Thanks Jérôme, I will look into your code. Having other filter might be useful for my case.
While looking for code, I've also found this (pure python) implementation: http://stackoverflow.com/questions/12729228/simple-efficient-bilinear-interpolation-of-images-in-numpy-and-python Nicolas > On 14 Dec 2014, at 09:03, Jerome Kieffer <jerome.kief...@esrf.fr> wrote: > > On Sat, 13 Dec 2014 16:53:06 +0100 > "Nicolas P. Rougier" <nicolas.roug...@inria.fr> wrote: > >> >> Hi all, >> >> Does anyone has a simple 2D linear interpolation for resizing an image >> (without scipy) ? >> >> Ideally, something like ```def zoom(Z, ratio): ...``` where Z is a 2D scalar >> array and ratio the scaling factor. >> (I'm currently using ```scipy.ndimage.interpolation.zoom``` but I would like >> to avoid the scipy dependency) > > Hi Nicolas, > > I have a self-contained cython class for that: > https://github.com/kif/pyFAI/blob/master/src/bilinear.pyx > > The formula for bilinear interpolation in implemented there but it > needs some additionnal work for what you want to do. > > Beside this I implemented an antialiased downscaler using Lanczos (order 1, 2 > or 3) > https://github.com/kif/imagizer/blob/qt/src/down_sampler.pyx. > > Create a downscaler: > ds = down_sampler.DownScaler() > scaled_img = ds.scale(img, 4.5) > > In this case the interpolation will be done on a vinicy of (2*4.5*3+1) pixel > in the input image (and 2*3+1 in the output image) as it is doing Lanczos 3 > by default. > This implementation is 2x faster than the Antialiased downscaler in PIL. > > Cheers, > > -- > Jérôme Kieffer > Data analysis unit - ESRF > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
