Create preprocess.py

preprocess.py

@@ -0,0 +1,59 @@
+import numpy as np
+from PIL import Image
+
+
+def crop_and_resize(image_path, bbox_path, crop_path, resize_path):
+    img = Image.open(image_path)
+    width, height = img.size
+
+    with open(bbox_path, 'r') as f:
+        _, x_center, y_center, _, _ = map(float, f.readline().split())
+        x_center, y_center = int(x_center * width), int(y_center * height)
+
+    x1, x2 = max(0, x_center - 128), min(width, x_center + 128)
+    y1, y2 = max(0, y_center - 128), min(height, y_center + 128)
+
+    crop = img.crop((x1, y1, x2, y2))
+    assert crop.size == (256, 256)
+    crop.save(crop_path)
+
+    resize = crop.resize(size=(128, 128), resample=Image.BICUBIC)
+    assert resize.size == (128, 128)
+    resize.save(resize_path)
+
+
+def transform_intrinsic(intrinsic_path, bbox_path, crop_path, resize_path):
+    intrinsic = np.loadtxt(intrinsic_path)
+    fx, fy = intrinsic[0, 0], intrinsic[1, 1]
+    cx, cy = intrinsic[0, 2], intrinsic[1, 2]
+    width, height = cx * 2, cy * 2
+
+    with open(bbox_path, 'r') as f:
+        _, x_center, y_center, _, _ = map(float, f.readline().split())
+        x_center, y_center = int(x_center * width), int(y_center * height)
+    
+    x1, y1 = max(0, x_center - 128), max(0, y_center - 128)
+
+    K = np.array([[fx, 0, cx - x1],
+                  [0, fy, cy - y1],
+                  [0, 0, 1]])
+    np.savetxt(crop_path, K, fmt="%.5f", delimiter=" ")
+
+    K[:2] /= 2
+    np.savetxt(resize_path, K, fmt="%.5f", delimiter=" ")
+
+
+if __name__ == "__main__":
+    # crop and resize image
+    image_path = '640x480/image/0000_00.png'
+    bbox_path = '640x480/bbox/0000_00.txt'
+    crop_path = '256x256/image/0000_00.png'
+    resize_path = '128x128/image/0000_00.png'
+    crop_and_resize(image_path, bbox_path, crop_path, resize_path)
+
+    # transform intrinsic matrix
+    intrinsic_path = '640x480/intrinsic.txt'
+    bbox_path = '640x480/bbox/0000_00.txt'
+    crop_path = '256x256/intrinsic/0000_00.txt'
+    resize_path = '128x128/intrinsic/0000_00.txt'
+    transform_intrinsic(intrinsic_path, bbox_path, crop_path, resize_path)