For simplicity, let's assume that the image origin is (0,0) (i.e., it's not a
"crop" or "overscan" image). We can think about images that are wider than they
are long ("landscape"), or longer than wide ("portrait").
I think you want something like the following, which uses the goal width for
landscape and the goal height for portrait, and recomputes the proper size in
the other direction:
goal_width = ...
goal_height = ...
buf = oiio.ImageBuf(file)
spec = buf.spec()
w = spec.width
h = spec.height
aspect = float(w) / float(h)
if aspect >= 1.0 :
# source image is landscape (or square)
resize_factor = float(goal_width) / w
goal_height = int(goal_height * resize_factor)
else :
# source image is portrait
resize_factor = float(goal_height) / h
goal_width = int(goal_width * resize_factor)
resized = oiio.ImageBuf(oiio.ImageSpec (goal_width, goal_height,
spec.nchannels, spec.format))
oiio.ImageBufAlgo.resize(resized, buf)
resized.write(output)
That's off the top of my head, you should test it and adjust if I've made
mistakes. But that's the gist.
Aside: note that when I create the resized buf, I used the number of channels
and data format of the original file, which is a bit more robust than
hard-coding it to 3 chans float as you did in the original.
> On Jun 19, 2018, at 5:28 AM, John Martini <[email protected]> wrote:
>
> Using python and OpenImageIO how can I resize an image given the maximum
> width and height for the output?
>
> https://stackoverflow.com/questions/50914650/resize-image-using-python-openimageio-maintain-aspect-ratio
>
> <https://stackoverflow.com/questions/50914650/resize-image-using-python-openimageio-maintain-aspect-ratio>
>
> I've been messing around with this for a few days now and i'm still
> completely without a solution.
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> Oiio-dev mailing list
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--
Larry Gritz
[email protected]
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