def proj4_from_layer(layer_file: str):
""" Get pyproj Proj4 projection from layer file
:param layer_file:
:return:
"""
check_file(layer_file)
try:
src_ds = ogr.Open(layer_file)
return src_ds.GetLayer().GetSpatialRef().ExportToProj4()
except RuntimeError:
raise ValueError("Unable to read layer file '%s'" % layer_file)
def proj4_from_raster(raster_file: str):
""" Get pyproj Proj4 projection from raster file
:param raster_file:
:return:
"""
check_file(raster_file)
try:
proj = gdal.Open(raster_file).GetProjection()
except RuntimeError:
raise ValueError("Unable to read raster file '{}'".format(raster_file))
return proj4_from_wkt(proj)
def read_img(img_file: str):
""" Read img file associated with hdr header files
:param img_file:
:return:
"""
check_file(img_file, ext='.img')
hdr_file = os.path.splitext(img_file)[0] + ".hdr"
img_info = read_hdr(hdr_file)
with open(img_file, 'r') as file:
image = np.fromfile(file, img_info['data_type'])
image = image.reshape((img_info["x_size"], img_info["y_size"]))
return {"image": image, "attributes": img_info}
def read_hdr(hdr_file: str):
""" Read hdr header file for geospatial image
:param hdr_file:
:return:
"""
def data_type():
hdr_fields["data_type"] = np.dtype(data_type[int(value)])
def samples():
hdr_fields["x_size"] = int(value)
def lines():
hdr_fields["y_size"] = int(value)
def map_info():
# Pixel easting and northing: it seems envi header files store top-left pixel centre of the image...
val = value[1:-1].replace(" ", "").split(",")
hdr_fields["proj"] = val[0]
hdr_fields["x_res"] = float(val[5])
hdr_fields["y_res"] = float(val[6])
hdr_fields["x_origin"] = float(val[3]) - hdr_fields["x_res"] / 2
hdr_fields["y_origin"] = float(val[4]) + hdr_fields["y_res"] / 2
check_file(hdr_file, ext='.hdr')
options = {'data type': data_type, 'samples': samples, 'lines': lines, 'map info': map_info}
hdr_fields = {}
data_type = {1: np.byte, 2: np.int16, 3: np.int32, 4: np.float32, 5: np.float64, 6: np.complex, 9: np.complex64,
12: np.uint16, 13: np.uint32, 14: np.int64, 15: np.uint64}
with open(hdr_file, 'r') as file:
for line in file.readlines():
try:
key, value = line.split(sep=" = ", maxsplit=1) # Or re.split("\s*=\s*(.+)", line)[0:-1],
# or re.search("([^\=]+)\s+\=\s*(.+)", line)
if key in options.keys():
options[key]()
except ValueError:
pass
return hdr_fields
def from_hdr(hdr_file: str):
""" Get geo grid from envi geospatial header file
:param hdr_file:
:return:
"""
check_file(hdr_file, '.hdr')
hdr_info = read_hdr(hdr_file)
if hdr_info['y_res'] != hdr_info['x_res']:
raise AttributeError("X and Y image resolution must be the same")
res = hdr_info['y_res']
ll_corner = (hdr_info['y_origin'] - hdr_info['y_size'] * res + res / 2,
hdr_info['x_origin'] + res / 2)
ur_corner = (hdr_info['y_origin'] - res / 2,
hdr_info['x_origin'] + hdr_info['x_size'] * res - res / 2)
if "Lat/Lon" in hdr_info["proj"]:
geotype = "latlon"
else:
geotype = "equal"
return GeoGrid(ll_corner, ur_corner, res, geotype)