我正在使用 MATLAB 和 python 读取 bin 文件。 他们以不同的方式阅读 header

Question

I am trying to read a binary file using MATLAB and python. MATLAB is producing header

[80 0 8 0 1780 400 357 22441] whereas python is reading the header

[ 80 8 1780 357 258 22440 2040 2048].

What is the wrong I am doing??? I am running both on windows.

**MATLAB code:** 
    fid = fopen(file_name);
    fread(fid,isTherePos(1)-1,'uint32','l'); 
    header = fread(fid,8,'uint16','l')

**Python code:** 
     with open(filename, mode='rb') as f:
       b = f.read()
       np_data = np.frombuffer(b, dtype='<I')
       srtOfLine = LidarMRC.findStartOfLine(filename)
       header = np_data[srtOfLine[0][0]:srtOfLine[0][0] +8].astype('<H')
       print(header)

Answer 1

In the MATLAB code, you read the first "isTherePos(1)-1" bytes as 32-bit values. Then you read the header as 8x 16-bit values.

In the Python code, you read the whole file into np_data as 32-bit values. The "astype" function does not re-interpret those bytes. It takes each 32-bit entity and truncates it to 16 bits, which is exactly what you see.

You should read np_data as dtype=np.uint16 , then adjust your srtOfLine number to multiply by 2.