Python PIL bytes to Image

Question

import PIL
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
import urllib.request

with urllib.request.urlopen('http://pastebin.ca/raw/2311595') as in_file:
    hex_data = in_file.read()
print(hex_data)
img = Image.frombuffer('RGB', (320,240), hex_data) #i have tried fromstring
draw = ImageDraw.Draw(img)
font = ImageFont.truetype("arial.ttf",14)
draw.text((0, 220),"This is a test11",(255,255,0),font=font)
draw = ImageDraw.Draw(img)
img.save("a_test.jpg")

i m trying to convert binary to image,and then draw the text.but i get the error with:

img = Image.frombuffer('RGB', (320,240), hex_data) 
raise ValueError("not enough image data")
ValueError: not enough image data

i have uploaded the bytes string at here http://pastebin.ca/raw/2311595
and the picture size i can sure that is 320x240

ADDITIONAL

here is what i can sure the picture bytes string are from 320x240,just run the code will create a image from the bytes string

import urllib.request
import binascii
import struct

# Download the data.
with urllib.request.urlopen('http://pastebin.ca/raw/2311595') as in_file:
     hex_data = in_file.read()
# Unhexlify the data.
bin_data = binascii.unhexlify(hex_data)
print(bin_data)
# Remove the embedded lengths.
jpeg_data = bin_data
# Write out the JPEG.
with open('out.jpg', 'wb') as out_file:
    out_file.write(jpeg_data)

SOLVED, THIS IS THE CODE UPDATED

from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
import urllib.request
import io
import binascii

data = urllib.request.urlopen('http://pastebin.ca/raw/2311595').read()
r_data = binascii.unhexlify(data)
#r_data = "".unhexlify(chr(int(b_data[i:i+2],16)) for i in range(0, len(b_data),2))

stream = io.BytesIO(r_data)

img = Image.open(stream)
draw = ImageDraw.Draw(img)
font = ImageFont.truetype("arial.ttf",14)
draw.text((0, 220),"This is a test11",(255,255,0),font=font)
draw = ImageDraw.Draw(img)
img.save("a_test.png")

Solution 1

That image is not formed of raw bytes - rather it is an encoded JPEG file. Moreover, you are not parsing the ascii HEX representation of the stream into proper bytes: that is, an "ff" sequence in that file is being passed to PIL as two c letters "f" instead of a byte with the number 255.

So, first, you decode the string to a proper byte sequence - sorry for the convolution - it is likely there is a better way to do that, but I am on a slow day:

data = urllib.urlopen("http://pastebin.ca/raw/2311595").read()
r_data = "".join(chr(int(data[i:i+2],16)) for i in range(0, len(data),2)) 

Ah, C.Y. posted on hte comment - this way:

>>> import binascii
>>> b_data = binascii.unhexlify(data)

And now, you import it to PIL as a JPEG image:

>>> from PIL import Image
>>> import cStringIO as StringIO
>>> stream = StringIO.StringIO(b_data)
>>> img = Image.open(stream)
>>> img.size
(320, 240)

Solution 2

as other say, Python 3 better use io.BytesIO

import io
from PIL import Image

imageFileObj = open(imageFilename, "rb")
imageBinaryBytes = imageFileObj.read()
imageStream = io.BytesIO(imageBinaryBytes)
imageFile = Image.open(imageStream)
print("imageFile.size=%s" % imageFile.size)

Comments

[Fredrik Pihl]

the bytestring is 118216 bytes long; how can that be 320x240? RGB (3x8-bit pixels, true colour)

[Admin]

you can try bin_data = binascii.unhexlify(hex_data) the bytes,will become a picture

[Mark Ransom]

@C.Y when I try that I only get 9108 bytes, that's not even enough for 320x240 at 1 bit per pixel.

[Admin]

raise IOError("cannot identify image file") OSError: cannot identify image file #this is the error i get

[jsbueno]

C.Y.: did youdo the proper hex-decoding (in the 2 previous examples) before passing it to PIL?

[Admin]

@MarkRansom i m using python 3.3, and i have updated my code,it doesn't work

[Mark Ransom]

@C.Y go back to using unhexlify instead of join since Python 3 will interpret all those bytes as Unicode.

[mmgp]

@C.Y I didn't check your code or any other code in the question and answer. But, are you sure you actually have a working PIL build ? There is no PIL release for Python 3, are you using some third-party port and is it guaranteed to work in exactly the same way of the official one for Python 2 (note that PIL has a very limited test suite, so passing it guarantees nearly nothing) ?

[Admin]

@MarkRansom stream = io.StringIO(r_data) TypeError: initial_value must be str or None, not bytes //after i change to use unhexlify i get the error

[Mark Ransom]

@C.Y use BytesIO instead of StringIO.

[Admin]

@MarkRansom after i draw the text,i want to convert back bytes and store in Mysql Blob,how to convert back to bytes string?

[Mark Ransom]

@C.Y Image.save back into another BytesIO object should do it.

[Admin]

@MarkRansom are you missunderstanding? i want to convert img to bytes string.and store in Mysql database.

[Pedro P. Camellon]

I'm reading a png file from within a zip and this worked for me. Thanks!