Reversing bits in a byte
Hi, I have a 'bytes' object which contains a simple bitmap image (i.e. 1 bit per pixel). I can't work out how I would go about displaying this image. Does anyone have any thoughts? All the best, Rob Robert Flintham Trainee Clinical Scientist - MRI Tel: +44 (0)121 371 7000 Email: robert.flint...@uhb.nhs.uk Web: http://www.uhb.nhs.uk We're bringing the world's most advanced cancer treatments to Birmingham. Find out more at www.qecancerappeal.org<http://www.qecancerappeal.org> or text QEHB01 £5 to 70070 to donate £5 to our appeal. RRPPS Medical Physics - University Hospitals Birmingham NHS Foundation Trust 63 Melchett Road, Kings Norton, Birmingham, B30 3HP [cid:image001.gif@01CE1E6D.AF57F9D0] DISCLAIMER: This email and any attachments hereto contains proprietary information, some or all of which may be confidential or legally privileged. It is for the exclusive use of the intended recipient(s) only. If an addressing or transmission error has misdirected this e-mail and you are not the intended recipient(s), please notify the author by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail or any attachments, as this may be unlawful. <>-- http://mail.python.org/mailman/listinfo/python-list
RE: Reversing bits in a byte
Sorry, the subject line was for a related question that I decided not to ask, I forgot to change it when I changed my email. I've changed it now! I'm using Python 3.3 on Windows with the pydicom module (http://code.google.com/p/pydicom/). Using pydicom, I've ended up with a "bytes" object of length (512*512/8 = 32768) containing a 512x512 1-bit bitmap (i.e. each byte represents 8 pixels of either 1 or 0). When I print this to screen I get: 'b\x00\x00\x00.' I can unpack this to a tuple of the integer representations of binary data, but that doesn't really help as presume I need the binary (8 digit) representation to be able to translate that into an image. I wasn't sure which GUI library to use, so haven't specified one. As it's Python 3, Tkinter is available. I also have matplotlib and numpy installed, and PIL. Ideally, I'd like to be able to access the pixel data in the form of a numpy array so that I can perform image-processing tasks on the data. So now that I've explained myself slightly more fully, does anyone have any thoughts on how to do this? All the best, Rob Robert Flintham Trainee Clinical Scientist - MRI Tel: +44 (0)121 371 7000 Email: robert.flint...@uhb.nhs.uk Web: http://www.uhb.nhs.uk We're bringing the world's most advanced cancer treatments to Birmingham. Find out more at www.qecancerappeal.org or text QEHB01 £5 to 70070 to donate £5 to our appeal. RRPPS Medical Physics - University Hospitals Birmingham NHS Foundation Trust 63 Melchett Road, Kings Norton, Birmingham, B30 3HP ð Delivering the best in care -Original Message- From: Python-list [mailto:python-list-bounces+robert.flintham=uhb.nhs...@python.org] On Behalf Of Dave Angel Sent: 12 March 2013 12:47 To: python-list@python.org Subject: Re: Reversing bits in a byte On 03/11/2013 11:32 AM, Robert Flintham wrote: > Hi, > > I have a 'bytes' object which contains a simple bitmap image (i.e. 1 bit per > pixel). I can't work out how I would go about displaying this image. Does > anyone have any thoughts? > > All the best, > Rob > > How does your subject line relate to your question? But more importantly, what version of Python, what OS, and which GUI library (wxpython, qt, etc.) are you used to? Specify those, and somebody familiar with that particular library will probably pop up with an answer. -- DaveA -- http://mail.python.org/mailman/listinfo/python-list DISCLAIMER: This email and any attachments hereto contains proprietary information, some or all of which may be confidential or legally privileged. It is for the exclusive use of the intended recipient(s) only. If an addressing or transmission error has misdirected this e-mail and you are not the intended recipient(s), please notify the author by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail or any attachments, as this may be unlawful. -- http://mail.python.org/mailman/listinfo/python-list
RE: Reversing bits in a byte
Further to my earlier reply to Dave:
I'd like to either display the image in a GUI, or save it in a format that can
be opened easily in Windows (like a PNG or a 24-bit BMP).
I know the dimensions as it's coming from the header of a DICOM file. I'm
trying to analyse DICOM images where an 'overlay' image is stored as a bitmap
in the header information. So the bitmap data is one DICOM tag (6000,3000) and
the height and width of the overlay are in two other tags (6000,0010) and
(6000,0011).
All the best,
Rob
Robert Flintham
Trainee Clinical Scientist - MRI
Tel: +44 (0)121 371 7000
Email: robert.flint...@uhb.nhs.uk
Web: http://www.uhb.nhs.uk
We're bringing the world's most advanced cancer treatments to Birmingham.
