def plotcontrast(img):
"""
http://docs.astropy.org/en/stable/visualization/index.html
"""
vistypes = (None, LogNorm(), vis.AsinhStretch(),
vis.ContrastBiasStretch(1, 0.5), vis.HistEqStretch(img),
vis.LinearStretch(), vis.LogStretch(),
vis.PowerDistStretch(a=10.), vis.PowerStretch(a=10.),
vis.SinhStretch(), vis.SqrtStretch(), vis.SquaredStretch())
fg, ax = subplots(4, 3, figsize=(10, 10))
ax = ax.ravel()
for i, v in enumerate(vistypes):
#a = figure().gca()
a = ax[i]
if v and not isinstance(v, LogNorm):
norm = ImageNormalize(stretch=v)
a.set_title(str(v.__class__).split('.')[-1].split("'")[0])
else:
norm = v
a.set_title(str(v).split('.')[-1].split(" ")[0])
a.imshow(img, origin='lower', cmap='gray', norm=norm)
a.axis('off')
fg.suptitle('Matplotlib/AstroPy normalizations')
def plot_norm(self,
stretch='linear',
power=1.0,
asinh_a=0.1,
min_cut=None,
max_cut=None,
min_percent=None,
max_percent=None,
percent=None,
clip=True):
"""Create a matplotlib norm object for plotting.
This is a copy of this function that will be available in Astropy 1.3:
`astropy.visualization.mpl_normalize.simple_norm`
See the parameter description there!
Examples
--------
>>> image = SkyImage()
>>> norm = image.plot_norm(stretch='sqrt', max_percent=99)
>>> image.plot(norm=norm)
"""
import astropy.visualization as v
from astropy.visualization.mpl_normalize import ImageNormalize
if percent is not None:
interval = v.PercentileInterval(percent)
elif min_percent is not None or max_percent is not None:
interval = v.AsymmetricPercentileInterval(min_percent or 0.,
max_percent or 100.)
elif min_cut is not None or max_cut is not None:
interval = v.ManualInterval(min_cut, max_cut)
else:
interval = v.MinMaxInterval()
if stretch == 'linear':
stretch = v.LinearStretch()
elif stretch == 'sqrt':
stretch = v.SqrtStretch()
elif stretch == 'power':
stretch = v.PowerStretch(power)
elif stretch == 'log':
stretch = v.LogStretch()
elif stretch == 'asinh':
stretch = v.AsinhStretch(asinh_a)
else:
raise ValueError('Unknown stretch: {0}.'.format(stretch))
vmin, vmax = interval.get_limits(self.data)
return ImageNormalize(vmin=vmin, vmax=vmax, stretch=stretch, clip=clip)
def plotPrior(xdgmm, ax, c='black', lw=1, stretch=False):
for gg in range(xdgmm.n_components):
points = drawEllipse.plotvector(xdgmm.mu[gg], xdgmm.V[gg])
if stretch:
Stretch = av.PowerStretch(1. / 5)
alpha = np.power(xdgmm.weights[gg] / np.max(xdgmm.weights),
1. / 10)
else:
alpha = xdgmm.weights[gg] / np.max(xdgmm.weights)
ax.plot(points[0, :],
testXD.absMagKinda2absMag(points[1, :]),
c,
lw=lw,
alpha=alpha)
def get_offset(self, fitsobj, calcFFTs=False):
"""INPUT: instance of FITS
FNUC: gets pixel offset between fits objects
"""
logging.info('Calculating alignment offset %s <-- %s' %
(self, fitsobj))
if calcFFTs:
self.get_fft()
fitsobj.get_fft()
convolution = np.multiply(self.fft, np.conj(fitsobj.fft))
inverse = np.fft.ifft2(convolution)
stretch = viz.PowerStretch(0.4)
stretch = lambda x: x
plt.imshow(stretch(np.real(inverse)), cmap='pink')
plt.xlabel("Offset [pix]")
plt.ylabel("Offset [pix]")
plt.show()
a = np.argmax(inverse)
r = len(self.data[0])
dx = a / r
dy = a % r
if dx >= 0.5 * self.size[0]: dx = dx - self.size[0]
if dy >= 0.5 * self.size[1]: dy = dy - self.size[1]
return (dx, dy)
def create_figure(self,
frameno=0,
binning=1,
dpi=None,
stretch='log',
vmin=1,
vmax=5000,
cmap='gray',
data_col='FLUX',
annotate=True,
time_format='ut',
show_flags=False,
label=None):
"""Returns a matplotlib Figure object that visualizes a frame.
