def post(Jpapbp, cls, roundup, fname):
adjust = globals()["adjust_" + cls]
Jpapbp = adjust(Jpapbp, roundup)
save_ctab(transform(Jpapbp, inverse=True), fname + ext)
print(" Rounded up to {}; saved to \"{}\"".format(roundup, fname + ext))
Jpapbp = symmetrize(Jpapbp, bitonic=True, diffuse=False)
save_ctab(transform(Jpapbp, inverse=True), fname + "s" + ext)
print(" Symmetrized; saved to \"{}\"".format(fname + "s" + ext))
def ehtrainbow(
N=Nq,
Jp=73.16384, # maximizing minimal Cp for all hue
Cp=None,
hp0=32.1526953043875, # offset the hue so that value==0 is red
eps=1024 * np.finfo(np.float).eps,
**kwargs):
"""Create a perceptually uniform rainbow colormap"""
name = kwargs.pop('name', "new eht colormap")
hp = np.linspace(np.pi / 180 * (hp0), np.pi / 180 * (hp0 + 360), Nq + 1)
Jp = np.full(len(hp), Jp)
if Cp is not None:
if Cp == 'minmax':
Cp = min(max_chroma(Jp, hp))
ap = Cp * np.cos(hp)
bp = Cp * np.sin(hp)
Jpapbp = np.array([np.full(len(hp), Jp), ap, bp]).T
sRGB = transform(Jpapbp[:-1, :], inverse=True)
return ListedColormap(sRGB, name=name)
Cp = max_chroma(Jp, hp)
ap = Cp * np.cos(hp)
bp = Cp * np.sin(hp)
dE = np.sqrt((Jp[1:] - Jp[:-1])**2 + (ap[1:] - ap[:-1])**2 +
(bp[1:] - bp[:-1])**2)
cE = np.concatenate(([0], np.cumsum(dE)))
for i in range(256):
cE_new = np.linspace(0, max(cE), len(cE))
hp_new = np.interp(cE_new, cE, hp)
Cp_new = max_chroma(Jp, hp_new)
if np.max(abs(Cp - Cp_new)) < eps:
break
Cp = Cp_new
hp = hp_new
ap = Cp * np.cos(hp)
bp = Cp * np.sin(hp)
dE = np.sqrt((Jp[1:] - Jp[:-1])**2 + (ap[1:] - ap[:-1])**2 +
(bp[1:] - bp[:-1])**2)
cE = np.concatenate(([0], np.cumsum(dE)))
else:
print("WARNING: ehtuniform() has not fully converged")
Jpapbp = np.array([Jp, ap, bp]).T
sRGB = transform(Jpapbp[:-1, :], inverse=True)
return ListedColormap(np.clip(sRGB, 0, 1), name=name)
def _JChp(ax1, cmap):
"""Plot J', C', and h' of a colormap as function of the mapped value
Args:
ax1 (matplotlib.axes.Axes): The matplotlib Axes to be plot on.
cmap (string or matplotlib.colors.Colormap): The colormap to
be plotted.
"""
ctab = get_ctab(cmap) # get the colormap as a color table in sRGB
Jpapbp = transform(ctab) # transform color table into CAM02-UCS colorspace
Jp = Jpapbp[:, 0]
ap = Jpapbp[:, 1]
bp = Jpapbp[:, 2]
Cp = np.sqrt(ap * ap + bp * bp)
hp = np.arctan2(bp, ap) * 180 / np.pi
v = np.linspace(0.0, 1.0, len(Jp))
ax1.set_title(cmap if isinstance(cmap, basestring) else cmap.name)
ax1.set_xlabel("Value")
ax2 = ax1.twinx()
ax1.set_ylim(0, 100)
ax1.set_ylabel("J' & C' (0-100)")
ax2.set_ylim(-180, 180)
ax2.set_ylabel("h' (degrees)")
ax1.scatter(v, Jp, color=ctab)
ax1.plot(v, Cp, c='k', linestyle='--')
ax2.scatter(v[::15], hp[::15], s=12, c='k')
def ehtcmap(N=Nq,
Jpmin=15.0,
Jpmax=95.0,
Cpmin=0.0,
Cpmax=64.0,
hpmin=None,
hpmax=90.0,
hp=None,
**kwargs):
name = kwargs.pop('name', "new eht colormap")
Jp = np.linspace(Jpmin, Jpmax, num=N)
if hp is None:
if hpmin is None:
hpmin = hpmax - 60.0
q = 0.25 * (hpmax - hpmin)
hp = np.clip(np.linspace(hpmin - 3 * q, hpmax + q, num=N), hpmin,
hpmax)
elif callable(hp):
hp = hp(np.linspace(0.0, 1.0, num=N))
hp *= np.pi / 180.0
Cp = max_chroma(Jp, hp, Cpmin=Cpmin, Cpmax=Cpmax)
Jpapbp = np.stack([Jp, Cp * np.cos(hp), Cp * np.sin(hp)], axis=-1)
Jpapbp = symmetrize(Jpapbp, **kwargs)
sRGB = transform(Jpapbp, inverse=True)
return ListedColormap(np.clip(sRGB, 0, 1), name=name)
def mergecmap(cmplist, **kwargs):
"""Merge color maps
An inelegant function to merge a list of existing colormaps into
one.
TODO: design a more elegant interface.
