/usr/lib/python3/dist-packages/openalpr/openalpr.py is in python3-openalpr 2.2.4-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 | import ctypes
import json
import platform
# We need to do things slightly differently for Python 2 vs. 3
# ... because the way str/unicode have changed to bytes/str
if platform.python_version_tuple()[0] == '2':
# Using Python 2
bytes = str
_PYTHON_3 = False
else:
# Assume using Python 3+
unicode = str
_PYTHON_3 = True
def _convert_to_charp(string):
# Prepares function input for use in c-functions as char*
if type(string) == unicode:
return string.encode("UTF-8")
elif type(string) == bytes:
return string
else:
raise TypeError("Expected unicode string values or ascii/bytes values. Got: %r" % type(string))
def _convert_from_charp(charp):
# Prepares char* output from c-functions into Python strings
if _PYTHON_3 and type(charp) == bytes:
return charp.decode("UTF-8")
else:
return charp
class Alpr():
def __init__(self, country, config_file, runtime_dir):
"""
Initializes an OpenALPR instance in memory.
:param country: The default region for license plates. E.g., "us" or "eu"
:param config_file: The path to the OpenALPR config file
:param runtime_dir: The path to the OpenALPR runtime data directory
:return: An OpenALPR instance
"""
country = _convert_to_charp(country)
config_file = _convert_to_charp(config_file)
runtime_dir = _convert_to_charp(runtime_dir)
try:
# Load the .dll for Windows and the .so for Unix-based
if platform.system().lower().find("windows") != -1:
self._openalprpy_lib = ctypes.cdll.LoadLibrary("openalprpy.dll")
elif platform.system().lower().find("darwin") != -1:
self._openalprpy_lib = ctypes.cdll.LoadLibrary("libopenalprpy.dylib")
else:
self._openalprpy_lib = ctypes.cdll.LoadLibrary("libopenalprpy.so")
except OSError as e:
nex = OSError("Unable to locate the OpenALPR library. Please make sure that OpenALPR is properly "
"installed on your system and that the libraries are in the appropriate paths.")
if _PYTHON_3:
nex.__cause__ = e;
raise nex
self._initialize_func = self._openalprpy_lib.initialize
self._initialize_func.restype = ctypes.c_void_p
self._initialize_func.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p]
self._dispose_func = self._openalprpy_lib.dispose
self._dispose_func.argtypes = [ctypes.c_void_p]
self._is_loaded_func = self._openalprpy_lib.isLoaded
self._is_loaded_func.argtypes = [ctypes.c_void_p]
self._is_loaded_func.restype = ctypes.c_bool
self._recognize_file_func = self._openalprpy_lib.recognizeFile
self._recognize_file_func.restype = ctypes.c_void_p
self._recognize_file_func.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
self._recognize_array_func = self._openalprpy_lib.recognizeArray
self._recognize_array_func.restype = ctypes.c_void_p
self._recognize_array_func.argtypes = [ctypes.c_void_p, ctypes.POINTER(ctypes.c_ubyte), ctypes.c_uint]
self._free_json_mem_func = self._openalprpy_lib.freeJsonMem
self._set_country_func = self._openalprpy_lib.setCountry
self._set_country_func.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
self._set_prewarp_func = self._openalprpy_lib.setPrewarp
self._set_prewarp_func.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
self._set_default_region_func = self._openalprpy_lib.setDefaultRegion
self._set_default_region_func.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
self._set_detect_region_func = self._openalprpy_lib.setDetectRegion
self._set_detect_region_func.argtypes = [ctypes.c_void_p, ctypes.c_bool]
self._set_top_n_func = self._openalprpy_lib.setTopN
self._set_top_n_func.argtypes = [ctypes.c_void_p, ctypes.c_int]
self._get_version_func = self._openalprpy_lib.getVersion
self._get_version_func.argtypes = [ctypes.c_void_p]
self._get_version_func.restype = ctypes.c_void_p
self.alpr_pointer = self._initialize_func(country, config_file, runtime_dir)
def unload(self):
"""
Unloads OpenALPR from memory.