Parameters
----------
frameno : int
Image number in the target pixel file.
binning : int
Number of frames around `frameno` to co-add. (default: 1).
dpi : float, optional [dots per inch]
Resolution of the output in dots per Kepler CCD pixel.
By default the dpi is chosen such that the image is 440px wide.
vmin : float, optional
Minimum cut level (default: 1).
vmax : float, optional
Maximum cut level (default: 5000).
cmap : str, optional
The matplotlib color map name. The default is 'gray',
can also be e.g. 'gist_heat'.
raw : boolean, optional
If `True`, show the raw pixel counts rather than
the calibrated flux. Default: `False`.
annotate : boolean, optional
Annotate the Figure with a timestamp and target name?
(Default: `True`.)
show_flags : boolean, optional
Show the quality flags?
(Default: `False`.)
label : str
Label text to show in the bottom left corner of the movie.
Returns
-------
image : array
An array of unisgned integers of shape (x, y, 3),
representing an RBG colour image x px wide and y px high.
"""
# Get the flux data to visualize
flx = self.flux_binned(frameno=frameno,
binning=binning,
data_col=data_col)
# Determine the figsize and dpi
shape = list(flx.shape)
shape = [shape[1], shape[0]]
if dpi is None:
# Twitter timeline requires dimensions between 440x220 and 1024x512
# so we make 440 the default
dpi = 440 / float(shape[0])
# libx264 require the height to be divisible by 2, we ensure this here:
shape[0] -= ((shape[0] * dpi) % 2) / dpi
# Create the figureand display the flux image using matshow
fig = pl.figure(figsize=shape, dpi=dpi)
# Display the image using matshow
ax = fig.add_subplot(1, 1, 1)
if self.verbose:
print('{} vmin/vmax = {}/{} (median={})'.format(
data_col, vmin, vmax, np.nanmedian(flx)))
if stretch == 'linear':
stretch_fn = visualization.LinearStretch()
elif stretch == 'sqrt':
stretch_fn = visualization.SqrtStretch()
elif stretch == 'power':
stretch_fn = visualization.PowerStretch(1.0)
elif stretch == 'log':
stretch_fn = visualization.LogStretch()
elif stretch == 'asinh':
stretch_fn = visualization.AsinhStretch(0.1)
else:
raise ValueError('Unknown stretch: {0}.'.format(stretch))
transform = (stretch_fn +
visualization.ManualInterval(vmin=vmin, vmax=vmax))
flx_transform = 255 * transform(flx)
# Make sure to remove all NaNs!
flx_transform[~np.isfinite(flx_transform)] = 0
ax.imshow(flx_transform.astype(int),
aspect='auto',
origin='lower',
interpolation='nearest',
cmap=cmap,
norm=NoNorm())
if annotate: # Annotate the frame with a timestamp and target name?
fontsize = 3. * shape[0]
margin = 0.03
# Print target name in lower left corner
if label is None:
label = self.objectname
txt = ax.text(margin,
margin,
label,
family="monospace",
fontsize=fontsize,
color='white',
transform=ax.transAxes)
txt.set_path_effects([
path_effects.Stroke(linewidth=fontsize / 6.,
foreground='black'),
path_effects.Normal()
])
# Print a timestring in the lower right corner
txt2 = ax.text(1 - margin,
margin,
self.timestamp(frameno, time_format=time_format),
family="monospace",
fontsize=fontsize,
color='white',
ha='right',
transform=ax.transAxes)
txt2.set_path_effects([
path_effects.Stroke(linewidth=fontsize / 6.,
foreground='black'),
path_effects.Normal()
])
# Print quality flags in upper right corner
if show_flags:
flags = self.quality_flags(frameno)
if len(flags) > 0:
txt3 = ax.text(margin,
1 - margin,
'\n'.join(flags),
family="monospace",
fontsize=fontsize * 1.3,
color='white',
ha='left',
va='top',
transform=ax.transAxes,
linespacing=1.5,
backgroundcolor='red')
txt3.set_path_effects([
path_effects.Stroke(linewidth=fontsize / 6.,
foreground='black'),
path_effects.Normal()
])
ax.set_xticks([])
ax.set_yticks([])
ax.axis('off')
fig.subplots_adjust(left=0.0, right=1.0, top=1.0, bottom=0.0)
fig.canvas.draw()
return fig
