python las转txt

阳光穿透心脏的1/2处 2022-08-30 06:18 185阅读 0赞

[https://blog.csdn.net/qq\_22034353/article/details/102506188][https_blog.csdn.net_qq_22034353_article_details_102506188]

import struct
    
    
    class OneZeroHeader(object):
        """
        1.0版本
        """
    
        def __init__(self):
            self.file_signature = None  # 文件签名
            self.reserved = None  # 预留字段
            self.guid_1 = None  # 项目ID1
            self.guid_2 = None  # 项目ID2
            self.guid_3 = None  # 项目ID3
            self.guid_4 = None  # 项目ID4
            self.version_major = None  # 大版本
            self.version_minor = None  # 小版本
            self.system_identifier = None  # 硬件信息
            self.generating_software = None  # 软件信息
            self.flight_date_julian = None  # 文件创建天数
            self.year = None  # 文件创建年份
            self.header_size = None  # 头文件大小
            self.offset_to_data = None  # 点数据记录起始位置
            self.number_of_variable_length_records = None  # 可变数据记录长度
            self.point_data_record_format = None  # 点数据记录格式
            self.point_data_record_length = None  # 点数据记录长度
            self.number_of_point_records = None  # 总共的点数量
            self.number_of_points_by_return = None  # 回波点数量
            self.x_scale_factor = None  # x比例因子
            self.y_scale_factor = None  # y比例因子
            self.z_scale_factor = None  # z比例因子
            self.x_offset = None  # x偏移量
            self.y_offset = None  # y偏移量
            self.z_offset = None  # z偏移量
            self.max_x = None  # x最大值
            self.min_x = None  # x最小值
            self.max_y = None  # y最大值
            self.min_y = None  # y最小值
            self.max_z = None  # z最大值
            self.min_z = None  # z最小值
    
        def read_header(self, f):
            """
            读取头
            :param f:
            :return:
            """
            f.seek(0)
            self.file_signature = f.read(4).decode("utf-8")
            self.reserved = struct.unpack('L', f.read(4))[0]
            self.guid_1 = struct.unpack('L', f.read(4))[0]
            self.guid_2 = struct.unpack('H', f.read(2))[0]
            self.guid_3 = struct.unpack('H', f.read(2))[0]
            self.guid_4 = struct.unpack('8s', f.read(8))[0].decode("utf-8")
            self.version_major = struct.unpack('B', f.read(1))[0]
            self.version_minor = struct.unpack('B', f.read(1))[0]
            self.system_identifier = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.generating_software = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.flight_date_julian = struct.unpack('H', f.read(2))[0]
            self.year = struct.unpack('H', f.read(2))[0]
            self.header_size = struct.unpack('H', f.read(2))[0]
            self.offset_to_data = struct.unpack('L', f.read(4))[0]
            self.number_of_variable_length_records = struct.unpack('L', f.read(4))[0]
            self.point_data_record_format = struct.unpack('B', f.read(1))[0]
            self.point_data_record_length = struct.unpack('H', f.read(2))[0]
            self.number_of_point_records = struct.unpack('L', f.read(4))[0]
            self.number_of_points_by_return = struct.unpack('5L', f.read(20))[0]
            self.x_scale_factor = struct.unpack('d', f.read(8))[0]
            self.y_scale_factor = struct.unpack('d', f.read(8))[0]
            self.z_scale_factor = struct.unpack('d', f.read(8))[0]
            self.x_offset = struct.unpack('d', f.read(8))[0]
            self.y_offset = struct.unpack('d', f.read(8))[0]
            self.z_offset = struct.unpack('d', f.read(8))[0]
            self.max_x = struct.unpack('d', f.read(8))[0]
            self.min_x = struct.unpack('d', f.read(8))[0]
            self.max_y = struct.unpack('d', f.read(8))[0]
            self.min_y = struct.unpack('d', f.read(8))[0]
            self.max_z = struct.unpack('d', f.read(8))[0]
            self.min_z = struct.unpack('d', f.read(8))[0]
    
    
    class OneOneHeader(object):
        """
        1.1版本
        """
    
