- 2010.02.08 16:48 "Re: [Tiff] fftw and TIFF files", by Bob Friesenhahn
- 2010.02.08 17:43 "[Tiff] OpenImageIO; was Re: fftw and TIFF files", by Larry Gritz
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2010.02.08 21:39 "[Tiff] FFT on two TIFF images", by Richard Nolde
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2010.02.08 23:05 "Re: [Tiff] FFT on two TIFF images", by Andy Cave
- 2010.02.09 08:16 "Re: [Tiff] FFT on two TIFF images", by
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2010.02.08 23:05 "Re: [Tiff] FFT on two TIFF images", by Andy Cave
2010.02.09 09:11 "Re: [Tiff] FFT on two TIFF images", by John
On 9 February 2010 08:16, Gil, Debora, VF-ES (dgilalv) STU <debora.gil@vodafone.com> wrote:
Thanks Andy and Richard, some other people pointed out the possibility of using OpenImageIO. It looks good and I'll give it a try.
Another possibility might be the vips image processing library (I'm one of the maintainers). It uses libliff and libfftw and has convenient functions for doing various Fourier-domain correlation operations. It has a Python binding, so it's very easy to use.
http://www.vips.ecs.soton.ac.uk
It's LGPL. The Python binding doesn't currently work on WIndows. It comes with all the major Linux distributions.
So, in the receiving part, I have both, the sent image and the received image. I want to compare them, to see if the line has caused any error. Both images are of course the same size. I have several types of images, some are multipage TIFF.
I guess there is no paper involved?
If that's the case a very simple solution would be just so subtract the two images and count the non-zeros. You could normalise to the image size and calculate an error rate.
In vips python, that would be:
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#!/usr/bin/python
from vipsCC import *
a = VImage.VImage ("image1.tif")
b = VImage.VImage ("image2.tif")
# average absolute difference
# vips unpacks 1 bit images to 8 bits 0/255, so divide by that avg = (a.subtract (b)).abs ().avg () / 255
# that'll be very small, so display as errors - per - megapixel print 'errors per million pixels:', avg * 1000000
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John