinear() is used for genreating bilinear colormaps in the rgb colorspace

colorstamps.stamps.bilinear(l=256, c0=[1, 0.5, 0], c1=[0, 0.5, 1])

Returns an l by l colormap that interpolates linearly between 4 colors; black, c0, c1 and c0+c1.

Parameters

  • l – size of the colormap, defaults to 256

  • c0 – [r,g,b] array-like defining the color at the top left corner, defaults to [1,0.5,0] (orange)

  • c1 – [r,g,b] array-like defining the color at the bottom right corner, defaults to [0,0.5,1]] (light blue)

Returns

a (l,l,3) numpy array of rgb values

fig, axes = plt.subplots(1,4, figsize = (12,7), dpi = 75)

cmap = colorstamps.stamps.bilinear(c0 = [1,0.5,0], c1 = [0,0.5,1])
axes[0].imshow(cmap, origin = 'lower')
axes[0].set_title('c0 = [1,0.5,0], c1 = [0,0.5,1]')
cmap = colorstamps.stamps.bilinear(c0 = [0.5,1,0], c1 = [0.5,0,1])
axes[1].imshow(cmap, origin = 'lower')
axes[1].set_title('c0 = [0.5,1,0], c1 = [0.5,0,1]')
cmap = colorstamps.stamps.bilinear(c0 = [0,1,0], c1 = [0,0,1])
axes[2].imshow(cmap, origin = 'lower')
axes[2].set_title('c0 = [0,1,0], c1 = [0,0,1]')
cmap = colorstamps.stamps.bilinear(c0 = [1,0,0], c1 = [0,0,1])
axes[3].imshow(cmap, origin = 'lower')
axes[3].set_title('c0 = [1,0,0], c1 = [0,0,1]')

for ax in axes.ravel():
    ax.set_xticks([])
    ax.set_yticks([])
fig.patch.set_facecolor('white')
_images/bilinear0.png

get_2dcmap_from_mpl

colorstamps.stamps.get_2dcmap_from_mpl() is used for genreating 2d colormaps from 1d matplotlib colormaps

colorstamps.stamps.get_2dcmap_from_mpl(string, J=[15, 120], l=256, limit_sat='shared')

Generates a 2d colormap from a 1d colormap found in matplotlib

Parameters

  • string – name of the matplotlib colormap

  • J – limits to lighness on the y-axis, array like of length 2, default [15,120]

  • l – desired size (l,l,3) of the colormap

  • limit_sat – string, how to limit the saturation to say within the limits of the RGB colorspace ‘shared’: all hues share same limits ‘individual’: different hues have different limits

Returns

a (l,l,3) numpy array of rgb values

import matplotlib.pyplot as plt
import colorstamps
import numpy as np

n = int(np.sqrt(len(colorstamps.stamps.mpl_cmaps)))+1
fig, axes = plt.subplots(n,n, figsize = (20,24))
axes = axes.ravel()

for i, name in enumerate(colorstamps.stamps.mpl_cmaps):
    cmap = colorstamps.stamps.get_2dcmap_from_mpl(name, l = 64, limit_sat = 'individual')
    axes[i].imshow(cmap, origin = 'lower')
    axes[i].set_title(name)
    axes[i].invert_yaxis()

for ax in axes:
    ax.set_xticks([])
    ax.set_yticks([])

fig.patch.set_facecolor('white')
_images/mpl_colormaps.png

Helper functions for generating colormaps

colorstamps.stamps.mask_rgb(rgb, a, b, mask)

function that masks an rgb colormap with np.nan according to the string mask

Parameters

  • rgb – (l,l,3) matrix

  • a – values of a and b. if mask = ‘circle’ anyting with sqrt(a**2+b**2)>1 will be np.nan

  • b – values of a and b. if mask = ‘circle’ anyting with sqrt(a**2+b**2)>1 will be np.nan

  • mask – string: ‘circle’ -> masks everything outside a circle defined as where sqrt(a**2+b**2)>1 ‘no-mask’ -> do nothing ‘unavailable’-> masks invalid rgb values (i.e. <0 or >1)

colorstamps.stamps.set_ab_rot(Jab, ar, br, rot)

sets the [:,:,1] and [:,:,2] axes of a Jab colormap to ar and br then rotates the ab color plane according to the angle rot

Parameters

  • Jab – (l,l,3) colormap

  • ar – 1d array, typically made by np.linspace()

  • br – 1d array, typically made by np.linspace()

  • rot – angle in degrees

Returns

None (but Jab changed in-place)

colorstamps.stamps.parse_name_postfix(cmap, a, b)

if a cmap name has a postfix that details the quadrant/side, this will translate that to ranges in a and/or b. example: parse_name_postfix(‘cone tr’, a, b) return a and b so that they span the top right quadrant inputs a and b so that both can be returned even if only one is changed

Parameters

  • cmap – string, potentially with a postfix detailing quadrant/side following a space, i.e. ‘cone tr’. The postfix translates: ‘b’ -> bottom, ‘t’ -> top, ‘l’ -> left, ‘r’ -> right. Any combination (b,t)+(l,r) is possible to select quadrants

  • a – current limits for a, not checked but should be a tuple of length 2

  • b – current limits for b, not checked but should be a tuple of length 2

Returns

cmap (stripped of the postfix) a, tuple of length 2 b, tuple of length 2

Return type

tuple (cmap, a, b)

colorstamps.stamps.get_sat_limts()

returns the a 2d matrix of approximate limits to sat (radius in a-b space) in terms of phi and J

colorstamps.stamps.apply_sat_limit(Jab, limit_sat='shared')

apply a saturation limit to Jab in order to ensure valid saturation when the limit of the RGB colorspace is reached

Parameters

  • Jab – np array of shape (n,m,3) encoded in the colorspace

  • limit_sat – ‘shared’ or ‘individual’ if ‘shared’, all hues share same limit to saturation (the minimum where all saturation values present in the colormap can be represented) if ‘individual’, different hues have different sauration limits

Returns

None (Jab is modified in-place)

colorstamps.stamps.apply_radial_sat_limit(Jab, limit_sat='shared')

apply a radial saturation limit to Jab in order to make the saturation radial when the limit of the RGB colorspace is reached the behaviour if limit_sat == ‘shared’ is different from apply_sat_limit() in this function all possible hues are always included, but for apply_sat_limit() only present hues are considered

Parameters

  • Jab – np array of shape (n,m,3) encoded in the colorspace

  • limit_sat – ‘shared’ or ‘individual’ if ‘shared’, all hues share same limit to saturation (the minimum where all are present) if ‘individual’, different hues have different sauration limits

Returns

None (Jab is modified in-place)