def set_normalization(self,
stretch=None,
interval=None,
stretchkwargs={},
intervalkwargs={},
perm_linear=None):
if stretch is None:
if self.stretch is None:
stretch = 'linear'
else:
stretch = self.stretch
if isinstance(stretch, str):
print(stretch,
' '.join([f'{k}={v}' for k, v in stretchkwargs.items()]))
if self.data is None: #can not calculate objects yet
self.stretch_kwargs = stretchkwargs
else:
kwargs = self.prepare_kwargs(
self.stretch_kws_defaults[stretch], self.stretch_kwargs,
stretchkwargs)
if perm_linear is not None:
perm_linear_kwargs = self.prepare_kwargs(
self.stretch_kws_defaults['linear'], perm_linear)
print(
'linear', ' '.join([
f'{k}={v}' for k, v in perm_linear_kwargs.items()
]))
if stretch == 'asinh': # arg: a=0.1
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.AsinhStretch(**kwargs))
elif stretch == 'contrastbias': # args: contrast, bias
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.ContrastBiasStretch(**kwargs))
elif stretch == 'histogram':
stretch = vis.CompositeStretch(
vis.HistEqStretch(self.data, **kwargs),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'log': # args: a=1000.0
stretch = vis.CompositeStretch(
vis.LogStretch(**kwargs),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'powerdist': # args: a=1000.0
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.PowerDistStretch(**kwargs))
elif stretch == 'power': # args: a
stretch = vis.CompositeStretch(
vis.PowerStretch(**kwargs),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'sinh': # args: a=0.33
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.SinhStretch(**kwargs))
elif stretch == 'sqrt':
stretch = vis.CompositeStretch(
vis.SqrtStretch(),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'square':
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.SquaredStretch())
else:
raise ValueError('Unknown stretch:' + stretch)
else:
if stretch == 'linear': # args: slope=1, intercept=0
stretch = vis.LinearStretch(**kwargs)
else:
raise ValueError('Unknown stretch:' + stretch)
self.stretch = stretch
if interval is None:
if self.interval is None:
interval = 'zscale'
else:
interval = self.interval
if isinstance(interval, str):
print(interval,
' '.join([f'{k}={v}' for k, v in intervalkwargs.items()]))
kwargs = self.prepare_kwargs(self.interval_kws_defaults[interval],
self.interval_kwargs, intervalkwargs)
if self.data is None:
self.interval_kwargs = intervalkwargs
else:
if interval == 'minmax':
interval = vis.MinMaxInterval()
elif interval == 'manual': # args: vmin, vmax
interval = vis.ManualInterval(**kwargs)
elif interval == 'percentile': # args: percentile, n_samples
interval = vis.PercentileInterval(**kwargs)
elif interval == 'asymetric': # args: lower_percentile, upper_percentile, n_samples
interval = vis.AsymmetricPercentileInterval(**kwargs)
elif interval == 'zscale': # args: nsamples=1000, contrast=0.25, max_reject=0.5, min_npixels=5, krej=2.5, max_iterations=5
interval = vis.ZScaleInterval(**kwargs)
else:
raise ValueError('Unknown interval:' + interval)
self.interval = interval
if self.img is not None:
self.img.set_norm(
vis.ImageNormalize(self.data,
interval=self.interval,
stretch=self.stretch,
clip=True))
def get_image(data, fmt='JPEG', norm='percentile', lo=None, hi=None,
zcontrast=0.25, nsamples=1000, krej=2.5, max_iterations=5,
stretch='linear', a=None, bias=0.5, contrast=1, cmap=None,
dpi=100, **kwargs):
u"""
Return a byte array containing image in the given format
Image scaling is done using `~astropy.visualization`. It includes
normalization of the input data (mapping to [0, 1]) and stretching -
optional non-linear mapping [0, 1] -> [0, 1] for contrast enhancement.
A colormap can be applied to the normalized data. Conversion to the target
image format is done by matplotlib or Pillow.
