是否有方法将las文件块转换为另一种las文件类型？

Question

转换函数似乎只有在执行laspy.read()时才能工作。但是，块迭代器的全部要点是不需要一次读取完整的文件。这就是我认为laspy.convert()的一个例子将与块迭代器一起工作的方式。

            # READ IN FILE
            with laspy.open(scan.las_file, mode='r') as las_open:
                for chunk in las_open.chunk_iterator(1_000_000):
                   chunk = laspy.convert(chunk,file_version='1.2', point_format_id=2)

                    # WRITE TO FILE
                    file_path = os.path.join(path, filename)
                    header = laspy.LasHeader(point_format=2, version='1.2')
                    with laspy.open(source=facility_path, mode='w', header=header) as las_write:
                        las_write.write_points(chunk)

但是，它会引发此错误：

\lib\site-packages\laspy\lib.py", line 318, in convert
    header = copy.deepcopy(source_las.header)
\lib\site-packages\laspy\point\record.py", line 230, in __getattr__
    raise AttributeError("{} is not a valid dimension".format(item)) from None
    AttributeError: header is not a valid dimension

Answer 1

laspy.convert需要一个LasData类型的对象，而不仅仅是点，块迭代器返回一个ScaleAwarePointRecord

要实现使用块读/写的转换，您必须创建一个用作缓冲区的点记录，并使用copy_fields_from。

示例：

with laspy.open(input_path, mode='r') as las_open:
    header = laspy.LasHeader(point_format=6, version='1.4')
    with laspy.open(output_path, header=header, mode="w") as las_write:

        buffer_chunk = laspy.PackedPointRecord.zeros(point_count=chunk_size, point_format=header.point_format)

        for input_chunk in las_open.chunk_iterator(chunk_size):
            output_chunk = buffer_chunk[:len(input_chunk)]
            output_chunk.copy_fields_from(input_chunk)
            las_write.write_points(output_chunk)