        def __init__(self):
            self.file_signature = None  # 文件签名
            self.file_source_id = None  # 文件ID
            self.reserved = None  # 预留字段
            self.project_id_1 = None  # 项目ID1
            self.project_id_2 = None  # 项目ID2
            self.project_id_3 = None  # 项目ID3
            self.project_id_4 = None  # 项目ID4
            self.version_major = None  # 大版本
            self.version_minor = None  # 小版本
            self.system_identifier = None  # 硬件信息
            self.generating_software = None  # 软件信息
            self.file_creation_day_of_year = None  # 文件创建天数
            self.file_creation_year = None  # 文件创建年份
            self.header_size = None  # 头文件大小
            self.offset_to_point_data = None  # 点数据记录起始位置
            self.number_of_variable_length_records = None  # 可变数据记录长度
            self.point_data_record_format = None  # 点数据记录格式
            self.point_data_record_length = None  # 点数据记录长度
            self.number_of_point_records = None  # 总共的点数量
            self.number_of_points_by_return = None  # 回波点数量
            self.x_scale_factor = None  # x比例因子
            self.y_scale_factor = None  # y比例因子
            self.z_scale_factor = None  # z比例因子
            self.x_offset = None  # x偏移量
            self.y_offset = None  # y偏移量
            self.z_offset = None  # z偏移量
            self.max_x = None  # x最大值
            self.min_x = None  # x最小值
            self.max_y = None  # y最大值
            self.min_y = None  # y最小值
            self.max_z = None  # z最大值
            self.min_z = None  # z最小值
    
        def read_header(self, f):
            f.seek(0)
            self.file_signature = f.read(4).decode("utf-8")
            self.file_source_id = struct.unpack('H', f.read(2))[0]
            self.reserved = struct.unpack('H', f.read(2))[0]
            self.project_id_1 = struct.unpack('L', f.read(4))[0]
            self.project_id_2 = struct.unpack('H', f.read(2))[0]
            self.project_id_3 = struct.unpack('H', f.read(2))[0]
            self.project_id_4 = struct.unpack('8s', f.read(8))[0].decode("utf-8")
            self.version_major = struct.unpack('B', f.read(1))[0]
            self.version_minor = struct.unpack('B', f.read(1))[0]
            self.system_identifier = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.generating_software = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.file_creation_day_of_year = struct.unpack('H', f.read(2))[0]
            self.file_creation_year = struct.unpack('H', f.read(2))[0]
            self.header_size = struct.unpack('H', f.read(2))[0]
            self.offset_to_point_data = struct.unpack('L', f.read(4))[0]
            self.number_of_variable_length_records = struct.unpack('L', f.read(4))[0]
            self.point_data_record_format = struct.unpack('B', f.read(1))[0]
            self.point_data_record_length = struct.unpack('H', f.read(2))[0]
            self.number_of_point_records = struct.unpack('L', f.read(4))[0]
            self.number_of_points_by_return = struct.unpack('5L', f.read(20))[0]
            self.x_scale_factor = struct.unpack('d', f.read(8))[0]
            self.y_scale_factor = struct.unpack('d', f.read(8))[0]
            self.z_scale_factor = struct.unpack('d', f.read(8))[0]
            self.x_offset = struct.unpack('d', f.read(8))[0]
            self.y_offset = struct.unpack('d', f.read(8))[0]
            self.z_offset = struct.unpack('d', f.read(8))[0]
            self.max_x = struct.unpack('d', f.read(8))[0]
            self.min_x = struct.unpack('d', f.read(8))[0]
            self.max_y = struct.unpack('d', f.read(8))[0]
            self.min_y = struct.unpack('d', f.read(8))[0]
            self.max_z = struct.unpack('d', f.read(8))[0]
            self.min_z = struct.unpack('d', f.read(8))[0]
    
    
    class OneTwoHeader(object):
        """
        1.2版本
        """
    
        def __init__(self):
            self.file_signature = None  # 文件签名
            self.file_source_id = None  # 文件ID
            self.global_encoding = None  # 全球编码
            self.project_id_1 = None  # 项目ID1
            self.project_id_2 = None  # 项目ID2
            self.project_id_3 = None  # 项目ID3
            self.project_id_4 = None  # 项目ID4
            self.version_major = None  # 大版本
            self.version_minor = None  # 小版本
            self.system_identifier = None  # 硬件信息
            self.generating_software = None  # 软件信息
            self.file_creation_day_of_year = None  # 文件创建天数
            self.file_creation_year = None  # 文件创建年份
            self.header_size = None  # 头文件大小
            self.offset_to_point_data = None  # 点数据记录起始位置
            self.number_of_variable_length_records = None  # 可变数据记录长度
            self.point_data_record_format = None  # 点数据记录格式
            self.point_data_record_length = None  # 点数据记录长度
            self.number_of_point_records = None  # 总共的点数量
            self.number_of_points_by_return = None  # 回波点数量
            self.x_scale_factor = None  # x比例因子
            self.y_scale_factor = None  # y比例因子
            self.z_scale_factor = None  # z比例因子
            self.x_offset = None  # x偏移量
            self.y_offset = None  # y偏移量
            self.z_offset = None  # z偏移量
            self.max_x = None  # x最大值
            self.min_x = None  # x最小值
            self.max_y = None  # y最大值
            self.min_y = None  # y最小值
            self.max_z = None  # z最大值
            self.min_z = None  # z最小值
    
        def read_header(self, f):
            f.seek(0)
            self.file_signature = f.read(4).decode("utf-8")
            self.file_source_id = struct.unpack('H', f.read(2))[0]
            self.global_encoding = struct.unpack('H', f.read(2))[0]
            self.project_id_1 = struct.unpack('L', f.read(4))[0]
            self.project_id_2 = struct.unpack('H', f.read(2))[0]
            self.project_id_3 = struct.unpack('H', f.read(2))[0]
            self.project_id_4 = struct.unpack('8s', f.read(8))[0].decode("utf-8")
            self.version_major = struct.unpack('B', f.read(1))[0]
            self.version_minor = struct.unpack('B', f.read(1))[0]
            self.system_identifier = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.generating_software = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.file_creation_day_of_year = struct.unpack('H', f.read(2))[0]
            self.file_creation_year = struct.unpack('H', f.read(2))[0]
            self.header_size = struct.unpack('H', f.read(2))[0]
            self.offset_to_point_data = struct.unpack('L', f.read(4))[0]
            self.number_of_variable_length_records = struct.unpack('L', f.read(4))[0]
            self.point_data_record_format = struct.unpack('B', f.read(1))[0]
            self.point_data_record_length = struct.unpack('H', f.read(2))[0]
            self.number_of_point_records = struct.unpack('L', f.read(4))[0]
            self.number_of_points_by_return = struct.unpack('5L', f.read(20))[0]
            self.x_scale_factor = struct.unpack('d', f.read(8))[0]
            self.y_scale_factor = struct.unpack('d', f.read(8))[0]
            self.z_scale_factor = struct.unpack('d', f.read(8))[0]
            self.x_offset = struct.unpack('d', f.read(8))[0]
            self.y_offset = struct.unpack('d', f.read(8))[0]
            self.z_offset = struct.unpack('d', f.read(8))[0]
            self.max_x = struct.unpack('d', f.read(8))[0]
            self.min_x = struct.unpack('d', f.read(8))[0]
            self.max_y = struct.unpack('d', f.read(8))[0]
            self.min_y = struct.unpack('d', f.read(8))[0]
            self.max_z = struct.unpack('d', f.read(8))[0]
            self.min_z = struct.unpack('d', f.read(8))[0]
    
    
    class OneThreeHeader(object):
        """
        1.3版本
        """
    
        def __init__(self):
            self.file_signature = None  # 文件签名
            self.file_source_id = None  # 文件ID
            self.global_encoding = None  # 全球编码
            self.project_id_1 = None  # 项目ID1
            self.project_id_2 = None  # 项目ID2
            self.project_id_3 = None  # 项目ID3
            self.project_id_4 = None  # 项目ID4
            self.version_major = None  # 大版本
            self.version_minor = None  # 小版本
            self.system_identifier = None  # 硬件信息
            self.generating_software = None  # 软件信息
            self.file_creation_day_of_year = None  # 文件创建天数
            self.file_creation_year = None  # 文件创建年份
            self.header_size = None  # 头文件大小
            self.offset_to_point_data = None  # 点数据记录起始位置
            self.number_of_variable_length_records = None  # 可变数据记录长度
            self.point_data_record_format = None  # 点数据记录格式
            self.point_data_record_length = None  # 点数据记录长度
            self.number_of_point_records = None  # 总共的点数量
            self.number_of_points_by_return = None  # 回波点数量
            self.x_scale_factor = None  # x比例因子
            self.y_scale_factor = None  # y比例因子
            self.z_scale_factor = None  # z比例因子
            self.x_offset = None  # x偏移量
            self.y_offset = None  # y偏移量
            self.z_offset = None  # z偏移量
            self.max_x = None  # x最大值
            self.min_x = None  # x最小值
            self.max_y = None  # y最大值
            self.min_y = None  # y最小值
            self.max_z = None  # z最大值
            self.min_z = None  # z最小值
            self.start_of_waveform_data_packet_record = None  # 波形数据包记录的开始位置
    
        def read_header(self, f):
            f.seek(0)
            self.file_signature = f.read(4).decode("utf-8")
            self.file_source_id = struct.unpack('H', f.read(2))[0]
            self.global_encoding = struct.unpack('H', f.read(2))[0]
            self.project_id_1 = struct.unpack('L', f.read(4))[0]
            self.project_id_2 = struct.unpack('H', f.read(2))[0]
            self.project_id_3 = struct.unpack('H', f.read(2))[0]
            self.project_id_4 = struct.unpack('8s', f.read(8))[0].decode("utf-8")
            self.version_major = struct.unpack('B', f.read(1))[0]
            self.version_minor = struct.unpack('B', f.read(1))[0]
            self.system_identifier = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.generating_software = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.file_creation_day_of_year = struct.unpack('H', f.read(2))[0]
            self.file_creation_year = struct.unpack('H', f.read(2))[0]
            self.header_size = struct.unpack('H', f.read(2))[0]
            self.offset_to_point_data = struct.unpack('L', f.read(4))[0]
            self.number_of_variable_length_records = struct.unpack('L', f.read(4))[0]
            self.point_data_record_format = struct.unpack('B', f.read(1))[0]
            self.point_data_record_length = struct.unpack('H', f.read(2))[0]
            self.number_of_point_records = struct.unpack('L', f.read(4))[0]
            self.number_of_points_by_return = struct.unpack('5L', f.read(20))[0]
            self.x_scale_factor = struct.unpack('d', f.read(8))[0]
            self.y_scale_factor = struct.unpack('d', f.read(8))[0]
            self.z_scale_factor = struct.unpack('d', f.read(8))[0]
            self.x_offset = struct.unpack('d', f.read(8))[0]
            self.y_offset = struct.unpack('d', f.read(8))[0]
            self.z_offset = struct.unpack('d', f.read(8))[0]
            self.max_x = struct.unpack('d', f.read(8))[0]
            self.min_x = struct.unpack('d', f.read(8))[0]
            self.max_y = struct.unpack('d', f.read(8))[0]
            self.min_y = struct.unpack('d', f.read(8))[0]
            self.max_z = struct.unpack('d', f.read(8))[0]
            self.min_z = struct.unpack('d', f.read(8))[0]
            self.start_of_waveform_data_packet_record = struct.unpack('Q', f.read(8))[0]
    
    
    class OneFourHeader(object):
        """
        1.4版本
        """
    
