I'm not sure what the resulting image should look like (do you have an example?), but if you want to unpack an packed image where each pixel has 12 bits into a 16-bit image, you could use this code:

import io
from PIL import Image

rawbytes = b'_\x00`\x00[\x00^\x00`\x00`\x00\\\x00\\\x00Z\x00\\\x00_\x00[\x00\\\x00\\\x00`\x00]\x00\\\x00^\x00_\x00\\\x00\\\x00]\x00]\x00_\x00]\x00]\x00Z\x00\\\x00^\x00\\\x00Z\x00^\x00_\x00]\x00^\x00Z\x00\\\x00Z\x00\\\x00]\x00_\x00]\x00^\x00Z\x00[\x00[\x00X\x00]\x00]\x00Z\x00'
im = Image.frombuffer("I;16", (5, 10), rawbytes, "raw", "I;12")
im.show()

(This solution is from the author himself. I have just moved it here.)

SOLUTION:

# This portion is part of my test code
byteImgIO = io.BytesIO()
byteImg = Image.open("some/location/to/a/file/in/my/directories.png")
byteImg.save(byteImgIO, "PNG")
byteImgIO.seek(0)
byteImg = byteImgIO.read()


# Non test code
dataBytesIO = io.BytesIO(byteImg)
Image.open(dataBytesIO)

The problem was with the way that Image.tobytes()was returning the byte object. It appeared to be invalid data and the 'encoding' couldn't be anything other than raw which still appeared to output wrong data since almost every byte appeared in the format \xff\. However, saving the bytes via BytesIO and using the .read() function to read the entire image gave the correct bytes that when needed later could actually be used.

You can use the BytesIO class to get a wrapper around strings that behaves like a file. The BytesIO object provides the same interface as a file, but saves the contents just in memory:

import io

with io.BytesIO() as output:
    image.save(output, format="GIF")
    contents = output.getvalue()

You have to explicitly specify the output format with the format parameter, otherwise PIL will raise an error when trying to automatically detect it.

If you loaded the image from a file it has a format property that contains the original file format, so in this case you can use format=image.format.

In old Python 2 versions before introduction of the io module you would have used the StringIO module instead.

When we use the method read_in_stream, we need to provide a stream. But the code BytesIO.getvalue will return the content of the stream as string or bytes. So please update code as below

buf = io.BytesIO()
image.save(buf, format='JPEG')
computervision_client.read_in_stream(buf)

For more details, please refer to here

Update

Regarding the issue, I suggest you use rest API to implement your need.

import io
import requests
from PIL import Image
import time
url = "{your endpoint}/vision/v3.1/read/analyze"
key = ''
headers = {
    'Ocp-Apim-Subscription-Key': key,
    'Content-Type': 'application/octet-stream'
}

// process image
...
with io.BytesIO() as buf:
    im.save(buf, 'jpeg')
    response = requests.request(
        "POST", url, headers=headers, data=buf.getvalue())
    
    # get result

    while True:
        res = requests.request(
            "GET", response.headers['Operation-Location'], headers=headers)
        status = res.json()['status']
        if status == 'succeeded':
            print(res.json()['analyzeResult'])
            break
        time.sleep(1)