Find out more at www.qecancerappeal.org or text QEHB01 £5 to 70070 to donate £5
to our appeal.
RRPPS
Medical Physics - University Hospitals Birmingham NHS Foundation Trust
63 Melchett Road, Kings Norton,
Birmingham, B30 3HP
ð Delivering the best in care
-Original Message-
From: Tim Chase [mailto:python.l...@tim.thechases.com]
Sent: 12 March 2013 13:21
To: Robert Flintham
Cc: 'python-list@python.org'
Subject: Re: Reversing bits in a byte
On 2013-03-11 15:32, Robert Flintham wrote:
> I have a 'bytes' object which contains a simple bitmap image (i.e.
> 1 bit per pixel). I can't work out how I would go about displaying
> this image. Does anyone have any thoughts?
You'd need to detail
- how you want to display it (console, GUI, web page)
- how you know what the dimensions are
- the bit order
It could be something as simple as
HEIGHT = 40
some_bytes = file('data.bin').read()
WIDTH = len(some_bytes) // HEIGHT
for i, byte in enumerate(some_bytes):
if i and i % WIDTH == 0:
print # a new line
for bit in range(8):
if byte & (1 << bit):
print '*',
else:
print ' ',
-tkc
> DISCLAIMER:
[trim a paragraph of useless junk]
Please remove these disclaimers if at all possible. You're posting to a public
forum, which pretty much waives all credibility to the disclaimer (not that
they've held much legal standing in any argument I've heard).
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"module could not be found" error
Hi, I'm trying to run the following, with representing an array of floating point numbers: import numpy as np import scipy as sp from scipy import optimize xdata= ydata= def t2fit(x,T2,A): return A * np.exp(-x/T2) popt, pcov = optimize.curve_fit(t2fit, xdata, ydata, p0=None, sigma=None) But I'm getting an ImportError: Traceback (most recent call last): File "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\pydevd.py", line 1397, in debugger.run(setup['file'], None, None) File "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\pydevd.py", line 1090, in run pydev_imports.execfile(file, globals, locals) #execute the script File "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\_pydev_execfile.py", line 38, in execfile exec(compile(contents+"\n", file, 'exec'), glob, loc) #execute the script File "K:\PROGRAMMING\MRI_Python\fatfrac.py", line 7, in from scipy import optimize File "K:\Python33\lib\site-packages\scipy\optimize\__init__.py", line 147, in from ._minimize import * File "K:\Python33\lib\site-packages\scipy\optimize\_minimize.py", line 29, in from .lbfgsb import _minimize_lbfgsb File "K:\Python33\lib\site-packages\scipy\optimize\lbfgsb.py", line 40, in from . import _lbfgsb ImportError: DLL load failed: The specified module could not be found. I've checked the path, and the file lbfgsb.py is definitely at that location (as are optimize.py and _minimize.py). Does anyone know why I'm getting the error? All the best, Rob Robert Flintham Trainee Clinical Scientist - MRI Tel: +44 (0)121 371 7000 Email: robert.flint...@uhb.nhs.uk Web: http://www.uhb.nhs.uk We're bringing the world's most advanced cancer treatments to Birmingham. Find out more at www.qecancerappeal.org<http://www.qecancerappeal.org> or text QEHB01 £5 to 70070 to donate £5 to our appeal. RRPPS Medical Physics - University Hospitals Birmingham NHS Foundation Trust 63 Melchett Road, Kings Norton, Birmingham, B30 3HP [cid:image001.gif@01CE24B3.0686DA50] DISCLAIMER: This email and any attachments hereto contains proprietary information, some or all of which may be confidential or legally privileged. It is for the exclusive use of the intended recipient(s) only. If an addressing or transmission error has misdirected this e-mail and you are not the intended recipient(s), please notify the author by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail or any attachments, as this may be unlawful. <>-- http://mail.python.org/mailman/listinfo/python-list
RE: "module could not be found" error
Joel: The 2.7 is the version number of the PyDev plugin for Eclipse, rather than the Python version number. Dave: I don't have access to the system's PATH environment variable because this computer is very tightly controlled. However, my user PATH environment contains "K:\Python33", which I haven't had a problem with before when importing modules from site-packages. The directory "site-packages\scipy\optimize" contains (among other things): __init.py__ _minimize.py _lbfgsb.pyd lbfgsb.py So I'm not entirely sure what it is that it can't find. All the best, Rob (Apologies for lengthy disclaimers, I can't get rid of them. Work email.) -Original Message- From: Python-list [mailto:python-list-bounces+robert.flintham=uhb.nhs...