        def __init__(self):
            self.file_signature = None  # 文件签名
            self.file_source_id = None  # 文件ID
            self.global_encoding = None  # 全球编码
            self.project_id_1 = None  # 项目ID1
            self.project_id_2 = None  # 项目ID2
            self.project_id_3 = None  # 项目ID3
            self.project_id_4 = None  # 项目ID4
            self.version_major = None  # 大版本
            self.version_minor = None  # 小版本
            self.system_identifier = None  # 硬件信息
            self.generating_software = None  # 软件信息
            self.file_creation_day_of_year = None  # 文件创建天数
            self.file_creation_year = None  # 文件创建年份
            self.header_size = None  # 头文件大小
            self.offset_to_point_data = None  # 点数据记录起始位置
            self.number_of_variable_length_records = None  # 可变数据记录长度
            self.point_data_record_format = None  # 点数据记录格式
            self.point_data_record_length = None  # 点数据记录长度
            self.legacy_number_of_point_records = None  # 老格式总共的点数量
            self.legacy_number_of_points_by_return = None  # 老格式回波点数量
            self.x_scale_factor = None  # x比例因子
            self.y_scale_factor = None  # y比例因子
            self.z_scale_factor = None  # z比例因子
            self.x_offset = None  # x偏移量
            self.y_offset = None  # y偏移量
            self.z_offset = None  # z偏移量
            self.max_x = None  # x最大值
            self.min_x = None  # x最小值
            self.max_y = None  # y最大值
            self.min_y = None  # y最小值
            self.max_z = None  # z最大值
            self.min_z = None  # z最小值
            self.start_of_waveform_data_packet_record = None  # 波形数据记录起始点
            self.start_of_first_extended_variable_length_record = None  # 扩展变长记录起始
            self.number_of_extended_variable_length_records = None  # 扩展变长记录数目
            self.number_of_point_records = None  # 点记录总数
            self.number_of_points_by_return = None  # 回波点数量
    
        def read_header(self, f):
            f.seek(0)
            self.file_signature = f.read(4).decode("utf-8")
            self.file_source_id = struct.unpack('H', f.read(2))[0]
            self.global_encoding = struct.unpack('H', f.read(2))[0]
            self.project_id_1 = struct.unpack('L', f.read(4))[0]
            self.project_id_2 = struct.unpack('H', f.read(2))[0]
            self.project_id_3 = struct.unpack('H', f.read(2))[0]
            self.project_id_4 = struct.unpack('8s', f.read(8))[0].decode("utf-8")
            self.version_major = struct.unpack('B', f.read(1))[0]
            self.version_minor = struct.unpack('B', f.read(1))[0]
            self.system_identifier = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.generating_software = struct.unpack('32s', f.read(32))[0].decode("utf-8")
            self.file_creation_day_of_year = struct.unpack('H', f.read(2))[0]
            self.file_creation_year = struct.unpack('H', f.read(2))[0]
            self.header_size = struct.unpack('H', f.read(2))[0]
            self.offset_to_point_data = struct.unpack('L', f.read(4))[0]
            self.number_of_variable_length_records = struct.unpack('L', f.read(4))[0]
            self.point_data_record_format = struct.unpack('B', f.read(1))[0]
            self.point_data_record_length = struct.unpack('H', f.read(2))[0]
            self.legacy_number_of_point_records = struct.unpack('L', f.read(4))[0]
            self.legacy_number_of_points_by_return = struct.unpack('5L', f.read(20))[0]
            self.x_scale_factor = struct.unpack('d', f.read(8))[0]
            self.y_scale_factor = struct.unpack('d', f.read(8))[0]
            self.z_scale_factor = struct.unpack('d', f.read(8))[0]
            self.x_offset = struct.unpack('d', f.read(8))[0]
            self.y_offset = struct.unpack('d', f.read(8))[0]
            self.z_offset = struct.unpack('d', f.read(8))[0]
            self.max_x = struct.unpack('d', f.read(8))[0]
            self.min_x = struct.unpack('d', f.read(8))[0]
            self.max_y = struct.unpack('d', f.read(8))[0]
            self.min_y = struct.unpack('d', f.read(8))[0]
            self.max_z = struct.unpack('d', f.read(8))[0]
            self.min_z = struct.unpack('d', f.read(8))[0]
            self.start_of_waveform_data_packet_record = struct.unpack('Q', f.read(8))[0]
            self.start_of_first_extended_variable_length_record = struct.unpack('Q', f.read(8))[0]
            self.number_of_extended_variable_length_records = struct.unpack('L', f.read(4))[0]
            self.number_of_point_records = struct.unpack('Q', f.read(8))[0]
            self.number_of_points_by_return = struct.unpack('15Q', f.read(120))[0]
    