:param array_like data: input 2D image data
:param str fmt: output image format
:param str norm: data normalization mode::
"manual": lower and higher clipping limits are set explicitly
"minmax": limits are set to the minimum and maximum data values
"percentile" (default): limits are set based on the specified fraction
of pixels
"zscale": use IRAF ZScale algorithm
:param int | float lo::
for ``norm`` == "manual", lower data limit
for ``norm`` == "percentile", lower percentile clipping value,
defaulting to 10
for ``norm`` == "zscale", lower limit on the number of rejected pixels,
defaulting to 5
:param int | float hi::
for ``norm`` == "manual", upper data limit
for ``norm`` == "percentile", upper percentile clipping value,
defaulting to 98
for ``norm`` == "zscale", upper limit on the number of rejected pixels,
defaulting to data.size/2
:param float zcontrast: for ``norm`` == "zscale", the scaling factor,
0 < zcontrast < 1, defaulting to 0.25
:param int nsamples: for ``norm`` == "zscale", the number of points in
the input array for determining scale factors, defaulting to 1000
:param float krej: for ``norm`` == "zscale", the sigma clipping factor,
defaulting to 2.5
:param int max_iterations: for ``norm`` == "zscale", the maximum number
of rejection iterations, defaulting to 5
:param str stretch: [0, 1] → [0, 1] mapping mode::
"asinh": hyperbolic arcsine stretch y = asinh(x/a)/asinh(1/a)
"contrast": linear bias/contrast-based stretch
y = (x - bias)*contrast + 0.5
"exp": exponential stretch y = (a^x - 1)/(a - 1)
"histeq": histogram equalization stretch
"linear" (default): direct mapping
"log": logarithmic stretch y = log(ax + 1)/log(a + 1)
"power": power stretch y = x^a
"sinh": hyperbolic sine stretch y = sinh(x/a)/sinh(1/a)
"sqrt": square root stretch y = √x
"square": power stretch y = x^2
:param float a: non-linear stretch parameter::
for ``stretch`` == "asinh", the point of transition from linear to
logarithmic behavior, 0 < a <= 1, defaulting to 0.1
for ``stretch`` == "exp", base of the exponent, a != 1, defaulting to
1000
for ``stretch`` == "log", base of the logarithm minus 1, a > 0,
defaulting to 1000
for ``stretch`` == "power", the power index, defaulting to 3
for ``stretch`` == "sinh", a > 0, defaulting to 1/3
:param float bias: for ``stretch`` == "contrast", the bias parameter,
defaulting to 0.5
:param float contrast: for ``stretch`` == "contrast", the contrast
parameter, defaulting to 1
:param str cmap: optional matplotlib colormap name, defaulting
to grayscale; when a non-grayscale colormap is specified,
the conversion is always done by matplotlib, regardless of the
availability of Pillow; see https://matplotlib.org/users/colormaps.html
for more info on matplotlib colormaps and
[name for name in matplotlib.cd.cmap_d.keys()
if not name.endswith('_r')]
to list the available colormap names
:param int dpi: target image resolution in dots per inch
:param kwargs: optional format-specific keyword arguments passed to Pillow,
e.g. "quality" for JPEG; see
`https://pillow.readthedocs.io/en/stable/handbook/
image-file-formats.html`_
:return: a bytes object containing the image in the given format
:rtype: bytes
"""
data = asanyarray(data)
# Normalize image data
if norm == 'manual':
if lo is None:
raise ValueError(
'Missing lower clipping boundary for norm="manual"')
if hi is None:
raise ValueError(
'Missing upper clipping boundary for norm="manual"')
elif norm == 'minmax':
lo, hi = data.min(), data.max()
elif norm == 'percentile':
if lo is None:
lo = 10
elif not 0 <= lo <= 100:
raise ValueError(
'Lower clipping percentile must be in the [0,100] range')
if hi is None:
hi = 98
elif not 0 <= hi <= 100:
raise ValueError(
'Upper clipping percentile must be in the [0,100] range')
if hi < lo:
raise ValueError(
'Upper clipping percentile must be greater or equal to '
'lower percentile')
lo, hi = percentile(data, [lo, hi])
elif norm == 'zscale':
if lo is None:
lo = 5
if hi is None:
hi = 0.5
else:
hi /= data.size
lo, hi = apy_vis.ZScaleInterval(
nsamples, zcontrast, hi, lo, krej, max_iterations).get_limits(data)
else:
raise ValueError('Unknown normalization mode "{}"'.format(norm))
data = clip((data - lo)/(hi - lo), 0, 1)
# Stretch the data
if stretch == 'asinh':
if a is None:
