def cartesian2logpolar(img, center=None, final_radius=None, initial_radius = None, phase_width = 3000):
"""
See also:
https://en.wikipedia.org/wiki/Log-polar_coordinates
"""
if center is None:
center=(img.shape[0]/2,img.shape[1]/2)
if final_radius is None:
final_radius=max(img.shape[0],img.shape[1])/2
if initial_radius is None:
initial_radius = 0
phase_width=img.shape[0]/2
theta , R = np.meshgrid(np.linspace(0, 2*np.pi, phase_width),
np.arange(initial_radius, final_radius))
Xcart = np.exp(R) * np.cos(theta) + center[0]
Ycart = np.exp(R) * np.sin(theta) + center[1]
Xcart = Xcart.astype(int)
Ycart = Ycart.astype(int)
if img.ndim ==3:
polar_img = img[Ycart,Xcart,:]
polar_img = np.reshape(polar_img,(final_radius-initial_radius,phase_width,img.shape[-1]))
else:
polar_img = img[Ycart,Xcart]
polar_img = np.reshape(polar_img,(final_radius-initial_radius,phase_width))
return polar_img
def marble(size=(256,256),xPeriod=3.0,yPeriod=10.0,turbPower=0.8,turbSize=None,seed=None):
"""
Generate a marble texture akin to blender and others
:param xPeriod: defines repetition of marble lines in x direction
:param yPeriod: defines repetition of marble lines in y direction
:param turbPower: add twists and swirls (when turbPower==0 it becomes a normal sine pattern)
:param turbSize: initial size of the turbulence default is max(w,h)/10
NOTE:
xPeriod and yPeriod together define the angle of the lines
xPeriod and yPeriod both 0 then it becomes a normal clouds or turbulence pattern
Optimized version of:
https://lodev.org/cgtutor/randomnoise.html
"""
w,h=size
turb=turbulence(size,turbSize,seed=seed)*turbPower
# determine where the pixels will cycle
cycleValue=np.ndarray((w,h))
for y in range(h):
for x in range(w):
cycleValue[x,y]=(x*xPeriod/w)+(y*yPeriod/h)
# add in the turbulence and then last of all, make it a sinewave
img=np.abs(np.sin((cycleValue+turb)*math.pi))
return img
def cartesian2polar(img, center=None, final_radius=None, initial_radius = None, phase_width = 3000):
"""
Comes from:
https://stackoverflow.com/questions/9924135/fast-cartesian-to-polar-to-cartesian-in-python
"""
img=numpyArray(img)
if center is None:
center=(img.shape[0]/2,img.shape[1]/2)
if final_radius is None:
final_radius=max(img.shape[0],img.shape[1])/2
if initial_radius is None:
initial_radius = 0
phase_width=img.shape[0]/2
theta , R = np.meshgrid(np.linspace(0, 2*np.pi, phase_width),
np.arange(initial_radius, final_radius))
Xcart = R * np.cos(theta) + center[0]
Ycart = R * np.sin(theta) + center[1]
Xcart = Xcart.astype(int)
Ycart = Ycart.astype(int)
if img.ndim ==3:
polar_img = img[Ycart,Xcart,:]
polar_img = np.reshape(polar_img,(final_radius-initial_radius,phase_width,img.shape[-1]))
else:
polar_img = img[Ycart,Xcart]
polar_img = np.reshape(polar_img,(final_radius-initial_radius,phase_width))
return polar_img
def woodRings(size=(256,256),xyPeriod=12.0,turbPower=0.15,turbSize=32.0,seed=None):
"""
Draw wood rings
:param xyPeriod: number of rings
:param turbPower: makes twists
:param turbSize: # initial size of the turbulence
Optimized version of:
https://lodev.org/cgtutor/randomnoise.html
"""
turb=turbulence(size,turbSize,seed=seed)*turbPower
dc=normalize(deltaC(size,magnitude=True))
img = np.abs(np.sin(xyPeriod * (dc+turb) * math.pi))
return normalize(img)
def clock2(size=(256,256),waveform="sine",frequency=(10,10),noise=0.2,noiseBasis="perlin",
noiseOctaves=4,noiseSoften=0.0,direction=0,invert=False,seed=None):
"""
a rotary clockface gradient
"""
noiseSize=max(size)/8 # TODO: pass this value in somehow
turb=turbulence(size,noiseSize,seed=seed)*noise
#points=np.ndarray((int(size[0]),int(size[1])))
angle=0.75-direction/360.0
dc=deltaC(size)
img=np.arctan2(dc[:,:,0],dc[:,:,1])/math.pi
img=np.abs(np.sin((((normalize(img)+angle)%1.0)+turb)*math.pi))
img=normalize(img)
if invert:
img=1.0-img
return img
def waveImage(size=(256,256),repeats=2,angle=0,wave='sine',radial=False):
"""
create an image based on a sine, saw, or triangle wave function
"""
ret=np.zeros(size)
if radial:
raise NotImplementedError() # TODO: Implement radial wave images
else:
twopi=2*pi
thetas=np.arange(size[0])*float(repeats)/size[0]*twopi
if wave=='sine':
ret[:,:]=0.5+0.5*np.sin(thetas)
elif wave=='saw':
n=np.round(thetas/twopi)
thetas-=n*twopi
ret[:,:]=np.where(thetas<0,thetas+twopi,thetas)/twopi
elif wave=='triangle':
ret[:,:]=1.0-2.0*np.abs(np.floor((thetas*(1.0/twopi))+0.5)-(thetas*(1.0/twopi)))
return ret
stripes = 37 # number of stripes per wave
N = 512 # image size in pixels
ite = 30 # iterations
phases = np.arange(0, 2 * pi, 2 * pi / ite)
image = np.empty((N, N))
d = np.arange(-N / 2, N / 2, dtype=np.float64)
xv, yv = np.meshgrid(d, d)
theta = np.arctan2(yv, xv)
r = np.log(np.sqrt(xv * xv + yv * yv))
r[np.isinf(r) == True] = 0
tcos = theta * np.cos(np.arange(0, pi, pi / k))[:, np.newaxis, np.newaxis]
rsin = r * np.sin(np.arange(0, pi, pi / k))[:, np.newaxis, np.newaxis]
inner = (tcos - rsin) * stripes
cinner = np.cos(inner)
sinner = np.sin(inner)
i = 0
for phase in phases:
image[:] = np.sum(cinner * np.cos(phase) - sinner * np.sin(phase),
axis=0) + k
plt.imshow(image.copy2numpy(), cmap="RdGy")
fig.savefig("quasi-{:03d}.png".format(i),
bbox_inches='tight',
pad_inches=0)
i += 1
def sin(x):
return np.abs(np.sin(x*math.pi))
