def get_coastline(bbox):
""" Get coastline GeoJSON within bounding box """
cmask = bfmask.open_vector(os.path.join(os.path.dirname(bfalg_ndwi.__file__), 'coastmask.shp'))
lons = [c[0] for c in bbox['features'][0]['geometry']['coordinates'][0]]
lats = [c[1] for c in bbox['features'][0]['geometry']['coordinates'][0]]
bbox = [min(lons), min(lats), max(lons), max(lats)]
gj = bfmask.get_features_as_geojson(cmask[1], bbox=bbox, union=True)
fname = 'tmpfile.geojson'
with open(fname, 'w') as f:
f.write(json.dumps(gj))
bfvec.simplify(fname, 0.025)
with open(fname) as f:
gj = json.load(f)
os.remove(fname)
return gj
def test_simplify(self):
""" Simplify GeoJSON geometries """
geoimg = download_image(self.test_url)
geoimg.set_nodata(0)
lines = vectorize.potrace(geoimg[0] > 9500, close=0)
fout = os.path.join(os.path.dirname(__file__), 'test.geojson')
vectorize.save_geojson(lines, fout)
# check file
df = ogr.Open(fout)
layer = df.GetLayer()
self.assertEqual(layer.GetFeatureCount(), len(lines))
geom = json.loads(layer.GetNextFeature().ExportToJson())
self.assertEqual(len(geom['geometry']['coordinates']), len(lines[0]))
df = None
# simplify and check file
vectorize.simplify(fout, tolerance=0.001)
df = ogr.Open(fout)
layer = df.GetLayer()
geom = json.loads(layer.GetNextFeature().ExportToJson())
self.assertEqual(len(geom['geometry']['coordinates']), 22)
def process(geoimg,
coastmask=defaults['coastmask'],
minsize=defaults['minsize'],
close=defaults['close'],
simple=defaults['simple'],
smooth=defaults['smooth'],
outdir='',
bname=None):
""" Process data from indir to outdir """
if bname is None:
bname = geoimg.basename()
if outdir is None:
outdir = tempfile.mkdtemp()
prefix = os.path.join(outdir, bname)
# calculate NWDI
fout = prefix + '_ndwi.tif'
logger.info('Saving NDWI to file %s' % fout,
action='Save file',
actee=fout,
actor=__name__)
imgout = alg.indices(geoimg, ['ndwi'], filename=fout)
# mask with coastline
if coastmask:
# open coastline vector
fname = os.path.join(os.path.dirname(__file__), 'coastmask.shp')
fout_coast = prefix + '_coastmask.tif'
try:
imgout = bfmask.mask_with_vector(imgout, (fname, ''),
filename=fout_coast)
except Exception as e:
if str(e) == 'No features after masking':
logger.warning(
'Image does not intersect coastal mask. Generating empty geojson file. Error: %s/'
% str(e))
geojson = {'type': 'FeatureCollection', 'features': []}
fout = prefix + '.geojson'
logger.info('Saving GeoJSON to file %s' % fout,
action='Save file',
actee=fout,
actor=__name__)
with open(fout, 'w') as f:
f.write(json.dumps(geojson))
return geojson
if str(e) == "'NoneType' object has no attribute 'ExportToJson'":
logger.warning(
'Image does not intersect coastal mask. Generating empty geojson file. Error: %s/'
% str(e))
geojson = {'type': 'FeatureCollection', 'features': []}
fout = prefix + '.geojson'
logger.info('Saving GeoJSON to file %s' % fout,
action='Save file',
actee=fout,
actor=__name__)
with open(fout, 'w') as f:
f.write(json.dumps(geojson))
return geojson
else:
logger.warning('Error encountered during masking. Error : %s' %
str(e))
raise RuntimeError(e)
# calculate optimal threshold
threshold = bfproc.otsu_threshold(imgout[0])
logger.debug("Otsu's threshold = %s" % threshold)
#import pdb; pdb.set_trace()
# save thresholded image
#if False: #logger.level <= logging.DEBUG:
fout = prefix + '_thresh.tif'
logger.debug('Saving thresholded image as %s' % fout)
logger.info('Saving threshold image to file %s' % fout,
action='Save file',
actee=fout,
actor=__name__)
imgout2 = gippy.GeoImage.create_from(imgout, filename=fout, dtype='byte')
imgout2.set_nodata(255)
#pdb.set_trace()
(imgout[0] > threshold).save(imgout2[0])
imgout = imgout2
# vectorize threshdolded (ie now binary) image
coastline = bfvec.potrace(imgout[0],
minsize=minsize,
close=close,
alphamax=smooth)
# convert coordinates to GeoJSON
geojson = bfvec.to_geojson(coastline, source=geoimg.basename())
# write geojson output file
fout = prefix + '.geojson'
logger.info('Saving GeoJSON to file %s' % fout,
action='Save file',
actee=fout,
actor=__name__)
with open(fout, 'w') as f:
f.write(json.dumps(geojson))
if simple is not None:
fout = bfvec.simplify(fout, tolerance=simple)
return geojson