def get_image_location_value(imagepath, x, y, xy_srs, bandindex):
"""
get the image value of given location(x,y) in bandindex
Args:
imagepath:the image path which the information query
x:x value
y:y value
xy_srs:the coordinate system of (x,y), the value is :pixel ,prj or lon_lat_wgs84
bandindex:the bandindex of image want to query
Returns:the certain value (float) of given location
"""
coordinate = ''
if xy_srs == 'pixel':
coordinate = ' '
elif xy_srs == 'prj':
coordinate = ' -geoloc '
elif xy_srs == 'lon_lat_wgs84':
coordinate = ' -wgs84 '
else:
basic.outputlogMessage('input error: %s is not right' % xy_srs)
assert False
command_str = 'gdallocationinfo -valonly ' + ' -b ' +str(bandindex) + coordinate \
+ ' '+imagepath + ' ' + str(x) +' '+ str(y)
result = basic.exec_command_string_output_string(command_str)
try:
result = float(result)
except ValueError:
basic.outputlogMessage(str(ValueError))
assert False
return result
def get_image_proj_extent(imagepath):
"""
get the extent of a image
Args:
imagepath:image path
Returns:(ulx:Upper Left X,uly: Upper Left Y,lrx: Lower Right X,lry: Lower Right Y)
"""
ulx = False
uly = False
lrx = False
lry = False
CommandString = 'gdalinfo -json ' + imagepath
imginfo = basic.exec_command_string_output_string(CommandString)
if imginfo is False:
return False
imginfo_obj = json.loads(imginfo)
# print imginfo_obj
# print type(imginfo_obj)
# print imginfo_obj.keys()
try:
cornerCoordinates = imginfo_obj['cornerCoordinates']
upperLeft_value = cornerCoordinates['upperLeft']
lowerRight_value = cornerCoordinates['lowerRight']
ulx = upperLeft_value[0]
uly = upperLeft_value[1]
lrx = lowerRight_value[0]
lry = lowerRight_value[1]
except KeyError:
basic.outputlogMessage(str(KeyError))
pass
return (ulx, uly, lrx, lry)
def get_image_max_min_value(imagepath):
"""
get image first band max vlaue and min value
Args:
imagepath: image path
Returns:(max value list, min value list) if successful, (False,False) otherwise
"""
max_value = []
min_value = []
CommandString = 'gdalinfo -json -stats ' + imagepath
imginfo = basic.exec_command_string_output_string(CommandString)
if imginfo is False:
return False
imginfo_obj = json.loads(imginfo)
try:
bands_info = imginfo_obj['bands']
for band_info in bands_info:
max_value.append(band_info['maximum'])
min_value.append(band_info['minimum'])
return (max_value, min_value)
except KeyError:
basic.outputlogMessage(str(KeyError))
pass
return (False, False)
def get_raster_or_vector_srs_info(spatial_data, format):
"""
get SRS(Spatial Reference System) information from raster or vector data
Args:
spatial_data: the path of raster or vector data
format: Any of the usual GDAL/OGR forms(complete WKT, PROJ.4, EPSG:n or a file containing the SRS)
Returns:the string of srs info in special format, False otherwise
"""
if io_function.is_file_exist(spatial_data) is False:
return False
CommandString = 'gdalsrsinfo -o ' + format + ' ' + spatial_data
result = basic.exec_command_string_output_string(CommandString)
if result.find('ERROR') >= 0:
return False
return result