:return: None
"""
self._openalprpy_lib.dispose(self.alpr_pointer)
def is_loaded(self):
"""
Checks if OpenALPR is loaded.
:return: A bool representing if OpenALPR is loaded or not
"""
return self._is_loaded_func(self.alpr_pointer)
def recognize_file(self, file_path):
"""
This causes OpenALPR to attempt to recognize an image by opening a file on
disk.
:param file_path: The path to the image that will be analyzed
:return: An OpenALPR analysis in the form of a response dictionary
"""
file_path = _convert_to_charp(file_path)
ptr = self._recognize_file_func(self.alpr_pointer, file_path)
json_data = ctypes.cast(ptr, ctypes.c_char_p).value
json_data = _convert_from_charp(json_data)
response_obj = json.loads(json_data)
self._free_json_mem_func(ctypes.c_void_p(ptr))
return response_obj
def recognize_array(self, byte_array):
"""
This causes OpenALPR to attempt to recognize an image passed in as a byte array.
:param byte_array: This should be a string (Python 2) or a bytes object (Python 3)
:return: An OpenALPR analysis in the form of a response dictionary
"""
if type(byte_array) != bytes:
raise TypeError("Expected a byte array (string in Python 2, bytes in Python 3)")
pb = ctypes.cast(byte_array, ctypes.POINTER(ctypes.c_ubyte))
ptr = self._recognize_array_func(self.alpr_pointer, pb, len(byte_array))
json_data = ctypes.cast(ptr, ctypes.c_char_p).value
json_data = _convert_from_charp(json_data)
response_obj = json.loads(json_data)
self._free_json_mem_func(ctypes.c_void_p(ptr))
return response_obj
def get_version(self):
"""
This gets the version of OpenALPR
:return: Version information
"""
ptr = self._get_version_func(self.alpr_pointer)
version_number = ctypes.cast(ptr, ctypes.c_char_p).value
version_number = _convert_from_charp(version_number)
self._free_json_mem_func(ctypes.c_void_p(ptr))
return version_number
def set_top_n(self, topn):
"""
Sets the number of returned results when analyzing an image. For example,
setting topn = 5 returns the top 5 results.
:param topn: An integer that represents the number of returned results.
:return: None
"""
self._set_top_n_func(self.alpr_pointer, topn)
def set_country(self, country):
"""
This sets the country for detecting license plates. For example,
setting country to "us" for United States or "eu" for Europe.
:param country: A unicode/ascii string (Python 2/3) or bytes array (Python 3)
:return: None
"""
country = _convert_to_charp(country)
self._set_country_func(self.alpr_pointer, country)
def set_prewarp(self, prewarp):
"""
Updates the prewarp configuration used to skew images in OpenALPR before
processing.
:param prewarp: A unicode/ascii string (Python 2/3) or bytes array (Python 3)
:return: None
"""
prewarp = _convert_to_charp(prewarp)
self._set_prewarp_func(self.alpr_pointer, prewarp)
def set_default_region(self, region):
"""
This sets the default region for detecting license plates. For example,
setting region to "md" for Maryland or "fr" for France.
:param region: A unicode/ascii string (Python 2/3) or bytes array (Python 3)
:return: None
"""
region = _convert_to_charp(region)
self._set_default_region_func(self.alpr_pointer, region)
def set_detect_region(self, enabled):
"""
This allows OpenALPR to attempt to detect the region of a license plate
automatically. By default this is disabled, but you can enable it here.
:param enabled: A boolean representing whether or not auto-detection is enabled
:return: None
"""
self._set_detect_region_func(self.alpr_pointer, enabled)
def __del__(self):
if self.is_loaded():
self.unload()
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
if self.is_loaded():
self.unload()
|