BytesIO对象到图像

Question

I'm trying to use Pillow in my program to save a bytestring from my camera to a file. Here's an example with a small raw byte string from my camera which should represent a greyscale image of resolution 10x5 pixels, using LSB and 12bit:

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'
rawIO = io.BytesIO(rawBytes)
rawIO.seek(0)
byteImg = Image.open(rawIO)
byteImg.save('test.png', 'PNG')

However I get the following error in line 7 (with Image.open ):

OSError: cannot identify image file <_io.BytesIO object at 0x00000000041FC9A8>

The docs from Pillow implied this was the way to go.

I tried to apply the solutions from

• PIL open() method not working with BytesIO
• PIL cannot identify image file for io.BytesIO object

but can't get it working. Why isn't this working?

Answer 1

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()