def stretch_hist_equalize(self, ch_nb):
"""Stretch the current image's colors by performing histogram
equalization on channel *ch_nb*.
"""
LOG.info("Perform a histogram equalized contrast stretch.")
if(self.channels[ch_nb].size ==
np.ma.count_masked(self.channels[ch_nb])):
LOG.warning("Nothing to stretch !")
return
arr = self.channels[ch_nb]
nwidth = 2048.0
carr = arr.compressed()
imhist, bins = np.histogram(carr, nwidth, normed=True)
cdf = imhist.cumsum() - imhist[0]
cdf = cdf / cdf[-1]
res = np.ma.empty_like(arr)
res.mask = np.ma.getmaskarray(arr)
res[~res.mask] = np.interp(carr, bins[:-1], cdf)
self.channels[ch_nb] = res
def add_overlay(self, color=(0, 0, 0)):
"""Add coastline and political borders to image, using *color*.
"""
import acpgimage
import _acpgpilext
import pps_array2image
self.convert("RGB")
import ConfigParser
conf = ConfigParser.ConfigParser()
conf.read(os.path.join(CONFIG_PATH, "geo_image.cfg"))
coast_dir = CONFIG_PATH
coast_file = os.path.join(coast_dir, conf.get("coasts", "coast_file"))
arr = np.zeros(self.channels[0].shape, np.uint8)
LOG.debug("Adding overlay: " + str(self.area_id))
if not isinstance(self.area_id, str):
area_id = self.area_id.area_id
else:
area_id = self.area_id
LOG.info("Add coastlines and political borders to image. " "Area = %s" % (area_id))
rimg = acpgimage.image(area_id)
rimg.info["nodata"] = 255
rimg.data = arr
area_overlayfile = "%s/coastlines_%s.asc" % (coast_dir, area_id)
LOG.info("Read overlay. Try find something prepared on the area...")
try:
overlay = _acpgpilext.read_overlay(area_overlayfile)
LOG.info("Got overlay for area: %s." % area_overlayfile)
except IOError:
LOG.info("Didn't find an area specific overlay." " Have to read world-map...")
overlay = _acpgpilext.read_overlay(coast_file)
LOG.info("Add overlay.")
overlay_image = pps_array2image.add_overlay(rimg, overlay, pil.fromarray(arr), color=1)
val = np.ma.asarray(overlay_image)
self.channels[0] = np.ma.where(val == 1, color[0], self.channels[0])
self.channels[0].mask = np.where(val == 1, False, np.ma.getmaskarray(self.channels[0]))
self.channels[1] = np.ma.where(val == 1, color[1], self.channels[1])
self.channels[1].mask = np.where(val == 1, False, np.ma.getmaskarray(self.channels[1]))
self.channels[2] = np.ma.where(val == 1, color[2], self.channels[2])
self.channels[2].mask = np.where(val == 1, False, np.ma.getmaskarray(self.channels[2]))
def save(self, filename, compression=6,
tags=None, gdal_options=None,
fformat=None, blocksize=256, **kwargs):
"""Save the image to the given *filename*. If the extension is "tif",
the image is saved to geotiff_ format, in which case the *compression*
level can be given ([0, 9], 0 meaning off). See also
:meth:`image.Image.save`, :meth:`image.Image.double_save`, and
:meth:`image.Image.secure_save`. The *tags* argument is a dict of tags
to include in the image (as metadata), and the *gdal_options* holds
options for the gdal saving driver. A *blocksize* other than 0 will
result in a tiled image (if possible), with tiles of size equal to
*blocksize*.
If the specified format *fformat* is not know to MPOP (and PIL), we
will try to import module *fformat* and call the method `fformat.save`.
.. _geotiff: http://trac.osgeo.org/geotiff/
"""
file_tuple = os.path.splitext(filename)
fformat = fformat or file_tuple[1][1:]
if fformat.lower() in ('tif', 'tiff'):
return self.geotiff_save(filename, compression, tags,
gdal_options, blocksize, **kwargs)
try:
# Let image.pil_save it ?
super(GeoImage, self).save(filename, compression, fformat=fformat)
except mpop.imageo.image.UnknownImageFormat:
# No ... last resort, try to import an external module.
LOG.info("Importing image saver module '%s'" % fformat)
try:
saver = __import__(fformat, globals(), locals(), ['save'])
except ImportError:
raise mpop.imageo.image.UnknownImageFormat(
"Unknown image format '%s'" % fformat)
saver.save(self, filename, **kwargs)
def add_overlay(self, color=(0, 0, 0), width=0.5, resolution=None):
"""Add coastline and political borders to image, using *color* (tuple
of integers between 0 and 255).
Warning: Loses the masks !
*resolution* is chosen automatically if None (default), otherwise it should be one of:
+-----+-------------------------+---------+
| 'f' | Full resolution | 0.04 km |
| 'h' | High resolution | 0.2 km |
| 'i' | Intermediate resolution | 1.0 km |
| 'l' | Low resolution | 5.0 km |
| 'c' | Crude resolution | 25 km |
+-----+-------------------------+---------+
"""
img = self.pil_image()
import ConfigParser
conf = ConfigParser.ConfigParser()
conf.read(os.path.join(CONFIG_PATH, "mpop.cfg"))
coast_dir = conf.get('shapes', 'dir')
LOG.debug("Getting area for overlay: " + str(self.area))
if self.area is None:
raise ValueError("Area of image is None, can't add overlay.")
from mpop.projector import get_area_def
if isinstance(self.area, str):
self.area = get_area_def(self.area)
LOG.info("Add coastlines and political borders to image.")
LOG.debug("Area = " + str(self.area))
if resolution is None:
x_resolution = ((self.area.area_extent[2] -
self.area.area_extent[0]) /
self.area.x_size)
y_resolution = ((self.area.area_extent[3] -
self.area.area_extent[1]) /
self.area.y_size)
res = min(x_resolution, y_resolution)
if res > 25000:
resolution = "c"
elif res > 5000:
resolution = "l"
elif res > 1000:
resolution = "i"
elif res > 200:
resolution = "h"
else:
resolution = "f"
LOG.debug("Automagically choose resolution " + resolution)
from pycoast import ContourWriterAGG
cw_ = ContourWriterAGG(coast_dir)
cw_.add_coastlines(img, self.area, outline=color,
resolution=resolution, width=width)
cw_.add_borders(img, self.area, outline=color,
resolution=resolution, width=width)
arr = np.array(img)
if len(self.channels) == 1:
self.channels[0] = np.ma.array(arr[:, :] / 255.0)
else:
for idx in range(len(self.channels)):
self.channels[idx] = np.ma.array(arr[:, :, idx] / 255.0)