    def get_header(f, version):
    
        if version == (1, 1):
            new_header = OneOneHeader()
        elif version == (1, 2):
            new_header = OneTwoHeader()
        elif version == (1, 3):
            new_header = OneThreeHeader()
        elif version == (1, 4):
            new_header = OneFourHeader()
        else:
            raise Exception("未找到对应文件版本")
    
        new_header.read_header(f)
        return new_header
    
    
    """
    定义点数据0~10格式解析
    """
    import struct
    
    
    class Point(object):
    
        def __init__(self, x_s_f, y_s_f, z_s_f, x_o, y_o, z_o):
            self.x_scale_factor = x_s_f
            self.y_scale_factor = y_s_f
            self.z_scale_factor = z_s_f
            self.x_offset = x_o
            self.y_offset = y_o
            self.z_offset = z_o
    
        def get_offset_bytes(self, point_data_record_format):
            """
            根据不同的点格式跳过的字节数
            :param point_data_record_format:点格式0~10
            :return:
            """
            # x,y,z共占12字节
            data_format = {
                0: 8,  # 点格式0 共20字节
                1: 16,  # 点格式1 共28字节
                2: 14,  # 点格式2 共26字节
                3: 22,  # 点格式3 共34字节
                4: 45,  # 点格式4 共57字节
                5: 51,  # 点格式5 共63字节
                6: 18,  # 点格式6 共30字节
                7: 24,  # 点格式7 共36字节
                8: 26,  # 点格式8 共38字节
                9: 47,  # 点格式9 共59字节
                10: 55,  # 点格式10 共67字节
            }
    
            offset_bytes = data_format.get(point_data_record_format, None)
            if offset_bytes is None:
                raise Exception(f"不存在当前的点格式{point_data_record_format}")
            return offset_bytes
    
        def read_point(self, f, offset_to_point_data, point_data_record_format, num):
            """
            读取当前文件中的点数据
            :param f:  数据文件
            :param offset_to_point_data: 点数据开始读取的地方
            :param point_data_record_format:  点数据格式0~10
            :param num: 读取多少个点
            :return: 读取的数据点
            """
            offset_bytes = self.get_offset_bytes(point_data_record_format)
            f.seek(offset_to_point_data)
            points = list()
    
            i = 0
            while i < num:
                point_bytes = f.read(12)
                x_record, y_record, z_record = struct.unpack_from('3l', point_bytes)
                x = x_record * self.x_scale_factor + self.x_offset
                y = y_record * self.y_scale_factor + self.y_offset
                z = z_record * self.z_scale_factor + self.z_offset
                i += 1
                f.read(offset_bytes)
                points.append((x, y, z))
    
            return points
    def get_version(f):
        f.read(24)
        version_major, version_minor = struct.unpack('2B', f.read(2))
        print(f"las版本:{version_major}.{version_minor}")
        return version_major, version_minor
    
    
    if __name__ == '__main__':
        # f = open(r'D:\data\dianyun\lumian.las', 'rb')
        f = open(r'G:\DeeperForensics-1.0\data-20200813-110417_1\data-20200813-110417_1.las', 'rb')
        version = get_version(f)
        header = get_header(f, version)
        print(header.__dict__)
    
        points = Point(header.x_scale_factor,
                       header.y_scale_factor,
                       header.z_scale_factor,
                       header.x_offset,
                       header.y_offset,
                       header.z_offset,
                       )
    
        data = points.read_point(f, header.offset_to_point_data,
                                 header.point_data_record_format,
                                 header.number_of_point_records)
    
        f.close()
    
        with open("point2.txt", 'a+') as f:
            for item in data:
                f.write(f'{item[0]},{item[1]},{item[2]}\n')

[https_blog.csdn.net_qq_22034353_article_details_102506188]: https://blog.csdn.net/qq_22034353/article/details/102506188