[Bug] "TypeError: Cannot handle this data type" when using numpy.ndarray with floats

[karolzak]

Getting an error when trying to run IPyPlot with images in numpy.ndarray format with float data type.

KeyError                                  Traceback (most recent call last)
~\Anaconda3\envs\py36tf2gpu\lib\site-packages\PIL\Image.py in fromarray(obj, mode)
   2644             typekey = (1, 1) + shape[2:], arr["typestr"]
-> 2645             mode, rawmode = _fromarray_typemap[typekey]
   2646         except KeyError:

KeyError: ((1, 1, 3), '<f4')

During handling of the above exception, another exception occurred:

TypeError                                 Traceback (most recent call last)
<ipython-input-36-2d4541c259ee> in <module>
      4 imgs = np.random.rand(3,128,128,3).astype(np.float32)
      5 
----> 6 ipyplot.plot_images(imgs)

d:\git\ipyplot\ipyplot\plotting.py in plot_images(images, labels, max_images, img_width, force_b64)
     90         labels = list(range(0, len(images)))
     91     html = _create_imgs_list_html(
---> 92         images, labels, max_images, img_width, force_b64=force_b64)
     93 
     94     _display(html)

d:\git\ipyplot\ipyplot\plotting.py in _create_imgs_list_html(images, labels, max_images, img_width, force_b64)
    238     html = ''.join([
    239         _create_img_html(x, img_width, label=y, force_b64=force_b64)
--> 240         for x, y in zip(images[:max_images], labels[:max_images])
    241     ])
    242     return html

d:\git\ipyplot\ipyplot\plotting.py in <listcomp>(.0)
    238     html = ''.join([
    239         _create_img_html(x, img_width, label=y, force_b64=force_b64)
--> 240         for x, y in zip(images[:max_images], labels[:max_images])
    241     ])
    242     return html

d:\git\ipyplot\ipyplot\plotting.py in _create_img_html(image, width, label, force_b64)
    230     if use_b64:
    231         html += '<img src="data:image/png;base64,%s" style="margin: 1px; width: %spx; border: 2px solid #ddd;"/>' % (
--> 232             _img_to_base64(image, width*2), width)  # NOQA E501
    233 
    234     return html + '</div>'

d:\git\ipyplot\ipyplot\plotting.py in _img_to_base64(image, max_size)
    206 def _img_to_base64(image, max_size):
    207     if type(image) is np.ndarray:
--> 208         image = Image.fromarray(image)
    209     elif type(image) is str or type(image) is str_:
    210         image = Image.open(image)

~\Anaconda3\envs\py36tf2gpu\lib\site-packages\PIL\Image.py in fromarray(obj, mode)
   2645             mode, rawmode = _fromarray_typemap[typekey]
   2646         except KeyError:
-> 2647             raise TypeError("Cannot handle this data type")
   2648     else:
   2649         rawmode = mode

TypeError: Cannot handle this data type

Minimum repro:

import ipyplot
import numpy as np

# this will fail:
imgs = np.random.rand(3,128,128,3).astype(np.float32)
ipyplot.plot_images(imgs)

# this will work:
ipyplot.plot_images((imgs * 255).astype(np.uint8))