@python.org] On Behalf Of Dave Angel Sent: 19 March 2013 15:24 To: python-list@python.org Subject: Re: "module could not be found" error On 03/19/2013 11:10 AM, Robert Flintham wrote: > Hi, > > I'm trying to run the following, with representing an array of > floating point numbers: > > > import numpy as np > import scipy as sp > from scipy import optimize > > xdata= > ydata= > > def t2fit(x,T2,A): > return A * np.exp(-x/T2) > > popt, pcov = optimize.curve_fit(t2fit, xdata, ydata, p0=None, > sigma=None) > > > But I'm getting an ImportError: > > Traceback (most recent call last): >File > "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\pydevd.py", line > 1397, in > debugger.run(setup['file'], None, None) >File > "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\pydevd.py", line > 1090, in run > pydev_imports.execfile(file, globals, locals) #execute the script > File > "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\_pydev_execfile.py", > line 38, in execfile > exec(compile(contents+"\n", file, 'exec'), glob, loc) #execute the script >File "K:\PROGRAMMING\MRI_Python\fatfrac.py", line 7, in > from scipy import optimize >File "K:\Python33\lib\site-packages\scipy\optimize\__init__.py", line 147, > in > from ._minimize import * >File "K:\Python33\lib\site-packages\scipy\optimize\_minimize.py", line 29, > in > from .lbfgsb import _minimize_lbfgsb >File "K:\Python33\lib\site-packages\scipy\optimize\lbfgsb.py", line 40, in > > from . import _lbfgsb > ImportError: DLL load failed: The specified module could not be found. > > > I've checked the path, and the file lbfgsb.py is definitely at that location > (as are optimize.py and _minimize.py). Does anyone know why I'm getting the > error? > You're on Windows, so presumably you're using the PATH environment variable for the following search. You checked the path for what file? it's looking for _lhfgsb.dll, or maybe _lhfgsb.pyc which is imported by lbfgsh.py. The latter file is found, as you can tell from the stack trace. That's the file you got the error in. So perhaps the dll isn't being loaded into a directory that's on the PATH. -- DaveA -- http://mail.python.org/mailman/listinfo/python-list DISCLAIMER: This email and any attachments hereto contains proprietary information, some or all of which may be confidential or legally privileged. It is for the exclusive use of the intended recipient(s) only. If an addressing or transmission error has misdirected this e-mail and you are not the intended recipient(s), please notify the author by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail or any attachments, as this may be unlawful. -- http://mail.python.org/mailman/listinfo/python-list
Drag and drop in Windows
Hello all,
Sorry to post such a generic question, but after searching the interwebs I'm
not really any wiser about how to start with this.
I'm currently on:
Windows XP
Python 2.7
I'm trying to create a small window in Python 2.7, that when you drop a file
onto it from Windows explorer returns the file's path so that I can then go on
to open the file and do whatever with it. I was planning on using Tkinter
because that's what I've used before for GUI's, but I can be swayed from this
if needs be.
I've found this (TkDND):
http://wiki.tcl.tk/2768
But I don't know how to implement this in Python. The Windows binary for it
comes as a set of ".tcl" files and a single ".dll" file.
The two options I've stumbled across seem to be
1. a Python wrapper for the DLL (I think to wrap C code??), which can then be
imported like you'd import a Python package
2. direct implementation of the Tcl file [tk.eval('source ...')], but I don't
reallu understand what's going on with this - can you only execute a "main" bit
of Tcl files rather than implementing individual functions?
Any input (however minimal) is definitely appreciated! I've included what I
think are probably the relevant functions from the Tcl files at the bottom of
the email, but I don't really understand the nuts and bolts of the code.
All the best,
Rob
[From "tkdnd.tcl"...]
#
# Command tkdnd::drag_source
#
proc tkdnd::drag_source { mode path { types {} } { event 1 } } {
set tags [bindtags $path]
set idx [lsearch $tags "TkDND_Drag*"]
switch -- $mode {
register {
if { $idx != -1 } {
bindtags $path [lreplace $tags $idx $idx TkDND_Drag$event]
} else {
bindtags $path [concat $tags TkDND_Drag$event]
}
set types [platform_specific_types $types]
set old_types [bind $path <>]
foreach type $types {
if {[lsearch $old_types $type] < 0} {lappend old_types $type}
}
bind $path <> $old_types
}
unregister {
if { $idx != -1 } {
bindtags $path [lreplace $tags $idx $idx]
}
}
}
};# tkdnd::drag_source
[From "tkdnd_windows.tcl"...]
