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Python Discussion Thread
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Feb 27th, 2009

Reading image as binary file

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Hello,

Is there a way to read an imagefile into a binary string?

I know I can use

Python Syntax (Toggle Plain Text)
open(FILE,"rb")
open(FILE,"rb")

but this produces something unreadable that looks a bit like hexdata (I'm a newbie here :-). What I am trying to accomplish is to convert it to a string of ones and zeros. Is this possible?

Thx in advance!

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Bart6114

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Feb 27th, 2009

Re: Reading image as binary file

Search this forum for Vega's decimal to binary converter. Your code is reading the data correctly; now you just have to find the right way to display it.

Jeff

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Feb 28th, 2009

Re: Reading image as binary file

Thank you for you're reply, but I still can't figure out how to do this.
Vesa's codesnippet is meant for decimal types and not for binarystrings (atleast to my understanding ;).

Python Syntax (Toggle Plain Text)
while n >0:
	Bstr=str(n % 2) + Bstr
	n= n>>1
	print(n)
while n >0:
	Bstr=str(n % 2) + Bstr
	n= n>>1
	print(n)

While this works fine for decimals, it does not read binarystrings that I opened trough;

Python Syntax (Toggle Plain Text)
File=open(FILE, "rb")
for line in File:<blockquote>Bstr=(line % 2) + Bstr</blockquote>
File=open(FILE, "rb")
for line in File:<blockquote>Bstr=(line % 2) + Bstr</blockquote>

Because this doesn't work for bin types.

for example;

Quote ...

>>> b=bin(5)
>>> b
'0b101'
>>> (b % 2)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: not all arguments converted during string formatting
>>>

And this seems pretty logical as it is not an int, float, or decimaltype. How do you suggest I'd use vesa's sample to output a file opened as binary ("rd") to one's and zero's?

Thx in advance!

Bart6114

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Mar 1st, 2009

Re: Reading image as binary file

I took code I had to dump hexadecimal image data and added a binary option to it ,,,

python Syntax (Toggle Plain Text)
# hexadecimal and binary dump of image file data
# modified to work with Python30
 
import binascii
 
try:
    # pick an image file you have in the working directory
    # or give the full file path ...
    image_file = 'py.ico'
    fin = open(image_file, "rb")
    data = fin.read()
    fin.close()
except IOError:
    print("Image file %s not found" % imageFile)
    raise SystemExit
 
# convert every byte of data to the corresponding 2-digit hexadecimal
hex_str = str(binascii.hexlify(data))
# now create a list of 2-digit hexadecimals
hex_list = []
bin_list = []
for ix in range(2, len(hex_str)-1, 2):
    hex = hex_str[ix]+hex_str[ix+1]
    hex_list.append(hex)
    bin_list.append(bin(int(hex, 16))[2:])
 
#print(bin_list)
bin_str = "".join(bin_list)
print(bin_str)
# hexadecimal and binary dump of image file data
# modified to work with Python30

import binascii

try:
    # pick an image file you have in the working directory
    # or give the full file path ...
    image_file = 'py.ico'
    fin = open(image_file, "rb")
    data = fin.read()
    fin.close()
except IOError:
    print("Image file %s not found" % imageFile)
    raise SystemExit

# convert every byte of data to the corresponding 2-digit hexadecimal
hex_str = str(binascii.hexlify(data))
# now create a list of 2-digit hexadecimals
hex_list = []
bin_list = []
for ix in range(2, len(hex_str)-1, 2):
    hex = hex_str[ix]+hex_str[ix+1]
    hex_list.append(hex)
    bin_list.append(bin(int(hex, 16))[2:])

#print(bin_list)
bin_str = "".join(bin_list)
print(bin_str)

The binary string output is pretty useless, since you can never recover any data back.

If you want to send binary image data as a string, you have to use Python module base64.

Last edited by vegaseat; Mar 1st, 2009 at 3:06 am.

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DaniWeb's Hypocrite

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Mar 1st, 2009

Re: Reading image as binary file

Thank a lot Vegaseat!

This is exactly what I needed. I know I can't recover any data back. But I'm gonna use it to feed it through a neural net. Seeing the output I think it's not very effective analysing image data (I'm now using PIL for that). But I think it can be very useful while analysing textinput with a neuralnet!

Thanks again!

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