Add a script to resize apriltag image with nearest neighbor method

tool/resize_apriltag.py

@@ -0,0 +1,98 @@
+'''
+Resize the original apriltag images to 60x60mm with 300dpi
+and add black dots at the corners.
+'''
+import os
+from PIL import Image, ImageDraw
+
+
+def resize_image(image, new_width_mm, new_height_mm, dpi=300):
+    '''
+    Resize the image to the specified dimensions in mm at the specified DPI.
+    '''
+    # Calculate the pixel dimensions
+    # 25.4 is the number of mm in an inch
+    new_width_px = int(new_width_mm / 25.4 * dpi)
+    new_height_px = int(new_height_mm / 25.4 * dpi)
+
+    # Resize the image
+    resized_image = image.resize((new_width_px, new_height_px), Image.NEAREST)
+
+    return resized_image
+
+
+def add_dots_to_image(image, dot_size=3):
+    '''
+    Add black dots at the corners of the image the visibility of the margin
+    '''
+    # Create a drawing context
+    draw = ImageDraw.Draw(image)
+
+    # Get image dimensions
+    width, height = image.size
+
+    # Add black dots at the corners
+    # Top-left corner
+    draw.rectangle([0, 0, dot_size, dot_size], fill="black")
+    # Top-right corner
+    draw.rectangle([width - dot_size, 0, width, dot_size], fill="black")
+    # Bottom-left corner
+    draw.rectangle([0, height - dot_size, dot_size, height], fill="black")
+    # Bottom-right corner
+    draw.rectangle([width - dot_size, height - dot_size,
+                   width, height], fill="black")
+
+    return image
+
+
+def load_image(image_path):
+    '''
+    Load an image from the specified file path.
+    '''
+    return Image.open(image_path)
+
+
+def save_image(image, output_path, dpi=300):
+    '''
+    Save the image with DPI information
+    '''
+    image.save(output_path, dpi=(dpi, dpi))
+
+
+def process_images_in_directory(
+        input_directory, output_directory, new_width_mm, new_height_mm, dpi=300, dot_size=3):
+    '''
+    Process all images in the input directory and save the results in the output directory.
+    '''
+    os.makedirs(output_directory, exist_ok=True)
+
+    # Loop through all files in the input directory
+    for filename in os.listdir(input_directory):
+        if filename.lower().endswith(('.png', '.jpg', '.jpeg', '.bmp', '.gif')):
+            input_path = os.path.join(input_directory, filename)
+            output_path = os.path.join(output_directory, filename)
+
+            # Step 1: Load image
+            image = load_image(input_path)
+
+            # Step 2: Resize image
+            resized_image = resize_image(
+                image, new_width_mm, new_height_mm, dpi)
+
+            # Step 3: Add dots to resized image
+            final_image = add_dots_to_image(resized_image, dot_size)
+
+            # Save the final image
+            save_image(final_image, output_path, dpi)
+
+
+if __name__ == "__main__":
+    INPUT_DIRECTORY = '36h11_original'
+    OUTPUT_DIRECTORY = '36h11_60x60'
+    NEW_WIDTH_MM = 60
+    NEW_HEIGHT_MM = 60
+    DPI = 300
+    DOT_SIZE_AROUND_MARGIN = 3
+
+    process_images_in_directory(
+        INPUT_DIRECTORY, OUTPUT_DIRECTORY, NEW_WIDTH_MM, NEW_HEIGHT_MM, DPI, DOT_SIZE_AROUND_MARGIN)