ValueError: Could not find a backend to open `50g.exr`` with iomode `wi`

Greetings! I would like to save a 16bit rgb array as .exr file. I use a camera, capturing multiple images for multi exposure fusion (hdr merge). Iam in the Solarpower buisness. I will predict the hitting radiance with SkyCams.

I would like to continue my work with these 16 bit raw bayer array safed as .exr (.tga would also work)

def exposure_bracket():

picam2 = Picamera2()
config = picam2.create_still_configuration(raw={"format": "SRGGB12", "size": (2032, 1520)})
picam2.configure(config)

exposures = [50, 100, 150, 250, 400, 650, 1050, 1700, 2750] # in Microseconds

for exp in exposures:

	picam2.set_controls({"ExposureTime": exp, "AnalogueGain": 1, "ColourGains": (1.0,1.0)})
	picam2.start()
	time.sleep(0.5)
	array = picam2.capture_array("raw")
	picam2.stop()
	
	array16 = array.view(np.uint16)
	array16 *= 16  # Bump 12-bit range up to 16
	arrayX = array16.astype("float32")

        imageio.imwrite(f'{exp}g.exr', arrayX)

	rgb_array = np.zeros((760, 1016, 3), dtype=np.uint16)
	rgb_array[:, :, 0] = array16[1::2, 1::2] # red
	# Must avoid overflowing 16-bits in the addition here:
	rgb_array[:, :, 1] = (array16[0::2, 1::2].astype(int) + array16[1::2, 0::2]) / 2 # green
	rgb_array[:, :, 2] = array16[0::2, 0::2] # blue
	rgb_arrayX = rgb_array.astype("float32")

	imageio.imwrite(f'{exp}rgb.exr', rgb_arrayX)

imageio.plugins.freeimage.download() exposure_bracket()

[FirefoxMetzger]

@Bra1nsen Did you perform the post-installation step of downloading the FreeImage binary (documentation here)?

Once installed, the following EXR round-trip of writing an image and reading it back works fine on my end:

import imageio.v3 as iio
import numpy as np

expected = np.full((128, 128, 3), 0.42, dtype=np.float32)
buffer = iio.imwrite("<bytes>", expected, extension=".exr")

actual = iio.imread(buffer)

np.allclose(actual, expected)

[Bra1nsen]

hey firefox. I just tried you snippet:

Exception ignored in: <function PluginV3.__del__ at 0xb4f13d18>
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/dist-packages/imageio/core/v3_plugin_api.py", line 367, in __del__
    self.close()
  File "/usr/local/lib/python3.9/dist-packages/imageio/core/v3_plugin_api.py", line 354, in close
    self.request.finish()
  File "/usr/local/lib/python3.9/dist-packages/imageio/core/request.py", line 551, in finish
    bytes = Path(self._filename_local).read_bytes()
  File "/usr/lib/python3.9/pathlib.py", line 1248, in read_bytes
    with self.open(mode='rb') as f:
  File "/usr/lib/python3.9/pathlib.py", line 1241, in open
    return io.open(self, mode, buffering, encoding, errors, newline,
  File "/usr/lib/python3.9/pathlib.py", line 1109, in _opener
    return self._accessor.open(self, flags, mode)
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/imageio_gx2ec4ep.exr'