Question: From a stream of TCP segments, I pulled binary data with the help of wireshark, which I later found out is a bmp file. Then I load one big line of binary data, clear it from spaces, newline character and intermediate "=". I mean their separation at the end of each TCP segment. Then I execute the following code: import base64 tst = sec_orig.replace('\n', '').replace(' ', '').replace('=', '') decoded_data = base64.b64decode(tst + '=', altchars=None, validate=True)  Raw data from wireshark: Qk02MAEAAAAAADYEAAAoAAAAQAEAAPAAAAABAAgAAAAAAAAAAABCCwAAQgsAAAABAAAAAQAAAAAA AAAAAAAAAKAAAPAAAPAAAAAA/PwA/PwAAPxw/AD8/PwAoKCgAEBAQABQMAAAWFhYANCg0ACgkHAA oJBwANDQ0ADYyLQA1JgAANyEAAC4uLgAaPR0APCoAAAgICAAAJD8AAAA+ACoqKgAvLy8AMzMzADc 3NwA7OzsAPz8/AAAAAAAAAAQAAAAIAAAADAAAABEAAAAVAAAAGQAAAB0AAAAiAAAAJgAAACoAAAA vAAAAMwAAADcAAAA7AAAAPwAAAAAAAAQAAAAIAAAADAAAABEAAAAVAAAAGQAAAB0AAAAiAAAAJgA AACoAAAAvAAAAMwAAADcAAAA7AAAAPwAAAAAAAAQAAAAIAAAADAAAABEAAAAVAAAAGQAAAB0AAAA iAAAAJgAAACoAAAAvAAAAMwAAADcAAAA7AAAAPwAAAD8AAAA/BAAAPwgAAD8MAAA/EQAAPxUAAD8 ZAAA/HQAAPyIAAD8mAAA/KgAAPy8AAD8zAAA/NwAAPzsAAD8/AAA/PwAAOz8AADc/AAAzPwAALz8 AACo/AAAmPwAAIj8AAB0/AAAZPwAAFT8AABE/AAAMPwAACD8AAAQ/AAAAPwAAAD8AAAA/BAAAPwg AAD8MAAA/EQAAPxUAAD8ZAAA/HQAAPyIAAD8mAAA/KgAAPy8AAD8zAAA/NwAAPzsAAD8/AAA/PwA AOz8AADc/AAAzPwAALz8AACo/AAAmPwAAIj8AAB0/AAAZPwAAFT8AABE/AAAMPwAACD8AAAQ/AAA APwAAAD8ABAA/AAgAPwAMAD8AEQA/ABUAPwAZAD8AHQA/ACIAPwAmAD8AKgA/AC8APwAzAD8ANwA /ADsAPwA/AD8APwA/AD8AOwA/ADcAPwAzAD8ALwA/ACoAPwAmAD8AIgA/AB0APwAZAD8AFQA/ABE APwAMAD8ACAA/AAQAPwAAAAAAAAA ... BQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUF BQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUF BQUFBQUFBQUFBQUFBQUFBQkFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUF BQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUJ  And I get a certain binary string from base64: b'BM60\x01\x00\x00\x00\x00\x006\x04\x00\x00(\x00\x00\x00@\x01\x00\x00\xf0\x00\x00\x00\x01\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00B\x0b\x00\x00B\x0b\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xa0\x00\x00\xf0\x00\x00\xf0\x00\x00\x00\x00\xfc\xfc\x00\xfc\xfc\x00\x00\xfcp\xfc\x00\xfc\xfc\xfc\x00\xa0\xa0\xa0\x00@@@\x00P0\x00\x00XXX\x00\xd0\xa0\xd0\x00\xa0\x90p\x00\xa0\x90p\x00\xd0\xd0\xd0\x00\xd8\xc8\xb4\x00\xd4\x98\x00\x00\xdc\x84\x00\x00\xb8\xb8\xb8\x00h\xf4t\x00\xf0\xa8\x00\x00 \x00\x00\x90\xfc\x00\x00\x00\xf8\x00\xa8\xa8\xa8\x00\xbc\xbc\xbc\x00\xcc\xcc\xcc\x00\xdc\xdc\xdc\x00\xec\xec\xec\x00 ... \t\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\t'  Then using the Pillow library I display this image obtained from the TCP stream segments and get the following image: from PIL import Image import io Image.open(io.BytesIO(decoded_data))  distorted bmp image  As far as I understand, somewhere somehow incorrectly taken shift relative to bmp color matrix, but I do not understand where I make a mistake, can you please suggest The image is displayed, but with a staggered pitch that I don't know how to normalize yet.

Answer: Using this script, I get an uncorrupted image shown: import io from pathlib import Path import yaml from PIL import Image packets = yaml.safe_load(Path("5bksih1B.txt").read_text()) raw = b"".join([p["data"] for p in packets]) im = Image.open(io.BytesIO(raw)) im.show()  There are two 320x240 images in the full data you pasted, here are the results:   Note: that "marker" Qk02MA you noticed is actually the start of a bitmap header: >>> import base64 >>> base64.b64decode("Qk02MA==") b'BM60'  To continuously read frames from a stream, first parse this header, and then consume the correct amount of bytes from a buffer.