Warning with pyotb.Input and propagating pixel type for unint8

Warning with pyotb.Input and propagating unint8 pixel type

OK with float32 and int16 :

import otbApplication
import pyotb

img_float32_path = "image_float32.tif"
img_float32 = pyotb.Input(img_float32_path)

img_int6_path = "image_int16.tif"
img_int6 = pyotb.Input(img_int6_path)

But with unint8 :

img_unint8_path = "image_unint8.tif"
img_unint8 = pyotb.Input(img_unint8_path)

Gives :

2022-02-25 10:36:05 (WARNING) [pyOTB] ExtractROI: Could not propagate pixel type from inputs to output, no valid input found