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

Question

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
float64

>>> im2 = scipy.misc.imresize(im, 0.5)
>>> print im2.dtype
uint8

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

Answer 1

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))

2. 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.

Answer 2

you could also use the mode='F' option in the imresize function

imresize(image, factor, mode='F')