"""
name = kwargs.pop('name', "new eht colormap")
matchC = kwargs.pop('matchC', False)
ctabs = []
for cmp in cmplist:
ctab = get_ctab(cmp['name'])
if cmp.get('revert'):
ctab = ctab[::-1]
ctabs += [ctab]
if matchC:
n = len(ctabs[0])
mCp = getCp(ctabs[0])
for ctab in ctabs[1:]:
if len(ctab) != n:
raise ValueError("Fail to match chroma; " +
"colormap seguments have different lengths")
mCp = np.minimum(mCp, getCp(ctab))
for i in range(len(ctabs)):
Jpapbp = transform(ctabs[i])
Cp = np.sqrt(Jpapbp[:, 1] * Jpapbp[:, 1] +
Jpapbp[:, 2] * Jpapbp[:, 2])
f = mCp / (Cp + 1.0e-32)
Jpapbp[:, 1] *= f
Jpapbp[:, 2] *= f
ctabs[i] = transform(Jpapbp, inverse=True)
ctab = [crow for ctab in ctabs for crow in ctab] # flattern list of list
return ListedColormap(np.clip(ctab, 0, 1), name=name)
def gethue(color):
"""Get the hue of a color"""
if isinstance(color, float):
return color
if is_color_like(color):
RGB = to_rgba(color)[:3]
else:
raise ValueError("color is not color like")
Jp, ap, bp = transform(np.array([RGB]))[0]
hp = np.arctan2(bp, ap) * 180 / np.pi
print("Decode color \"{}\"; h' = {}".format(color, hp))
return hp
def visualize_colors(ax, Jp=73.16384, L=50):
N = 2 * (8*L) + 1
aP = np.linspace(-L,L,N)
bP = np.linspace(-L,L,N)
ap, bp = np.meshgrid(aP, bP)
Jpapbp = np.array([np.full(N*N, Jp), ap.flatten(), bp.flatten()]).T
sRGB = transform(Jpapbp, inverse=True)
sRGB[invalid(sRGB),:] = 0
ax.imshow(sRGB.reshape(N,N,3),
origin='lower',
extent=[-L,L,-L,L])
ax.set_xlabel("a'")
ax.set_ylabel("b'")
def pre(cname):
return transform(get_ctab(get_cmap(cname)))
def getCp(ctab):
Jpapbp = transform(ctab)
return np.sqrt(Jpapbp[:, 1] * Jpapbp[:, 1] + Jpapbp[:, 2] * Jpapbp[:, 2])
def ehtuniform(
N=Nq,
JpL=6.25,
JpR=93.75, # consistent with 17 quantize levels
CpL=0.0,
CpR=64.0,
hpL='coral',
hpR='gold',
hpD=None,
eps=1024 * np.finfo(np.float).eps,
**kwargs):
"""Create a perceptually uniform colormap"""
name = kwargs.pop('name', "new eht colormap")
hpL = gethue(hpL) * np.pi / 180.0
hpR = gethue(hpR) * np.pi / 180.0
if hpD is None:
dhp = hpR - hpL
while dhp < 0:
dhp += 2 * np.pi
while dhp > 2 * np.pi:
dhp -= 2 * np.pi
hpD = +1 if dhp < np.pi else -1
if (hpR - hpL) * hpD < 0.0:
hpR += hpD * 2.0 * np.pi
Jp = np.linspace(JpL, JpR, N)
hp = np.linspace(hpL, hpR, N - 2)
Cp = max_chroma(Jp[1:-1], hp)
Cp = np.concatenate(([CpL], Cp, [CpR]))
hp = np.concatenate(([hpL], hp, [hpR]))
ap = Cp * np.cos(hp)
bp = Cp * np.sin(hp)
dE = np.sqrt((Jp[1:] - Jp[:-1])**2 + (ap[1:] - ap[:-1])**2 +
(bp[1:] - bp[:-1])**2)
cE = np.concatenate(([0], np.cumsum(dE)))
for i in range(256):
cE_new = np.linspace(0, max(cE), len(cE))
hp_new = np.interp(cE_new, cE, hp)
Cp_new = np.interp(cE_new, cE, Cp)
if hpD > 0:
edgeL = hp_new <= hpL
edge = np.logical_and(hpL < hp_new, hp_new < hpR)
edgeR = hpR <= hp_new
else:
edgeL = hp_new >= hpL
edge = np.logical_and(hpL > hp_new, hp_new > hpR)
edgeR = hpR >= hp_new
Cp_tmp = max_chroma(Jp[edge], hp_new[edge])
Cp_new[edgeL] *= Cp_tmp[0] / Cp_new[edge][0]
Cp_new[edgeR] *= Cp_tmp[-1] / Cp_new[edge][-1]
Cp_new[edge] = Cp_tmp
if np.max(abs(Cp - Cp_new)) < eps:
break
Cp = Cp_new
hp = hp_new
ap = Cp * np.cos(hp)
bp = Cp * np.sin(hp)
dE = np.sqrt((Jp[1:] - Jp[:-1])**2 + (ap[1:] - ap[:-1])**2 +
(bp[1:] - bp[:-1])**2)
cE = np.concatenate(([0], np.cumsum(dE)))
else:
print("WARNING: ehtuniform() has not fully converged")
Jpapbp = np.array([Jp, ap, bp]).T
sRGB = transform(Jpapbp, inverse=True)
return ListedColormap(np.clip(sRGB, 0, 1), name=name)