[PyQt] QImage.save() traceback

[Sergi Blanch i Torné]

I don't like to be rude insisting, but after the script no one says anything 
in the list. My question can be reduced to if it's possible to have more 
information that a False when I save the image.

Thanks

/Sergi.

On Wednesday 07 May 2008 09:20:54 Sergi Blanch i Torné wrote:
> On Tuesday 06 May 2008 21:24:49 Hans-Peter Jansen wrote:
> > [ignore the last message..]
> >
> > Am Dienstag, 6. Mai 2008 schrieb Sergi Blanch i Torné:
> > > On Tuesday 06 May 2008 13:28:50 Hans-Peter Jansen wrote:
> > > > Am Dienstag, 6. Mai 2008 schrieb Sergi Blanch i Torné:
> > > > > Hi,
> > > > >
> > > > > I'm try to save some images from a QImage object, but the save
> > > > > method is only responding me false. I try to fix why this method
> > > > > cannot do that, but I could know the real reason.
> > > > >
> > > > > Do you know how to allows this method to be more expressive to
> > > > > explains me something?
> > > >
> > > > Our favorite PyQt-ML mantra applies:
> > > >
> > > > Om, please provide a self contained example demonstrating your
> > > > problem, Om.
> > > >
> > > > Pete
> > >
> > > mmm, interesting, It can be useful (joking).
> >
> > Well, while I made a funny statement, it was meant serious.
>
> Ok, but I say kidding because my missing information was the really
> important thing to ask where. Let me send the information that you ask for.
>
> > > Yes, I want to explain the
> > > situation. I'm loading the image from PyTango (the tango's[1] python
> > > binding):
> > > from PyQt4 import QtCore, QtGui, Qt
> > > import PyTango
> > > attrImg = PyTango.AttributeProxy("lt/di/iba-01/ROIImage")
> > > imgData,imgDimX,imgDimY =
> > > attrImg.read().value,attrImg.read().dim_x,attrImg.read().dim_y
> > >
> > > And where we have an image composed by unsigned shorts, it needs a
> > > little manipulation, to have an unsigned char array, with a method
> > > like: def convertfrom(image):
> > > 		shift = 4
> > > 		return "".join(chr(i>>shift) for i in image )
> > >
> > > call like:
> > > imgData8 = convertfrom(imgData)
> > > To construct the object:
> > > image =
> > > QtGui.QImage(imgData8,imgDimX,imgDimY,imgDimX,QtGui.QImage.Format_Index
> > >ed 8)
> > >
> > > Finally the save call is:
> > > image.save("/tmp/image.png","PNG")
> > > image.save("/tmp/image.jpg","JPG")
> > > image.save("/tmp/image.tiff","TIFF")
> > >
> > > And all this calls return False (and the file is not in the directory).
> > > The image is shown in a widget and it seems nice.
> >
> > You didn't provide a self contained example again. Reduce your problem to
> > a pure PyQt script, and provide the image somehow, if you really expect
> > help from this list.
>
> I attach an standalone python script, without tango, using a simply black
> image. Before I was using ipython.
> Maybe I can provide a little more information, because changing the format
> of the image I found how to save it, and further more from the attached
> script I receive the message 'libpng error: Valid palette required for
> paletted images' for the first 8 bit grayscale image (not the second!).
>
> My main question is how I can have a longer answer that true of false,
> because having only this I cannot distinguish if the problem becomes from
> the image, the filesystem, or wherever.
>
> Thanks
>
> /Sergi.