imresize in PIL/scipy.misc only works for uint8 images? any alternatives?


It seems the imresize implemented in PIL/scipy.misc only works for uint8 images

>>> import scipy.misc
>>> im = np.random.rand(100,200)
>>> print im.dtype

>>> im2 = scipy.misc.imresize(im, 0.5)
>>> print im2.dtype

Is there any way around this? I’d like to deal HDR images and therefore needs to deal with float64 or float32 images. Thanks.


Thanks to cgohlke’s comment. Below are two alternatives I found that works for float-number images.

  1. Use scipy.ndimage.interpolation.zoom

For single-channel images: im2 = scipy.ndimage.interpolation.zoom(im, 0.5)

For 3-channel images: im2 = scipy.ndimage.interpolation.zoom(im, (0.5, 0.5, 1.0))

  1. Use OpenCV.

im2 = cv2.resize(im, (im.shape[1]/2, im.shape[0]/2))

This works for both single-channel and 3-channel images. Note that one needs to revert the shape order in second parameter.

Answered By – Ying Xiong

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0

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