If you're up for using numpy, this will get you the half float values without too much extra work: oiioFloats = inputImage.read_image(oiio.HALF) oiioHalfs = np.frombuffer(np.getbuffer(np.float32(oiioFloats)), dtype=np.float16)
One note, the current OIIO Python implementation doesn't promote the halfs to float on read. The 'float' values in the returned buffer are actually each two concatenated half values, and the float buffer will have half as many entries as you would expect. Example usage for reading here: https://github.com/hpd/CLF/blob/master/python/aces/filterImageWithCLF.py#L126 and the reverse for writing: https://github.com/hpd/CLF/blob/master/python/aces/filterImageWithCLF.py#L193 HP On Wed, Feb 17, 2016 at 3:25 PM, Larry Gritz <[email protected]> wrote: > In C++, you can just call read_scanlines and pass format=UNKNOWN to get > back the raw data in its original format. > > The problem is that in Python, there is no 'half' so it's not quite sure > what to return. > > I kinda like the decoupling of the raw reads (read_native_*) which are the > part overloaded by the individual format readers, from the app-callable > read_*. So perhaps rather than exposing read_native_*, we should just > modify the Python bindings for read_* to notice that if the native raw data > is not a type representable in Python, to return it as an unsigned > character array? > > > > On Feb 17, 2016, at 2:55 PM, Andrew Gartner <[email protected]> > wrote: > > > > Hey all, > > > > Apologies if this has come up before, but I'm curious if anyone had > considered exposing ImageInput.read_native_scanlines() on the python side > before. The reason I ask is mainly because the half datatype doesn't exist > in the native python array class which OIIO uses for python reads. > Currently the python array will punt and for anything to float (which I'd > rather avoid). > > > > I had put together an implementation in OIIO 1.5 that simply took the > pixel size as a parameter and exposed read_native_scanlines that way and > that allowed me to get the right data properly into either numpy or a raw > char python array. However, I'd rather not be forked off like that as it's > a headache trying to remain current with the mainline, plus others may find > it useful. > > > > Does anyone think exposing the function in general makes sense? I'm > happy to send the implementation if anyone cares to see it as well. > > > > Cheers, > > > > ~Andrew > > > > -- > Larry Gritz > [email protected] > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >
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