Replace samples/vision_inference with a Python script + README. (#9403)
Also remove image_util and third_party/stblib, which were only used for the C code in that sample.
Progress on https://github.com/google/iree/issues/9374
diff --git a/samples/vision_inference/convert_to_float_grayscale.py b/samples/vision_inference/convert_to_float_grayscale.py
new file mode 100644
index 0000000..0b2e8fb
--- /dev/null
+++ b/samples/vision_inference/convert_to_float_grayscale.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+
+# Copyright 2022 The IREE Authors
+#
+# Licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+import sys
+from PIL import Image
+import numpy as np
+
+# Read image from stdin (in any format supported by PIL).
+with Image.open(sys.stdin.buffer) as color_img:
+ # Convert to grayscale.
+ grayscale_img = color_img.convert('L')
+ # Rescale to a float32 in range [0.0, 1.0].
+ grayscale_arr = np.array(grayscale_img)
+ grayscale_arr_f32 = grayscale_arr.astype(np.float32) / 255.0
+ # Write bytes back out to stdout.
+ sys.stdout.buffer.write(grayscale_arr_f32.tobytes())