#
# Command olednd::_GetDragSource
#
proc olednd::_GetDragSource { } {
variable _drag_source
return $_drag_source
};# olednd::_GetDragSource
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RE: Drag and drop in Windows
Thanks Christian.
I've tried the following code:
import Tkinter
root = Tkinter.Tk()
root.title("DICOM Opener")
root.tk.eval('lappend auto_path {K:/Python27/Lib/site-packages/tkdnd2.6}')
root.tk.eval('package require tkdnd')
But I get the following traceback:
Traceback (most recent call last):
File "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\pydevd.py",
line 1397, in
debugger.run(setup['file'], None, None)
File "K:\eclipse\plugins\org.python.pydev_2.7.1.2012100913\pysrc\pydevd.py",
line 1090, in run
pydev_imports.execfile(file, globals, locals) #execute the script
File "K:\PROGRAMMING\mripy\dicom_opener.py", line 7, in
root.tk.eval('package require tkdnd')
_tkinter.TclError: couldn't load library
"K:/Python27/Lib/tkdnd2.6/tkdnd26.dll": invalid argument
Is "invalid argument" as generic as it sounds, or does it mean something
specific in this case? Is Tcl expecting an additional argument in the 'package
require' line?
I assume the append auto path line is correct as it seems to have found the DLL
(presumably from pkgIndex.tcl).
Apologies for any disclaimers that pad out this message - it's a work email
account and they get added after I hit "send".
All the best,
Rob
-Original Message-
From: Python-list
[mailto:python-list-bounces+robert.flintham=uhb.nhs...@python.org] On Behalf Of
Christian Gollwitzer
Sent: 29 April 2013 21:38
To: python-list@python.org
Subject: Re: Drag and drop in Windows
Hi Robert,
Am 29.04.13 12:25, schrieb Robert Flintham:
> I've found this (TkDND):
>
> http://wiki.tcl.tk/2768
> But I don't know how to implement this in Python. The Windows binary > for
> it comes as a set of ".tcl" files and a single ".dll" file.
> 2.direct implementation of the Tcl file [tk.eval('source ...')], but I >
> don't reallu understand what's going on with this - can you only execute >
> a "main" bit of Tcl files rather than implementing individual functions?
I can only comment on the Tcl side, since I'm not an expert in the Tkinter
coupling mechanism. TkDND is indeed the way to go if you want native
drag'n'drop support. The first step would indeed be to load the package into
the Tcl interpreter. You need to:
1) Create a folder for the packages, put the files in a subfolder Typically,
this is something like lib/tkdnd, and at that level there must be the
"pkgIndex.tcl" file
2) Append the lib/ folder to the auto path tk.eval('lappend auto_path
{mypath/lib}') (the braces are Tcl's quoting mechanism)
3) load the package
tk.eval('package require tkdnd')
Then, you need to "register the target", i.e. declare a widget that it accepts
files. Here, you need the Tk path name of the widget, which is retrieved by
__str__:
tk.eval('tkdnd::drop_target register ' + yourwidget +' *')
Then, if you drop something, the widget recieves a virtual event
<> . Now this is tricky, I don't know how to bind to that
event. Following the tutorial for Tcl on http://wiki.tcl.tk/36708, I suppose
something like
yourwidget.bind("<>", filesdropped)
should in principle work, but how to get the data out of it? It is stuffed into
the %D bind substitution. Usual events store the MouseWheel distance in this
field; so maybe you can get it from the field event.delta. I can't test it now,
but I am a bit skeptical whether this works with the guts of TkInter. If not,
you'd need to do some more forwarding from the Tcl side.
Christian
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RE: Drag and drop in Windows
Thanks Kevin, that looks great. It's having trouble finding TkDND though - is there a certain place in the "Python27" directory that it's most likely to look? It's currently under Lib/site-packages, but I'm suspicious that Tk/Tkinter has its own library somewhere. Christian - you were right. The TkDND DLL looks to be for x64. Is there a way around this? All the best, Rob -Original Message- From: Python-list [mailto:python-list-bounces+robert.flintham=uhb.nhs...@python.org] On Behalf Of Kevin Walzer Sent: 01 May 2013 00:10 To: python-list@python.org Subject: Re: Drag and drop in Windows Official link: http://tkinterdnd.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list DISCLAIMER: This email and any attachments hereto contains proprietary information, some or all of which may be confidential or legally privileged. It is for the exclusive use of the intended recipient(s) only. If an addressing or transmission error has misdirected this e-mail and you are not the intended recipient(s), please notify the author by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail or any attachments, as this may be unlawful. -- http://mail.python.org/mailman/listinfo/python-list
