h5conversion.py

#script to extract MIR image from HDF5 file and save as PNG

import h5py
import numpy as np
from PIL import Image
import os

count = 2
def extract_mir_image(h5_file, output_path=f"{count}.png"):
    global count
    with h5py.File(h5_file, 'r') as f:
        img_data = f['IMG_MIR'][0]  # Shape: (1616, 1737)
        
        # Normalize to 0-255 for 8-bit grayscale image
        img_min = img_data.min()
        img_max = img_data.max()
        print(f"Original value range: {img_min} to {img_max}")
        
        # Handle special fill values (1023)
        fill_value = f['IMG_MIR'].attrs.get('_FillValue', [None])[0]
        if fill_value is not None:
            img_data = np.where(img_data == fill_value, 0, img_data)

        # Normalize and clip
        norm_img = ((img_data - img_min) / (img_max - img_min) * 255).astype(np.uint8)

        # Save image
        Image.fromarray(norm_img).save(output_path)
        print(f"Saved image as: {output_path}")
        count += 1

# Example usage
extract_mir_image("3RIMG_01JUL2025_0115_L1C_ASIA_MER_V01R00_B5.h5")