a = 0.1
apy_vis.AsinhStretch(a)(data, out=data)
elif stretch == 'contrast':
if bias != 0.5 or contrast != 1:
apy_vis.ContrastBiasStretch(contrast, bias)(data, out=data)
elif stretch == 'exp':
if a is None:
a = 1000
apy_vis.PowerDistStretch(a)(data, out=data)
elif stretch == 'histeq':
apy_vis.HistEqStretch(data)(data, out=data)
elif stretch == 'linear':
pass
elif stretch == 'log':
if a is None:
a = 1000
apy_vis.LogStretch(a)(data, out=data)
elif stretch == 'power':
if a is None:
a = 3
apy_vis.PowerStretch(a)(data, out=data)
elif stretch == 'sinh':
if a is None:
a = 1/3
apy_vis.SinhStretch(a)(data, out=data)
elif stretch == 'sqrt':
apy_vis.SqrtStretch()(data, out=data)
elif stretch == 'square':
apy_vis.SquaredStretch()(data, out=data)
else:
raise ValueError('Unknown stretch mode "{}"'.format(stretch))
buf = BytesIO()
try:
# Choose the backend for making an image
if cmap is None:
cmap = 'gray'
if cmap == 'gray':
try:
# noinspection PyPackageRequirements,PyPep8Naming
from PIL import Image as pil_image
except ImportError:
pil_image = None
else:
pil_image = None
if pil_image is not None:
# Use Pillow for grayscale output if available; flip the image to
# match the bottom-to-top FITS convention and convert from [0,1] to
# unsigned byte
pil_image.fromarray(
(data[::-1]*255 + 0.5).astype(uint8),
).save(buf, fmt, dpi=(dpi, dpi), **kwargs)
else:
# Use matplotlib for non-grayscale colormaps or if PIL is not
# available
# noinspection PyPackageRequirements
from matplotlib import image as mpl_image
if fmt.lower() == 'png':
# PNG images are saved upside down by matplotlib, regardless of
# the origin parameter
data = data[::-1]
# noinspection PyTypeChecker
mpl_image.imsave(
buf, data, cmap=cmap, format=fmt, origin='lower', dpi=dpi)
return buf.getvalue()
finally:
buf.close()
def create_figure(self,
output_filename,
survey,
stretch='log',
vmin=1,
vmax=None,
min_percent=1,
max_percent=95,
cmap='gray',
contour_color='red',
data_col='FLUX'):
"""Returns a matplotlib Figure object that visualizes a frame.
Parameters
----------
vmin : float, optional
Minimum cut level (default: 0).
vmax : float, optional
Maximum cut level (default: 5000).
cmap : str, optional
The matplotlib color map name. The default is 'gray',
can also be e.g. 'gist_heat'.
raw : boolean, optional
If `True`, show the raw pixel counts rather than
the calibrated flux. Default: `False`.
Returns
-------
image : array
An array of unisgned integers of shape (x, y, 3),
representing an RBG colour image x px wide and y px high.
"""
# Get the flux data to visualize
# Update to use TPF
flx = self.TPF.flux_binned()
# print(np.shape(flx))
# calculate cut_levels
if vmax is None:
vmin, vmax = self.cut_levels(min_percent, max_percent, data_col)
# Determine the figsize
shape = list(flx.shape)
# print(shape)
# Create the figure and display the flux image using matshow
fig = plt.figure(figsize=shape)
# Display the image using matshow
# Update to generate axes using WCS axes instead of plain axes
ax = plt.subplot(projection=self.TPF.wcs)
ax.set_xlabel('RA')
ax.set_ylabel('Dec')
if self.verbose:
print('{} vmin/vmax = {}/{} (median={})'.format(
data_col, vmin, vmax, np.nanmedian(flx)))
if stretch == 'linear':
stretch_fn = visualization.LinearStretch()
elif stretch == 'sqrt':
stretch_fn = visualization.SqrtStretch()
elif stretch == 'power':
stretch_fn = visualization.PowerStretch(1.0)
elif stretch == 'log':
stretch_fn = visualization.LogStretch()
elif stretch == 'asinh':
stretch_fn = visualization.AsinhStretch(0.1)
else:
raise ValueError('Unknown stretch: {0}.'.format(stretch))
transform = (stretch_fn +
visualization.ManualInterval(vmin=vmin, vmax=vmax))
ax.imshow((255 * transform(flx)).astype(int),
aspect='auto',
origin='lower',
interpolation='nearest',
cmap=cmap,
norm=NoNorm())
ax.set_xticks([])
ax.set_yticks([])
current_ylims = ax.get_ylim()
current_xlims = ax.get_xlim()
pixels, header = surveyquery.getSVImg(self.TPF.position, survey)
levels = np.linspace(np.min(pixels), np.percentile(pixels, 95), 10)
ax.contour(pixels,
transform=ax.get_transform(WCS(header)),
levels=levels,
colors=contour_color)
ax.set_xlim(current_xlims)
ax.set_ylim(current_ylims)
fig.canvas.draw()
plt.savefig(output_filename, bbox_inches='tight', dpi=300)
return fig