don't multiply by 255 is data is already uint8

Author: ThomasWagnerJKU

tikzplotlib/_image.py

@@ -34,6 +34,8 @@ def draw_image(data, obj):
             img_array = numpy.flipud(img_array)
 
         # Convert mpl image to PIL
+        if img_array.dtype != numpy.uint8:
+            img_array = numpy.uint8(img_array * 255)
         image = PIL.Image.fromarray(numpy.uint8(img_array * 255))
 
         # If the input image is PIL: